Lewis Chapter 35

When analyzing an electrocardiographic (ECG) rhythm strip of a patient with a regular cardiac rhythm, the nurse finds there are 25 small blocks from one R wave to the next. The nurse calculates the patient's heart rate as ____________________.

60 There are 1500 small blocks in a minute, and the nurse will divide 1500 by 25. DIF: Cognitive Level: Knowledge REF: 819-821 OBJ: Special Questions: Alternate Item Format TOP: Nursing Process: Assessment

A patient with dilated cardiomyopathy has new onset atrial fibrillation that has been unresponsive to drug therapy for several days. The priority teaching needed for this patient would include information about a. anticoagulant therapy. b. permanent pacemakers. c. electrical cardioversion. d. IV adenosine (Adenocard).

A (Atrial fibrillation therapy that has persisted for more than 48 hours requires anticoagulant treatment for 3 weeks before attempting cardioversion. This is done to prevent embolization of clots from the atria. Cardioversion may be done after several weeks of anticoagulation therapy. Adenosine is not used to treat atrial fibrillation. Pacemakers are routinely used for patients with bradydysrhythmias. Information does not indicate that the patient has a slow heart rate.)

A patient's cardiac monitor shows a pattern of undulations of varying contours and amplitude with no measurable ECG pattern. The patient is unconscious and pulseless. Which action should the nurse take first? a. Perform immediate defibrillation. b. Give epinephrine (Adrenalin) IV. c. Prepare for endotracheal intubation. d. Give ventilations with a bag-valve-mask device.

A (The patient's rhythm and assessment indicate ventricular fibrillation and cardiac arrest; the initial action should be to defibrillate. If a defibrillator is not immediately available or is unsuccessful in converting the patient to a better rhythm, the other actions may be appropriate.)

The nurse is reviewing the electrocardiogram (ECG) rhythm strip obtained on a client with a diagnosis of myocardial infarction. The nurse notes that the PR interval is 0.20 second. The nurse should make which interpretation about this finding?

A normal finding The PR interval represents the time it takes for the cardiac impulse to spread from the atria to the ventricles. The normal range for the PR interval is 0.12 to 0.20 second. Options 2, 3, and 4 are incorrect.

Ventricular Tachycardia: Treatment

A run of three or more PVCs. Ventricle is the pacemaker. Monomorphic: QRS same shape Polymorphic: QRS different shape Sustained: pulse Unsustained: no pulse -Treat underlying cause. Procainamide, sotalol, amiodarone. Polymorphic: -magnesium, isoproterenol, phenytoin -Cardioversion

When analyzing an electrocardiographic (ECG) rhythm strip of a patient with a regular heart rhythm, the nurse counts 30 small blocks from one R wave to the next. The nurse calculates the patient's heart rate as ____.

ANS: 50 There are 1500 small blocks in a minute, and the nurse will divide 1500 by 30. DIF: Cognitive Level: Remember (knowledge) REF: 789-790 TOP: Nursing Process: Assessment MSC: NCLEX: Physiological Integrity

When preparing to defibrillate a patient. In which order will the nurse perform the following steps? (Put a comma and a space between each answer choice [A, B, C, D, E].) a. Turn the defibrillator on. b. Deliver the electrical charge. c. Select the appropriate energy level. d. Place the paddles on the patient's chest. e. Check the location of other staff and call out "all clear."

ANS: A, C, D, E, B This order will result in rapid defibrillation without endangering hospital staff. DIF: Cognitive Level: Analyze (analysis) REF: 802 TOP: Nursing Process: Implementation MSC: NCLEX: Physiological Integrity

An elderly patient presents to the emergency department after a fall. She states she does not remember the incident. What is most important to assess first? A. Heart rate and rhythm B. Hemoglobin C. Home environment D. Alcohol consumption

ANS: A Although all options will be assessed eventually, determining a cardiac cause for this brief lapse of consciousness is most important. Reference: 839

Which action by a new registered nurse (RN) who is orienting to the progressive care unit indicates a good understanding of the treatment of cardiac dysrhythmias? a. Injects IV adenosine (Adenocard) over 2 seconds to a patient with supraventricular tachycardia b. Obtains the defibrillator and quickly brings it to the bedside of a patient whose monitor shows asystole c. Turns the synchronizer switch to the "on" position before defibrillating a patient with ventricular fibrillation d. Gives the prescribed dose of diltiazem (Cardizem) to a patient with new-onset type II second degree AV block

ANS: A Adenosine must be given over 1 to 2 seconds to be effective. The other actions indicate a need for more education about treatment of cardiac dysrhythmias. The RN should hold the diltiazem until talking to the health care provider. The treatment for asystole is immediate CPR. The synchronizer switch should be "off" when defibrillating

The patient has a permanent cardiac pacemaker. On the electrocardiographic tracing, you notice a spike before each P wave. What action should you take? A. Assess the patient for syncope. B. Document the findings. C. Notify the physician. D. Take blood pressure in both arms.

ANS: B These pacer spikes show that the pacemaker is firing and the atrium is responding to the impulse. It is a normal, expected finding in this situation. Reference: 834-835

Which teaching points should you include when providing discharge instructions to a patient with a new permanent pacemaker and to the caregiver (select all that apply)? A. Avoid or limit air travel. B. Take and record a pulse rate daily. C. Obtain and wear a Medic Alert ID or bracelet at all times. D. Avoid lifting the arm on the side of the pacemaker above the shoulder. E. Avoid microwave ovens because they interfere with pacemaker function.

ANS: B,C,D Air travel is not restricted. Inform airport security about the pacemaker because it may set off the metal detector. If a hand-held screening wand is used, it should not be placed directly over the pacemaker. Manufacturer information may vary regarding the effect of metal detectors on the function of the pacemaker. The patient should monitor the pulse and inform the primary care provider if it drops below predetermined rate. A Medic Alert ID or bracelet should be worn at all times. The patient should avoid lifting the arm on the pacemaker side above the shoulder until it is approved by the primary care provider. Microwave ovens are safe to use and do not interfere with pacemaker function. Table 36-13 provides additional discharge teaching guidelines for a patient with a pacemaker. Reference: 837

The patient has an electrocardiographic (ECG) tracing that is 50 beats/minute, the rhythm is regular, and there is a P wave before every QRS complex. The QRS has a normal shape and duration, and the PR interval is normal. What is you response? A. Administer atropine by intravenous push (IVP). B. Administer epinephrine by IVP. C. Monitor the patient for syncope. D. Attach an external pacemaker.

ANS: C The rhythm described is sinus bradycardia. Treatment depends on the patient's response and whether adequate perfusion is occurring. If the patient tolerates the rhythm, no treatment is given. Reference: 824

A patient who is on the progressive care unit develops atrial flutter, rate 150, with associated dyspnea and chest pain. Which action that is included in the hospital dysrhythmia protocol should the nurse do first? a. Obtain a 12-lead electrocardiogram (ECG). b. Notify the health care provider of the change in rhythm. c. Give supplemental O2 at 2 to 3 L/min via nasal cannula. d. Assess the patient's vital signs including oxygen saturation.

ANS: C Because this patient has dyspnea and chest pain in association with the new rhythm, the nurse's initial actions should be to address the patient's airway, breathing, and circulation (ABC) by starting with oxygen administration. The other actions also are important and should be implemented rapidly. DIF: Cognitive Level: Apply (application) REF: 793 OBJ: Special Questions: Prioritization TOP: Nursing Process: Implementation MSC: NCLEX: Physiological Integrity

Which nursing action can the registered nurse (RN) delegate to experienced unlicensed assistive personnel (UAP) working as a telemetry technician on the cardiac care unit? a. Decide whether a patient's heart rate of 116 requires urgent treatment. b. Monitor a patient's level of consciousness during synchronized cardioversion. c. Observe cardiac rhythms for multiple patients who have telemetry monitoring. d. Select the best lead for monitoring a patient admitted with acute coronary syndrome.

ANS: C UAP serving as telemetry technicians can monitor cardiac rhythms for individuals or groups of patients. Nursing actions such as assessment and choice of the most appropriate lead based on ST segment elevation location require RN-level education and scope of practice

The nurse has received change-of-shift report about the following patients on the progressive care unit. Which patient should the nurse see first? a. A patient who is in a sinus rhythm, rate 98, after having electrical cardioversion 2 hours ago b. A patient with new onset atrial fibrillation, rate 88, who has a first dose of warfarin (Coumadin) due c. A patient with second-degree atrioventricular (AV) block, type 1, rate 60, who is dizzy when ambulating d. A patient whose implantable cardioverter-defibrillator (ICD) fired two times today who has a dose of amiodarone (Cordarone) due

ANS: D The frequent firing of the ICD indicates that the patient's ventricles are very irritable, and the priority is to assess the patient and administer the amiodarone. The other patients may be seen after the amiodarone is administered

ECG: Atrial Fibrillation

Atrial rate is 350-600 beats/min and irregular. Ventricular is > or <100 beats/min and irregular. -P wave becomes fibrillatory waves -PR interval is not measurable -QRS complex usually normal

A patient develops sinus bradycardia at a rate of 32 beats/minute, has a BP of 80/36 mm Hg, and is complaining of feeling faint. Which action should the nurse take? a. Continue to monitor the rhythm and BP. b. Apply the transcutaneous pacemaker (TCP). c. Have the patient perform the Valsalva maneuver. d. Give the scheduled dose of diltiazem (Cardizem).

