Dysrhythmias- Ch. 35

The nurse performs discharge teaching for a patient with an implantable cardioverter-defibrillator (ICD). 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."

"I can expect redness and swelling of the incision site for a few days."

The nurse is doing discharge teaching with the patient who received an implantable cardioverter-defibrillator (ICD) in the left side. Which statement by the patient indicates to the nurse that further teaching is required? 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."

"I cannot fly because it will damage the ICD."

A patient develops third-degree heart block and 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 and rhythm back to normal." 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."

"The device delivers a current through your skin that can be uncomfortable."

P wave normal duration

0.06-0.12

ST segment normal duration

0.12

PR interval normal duration

0.12-0.20

T wave normal duration

0.16

QT interval normal duration

0.34-0.43

When computing a heart rate from the electrocardiography (ECG) tracing, the nurse counts 15 of the small blocks between the R waves of a patient whose rhythm is regular. What does the nurse calculate the patient's heart rate to be? a. 60 beats/min b. 75 beats/min c. 100 beats/min d. 150 beats/min

100 beats/min (Because 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).)

The ECG pattern of a patient with a regular HR reveals 20 small squares between each R-R interval. What is the patient's heart rate? ________ bpm

75 (1500 ÷ 20 = 75 bpm)

A patient with a regular heart rate (HR) has four QRS complexes between every 3-second marker on the ECG paper. Calculate the patient's heart rate. _________ bpm

80 (4 (beats per 3 seconds) + 4 = 8 × 10 = 80 bpm)

Q wave normal duration

< 0.03

QRS interval normal duration

< 0.12

The nurse is monitoring the electrocardiograms 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-yr-old man with a fever and sinus tachycardia with a rate of 110 beats/min b. A 72-yr-old woman with atrial fibrillation with 60 to 80 QRS complexes per minute c. A 52-yr-old man with premature ventricular contractions (PVCs) at a rate of 12 per minute d. A 42-yr-old woman with first-degree AV block and sinus bradycardia at a rate of 56 beats/min

A 52-yr-old man with premature ventricular contractions (PVCs) at a rate of 12 per minute (Frequent premature ventricular contractions (PVCs) (>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 myocardial infarction 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.)

Which rhythm pattern finding is indicative of PVCs? a. A QRS complex ≥0.12 second followed by a P wave b. Continuous wide QRS complexes with a ventricular rate of 160 bpm c. P waves hidden in QRS complexes with a regular rhythm of 120 bpm d. Saw-toothed P waves with no measurable PR interval and an irregular rhythm

A QRS complex ≥0.12 second followed by a P wave (PVC is an ectopic beat that causes a wide, distorted QRS complex ≥0.12 second because the impulse is not conducted normally through the ventricles. Because it is premature, it precedes the P wave and the P wave may be hidden in the QRS complex, or the ventricular impulse may be conducted retrograde and the P wave may be seen following the PVC but the rhythm is not regular. Continuous wide QRS complexes with a ventricular rate between 150 and 250 bpm are seen in ventricular tachycardia, whereas saw-toothed P waves are characteristic of atrial flutter.)

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 repolarization of the atria d. A problem with conduction from the SA node to the ventricular cells

A problem with conduction from the SA node to the ventricular cells (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 of the impulse from the atria to the Purkinje fibers is delayed.)

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? a. Digoxin b. Adenosine c. Metoprolol d. 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.)

What action is included in the nurse's responsibilities in preparing to administer defibrillation? a. Applying gel pads to the patient's chest b. Setting the defibrillator to deliver 50 joules c. Setting the defibrillator to a synchronized mode d. Sedating the patient with midazolam (Versed) before defibrillation

Applying gel pads to the patient's chest (In preparation for defibrillation the nurse should apply conductive materials (e.g., saline pads, electrode gel, defibrillator gel pads) to the patient's chest to decrease electrical impedance and prevent burns. For defibrillation, the initial shock is 200 joules with biphasic defibrillators and the synchronizer switch used for cardioversion must be turned off. Sedatives may be used before cardioversion if the patient is conscious but the patient in ventricular fibrillation is unconscious.)

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 arm c. Assessing the incision for any redness, swelling, or discharge d. Applying wet-to-dry dressings every 4 hours to the insertion site

Assessing the incision for any redness, swelling, or discharge

Name the rhythm

Atrial fibrillation

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? a. Sinus tachycardia b. Atrial fibrillation c. Ventricular fibrillation d. 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.)