B The patient is experiencing symptomatic bradycardia, and treatment with TCP is appropriate. Continued monitoring of the rhythm and BP is an inadequate response. Calcium channel blockers will further decrease the heart rate, and the diltiazem should be held. The Valsalva maneuver will further decrease the rate. DIF: Cognitive Level: Application REF: 823-825 | 835-836 OBJ: Special Questions: Prioritization TOP: Nursing Process: Implementation

A patient whose heart monitor shows sinus tachycardia, rate 132, is apneic and has no palpable pulses. What is the first action that the nurse should take? a. Perform synchronized cardioversion. b. Start cardiopulmonary resuscitation (CPR). c. Administer atropine per agency dysrhythmia protocol. d. Provide supplemental oxygen via non-rebreather mask.

B (The patient's clinical manifestations indicate pulseless electrical activity and the nurse should immediately start CPR. The other actions would not be of benefit to this patient.)

A patient reports dizziness and shortness of breath for several days. During cardiac monitoring in the emergency department (ED), the nurse obtains the following electrocardiographic (ECG) tracing. The nurse interprets this heart rhythm as a. junctional escape rhythm. b. accelerated idioventricular rhythm. c. third-degree atrioventricular (AV) block. d. sinus rhythm with premature atrial contractions (PACs).

C (The inconsistency between the atrial and ventricular rates and the variable P-R interval indicate that the rhythm is third-degree AV block. Sinus rhythm with PACs will have a normal rate and consistent P-R intervals with occasional PACs. An accelerated idioventricular rhythm will not have visible P waves.)

A patient who is complaining of a "racing" heart and feeling "anxious" comes to the emergency department. The nurse places the patient on a heart monitor and obtains the following electrocardiographic (ECG) tracing. Which action should the nurse take next? a. Prepare to perform electrical cardioversion. b. Have the patient perform the Valsalva maneuver. c. Obtain the patient's vital signs including oxygen saturation. d. Prepare to give a -blocker medication to slow the heart rate.

C (The patient has sinus tachycardia, which may have multiple etiologies such as pain, dehydration, anxiety, and myocardial ischemia. Further assessment is needed before determining the treatment. Vagal stimulation or -blockade may be used after further assessment of the patient. Electrical cardioversion is used for some tachydysrhythmias, but would not be used for sinus tachycardia.)

Premature Ventricular Contractions: Treatment

Contraction coming from an ectopic focus in the ventricles. Premature occurrence of the QRS complex. Multifocal: arise from different foci, different shape Unifocal: same shape Bigeminy: evert other beat is a PVC Trigeminy: every third beat is a PVC Couplet: two consecutive PVCs -Treat underlying cause -Beta-blockers, procainamide, amiodarone

When analyzing the waveforms of a patient's electrocardiogram (ECG), the nurse will need to investigate further upon finding a a. T wave of 0.16 second. b. P-R interval of 0.18 second. c. Q-T interval of 0.34 second. d. QRS interval of 0.14 second.

D Because the normal QRS interval is 0.04 to 0.10 seconds, the patient's QRS interval of 0.14 seconds indicates that the conduction through the ventricular conduction system is prolonged. The P-R interval, Q-T interval, and T wave interval are within the normal range. DIF: Cognitive Level: Application REF: 822 TOP: Nursing Process: Assessment

A patient has a normal cardiac rhythm and a heart rate of 72 beats/minute. The nurse determines that the P-R interval is 0.24 seconds. The most appropriate intervention by the nurse would be to a. notify the health care provider immediately. b. give atropine per agency dysrhythmia protocol. c. prepare the patient for temporary pacemaker insertion. d. document the finding and continue to monitor the patient.

D (First-degree atrioventricular (AV) block is asymptomatic and requires ongoing monitoring because it may progress to more serious forms of heart block. The rate is normal, so there is no indication that atropine is needed. Immediate notification of the health care provider about an asymptomatic rhythm is not necessary)

A patient who was admitted with a myocardial infarction experiences a 45-second episode of ventricular tachycardia, then converts to sinus rhythm with a heart rate of 98 beats/minute. Which of the following actions should the nurse take next? a. Immediately notify the health care provider. b. Document the rhythm and continue to monitor the patient. c. Perform synchronized cardioversion per agency dysrhythmia protocol. d. Prepare to give IV amiodarone (Cordarone) per agency dysrhythmia protocol.

D (The burst of sustained ventricular tachycardia indicates that the patient has significant ventricular irritability, and antidysrhythmic medication administration is needed to prevent further episodes. The nurse should notify the health care provider after the medication is started. Defibrillation is not indicated given that the patient is currently in a sinus rhythm. Documentation and continued monitoring are not adequate responses to this situation.)

A patient develops sinus bradycardia at a rate of 32 beats/minute, has a blood pressure (BP) of 80/42 mm Hg, and is complaining of feeling faint. Which actions should the nurse take next? a. Recheck the heart rhythm and BP in 5 minutes. b. Have the patient perform the Valsalva maneuver. c. Give the scheduled dose of diltiazem (Cardizem). d. Apply the transcutaneous pacemaker (TCP) pads.

D (The patient is experiencing symptomatic bradycardia, and treatment with TCP is appropriate. Continued monitoring of the rhythm and BP is an inadequate response. Calcium channel blockers will further decrease the heart rate, and the diltiazem should be held. The Valsalva maneuver will further decrease the rate.)

A client has received antidysrhythmic therapy for the treatment of premature ventricular contractions (PVCs). The nurse evaluates this therapy as most effective if the client's PVCs continued to exhibit which finding?

Decrease to a frequency of less than 6 per minute PVCs are considered dangerous when they are frequent (more than 6 per minute), occur in pairs or couplets, are multifocal (multiform), or fall on the T wave. In each of these instances, the client's cardiac rhythm is likely to degenerate into ventricular tachycardia or ventricular fibrillation, both of which are potentially deadly dysrhythmias.

Paroxysmal Supraventricular Tachycardia: Treatment

Dysrhythmia starting in an ectopic focus anywhere above the bifurcation of the bundle of His. -Vagal stimulation (Valsalva, carotid massage, coughing) -Adenonsine to convert to sinus rhythm, beta-adrenergic blockers, calcium channel blockers, and amiodarone. -Cardioversion

The nurse is assessing an electrocardiogram (ECG) rhythm strip for a client. The P waves and QRS complexes are regular. The PR interval is 0.14 second, and the QRS complexes measure 0.08 second. The overall heart rate is 82 beats/min. The nurse interprets the cardiac rhythm to be which rhythm?

Normal sinus rhythm Normal sinus rhythm is defined as a regular rhythm with an overall rate of 60 to 100 beats/min. The PR and QRS measurements are normal, measuring 0.12 to 0.20 second and 0.04 to 0.10 second, respectively.

ECG: Ventricular Fibrillation

Not measurable and irregular. -Absent P wave -PR interval not measurable -QRS complex not measurable

Pulseless Electrical Activity: Treatment

Organized electrical activity on ECG but no mechanical activity of the ventricles and no pulse. -CPR and ACLS, epinephrine, intubation

The nurse observes ventricular tachycardia (VT) on the patient's monitor. What evaluation made by the nurse led to this interpretation? Unmeasurable rate and rhythm Rate 150 beats/min; inverted P wave Rate 200 beats/min; P wave not visible Rate 125 beats/min; normal QRS complex

Rate 200 beats/min; P wave not visible VT is associated with a rate of 150 to 250 beats/min; the P wave is not normally visible. Rate and rhythm are not measurable in ventricular fibrillation. P wave inversion and a normal QRS complex are not associated with VT.

A client's electrocardiogram (ECG) strip shows atrial and ventricular rates of 70 complexes/min. The PR interval is 0.16 second, the QRS complex measures 0.06 second, and the PP interval is slightly irregular. How should the nurse interpret this rhythm?

Sinus dysrhythmia Sinus dysrhythmia has all of the characteristics of normal sinus rhythm except for the presence of an irregular PP interval. This irregular rhythm occurs because of phasic changes in the rate of firing of the sinoatrial node, which may occur with vagal tone and with respiration. Cardiac output is not affected.

The nurse is evaluating a client's response to cardioversion. Which observation would be of highest priority to the nurse?

Status of airway Nursing responsibilities after cardioversion include maintenance first of a patent airway, and then oxygen administration, assessment of vital signs and level of consciousness, and dysrhythmia detection.

Atrial Fibrillation: Treatment

Total disorganization of atrial electrical activity because of multiple ectopic foci resulting in loss of effectiveness of atrial contraction. Thrombi can form due to stasis. -Rate control: calcium channel blockers (diltiazem), beta-blockers (metoprolol), dronedarone, and digoxin. -Cardioversion -Long-term anticoagulation therapy: Warfarin

ECG: Premature Ventricular Contraction

Underlying rhythm can be any rate. Regular or irregular. PVCs occur at variable rates. -P wave not usually visible -PR interval not measurable -QRS complex wide and distorted

ECG: Premature Atrial Contraction

Usually 60-100 beats/min and irregular. -P wave abnormal shape -PR interval normal -QRS complex usually normal

Shockable Rhythms (2)

V-Tach with no pulse V-Fib

The nurse is watching the cardiac monitor and notices that the rhythm suddenly changes. No P waves or QRS complexes are seen; instead, the monitor screen shows an irregular wavy line. The nurse interprets that the client is experiencing which rhythm?

Ventricular fibrillation Ventricular fibrillation is characterized by the absence of P waves and QRS complexes. The rhythm is instantly recognizable by the presence of coarse or fine fibrillatory waves on the cardiac monitoring screen. Sinus tachycardia has a recognizable P wave and QRS. Ventricular tachycardia is a regular pattern of wide QRS complexes. PVCs appear as irregular beats within a rhythm. Each of the incorrect options has a recognizable complex that appears on the monitoring screen.

The patient has hypokalemia, and the nurse obtains the following measurements on the rhythm strip: Heart rate of 86 with a regular rhythm; the P wave is 0.06 seconds (sec) and normal shape; the PR interval is 0.24 sec; the QRS is 0.09 sec. How should the nurse document this rhythm? a) First-degree AV block b) Second-degree AV block c) Premature atrial contraction (PAC) d) Premature ventricular contraction (PVC)

a) First-degree AV block (In first-degree AV block there is prolonged duration of AV conduction that lengthens the PR interval above 0.20 sec. In type I second-degree AV block the PR interval continues to increase in duration until a QRS complex is blocked. In Type II the PR interval may be normal or prolonged, the ventricular rhythm may be irregular, and the QRS is usually greater than 0.12 sec. PACs cause an irregular rhythm with a different-shaped P wave than the rest of the beats, and the PR interval may be shorter or longer. PVCs cause an irregular rhythm, and the QRS complex is wide and distorted in shape.)

The nurse is doing discharge teaching with the patient and spouse of the patient who just received an implantable cardioverter-defibrillator (ICD) in the left side. Which statement by the patient indicates to the nurse that the patient needs more teaching? a) "I will call the cardiologist if my ICD fires." b) "I cannot fly because it will damage the ICD." c) "I cannot move my left arm until it is approved" d) "I cannot drive until my cardiologist says it is okay."

b) "I cannot fly because it will damage the ICD." (The patient statement that flying will damage the ICD indicates misunderstanding about flying. The patient should be taught that informing TSA about the ICD can be done because it may set off the metal detector and if a hand-held screening wand is used, it should not be placed directly over the ICD. The other options indicate the patient understands the teaching.)

The patient's PR interval comprises six small boxes on the ECG graph. What does the nurse determine that this indicates? a. a normal finding b. a problem with ventricular depolarization c. a disturbance in the depolarization of the atria d. a problem, with conduction from the SA node to the ventricular cells

d. The normal PR interval is 0.12 to 0.20 seconds and reflects the time taken for the impulse to spread through the atria, AV node and bundle of His, the bundle branches, and Purkinje fibers. A PR interval of six small boxes is 0.24 second and indicates that the conduction if the impulse from the atria tot he Purkinje fibers is delayed.

The nurse would evaluate that defibrillation of a client was most successful if which observation was made? 1.Arousable, sinus rhythm, BP 116/72 mm Hg 2.Nonarousable, sinus rhythm, BP 88/60 mm Hg 3.Arousable, marked bradycardia, BP 86/54 mm Hg 4.Nonarousable, supraventricular tachycardia, BP 122/60 mm Hg

1. After defibrillation, the client requires continuous monitoring of electrocardiographic rhythm, hemodynamic status, and neurological status. Respiratory and metabolic acidosis develop during ventricular fibrillation because of lack of respiration and cardiac output. These can cause cerebral and cardiopulmonary complications. Arousable status, adequate blood pressure, and a sinus rhythm indicate successful response to defibrillation.

A client's electrocardiogram strip shows atrial and ventricular rates of 110 beats/minute. The PR interval is 0.14 second, the QRS complex measures 0.08 second, and the PP and RR intervals are regular. How should the nurse correctly interpret this rhythm? 1.Sinus tachycardia 2.Sinus bradycardia 3.Sinus dysrhythmia 4.Normal sinus rhythm

1. Sinus tachycardia has the characteristics of normal sinus rhythm, including a regular PP interval and normal-width PR and QRS intervals; however, the rate is the differentiating factor. In sinus tachycardia, the atrial and ventricular rates are greater than 100 beats/minute.

The nurse is evaluating a client's response to cardioversion. Which observation would be of highest priority to the nurse? 1.Blood pressure 2.Status of airway 3.Oxygen flow rate 4.Level of consciousness

2. Nursing responsibilities after cardioversion include maintenance first of a patent airway, and then oxygen administration, assessment of vital signs and level of consciousness, and dysrhythmia detection.

A client with myocardial infarction suddenly becomes tachycardic, shows signs of air hunger, and begins coughing frothy, pink-tinged sputum. Which finding would the nurse anticipate when auscultating the client's breath sounds? 1.Stridor 2.Crackles 3.Scattered rhonchi 4.Diminished breath sounds

2. Pulmonary edema is characterized by extreme breathlessness, dyspnea, air hunger, and the production of frothy, pink-tinged sputum. Auscultation of the lungs reveals crackles. Rhonchi and diminished breath sounds are not associated with pulmonary edema. Stridor is a crowing sound associated with laryngospasm or edema of the upper airway.

The nurse is reviewing an electrocardiogram rhythm strip. The P waves and QRS complexes are regular. The PR interval is 0.16 second, and QRS complexes measure 0.06 second. The overall heart rate is 64 beats/minute. Which would be a correct interpretation based on these characteristics? 1.Sinus bradycardia 2.Sick sinus syndrome 3.Normal sinus rhythm 4.First-degree heart block

3. Normal sinus rhythm is defined as a regular rhythm, with an overall rate of 60 to 100 beats/minute. The PR and QRS measurements are normal, measuring 0.12 to 0.20 second and 0.04 to 0.10 second, respectively.

A client has developed atrial fibrillation, with a ventricular rate of 150 beats/minute. The nurse should assess the client for which associated signs/symptoms? 1.Flat neck veins 2.Nausea and vomiting 3.Hypotension and dizziness 4.Hypertension and headache

3. The client with uncontrolled atrial fibrillation with a ventricular rate more than 100 beats/minute is at risk for low cardiac output because of loss of atrial kick. The nurse assesses the client for palpitations, chest pain or discomfort, hypotension, pulse deficit, fatigue, weakness, dizziness, syncope, shortness of breath, and distended neck veins.

The nurse notes that a client with sinus rhythm has a premature ventricular contraction that falls on the T wave of the preceding beat. The client's rhythm suddenly changes to one with no P waves, no definable QRS complexes, and coarse wavy lines of varying amplitude. How should the nurse correctly interpret this rhythm? 1.Asystole 2.Atrial fibrillation 3.Ventricular fibrillation 4.Ventricular tachycardia

3. Ventricular fibrillation is characterized by irregular chaotic undulations of varying amplitudes. Ventricular fibrillation has no measurable rate and no visible P waves or QRS complexes and results from electrical chaos in the ventricles.

The nurse is watching the cardiac monitor and notices that the rhythm suddenly changes. There are no P waves, the QRS complexes are wide, and the ventricular rate is regular but more than 140 beats/minute. The nurse determines that the client is experiencing which dysrhythmia? 1.Sinus tachycardia 2.Ventricular fibrillation 3.Ventricular tachycardia 4.Premature ventricular contractions

3. Ventricular tachycardia is characterized by the absence of P waves, wide QRS complexes (longer than 0.12 second), and typically a rate between 140 and 180 impulses/minute. The rhythm is regular.

Which information will the nurse include when teaching a patient who is scheduled to have a permanent pacemaker inserted for treatment of chronic atrial fibrillation with slow ventricular response? a. The pacemaker prevents or minimizes ventricular irritability. b. The pacemaker paces the atria at rates up to 500 impulses/minute. c. The pacemaker discharges if ventricular fibrillation and cardiac arrest occur. d. The pacemaker stimulates a heart beat if the patient's heart rate drops too low.

D The permanent pacemaker will discharge when the ventricular rate drops below the set rate. The pacemaker will not decrease ventricular irritability or discharge if the patient develops ventricular fibrillation. Since the patient has a slow ventricular rate, overdrive pacing will not be used. DIF: Cognitive Level: Application REF: 834-835 TOP: Nursing Process: Implementation

Ventricular Fibrillation: Treatment

Firing of multiple ectopic foci in the ventricle. -CPR and defibrillation -Epinephrine, vasopressin

Asystole: Treatment

Total absence of ventricular electrical activity. -CPR and ACLS -NO DEFIB -Epinephrine, vasopressin, intubation

When computing a heart rate from the ECG tracing, the nurse counts 15 of the small blocks between the R waves of a patient whose rhythm is regular. From these data, the nurse calculates the patient's heart rate to be a) 60 bpm b) 75 bpm c) 100 bpm d) 150 bpm

c) 100 bpm (Since each small block on the ECG paper represents 0.04 seconds, 1500 of these blocks represents 1 minute. By dividing the number of small blocks (15, in this case) into 1500, the nurse can calculate the heart rate in a patient whose rhythm is regular (in this case, 100).)

A client with myocardial infarction is developing cardiogenic shock. Because of the risk of myocardial ischemia, what condition should the nurse carefully assess the client for? 1.Bradycardia 2.Ventricular dysrhythmias 3.Rising diastolic blood pressure 4.Falling central venous pressure

2. Classic signs of cardiogenic shock as they relate to myocardial ischemia include low blood pressure and tachycardia. The central venous pressure would rise as the backward effects of the severe left ventricular failure became apparent. Dysrhythmias commonly occur as a result of decreased oxygenation and severe damage to greater than 40% of the myocardium.

Which action by a new nurse who is caring for a patient who has just had an implantable cardioverter-defibrillator (ICD) inserted indicates a need for more education about care of patients with ICDs? a. The nurse assists the patient to do active range of motion exercises for all extremities. b. The nurse assists the patient to fill out the application for obtaining a Medic Alert ID and bracelet. c. The nurse gives atenolol (Tenormin) to the patient without consulting first with the health care provider. d. The nurse teaches the patient that sexual activity usually can be resumed once the surgical incision is healed.