Name the rhythm

Atrial flutter

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

Automaticity (Automaticity describes the ability to discharge an electrical impulse spontaneously. Excitability is a property of myocardial tissue that enables it to be 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.)

A patient with a sinus node dysfunction has a permanent pacemaker inserted. Before discharge, what should the nurse include when teaching the patient? a. Avoid cooking with microwave ovens. b. Avoid standing near antitheft devices in doorways. c. Use mild analgesics to control the chest spasms caused by the pacing current. d. Start lifting the arm above the shoulder right away to prevent a "frozen shoulder."

Avoid standing near antitheft devices in doorways (The patient should avoid standing near antitheft devices in doorways of department stores and libraries but walking through them at normal pace is fine. High-output electrical generators or large magnets, such as those used in magnetic resonance imaging (MRI), can reprogram pacemakers and should be avoided. Microwave ovens pose no problems to pacemaker function but the arm should not be raised above the shoulder for 1 week after placement of the pacemaker. The pacing current of an implanted pacemaker is not felt by the patient but an external pacemaker may cause uncomfortable chest muscle contractions.)

Which effects result from sympathetic nervous system stimulation of β-adrenergic receptors? (select all that apply) a. vasoconstriction b. increased heart rate c. decreased heart rate d. increased rate of impulse conduction e. decreased rate of impulse conduction f. increased force of cardiac contraction

B,D,F

Priority Decision: A patient on the cardiac telemetry unit goes into ventricular fibrillation and is unresponsive. Following initiation of the emergency call system (Code Blue), what is the next priority for the nurse in caring for this patient? a. Begin CPR. b. Get the crash cart. c. Administer amiodarone IV. d. Defibrillate with 360 joules.

Begin CPR (Until the defibrillator is available, the patient needs CPR. Defibrillation is needed as soon as possible, so someone should bring the crash cart to the room. Defibrillation would be with 360 joules for monophasic defibrillators and 120 to 200 joules for biphasic defibrillators. Amiodarone is an antidysrhythmic that is part of the advanced cardiac life support (ACLS) protocol for ventricular fibrillation.)

While providing discharge instructions to the patient who has had an implantable cardioverter-defibrillator (ICD) inserted, the nurse teaches the patient that if the ICD fires, \ he or she should do what? a. Lie down. b. Call the cardiologist. c. Push the reset button on the pulse generator. d. Immediately take his or her antidysrhythmic medication.

Call the cardiologist (If the cardioverter-defibrillator delivers a shock, the patient has experienced a lethal dysrhythmia and needs to notify the cardiologist. The patient will want to lie down to allow recovery from the dysrhythmia. In the event that the patient loses consciousness or there is repetitive firing, a call should be placed to the emergency medical services (EMS) system by anyone who finds the patient.)

In the patient with a dysrhythmia, which assessment indicates decreased cardiac output (CO)? a. Hypertension and bradycardia b. Chest pain and decreased mentation c. Abdominal distention and hepatomegaly d. Bounding pulses and a ventricular heave

Chest pain and decreased mentation (Symptoms of decreased cardiac output (CO) related to cardiac dysrhythmias include a sudden drop in BP and symptoms of hypoxemia, such as decreased mentation, chest pain, and dyspnea. Peripheral pulses are weak and the HR may be increased or decreased, depending on the type of dysrhythmia present.)

Priority Decision: A patient's rhythm strip indicates a normal HR and rhythm with normal P waves and QRS complexes, but the PR interval is 0.26 second. What is the most appropriate action by the nurse? a. Continue to assess the patient. b. Administer atropine per protocol. c. Prepare the patient for synchronized cardioversion. d. Prepare the patient for placement of a temporary pacemaker.

Continue to assess the patient (A rhythm pattern that is normal except for a prolonged P-R interval is characteristic of a first-degree heart block. First-degree heart blocks are not treated but are observed for progression to higher degrees of heart block. Atropine is administered for bradycardia. Synchronized cardioversion is used for atrial fibrillation with a rapid ventricular response or supraventricular tachycardia (SVT). Pacemakers are used for higher-degree heart blocks.)