A The patient should avoid moving the arm on the ICD insertion site until healing has occurred in order to prevent displacement of the ICD leads. The other actions by the new nurse are appropriate for this patient. DIF: Cognitive Level: Application REF: 833-835 TOP: Nursing Process: Evaluation

The emergency department patient is in paroxysmal supraventricular tachycardia (PSVT) at a rate of 170 beats/minute. Which treatment do you anticipate first? A. Sotalol (Betapace) by slow IVP B. Adenosine (Adenocard) by fast IVP C. Defibrillation D. Digoxin (Lanoxin)

ANS: B PSVT is a dysrhythmia originating in an ectopic focus anywhere above the bifurcation of the bundle of His. Treatment includes vagal stimulation (e.g., Valsalva maneuver, coughing) and intravenous (IV) adenosine as the first drug of choice. The drug has a short half-life and is given rapid IVP. Other drugs are β-adrenergic blockers, calcium channel blockers, and amiodarone. Defibrillation is used if the vagal stimulation and drug therapy are ineffective and the patient becomes hemodynamically unstable. Digoxin is not used for this dysrhythmia but typically is used for atrial fibrillation. Reference: 826

The nurse obtains a rhythm strip on a patient who has had a myocardial infarction and makes the following analysis: no visible P waves, P-R interval not measurable, ventricular rate 162, R-R interval regular, and QRS complex wide and distorted, QRS duration 0.18 second. The nurse interprets the patient's cardiac rhythm as a. atrial flutter. b. sinus tachycardia. c. ventricular fibrillation. d. ventricular tachycardia.

ANS: D The absence of P waves, wide QRS, rate >150 beats/minute, and the regularity of the rhythm indicate ventricular tachycardia. Atrial flutter is usually regular, has a narrow QRS configuration, and has flutter waves present representing atrial activity. Sinus tachycardia has P waves. Ventricular fibrillation is irregular and does not have a consistent QRS duration. DIF: Cognitive Level: Apply (application) REF: 794 TOP: Nursing Process: Assessment MSC: NCLEX: Physiological Integrity

For which dysrhythmia is defibrillation primarily indicated? A. Ventricular fibrillation B. Third-degree AV block C. Uncontrolled atrial fibrillation D. Ventricular tachycardia with a pulse

ANS:A Defibrillation is always indicated in the treatment of ventricular fibrillation. Drug treatments are normally used in the treatment of uncontrolled atrial fibrillation and for ventricular tachycardia with a pulse (if the patient is stable). Otherwise, synchronized cardioversion is used (as long as the patient has a pulse). Pacemakers are the treatment of choice for third-degree heart block. Reference: 833

A patient has received instruction on the management of a new permanent pacemaker before discharge from the hospital. The nurse recognizes that teaching has been effective when the patient tells the nurse, a. "It will be 6 weeks before I can take a bath or return to my usual activities." b. "I will notify the airlines when I make a reservation that I have a pacemaker." c. "I won't lift the arm on the pacemaker side up very high until I see the doctor." d. "I must avoid cooking with a microwave oven or being near a microwave in use."

C The patient is instructed to avoid lifting the arm on the pacemaker side above the shoulder to avoid displacing the pacemaker leads. The patient should notify airport security about the presence of a pacemaker before going through the metal detector, but there is no need to notify the airlines when making a reservation. Microwave oven use does not affect the pacemaker. The insertion procedure involves minor surgery that will have a short recovery period. DIF: Cognitive Level: Application REF: 837 TOP: Nursing Process: Evaluation

The nurse has obtained this 6-sec rhythm strip from her patient's monitor: Visible normal P waves, normal PR interval, 13 consistent QRS complexes. What should the nurse document this rhythm indicates? Sinus tachycardia Sinus bradycardia Ventricular fibrillation Ventricular tachycardia

Sinus tachycardia This rhythm strip shows sinus tachycardia because the rate on this strip is above 101 beats/min, and it displays normal P wave, PR interval, and QRS complex. Sinus bradycardia would look similar to sinus tachycardia but with a rate less than 60 beats/min. Ventricular fibrillation does not have a measureable heart rate, PR interval, or QRS, and the P wave is not visible and the rhythm is irregular and chaotic. Ventricular tachycardia has a rate of 150 to 250 beats/mins, with a regular or irregular rhythm and P waves occurring independently of the QRS complex.

A 50-year-old man who develops third-degree heart block reports feeling chest pressure and shortness of breath. Which instructions should the nurse provide to the patient before initiating emergency transcutaneous pacing? a) "The device will convert your heart rate to a normal rate." b) "The device uses overdrive pacing to slow the heart to a normal rate." c) "The device is inserted through a large vein and threaded into your heart." d) "The device delivers a current through your skin that can be uncomfortable."

d) "The device delivers a current through your skin that can be uncomfortable." (Before initiating transcutaneous pacing (TCP) therapy, it is important to tell the patient what to expect. The nurse should explain that the muscle contractions created by the pacemaker when the current passes through the chest wall are uncomfortable. Pacing for complete heart block will not convert the heart rhythm to normal. Overdrive pacing is used for very fast heart rates. Transcutaneous pacing is delivered through pacing pads adhered to the skin.)

Which laboratory test results may be associated with peaked or tall, tented T waves on a client's electrocardiogram (ECG)?

Potassium level of 6.8 mEq/L Hyperkalemia can cause tall, peaked or tented T waves on the ECG. Levels of potassium 5.0 mEq/L or greater indicate hyperkalemia. Options 1, 2, and 4 are normal levels.

The charge nurse is explaining the concept of pacemaker failure to capture to the new graduate. What information should the charge nurse give? A. It occurs when the electrical charge is insufficient. B. It occurs when the pacemaker does not recognize spontaneous heart activity. C. A complication is ventricular tachycardia. D. First-line treatment when this occurs is to turn down the electrical charge.

ANS: A Failure to capture occurs when the electrical charge to the myocardium is insufficient to produce atrial or ventricular contraction. It can result in serious bradycardia, and treatment includes increasing the electrical charge. Failure to sense occurs when the pacemaker fails to recognize spontaneous atrial or ventricular activity and fires inappropriately. This can result in ventricular tachycardia. Reference: 836

You are watching the cardiac monitor, and a patient's rhythm suddenly changes. There are no P waves. Instead, there are fine, wavy lines between the QRS complexes. The QRS complexes each measure 0.08 second (narrow), but they occur irregularly with a rate of 120 beats/minute. You correctly interpret that this rhythm is A. sinus tachycardia. B. atrial fibrillation. C. ventricular fibrillation. D. ventricular tachycardia.

ANS: B Atrial fibrillation is represented on the cardiac monitor by irregular R-R intervals and small fibrillatory (F) waves. There are no normal P waves because the atria are not contracting, just fibrillating. Reference: 827

The patient has a pacemaker set for 70 beats/minute. When taking the patient's pulse, you obtain a heart rate of 60 beats/minute. What is the best interpretation of this finding? A. The patient's heart has become more effective. B. The pacemaker is not working properly. C. The patient is tolerating a lower heart rate now. D. The pacemaker is sensing a ventricular rhythm.

ANS: B If the pacemaker is set for 70 beats/minute, a slower rate means that the pacemaker is not working properly and the patient's spontaneous rate has taken over. This situation needs to be evaluated. Reference: 836-837

You obtain a 6-second rhythm strip, and document the following analysis: atrial rate of 70 beats/minute, regular; ventricular rate of 40 beats/minute, regular; QRS of 0.04 second; no relationship between P waves and QRS complexes; and atria and ventricles beating independently of each other. What is the correct interpretation of this rhythm strip? A. Sinus dysrhythmias B. Third-degree heart block C. Wenckebach phenomenon D. Premature ventricular contractions

ANS: B Third-degree heart block represents a loss of communication between the atrium and ventricles. This is depicted on the rhythm strip because there is no relationship between the P waves, representing atrial contraction, and QRS complexes, representing ventricular contraction. The atria are beating totally on their own at 70 beats/minute, whereas the ventricles are pacing themselves at 40 beats/minute. Reference: 830

Which ECG characteristics are consistent with a diagnosis of ventricular tachycardia (VT)? A. Unmeasurable rate and rhythm B. Rate of 150 beats/minute; inverted P wave C. Rate of 200 beats/minute; P wave not visible D. Rate of 125 beats/minute; normal QRS complex

ANS: C VT is associated with a rate of 150 to 250 beats/minute, and the P wave is not normally visible. P-wave inversion and a normal QRS complex are not associated with VT. Rate and rhythm are not measurable in ventricular fibrillation. Reference: 831

The patient has chronic atrial fibrillation (AF). What action do you anticipate? A. Monitoring the PR interval B. Defibrillation with 360 joule C. Teaching the patient to monitor the pulse deficit D. Teaching the patient to take an anticoagulant daily

ANS: D The chaotic atrial activity results in blood stasis that can lead to embolic events. Patients with chronic AF are given an anticoagulant, most often warfarin (Coumadin), to prevent the formation of emboli. There is no PR interval in AF because the P wave is absent, replaced by chaotic fibrillatory waves. Defibrillation is an elective procedure in chronic AF and is performed at lower levels of electricity. Pulse deficit is a higher-level skill and is not taught to the patient. Reference: 827

Which laboratory result for a patient with multifocal premature ventricular contractions (PVCs) is most important for the nurse to communicate to the health care provider? a. Blood glucose 243 mg/dL b. Serum chloride 92 mEq/L c. Serum sodium 134 mEq/L d. Serum potassium 2.9 mEq/L

ANS: D Hypokalemia increases the risk for ventricular dysrhythmias such as PVCs, ventricular tachycardia, and ventricular fibrillation. The health care provider will need to prescribe a potassium infusion to correct this abnormality. Although the other laboratory values also are abnormal, they are not likely to be the etiology of the patient's PVCs and do not require immediate correction

The nurse needs to quickly estimate the heart rate for a patient with a regular heart rhythm. Which method will be best to use? a. Count the number of large squares in the R-R interval and divide by 300. b. Print a 1-minute electrocardiogram (ECG) strip and count the number of QRS complexes. c. Calculate the number of small squares between one QRS complex and the next and divide into 1500. d. Use the 3-second markers to count the number of QRS complexes in 6 seconds and multiply by 10.

ANS: D This is the quickest way to determine the ventricular rate for a patient with a regular rhythm. All the other methods are accurate, but take longer

A 19-year-old student comes to the student health center at the end of the semester complaining that, "My heart is skipping beats." An electrocardiogram (ECG) shows occasional premature ventricular contractions (PVCs). What action should the nurse take next? a. Start supplemental O2 at 2 to 3 L/min via nasal cannula. b. Ask the patient about current stress level and caffeine use. c. Ask the patient about any history of coronary artery disease. d. Have the patient taken to the hospital emergency department (ED).

B In a patient with a normal heart, occasional PVCs are a benign finding. The timing of the PVCs suggests stress or caffeine as possible etiologic factors. It is unlikely that the patient has coronary artery disease, and this should not be the first question the nurse asks. The patient is hemodynamically stable, so there is no indication that the patient needs to be seen in the ED or that oxygen needs to be administered. DIF: Cognitive Level: Apply (application) REF: 799 OBJ: Special Questions: Prioritization TOP: Nursing Process: Implementation MSC:

A patient has a junctional escape rhythm on the monitor. The nurse will expect the patient to have a heart rate of _____ beats/minute. a. 15 to 20 b. 20 to 40 c. 40 to 60 d. 60 to 100

C (If the sinoatrial (SA) node fails to discharge, the atrioventricular (AV) node will automatically discharge at the normal rate of 40 to 60 beats/minute. The slower rates are typical of the bundle of His and the Purkinje system and may be seen with failure of both the SA and AV node to discharge. The normal SA node rate is 60 to 100 beats/minute.)

A nurse is reinforcing instructions to a hospitalized client with heart block about the fundamental concepts regarding the cardiac rhythm. The nurse explains to the client that the normal site in the heart responsible for initiating electrical impulses is which site?

Sinoatrial (SA) node

The nurse prepares to defibrillate a patient. For which dysrhythmia has the nurse observed in this patient? Ventricular fibrillation Third-degree AV block Uncontrolled atrial fibrillation Ventricular tachycardia with a pulse

Ventricular fibrillation Defibrillation is always indicated in the treatment of ventricular fibrillation. Drug treatments are normally used in the treatment of uncontrolled atrial fibrillation and for ventricular tachycardia with a pulse (if the patient is stable). Otherwise, synchronized cardioversion is used (as long as the patient has a pulse). Pacemakers are the treatment of choice for third-degree heart block.

The nurse in a medical unit is caring for a client with heart failure. The client suddenly develops extreme dyspnea, tachycardia, and lung crackles and the nurse suspects pulmonary edema. The nurse immediately asks another nurse to contact the health care provider and prepares to implement which priority interventions? Select all that apply. 1.Administering oxygen 2.Inserting a Foley catheter 3.Administering furosemide (Lasix) 4.Administering morphine sulfate intravenously 5.Transporting the client to the coronary care unit 6.Placing the client in a low Fowler's side-lying position

1,2,3,4 Pulmonary edema is a life-threatening event that can result from severe heart failure. In pulmonary edema, the left ventricle fails to eject sufficient blood, and pressure increases in the lungs because of the accumulated blood. Oxygen is always prescribed, and the client is placed in a high Fowler's position to ease the work of breathing. Furosemide, a rapid-acting diuretic, will eliminate accumulated fluid. A Foley catheter is inserted to measure output accurately. Intravenously administered morphine sulfate reduces venous return (preload), decreases anxiety, and also reduces the work of breathing. Transporting the client to the coronary care unit is not a priority intervention. In fact, this may not be necessary at all if the client's response to treatment is successful.

The nurse is watching the cardiac monitor, and a client's rhythm suddenly changes. There are no P waves; instead, there are fibrillatory waves before each QRS complex. How should the nurse correctly interpret the client's heart rhythm? 1.Atrial fibrillation 2.Sinus tachycardia 3.Ventricular fibrillation 4.Ventricular tachycardia

1. Atrial fibrillation is characterized by a loss of P waves and fibrillatory waves before each QRS complex. The atria quiver, which can lead to thrombus formation.

A client is admitted to an emergency department with chest pain that is consistent with myocardial infarction based on elevated troponin levels. Heart sounds are normal and vital signs are noted on the client's chart. The nurse should alert the health care provider because these changes are most consistent with which complication? Refer to chart. 1. Cardiogenic shock 2. Cardiac tamponade 3. Pulmonary embolism 4. Dissecting thoracic aortic aneurysm

1. Cardiogenic shock occurs with severe damage (more than 40%) to the left ventricle. Classic signs include hypotension, a rapid pulse that becomes weaker, decreased urine output, and cool, clammy skin. Respiratory rate increases as the body develops metabolic acidosis from shock. Cardiac tamponade is accompanied by distant, muffled heart sounds and prominent neck vessels. Pulmonary embolism presents suddenly with severe dyspnea accompanying the chest pain. Dissecting aortic aneurysms usually are accompanied by back pain.

A client has frequent bursts of ventricular tachycardia on the cardiac monitor. What should the nurse be most concerned about with this dysrhythmia? 1.It can develop into ventricular fibrillation at any time. 2.It is almost impossible to convert to a normal rhythm. 3.It is uncomfortable for the client, giving a sense of impending doom. 4.It produces a high cardiac output that quickly leads to cerebral and myocardial ischemia.

1. Ventricular tachycardia is a life-threatening dysrhythmia that results from an irritable ectopic focus that takes over as the pacemaker for the heart. The low cardiac output that results can lead quickly to cerebral and myocardial ischemia. Clients frequently experience a feeling of impending doom. Ventricular tachycardia is treated with antidysrhythmic medications, cardioversion (if client is awake), or defibrillation (loss of consciousness). Ventricular tachycardia can deteriorate into ventricular fibrillation at any time.

ECG: Ventricular Tachycardia

150-250 beats/min. Can be regular or irregular. -P wave not usually visible -PR interval not measurable -QRS complex wide and distorted

A client who had cardiac surgery 24 hours ago has had a urine output averaging 20 mL/hour for 2 hours. The client received a single bolus of 500 mL of intravenous fluid. Urine output for the subsequent hour was 25 mL. Daily laboratory results indicate that the blood urea nitrogen level is 45 mg/dL and the serum creatinine level is 2.2 mg/dL. On the basis of these findings, the nurse would anticipate that the client is at risk for which problem? 1.Hypovolemia 2.Acute kidney injury 3.Glomerulonephritis 4.Urinary tract infection

2. The client who undergoes cardiac surgery is at risk for renal injury from poor perfusion, hemolysis, low cardiac output, or vasopressor medication therapy. Renal injury is signaled by decreased urine output and increased blood urea nitrogen and creatinine levels. The client may need medications to increase renal perfusion and possibly could need peritoneal dialysis or hemodialysis. No data in the question indicate the presence of hypovolemia, glomerulonephritis, or urinary tract infection.

A client in ventricular fibrillation is about to be defibrillated. A nurse knows that to convert this rhythm effectively, the monophasic defibrillator machine should be set at which energy level (in joules, J) for the first delivery? 1.50 J 2.120 J 3.200 J 4.360 J

4. The energy level used for all defibrillation attempts with a monophasic defibrillator is 360 joules.

A client is having frequent premature ventricular contractions. The nurse should place priority on assessment of which item? 1.Sensation of palpitations 2.Causative factors, such as caffeine 3.Blood pressure and oxygen saturation 4.Precipitating factors, such as infection

3. Premature ventricular contractions can cause hemodynamic compromise. Therefore, the priority is to monitor the blood pressure and oxygen saturation. The shortened ventricular filling time can lead to decreased cardiac output. The client may be asymptomatic or may feel palpitations. Premature ventricular contractions can be caused by cardiac disorders, states of hypoxemia, or by any number of physiological stressors, such as infection, illness, surgery, or trauma, and by intake of caffeine, nicotine, or alcohol.

The nurse is caring for a client who has just had implantation of an automatic internal cardioverter-defibrillator. The nurse immediately would assess which item based on priority? 1.Anxiety level of the client and family 2.Presence of a Medic-Alert card for the client to carry 3.Knowledge of restrictions of postdischarge physical activity 4.Activation status of the device, heart rate cutoff, and number of shocks it is programmed to deliver

4. The nurse who is caring for the client after insertion of an automatic internal cardioverter-defibrillator needs to assess device settings, similar to after insertion of a permanent pacemaker. Specifically, the nurse needs to know whether the device is activated, the heart rate cutoff above which it will fire, and the number of shocks it is programmed to deliver. The remaining options are also nursing interventions but are not the priority.

A client with variant angina is scheduled to receive an oral calcium channel blocker twice daily. Which statement by the client indicates the need for further teaching? 1. "I should notify my doctor if my feet or legs start to swell." 2. "My doctor told me to call his office if my pulse rate decreases below 60." 3. "Avoiding grapefruit juice will definitely be a challenge for me, since I usually drink it every morning with breakfast." 4. "My spouse told me that since I have developed this problem, we are going to stop walking in the mall every morning."