In the patient experiencing ventricular fibrillation (VF), what is the rationale for using cardiac defibrillation? a. Enhance repolarization and relaxation of ventricular myocardial cells b. Provide an electrical impulse that stimulates normal myocardial contractions c. Depolarize the cells of the myocardium to allow the SA node to resume pacemaker function d. Deliver an electrical impulse to the heart at the time of ventricular contraction to convert the heart to a sinus rhythm

Depolarize the cells of the myocardium to allow the SA node to resume pacemaker function (The intent of defibrillation is to apply an electrical current to the heart that will depolarize the cells of the myocardium so that subsequent repolarization of the cells will allow the SA node to resume the role of pacemaker. An artificial pacemaker provides an electrical impulse that stimulates normal myocardial contractions. Synchronized cardioversion involves delivery of a shock that is programmed to occur during the QRS complex of the ECG but this cannot be done during ventricular fibrillation because there is no normal ventricular contraction or QRS complex.)

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? a. Lidocaine and amiodarone b. Digoxin and procainamide c. Epinephrine and/or vasopressin d. 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 patient has a potassium level of 2.9 mEq/L, 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, and 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)

First-degree AV block (In first-degree atrioventricular (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.)

What accurately describes electrocardiographic (ECG) monitoring? a. Depolarization of the cells in the ventricles produces the T wave on the ECG. b. An abnormal cardiac impulse that arises in the atria, ventricles, or atrioventricular (AV) junction can create a premature beat that is known as an artifact. c. Lead placement for V1 includes one lead each for right arm, right leg, left arm, and left leg with the fifth lead on the fourth intercostal space to the right of the sternal border. d. If the sinoatrial (SA) node fails to discharge an impulse or discharges very slowly, a secondary pacemaker in the AV node is able to discharge at a rate of 30 to 40 times per minute.

Lead placement for V1 includes one lead each for right arm, right leg, left arm, and left leg with the fifth lead on the fourth intercostal space to the right of the sternal border. (The V1 leads are placed toward each limb and centrally at the fourth intercostal space to the right of the sternal border. Depolarization of the ventricular cells produces the QRS interval on the ECG. The T wave is produced by repolarization of the ventricular cells. Abnormal cardiac impulses from the atria, ventricles, or atrioventricular (AV) junction create ectopic beats. Artifacts are seen with leads or electrodes that are not secure, with muscle activity or electrical interference. The rate produced by the AV node pacing in a junctional escape rhythm is 40 to 60 bpm. If the His-Purkinje system is blocked, the heart rate is 20 to 40 bpm.)

A 54-year-old patient who has no structural heart disease has an episode of syncope. An upright tilt table test is performed to rule out neurocardiogenic syncope. The nurse explains to the patient that if neurocardiogenic syncope is the problem, the patient will experience what? a. No change in HR or BP b. Palpitations and dizziness c. Tachydysrhythmias and chest pain d. Marked bradycardia and hypotension

Marked bradycardia and hypotension (One of the most common causes of syncope is neurocardiogenic syncope, or "vasovagal" syncope. In this type of syncope there is accentuated adrenergic activity in the upright position, with intense activation of cardiopulmonary receptors resulting in marked bradycardia and hypotension. Normally testing with the upright tilt table causes activation of the renin-angiotensin-aldosterone system and compensation to increase CO and maintain BP when blood pools in the extremities. However, patients with neurocardiogenic syncope experience a marked decrease in BP and HR.)

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. Myocardia injury b. Myocardial ischemia c. Myocardial infarction d. A pacemaker is present.

Myocardial ischemia

What is A?

P

waveform on ECG that lasts 0.06 to 0.12 seconds

P wave

waveform on ECG measured from beginning of P wave to beginning of QRS complex; last 0.12 to 0.20 seconds

PR interval

Which rhythm abnormality has an increased risk of ventricular tachycardia and ventricular fibrillation? a. PAC b. PVC on the T wave c. Accelerated idioventricular rhythm d. Premature ventricular contraction (PVC) couplet

PVC on the T wave (When premature ventricular contraction (PVC) falls on the T wave of the preceding beat, R-on-T phenomenon occurs. Because the ventricle is repolarizing and there is increased excitability of cardiac cells, there is an increased risk of ventricular tachycardia or ventricular fibrillation. The other options do not increase this risk.)

Name the rhythm

Paroxysmal Supraventricular Tachycardia

What describes refractoriness? a. Abnormal electrical impulses b. Period in which heart tissue cannot be stimulated c. Areas of the heart do not repolarize at the same rate because of depressed conduction d. Sodium migrates rapidly into the cell so it is positive compared to the outside of the cell

Period in which heart tissue cannot be stimulated (Refractoriness is the period in which heart tissue cannot be stimulated. Ectopic foci are abnormal electrical impulses. Reentrant excitation causing premature beats may occur when areas of the heart do not repolarize simultaneously with depressed conduction. Depolarization of cardiac cells occurs when sodium migrates rapidly into the cell.)