4 Rationale: Variant angina, or Prinzmetal's angina, is pro- longed and severe and occurs at the same time each day, most often at rest. The pain is a result of coronary artery spasm. The treatment of choice is usually a calcium channel blocker, which relaxes and dilates the vascular smooth muscle, thus relieving the coronary artery spasm in variant angina. Adverse effects can include peripheral edema, hypotension, bradycardia, and heart failure. Grapefruit juice interacts with calcium channel blockers and should be avoided. If bradycardia occurs, the client should contact the health care provider. Clients should also be taught to change positions slowly to prevent orthostatic hypotension. Physical exertion does not cause this type of angina; therefore, the client should be able to continue morning walks with his or her spouse.

A client in sinus bradycardia, with a heart rate of 45 beats/minute, complains of dizziness and has a blood pressure of 82/60 mm Hg. Which prescription should the nurse anticipate will be prescribed? 1.Defibrillate the client. 2.Administer digoxin (Lanoxin). 3.Continue to monitor the client. 4.Prepare for transcutaneous pacing.

4. Hypotension and dizziness are signs of decreased cardiac output. Transcutaneous pacing provides a temporary measure to increase the heart rate and thus perfusion in the symptomatic client. Defibrillation is used for treatment of pulseless ventricular tachycardia and ventricular fibrillation. Digoxin will further decrease the client's heart rate. Continuing to monitor the client delays necessary intervention.

A client admitted to the hospital with chest pain and a history of type 2 diabetes mellitus is scheduled for cardiac catheterization. Which medication would need to be withheld for 24 hours before the procedure and for 48 hours after the procedure? 1.Regular insulin 2.Glipizide (Glucotrol) 3.Repaglinide (Prandin) 4.Metformin (Glucophage)

4. Metformin (Glucophage) needs to be withheld 24 hours before and for 48 hours after cardiac catheterization because of the injection of contrast medium during the procedure. If the contrast medium affects kidney function, with metformin in the system, the client would be at increased risk for lactic acidosis. The medications in the remaining options do not need to be withheld 24 hours before and 48 hours after cardiac catheterization.

The nurse is assisting to defibrillate a client in ventricular fibrillation. After placing the paddles on the client's chest and before discharging them, which intervention should be done? 1.Ensure that the client has been intubated. 2.Set the defibrillator to the "synchronize" mode. 3.Administer an amiodarone bolus intravenously. 4.Confirm that the rhythm is actually ventricular fibrillation.

4. Until the defibrillator is attached and charged, the client is resuscitated by using cardiopulmonary resuscitation. Once the defibrillator has been attached, the electrocardiogram is checked to verify that the rhythm is ventricular fibrillation or pulseless ventricular tachycardia. Leads also are checked for any loose connections. A nitroglycerin patch, if present, is removed. The client does not have to be intubated to be defibrillated. The machine is not set to the synchronous mode because there is no underlying rhythm with which to synchronize. Amiodarone may be given subsequently but is not required before defibrillation.

A 20-year-old has a mandatory electrocardiogram (ECG) before participating on a college soccer team and is found to have sinus bradycardia, rate 52. Blood pressure (BP) is 114/54, and the student denies any health problems. What action by the nurse is most appropriate? a. Allow the student to participate on the soccer team. b. Refer the student to a cardiologist for further diagnostic testing. c. Tell the student to stop playing immediately if any dyspnea occurs. d. Obtain more detailed information about the student's family health history.

A (In an aerobically trained individual, sinus bradycardia is normal. The student's normal BP and negative health history indicate that there is no need for a cardiology referral or for more detailed information about the family's health history. Dyspnea during an aerobic activity such as soccer is normal.)

To determine whether there is a delay in impulse conduction through the atria, the nurse will measure the duration of the patient's: a. P wave. b. Q wave. c. P-R interval. d. QRS complex.

A (The P wave represents the depolarization of the atria. The P-R interval represents depolarization of the atria, atrioventricular (AV) node, bundle of His, bundle branches, and the Purkinje fibers. The QRS represents ventricular depolarization. The Q wave is the first negative deflection following the P wave and should be narrow and short.)

The patient has a heart rate of 40 beats/minute. The P waves are regular, and the Q waves are regular, but there is no relationship between the P wave and QRS complex. What treatment do you anticipate? A. Pacemaker B. Continue to monitor C. Carotid massage D. Defibrillation

ANS: A In third-degree atrioventricular (AV) block, there is no correlation between the impulse from the atrium to the ventricles and the ventricular rhythm seen. A pacemaker eventually is required. Action must be taken because this usually results in reduced cardiac output with subsequent ischemia if untreated. Carotid massage is vagal stimulation, and it can cause bradycardia. There is a problem in conduction, not abnormal contraction, and defibrillation is not used. Reference: 830

Which intervention by a new nurse who is caring for a patient who has just had an implantable cardioverter-defibrillator (ICD) inserted indicates a need for more education about care of patients with ICDs? a. The nurse assists the patient to do active range of motion exercises for all extremities. b. The nurse assists the patient to fill out the application for obtaining a Medic Alert ID. c. The nurse gives amiodarone (Cordarone) to the patient without first consulting with the health care provider. d. The nurse teaches the patient that sexual activity usually can be resumed once the surgical incision is healed.

ANS: A The patient should avoid moving the arm on the ICD insertion site until healing has occurred in order to prevent displacement of the ICD leads. The other actions by the new nurse are appropriate for this patient. DIF: Cognitive Level: Apply (application) REF: 803 TOP: Nursing Process: Evaluation MSC: NCLEX: Safe and Effective Care Environment

The nurse notes that a patient's cardiac monitor shows that every other beat is earlier than expected, has no visible P wave, and has a QRS complex that is wide and bizarre in shape. How will the nurse document the rhythm? a. Ventricular couplets b. Ventricular bigeminy c. Ventricular R-on-T phenomenon d. Multifocal premature ventricular contractions

ANS: B Ventricular bigeminy describes a rhythm in which every other QRS complex is wide and bizarre looking. Pairs of wide QRS complexes are described as ventricular couplets. There is no indication that the premature ventricular contractions (PVCs) are multifocal or that the R-on-T phenomenon is occurring

Which action should the nurse perform when preparing a patient with supraventricular tachycardia for cardioversion who is alert and has a blood pressure of 110/66 mm Hg? a. Turn the synchronizer switch to the "off" position. b. Give a sedative before cardioversion is implemented. c. Set the defibrillator/cardioverter energy to 360 joules. d. Provide assisted ventilations with a bag-valve-mask device.

ANS: B When a patient has a nonemergency cardioversion, sedation is used just before the procedure. The synchronizer switch is turned "on" for cardioversion. The initial level of joules for cardioversion is low (e.g., 50). Assisted ventilations are not indicated for this patient

You are caring for a patient 24 hours after pacemaker insertion. Which nursing intervention is most appropriate at this time? A. Reinforcing the pressure dressing as needed B. Encouraging range-of-motion exercises of the involved arm C. Assessing the incision for any redness, swelling, or discharge D. Applying wet-to-dry dressings every 4 hours to the insertion site

ANS: C After pacemaker insertion, it is important for the patient to limit activity of the involved arm to minimize pacemaker lead displacement. The nonpressure dressing is kept dry until removed, usually 24 hours postoperatively. It is important for you to observe signs of infection by assessing for redness, swelling, or discharge from the incision site. Reference: 836-837

What term is applied to a pacemaker that is implanted for the purpose of terminating atrial tachycardias? A. Temporary pacemaker B. Antitachycardia pacing C. Overdriving pacing D. Cardiac resynchronization therapy

ANS: C Overdrive pacing involves pacing the atrium at a rate of 200 to 500 impulses per minute in an attempt to terminate atrial tachycardias (e.g., atrial flutter with a rapid ventricular response). A temporary pacemaker is a category of pacemakers used temporarily with the power source outside the body. Antitachycardia pacing delivers a stimulus to the ventricle to terminate tachydysrhythmias. Cardiac resynchronization therapy is a technique to resynchronize the cardiac cycle by pacing both ventricles. Reference: 835

Which statement best describes the electrical activity of the heart represented by measuring the PR interval on the ECG? A. The length of time it takes to depolarize the atrium B. The length of time it takes for the atria to depolarize and repolarize C. The length of time for the electrical impulse to travel from the sinoatrial (SA) node to the Purkinje fibers D. The length of time it takes for the electrical impulse to travel from the SA node to the AV node

ANS: C The electrical impulse in the heart must travel from the SA node through the AV node and into the Purkinje fibers for synchronous atrial and ventricular contraction to occur. The P wave represents atrial contraction, and the R wave is part of the QRS complex that represents ventricular contraction. When measuring the time from the beginning of the P wave to the beginning of the QRS (PR interval), you are identifying the length of time it takes for the electrical impulse to travel from the SA node to the Purkinje fibers. Reference: 818-819

A patient admitted with acute coronary syndrome (ACS) has continuous ECG monitoring. An examination of the rhythm strip reveals the following characteristics: atrial rate of 74 beats/minute and regular; ventricular rate of 62 beats/minute and irregular; P wave with a normal shape; PR interval that lengthens progressively until a P wave is not conducted; and QRS complex with a normal shape. Your priority nursing intervention involves A. performing synchronized cardioversion. B. administering 1 mg of epinephrine by IVP. C. observing for symptoms of hypotension or angina. D. preparing the patient for a transcutaneous pacemaker.

ANS: C The rhythm is a second-degree AV block, type I (Mobitz I or Wenckebach heart block). The rhythm is identified by a gradual lengthening of the PR interval. Type I AV block is usually a result of myocardial ischemia or infarction and typically is transient and well tolerated. You should assess for bradycardia, hypotension, and angina. If the patient becomes symptomatic, atropine or a temporary pacemaker may be needed. Reference: 830

The ECG monitor of a patient in the cardiac care unit after a myocardial infarction (MI) indicates ventricular bigeminy with a rate of 50 beats/minute. You anticipate A. performing defibrillation. B. treatment with IV lidocaine. C. insertion of a temporary, transvenous pacemaker. D. assessing the patient's response to the dysrhythmia.

ANS: D A premature ventricular contraction (PVC) is a contraction originating in an ectopic focus in the ventricles. When every other beat is a PVC, the rhythm is called ventricular bigeminy. PVCs are usually a benign finding in the patient with a normal heart. In heart disease, PVCs may reduce the cardiac output and precipitate angina and heart failure, depending on the frequency. Because PVCs in coronary artery disease or acute MI indicate ventricular irritability, the patient's physiologic response to PVCs must be monitored. Assessment of the patient's hemodynamic status is important to determine whether treatment with drug therapy is needed. Reference: 830

When analyzing the rhythm of a patient's electrocardiogram (ECG), the nurse will need to investigate further upon finding a(n) a. isoelectric ST segment. b. P-R interval of 0.18 second. c. Q-T interval of 0.38 second. d. QRS interval of 0.14 second.

ANS: D Because the normal QRS interval is 0.04 to 0.10 seconds, the patient's QRS interval of 0.14 seconds indicates that the conduction through the ventricular conduction system is prolonged. The P-R interval and Q-T interval are within normal range, and ST segment should be isoelectric (flat).

You prepare a patient for synchronized cardioversion knowing that cardioversion differs from defibrillation in that A. defibrillation requires lower dose of electrical energy. B. cardioversion is indicated for treatment of atrial bradydysrhythmias. C. defibrillation is synchronized to deliver a shock during the QRS complex. D. patients should be sedated if cardioversion is done on a nonemergent basis.

ANS:D Synchronized cardioversion is the therapy of choice for the patient with hemodynamically unstable ventricular or supraventricular tachydysrhythmias. A synchronized circuit in the defibrillator delivers a countershock that is programmed to occur on the R wave of the QRS complex seen on the ECG tracing. The synchronizer switch must be turned on when cardioversion is planned. The procedure for synchronized cardioversion is the same as for defibrillation, with the following exceptions. If synchronized cardioversion is done on a nonemergent basis, the patient is sedated before the procedure. The initial energy needed for synchronized cardioversion is less than the energy needed for defibrillation. Reference: 833

A patient reports dizziness and shortness of breath and is admitted with a dysrhythmia. Which medication, if ordered, requires the nurse to carefully monitor the patient for asystole? Digoxin Adenosine Metoprolol Atropine sulfate

Adenosine IV adenosine is the first drug of choice to convert supraventricular tachycardia to a normal sinus rhythm. Adenosine is administered IV rapidly (over 1 or 2 seconds) followed by a rapid, normal saline flush. The nurse should monitor the patient's electrocardiogram continuously because a brief period of asystole after adenosine administration is common and expected. Atropine sulfate increases heart rate, whereas lanoxin and metoprolol slow the heart rate.

The nurse observes no P waves on the patients monitor strip. There are fine, wavy lines between the QRS complexes. The QRS complexes measure 0.08 sec (narrow), but they occur irregularly with a rate of 120 beats/min. What does the nurse determine the rhythm to be? Sinus tachycardia Atrial fibrillation Ventricular fibrillation Ventricular tachycardia

Atrial fibrillation Atrial fibrillation is represented on the cardiac monitor by irregular R-R intervals and small fibrillatory (f) waves. There are no normal P waves because the atria are not truly contracting, just fibrillating. Sinus tachycardia is a sinus rate above 100 beats/min with normal P waves. Ventricular fibrillation is seen on the ECG without a visible P wave; an unmeasurable heart rate, PR or QRS; and the rhythm is irregular and chaotic. Ventricular tachycardia is seen as three or more premature ventricular contractions that have distorted QRS complexes with regular or irregular rhythm, and the P wave is usually buried in the QRS complex without a measurable PR interval.

The nurse notes that a client's cardiac rhythm shows absent P waves and no PR interval. How should the nurse interpret this rhythm?

Atrial fibrillation In atrial fibrillation, the P waves may be absent. There is no PR interval, and the QRS duration usually is normal and constant. Bradycardia is a slowed heart rate, and tachycardia is a fast heart rate. In NSR a P wave precedes each QRS complex, the rhythm is essentially regular, the PR interval is 0.12 to 0.20 seconds in duration, and the QRS interval is 0.06 to 0.10 seconds in duration.

A hospitalized client's serum calcium level is 7.9 mg/dL. The nurse is immediately concerned and takes action, knowing that this level could ultimately lead to which complication?

Cardiac arrest The normal calcium level is 8.6 to 10 mg/dL. A low calcium level could lead to severe ventricular dysrhythmias, prolonged QT interval, and ultimately cardiac arrest. Calcium is needed by the heart for contraction. Calcium ions move across cell membranes into cardiac cells during depolarization and move back during repolarization. Depolarization is responsible for cardiac contraction. Options 1 and 3 are unrelated to calcium levels. Elevated calcium levels can lead to urinary stone formation. The nurse would take action and contact the health care provider when a calcium level is abnormal.

A patient's cardiac monitor shows sinus rhythm, rate 64. The P-R interval is 0.18 seconds at 1:00 AM, 0.22 seconds at 2:30 PM, and 0.28 seconds at 4:00 PM. Which action should the nurse take next? a. Place the transcutaneous pacemaker pads on the patient. b. Administer atropine sulfate 1 mg IV per agency dysrhythmia protocol. c. Document the patient's rhythm and assess the patient's response to the rhythm. d. Call the health care provider before giving the next dose of metoprolol (Lopressor).

D (The patient has progressive first-degree atrioventricular (AV) block, and the -blocker should be held until discussing the medication with the health care provider. Documentation and assessment are appropriate but not fully adequate responses. The patient with first-degree AV block usually is asymptomatic, and a pacemaker is not indicated. Atropine is sometimes used for symptomatic bradycardia, but there is no indication that this patient is symptomatic.)

After providing a patient with discharge instructions on the management of a new permanent pacemaker, the nurse knows that teaching has been effective when the patient states a. "I will avoid cooking with a microwave oven or being near one in use." b. "It will be 1 month before I can take a bath or return to my usual activities." c. "I will notify the airlines when I make a reservation that I have a pacemaker." d. "I won't lift the arm on the pacemaker side up very high until I see the doctor."

D (The patient is instructed to avoid lifting the arm on the pacemaker side above the shoulder to avoid displacing the pacemaker leads. The patient should notify airport security about the presence of a pacemaker before going through the metal detector, but there is no need to notify the airlines when making a reservation. Microwave oven use does not affect the pacemaker. The insertion procedure involves minor surgery that will have a short recovery period.)

A hospitalized client is experiencing a decrease in blood pressure. The nurse plans care for the client, knowing that this change will have which primary effect on his or her heart?

Decreased myocardial blood flow The primary effect of a decrease in blood pressure is reduced blood flow to the myocardium. This in turn decreases oxygenation of the cardiac tissue. Cardiac tissue is likely to become more excitable or irritable in the presence of hypoxia. Correspondingly, the heart rate is likely to increase, not decrease, in response to this change. The effects of tissue ischemia lead to decreased contractility over time.

The nurse observes a flat line on the patient's monitor and the patient is unresponsive without pulse. What medications does the nurse prepare to administer? Lidocaine and amiodarone Digoxin and procainamide Epinephrine and/or vasopressin β-adrenergic blockers and dopamine

Epinephrine and/or vasopressin Normally, the patient in asystole cannot be successfully resuscitated. However, administration of epinephrine or vasopressin may prompt the return of depolarization and ventricular contraction. Lidocaine and amiodarone are used for ventricular tachycardia or ventricular fibrillation. Digoxin and procainamide are used for ventricular rate control. β-adrenergic blockers are used to slow heart rate, and dopamine is used to increase heart rate.

The nurse obtains a 6-second rhythm strip and charts the following analysis: Atrial data - Rate: 70, regular. Variable PR interval Independent beats. Rate: 40, regular. Isolated escape beats Ventricular data - QRS: 0.04 sec. Additional data - P wave and QRS complexes unrelated What is the correct interpretation of this rhythm strip? Sinus dysrhythmia Third-degree heart block Wenckebach phenomenon Premature ventricular contractions

Third-degree heart block Third-degree heart block represents a loss of communication between the atrium and ventricles from atrioventricular node dissociation. This is depicted on the rhythm strip as no relationship between the P waves (representing atrial contraction) and QRS complexes (representing ventricular contraction). Whereas the atria are beating totally on their own at 70 beats/min, the ventricles are pacing themselves at 40 beats/min. Sinus dysrhythmia is seen with a slower heart rate with exhalation and an increased heart rate with inhalation. In Wenckebach heart block, there is a gradual lengthening of the PR interval until an atrial impulse is nonconducted and a QRS complex is blocked or missing. Premature ventricular contractions are the early occurrence of a wide, distorted QRS complex.