Name the rhythm

Premature Atrial Contractions

The nurse is evaluating the telemetry ECG rhythm strip. How should the nurse document the distorted P wave causing an irregular rhythm? a. Atrial flutter b. Sinus bradycardia c. Premature atrial contraction (PAC) d. Paroxysmal supraventricular tachycardia (PSVT)

Premature atrial contraction (PAC) (The premature atrial contraction (PAC) has a distorted P wave that may feel like a skipped beat to the patient. Atrial flutter is an atrial tachydysrhythmia with recurring, regular, saw-toothed flutter waves from the same focus in the right or possibly left atrium. Sinus bradycardia has a regular heart rate less than 100 bpm. Paroxysmal supraventricular tachycardia (PSVT) starts in an ectopic focus above the bundle of His and may be triggered by PAC. If seen, the P wave may have an abnormal shape and has a spontaneous start and termination with a rate of 150 to 220 bpm.)

Priority Decision: A patient with an acute MI is having multifocal PVCs and ventricular couplets. He is alert and has a BP of 118/78 mm Hg with an irregular pulse of 86 bpm. What is the priority nursing action at this time? a. Continue to assess the patient. b. Ask the patient to perform Valsalva maneuver. c. Prepare to administer antidysrhythmic drugs per protocol. d. Be prepared to administer cardiopulmonary resuscitation (CPR).

Prepare to administer antidysrhythmic drugs per protocol (Multifocal PVCs in a patient with an MI indicate significant ventricular irritability that may lead to ventricular tachycardia or ventricular fibrillation. Antidysrhythmics, such as β-adrenergic blockers, procainamide, amiodarone, or lidocaine, may be used to control the dysrhythmias. Valsalva maneuver may be used to treat paroxysmal supraventricular tachycardia. The nurse must always be ready to perform cardiopulmonary resuscitation (CPR).)

A patient informs the nurse of experiencing syncope. Which nursing action should the nurse prioritize in the patient's subsequent diagnostic workup? a. Preparing to assist with a head-up tilt-test b. Preparing an IV dose of a β-adrenergic blocker c. Assessing the patient's knowledge of pacemakers d. Teaching the patient about the role of antiplatelet aggregators

Preparing to assist with a head-up tilt-test (In patients without structural heart disease, the head-up tilt-test is a common component of the diagnostic workup after episodes of syncope. IV β-blockers are not indicated, although an IV infusion of low-dose isoproterenol may be started in an attempt to provoke a response if the head-up tilt-test did not have a response. Addressing pacemakers is premature and inappropriate at this stage of diagnosis. Patient teaching surrounding antiplatelet aggregators is not directly relevant to the patient's syncope at this time.)

What is B?

Q

depolarization from the AV node throughout ventricles; lasts <0.12 seconds

QRS interval

time of depolarization and repolarization of ventricles

QT interval

What is C?

R

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

Rate 200 beats/min; P wave not visible

What is D?

S

A P wave on an ECG represents an impulse arising at the a. SA node and repolarizing the atria b. SA node and depolarizing the atria c. AV node and depolarizing the atria d. AV node and spreading to the bundle of His

SA node and depolarizing the atria

A patient with chest pain that is unrelieved by nitroglycerin is admitted to the coronary care unit for observation and diagnosis. While the patient has continuous ECG monitoring, what finding would most concern the nurse? a. Occasional PVCs b. An inverted T wave c. ST segment elevation d. A PR interval of 0.18 second

ST segment elevation (ST segment elevation indicates injury or infarction of an area of the heart. An inverted T wave is most often associated with ischemia and resolves when blood flow is restored. Occasional PVCs may be normal or may be the result of electrolyte imbalance or hypoxia. They require continued observation. A PR interval of 0.18 second is within normal range.)

The patient is brought to the emergency department with acute coronary syndrome (ACS). What changes should the nurse expect to see on the ECG if only myocardial injury has occurred? a. Absent P wave b. A wide Q wave c. Inverted T wave d. ST segment elevation

ST segment elevation (ST segment elevation is seen in myocardial injury. An absent or buried P wave can occur with PVCs, ventricular tachycardia, or ventricular fibrillation. A wide pathologic Q wave may be seen with infarction. T wave inversion may be seen with cardiac ischemia or within hours following an MI.)