The nurse has obtained this rhythm strip from her patient's monitor. Which description of this ECG is correct? (Picture on flip side) a) Sinus tachycardia b) Sinus bradycardia c) Ventricular fibrillation d) Ventricular tachycardia

a) Sinus tachycardia (This rhythm strip shows sinus tachycardia because the rate on this strip is above 101, and it displays normal P wave, PR interval, and QRS complex. Sinus bradycardia would look similar to sinus tachycardia but with a rate less than 60 beats per minute. Ventricular fibrillation does not have a measureable heart rate, PR interval, or QRS, and the P wave is not visible and the rhythm is irregular and chaotic. Ventricular tachycardia has a rate of 150 to 250 beats/minutes, with a regular or irregular rhythm and P waves occurring independently of the QRS complex.)

The nurse is watching the cardiac monitor, and a patient's rhythm suddenly changes. There are no P waves. Instead there are fine, wavy lines between the QRS complexes. The QRS complexes measure 0.08 sec (narrow), but they occur irregularly with a rate of 120 beats/min. The nurse correctly interprets this rhythm as what? a) Sinus tachycardia b) Atrial fibrillation c) Ventricular fibrillation d) Ventricular tachycardia

b) Atrial Fibrillation (Atrial fibrillation is represented on the cardiac monitor by irregular R-R intervals and small fibrillatory (f) waves. There are no normal P waves because the atria are not truly contracting, just fibrillating. Sinus tachycardia is a sinus rate above 100 beats/minute with normal P waves. Ventricular fibrillation is seen on the ECG without a visible P wave; an unmeasurable heart rate, PR or QRS; and the rhythm is irregular and chaotic. Ventricular tachycardia is seen as three or more premature ventricular contractions (PVCs) that have distorted QRS complexes with regular or irregular rhythm, and the P wave is usually buried in the QRS complex without a measurable PR interval.)

The patient is admitted with acute coronary syndrome (ACS). The ECG shows ST-segment depression and T-wave inversion. What should the nurse know that this indicates? a) Myocardial injury b) Myocardial ischemia c) Myocardial infarction d) A pacemaker is present

b) Myocardial ischemia (The ST depression and T wave inversion on the ECG of a patient diagnosed with ACS indicate myocardial ischemia from inadequate supply of blood and oxygen to the heart. Myocardial injury is identified with ST-segment elevation. Myocardial infarction is identified with ST-segment elevation and a widened and deep Q wave. A pacemaker's presence is evident on the ECG by a spike leading to depolarization and contraction.)

The patient has atrial fibrillation with a rapid ventricular response. The nurse knows to prepare for which treatment if an electrical treatment is planned for this patient? a) Defibrillation b) Synchronized cardioversion c) Automatic external defibrillator (AED) d) Implantable cardioverter-defibrillator (ICD)

b) Synchronized cardioversion (Synchronized cardioversion is planned for a patient with supraventricular tachydysrhythmias (atrial fibrillation with a rapid ventricular response). Defibrillation or AEDs are the treatment of choice to end ventricular fibrillation and pulseless ventricular tachycardia (VT). An ICD is used with patients who have survived sudden cardiac death (SCD), have spontaneous sustained VT, and are at high risk for future life-threatening dysrhythmias.)

What describes the refractory phase? a. abnormal electrical impulses b. Period in which heart tissue cannot be stimulated c. areas of the heart do not depolarize at the same rate because of depressed conduction d. Sodium migrates rapidly into the cel, so it is positive compared to the outside of the cell

b. Refractory phase is the period in which heart tissue cannot be stimulated. Ectopic foci produce abnormal electrical impulses. Reentrant excitation causing premature beats may occur when areas of the heart do not depolarize simultaneously with depressed conduction. Depolarization of cardiac cells occur when sodium migrates rapidly into the cell.

The nurse is monitoring the ECGs of several patients on a cardiac telemetry unit. The patients are directly visible to the nurse, and all of the patients are observed to be sitting up and talking with visitors. Which patient's rhythm would require the nurse to take immediate action? a) A 62-year old man with a fever and sinus tachycardia with a rate of 110 bpm b) A 72-year-old woman with atrial fibrillation with 60 to 80 QRS complexes per minute c) A 52 year old man with premature ventricular contractions (PVCs) at a rate of 12 per minute d) A 42 year old woman with first-degree AV block and sinus bradycardia at a rate of 56 bpm

c) A 52 year old man with premature ventricular contractions (PVCs) at a rate of 12 per minute (Frequent premature ventricular contractions (PVCs) (greater than 1 every 10 beats) may reduce the cardiac output and precipitate angina and heart failure, depending on their frequency. Because PVCs in CAD or acute MI indicate ventricular irritability, the patient's physiologic response to PVCs must be monitored. Frequent PVCs most likely must be treated with oxygen therapy, electrolyte replacement, or antidysrhythmic agents.)

The nurse is caring for a patient who is 24 hours postpacemaker insertion. Which nursing intervention is most appropriate at this time? a) Reinforcing the pressure dressing as needed b) Encouraging range-of-motion exercises of the involved arms c) Assessing the incision for any redness, swelling, or discharge d) Applying wet-to-dry dressings every 4 hours to the insertion site

c) Assessing the incision for any redness, swelling, or discharge (After pacemaker insertion, it is important for the nurse to observe signs of infection by assessing for any redness, swelling, or discharge from the incision site. The nonpressure dressing is kept dry until removed, usually 24 hours postoperatively. It is important for the patient to limit activity of the involved arm to minimize pacemaker lead displacement.)

Cardioversion is attempted for a 64-year-old man with atrial flutter and a rapid ventricular response. After the nurse delivers 50 joules by synchronized cardioversion, the patient develops ventricular fibrillation. Which action should the nurse take immediately? a) Administer 250 mL of 0.9% saline solution IV by rapid bolus b) Assess the apical pulse, blood pressure, and bilateral neck vein distention. c) Turn the synchronizer switch to the "off" position and recharge the device. d) Tell the patient to report any chest pain or discomfort and administer morphine sulfate

c) Tell the synchronizer switch to the "off" position and recharge the device. (Ventricular fibrillation produces no effective cardiac contractions or cardiac output. If during synchronized cardioversion the patient becomes pulseless or the rhythm deteriorates to ventricular fibrillation, the nurse should turn the synchronizer switch off and initiate defibrillation. Fluids, additional assessment, or treatment of pain alone will not restore an effective heart rhythm.)

The nurse is seeing artifact on the telemetry monitor. Which factors could contribute to this artifact? a) Disabled automaticity b) Electrodes in the wrong lead c) Too much hair under the electrodes d) Stimulation of the vagus nerve fibers

c) Too much hair under the electrodes (Artifact is caused by muscle activity, electrical interference, or insecure leads and electrodes that could be caused by excessive chest wall hair. Disabled automaticity would cause an atrial dysrhythmia. Electrodes in the wrong lead will measure electricity in a different plane of the heart and may have a different wave form than expected. Stimulation of the vagus nerve fibers causes a decrease in heart rate, not artifact.)

The nurse performs discharge teaching for a 74-year-old woman with an implantable cardioverter-defibrillator. Which statement by the patient indicates to the nurse that further teaching is needed? a) "The device may set off the metal detectors in an airport." b) "My family needs to keep up to date on how to perform CPR." c) "I should not stand next to antitheft devices at the exit of stores." d) "I can expect redness and swelling of the incision site for a few days."

d) "I can expect redness and swelling of the incision site for a few days." (Patients should be taught to report any signs of infection at incision site (e.g., redness, swelling, drainage) or fever to their primary care provider immediately. Teach the patient to inform airport security of presence of ICD because it may set off the metal detector. If hand-held screening wand is used, it should not be placed directly over the ICD. Teach the patient to avoid standing near antitheft devices in doorways of stores and public buildings, and to walk through them at a normal pace. Caregivers should learn cardiopulmonary resuscitation (CPR).)

A 38-year-old teacher who reported dizziness and shortness of breath while supervising recess is admitted with a dysrhythmia. Which medication, if ordered, requires the nurse to carefully monitor the patient for systole? a) Atropine sulfate b) Digoxin (Lanolin) c) Metoprolol (Lopressor) d) Adenosine (Adenocard)

d) Adenosine (Adenocard) (IV adenosine (Adenocard) is the first drug of choice to convert supraventricular tachycardia to a normal sinus rhythm. Adenosine is administered IV rapidly (over 1 or 2 seconds) followed by a rapid, normal saline flush. The nurse should monitor the patient's ECG continuously because a brief period of asystole after adenosine administration is common and expected. Atropine sulfate increases heart rate, whereas lanolin and metoprolol slow the heart rate.)

What describes the SA node's ability to discharge an electrical impulse spontaneously? a. Excitability b. Contractility c. conductivity d. automaticity

d. Automaticity describes the ability to discharge an electrical impulse spontaneously. Excitability is a property of myocardial tissue that enables it to depolarized by an impulse. Contractility is the ability of the chambers to respond mechanically to an impulse. Conductivity is the ability to transmit an impulse along a membrane.

What accurately describes the PR interval (select all that apply)? a. 0.16 seconds b. <0.12 seconds c. 0.06 to 0.12 d. 0.12 to 0.20 seconds e. time of depolarization and depolarization of ventricles f. measured from beginning of P wave to beginning of QRS complex

d. f. The expected PR interval is 0.12 to 0.20 seconds and is measured from the beginning of the P wave to the beginning of the QRS complex. The T wave is 0.16 seconds, the QRS interval is <0.12 seconds, the P wave is 0.06 to 0.12 seconds, and the QT interval is the time of depolarization and depolarization of the ventricles.