The nurse is monitoring the ECG of a patient admitted with ACS. Which ECG characteristics would be most suggestive of myocardial ischemia? a. Sinus rhythm with a pathologic Q wave b. Sinus rhythm with an elevated ST segment c. Sinus rhythm with a depressed ST segment d. Sinus rhythm with premature atrial contractions

Sinus rhythm with a depressed ST segment

The patient has atrial fibrillation with a rapid ventricular response. What electrical treatment option does the nurse prepare the patient for? a. Defibrillation b. Synchronized cardioversion c. Automatic external defibrillator (AED) d. Implantable cardioverter-defibrillator (ICD)

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, have spontaneous sustained VT, and are at high risk for future life-threatening dysrhythmias.)

What is E?

T

repolarization of the ventricles; lasts 0.16 seconds

T wave

Which statement best describes the electrical activity of the heart represented by measuring the PR interval on the electrocardiogram (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 sinoatrial (SA) node to the atrioventricular (AV) node

The length of time for the electrical impulse to travel from the sinoatrial (SA) node to the Purkinje fibers

A patient with no history of heart disease has a rhythm strip that shows an occasional distorted P wave followed by normal AV and ventricular conduction. What should the nurse question the patient about? a. The use of caffeine b. The use of sedatives c. Any aerobic training d. Holding of breath during exertion

The use of caffeine (A distorted P wave with normal conduction of the impulse through the ventricles is characteristic of a premature atrial contraction. In a normal heart, this dysrhythmia is frequently associated with emotional stress or the use of caffeine, tobacco, or alcohol. Sedatives rarely slow the heart rate (HR). Aerobic conditioning and holding of breath during exertion (Valsalva maneuver) often cause bradycardia.)

After defibrillation, the advanced cardiac life support (ACLS) nurse says that the patient has pulseless electrical activity (PEA). What is most important for the nurse to understand about this rhythm? a. The heart rate is 40 to 60 bpm. b. Hypoxemia and hypervolemia are common with PEA. c. There is dissociated activity of the ventricle and atrium. d. There is electrical activity with no mechanical response.

There is electrical activity with no mechanical response. (Pulseless electrical activity (PEA) occurs when there is electrical activity on the ECG but no mechanical activity on assessment and therefore no heart rate. PEA is the most common dysrhythmia seen after defibrillation and may be caused by hypovolemia, hypoxia, metabolic acidosis, altered potassium level, hypoglycemia, hypothermia, toxins, cardiac tamponade, thrombosis, tension pneumothorax, and trauma. Dissociated atria and ventricles is third-degree AV block.)

A patient with an acute myocardial infarction (MI) develops the following ECG pattern: atrial rate of 82 and regular; ventricular rate of 46 and regular; P wave and QRS complex are normal but there is no relationship between the P wave and the QRS complex. What dysrhythmia does the nurse identify this as and what treatment is expected? a. Sinus bradycardia treated with atropine b. Third-degree heart block treated with a pacemaker c. Atrial fibrillation treated with electrical cardioversion d. Type I second-degree AV block treated with observation

Third-degree heart block treated with a pacemaker (Third-degree or complete heart block is recognized with the atrial and ventricular dissociation and treated with a pacemaker. Sinus bradycardia does not have atrial and ventricular dissociation. Atrial fibrillation does not have normal P waves, as they are stimulated by ectopic foci. In type 1 second-degree AV heart block the P-R interval gradually lengthens and a QRS complex is dropped. Then the cycle begins again.)

The nurse determines there is artifact on the patient's telemetry monitor. Which factor should the nurse assess for that could correct this issue? a. Disabled automaticity b. Electrodes in the wrong lead c. Too much hair under the electrodes d. Stimulation of the vagus nerve fibers

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.)

Cardioversion is attempted for a patient with atrial flutter and a rapid ventricular response. After the delivering 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.

Turn the synchronizer switch to the "off" position and recharge the device.

What should the nurse reading the monitor strip call a rhythm with a regular PR interval but a blocked QRS complex? a. Asystole b. Atrial fibrillation c. First-degree AV block d. Type II second-degree AV block

Type II second-degree AV block (In type II second-degree AV block, a P wave is nonconducted without progressive P-R interval lengthening. It is usually from a block in a bundle branch, occurs in a ratio of 2 P waves-to-1 QRS complex, 3:1, and so on. Atrial fibrillation has a chaotic P wave. Asystole is absence of ventricular activity. First-degree AV block is a prolonged AV conduction time, so the P-R interval is prolonged.)

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

Ventricular fibrillation

14. A patient with an acute MI has sinus tachycardia of 126 bpm. The nurse recognizes that if this dysrhythmia is not treated, the patient is likely to experience a. hypertension. b. escape rhythms. c. ventricular tachycardia. d. an increase in infarct size.

an increase in infarct size (Although many factors can cause a sinus tachycardia, in the patient who has had an acute MI, tachycardia increases myocardial oxygen need in a heart that already has impaired circulation and may lead to increasing angina and further ischemia and necrosis.)

The ECG monitor of a patient in the cardiac care unit after an MI indicates ventricular bigeminy with a rate of 50 beats/min. The nurse would anticipate a. performing defibrillation. b. treating with IV amiodarone. c. inserting a temporary transvenous pacemaker. d. assessing the patient's response to the dysrhythmia.

assessing the patient's response to the dysrhythmia.

5. Which patient teaching points should the nurse include when providing discharge instructions to a patient with a new permanent pacemaker and the caregiver (SATA)? a. Avoid or limit air travel. b. Take and record a daily pulse rate. c. Obtain and wear a Medic Alert ID device at all times. d. Avoid lifting arm on the side of the pacemaker above shoulder. e. Avoid microwave ovens because they interfere with pacemaker function.

b,c,d

What accurately describes the PR interval (SATA)? a. 0.16 seconds b. <0.12 seconds c. 0.06 to 0.12 seconds d. 0.12 to 0.20 seconds e. Time of depolarization and repolarization 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 repolarization of the ventricles)

The nurse plans close monitoring for the patient during electrophysiologic testing because this test a. requires the use of dyes that irritate the myocardium. b. causes myocardial ischemia, resulting in dysrhythmias. c. involves the use of anticoagulants to prevent thrombus and embolism. d. induces dysrhythmias that may require cardioversion or defibrillation to correct.

induces dysrhythmias that may require cardioversion or defibrillation to correct. (Electrophysiologic testing involves electrical stimulation to various areas of the atrium and ventricle to determine the inducibility of dysrhythmias and frequently induces ventricular tachycardia or ventricular fibrillation. The patient may have "near-death" experiences and requires emotional support if this occurs. Dye and anticoagulants are used for coronary angiograms.)

Name the rhythm

normal sinus rhythm

A patient admitted with ACS has continuous ECG monitoring. An examination of the rhythm strip reveals the following characteristics: atrial rate 74 beats/min and regular; ventricular rate 62 beats/min and irregular; P wave normal shape; PR interval lengthens progressively until a P wave is not conducted; QRS normal shape. The priority nursing intervention would be to a. perform synchronized cardioversion. b. administer epinephrine 1 mg IV push. c. observe for symptoms of hypotension or angina. d. apply transcutaneous pacemaker pads on the patient.

observe for symptoms of hypotension or angina.

The nurse prepares a patient for synchronized cardioversion knowing that cardioversion differs from defibrillation in that a. defibrillation requires a lower dose of electrical energy. b. cardioversion is indicated to treat 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 nonemergency basis.

patients should be sedated if cardioversion is done on a nonemergency basis.

Name the rhythm

sinus bradycardia

Name the rhythm

sinus tachycardia

The nurse has obtained this rhythm strip from her patient's monitor. What should the nurse document this rhythm indicates? a. Sinus tachycardia b. Sinus bradycardia c. Ventricular fibrillation d. Ventricular tachycardia

sinus tachycardia

25. The use of catheter ablation therapy to "burn" areas of the cardiac conduction system is indicated for the treatment of a. sinus arrest. b. heart blocks. c. tachydysrhythmias. d. premature ventricular tachycardia.

tachydysrhythmias (Catheter ablation therapy uses radiofrequency energy to ablate or "burn" accessory pathways or ectopic sites in the atria, AV node, or ventricles that cause tachydysrhythmias.)

Important teaching for the patient scheduled for a radiofrequency catheter ablation procedure includes explaining that a. ventricular bradycardia may be induced and treated during the procedure. b. a catheter will be placed in both femoral arteries to allow double-catheter use. c. the procedure will destroy areas of the conduction system that are causing rapid heart rhythms. d. a general anesthetic will be given to prevent the awareness of any "sudden cardiac death" experiences.

the procedure will destroy areas of the conduction system that are causing rapid heart rhythms.