Chapter 31: Dysrhythmias
1. Which priority concept does the nurse focus on when a client is diagnosed with a dysrhythmia? A. Clotting B. Fluid and electrolyte balance C. Perfusion D. Acid-base balance
1. C Perfusion is the priority concept for the client with dysrhythmias. It occurs when there is adequate arterial blood flow through the peripheral tissues (peripheral perfusion) and blood that is pumped by the heart to oxygenate major body organs (central perfusion). Perfusion is a normal physiologic process of the body; without adequate perfusion, cell death can occur. When a client has a dysrhythmia, often perfusion is inadequate. Clotting and fluid and electrolyte balance are interrelated concepts for dysrhythmias. Acid-base imbalance may be a result of inadequate perfusion.
10. Which condition is indicated when the nurse notes ST segment elevation or one to two small blocks on a client's ECG? A. Ventricular irritability B. Subarachnoid hemorrhage C. Myocardial injury or ischemia D. Malfunction of the SA node
10. C The normal ST segment begins at the isoelectric line. ST elevation or depression is significant if displacement is 1 mm (one small box) or more above or below the line and is seen in two or more leads. ST elevation may indicate problems such as myocardial infarction, pericarditis, and hyperkalemia. ST depression is associated with hypokalemia, myocardial infarction, or ventricular hypertrophy.
11. Which serum electrolyte would the nurse check after noting tall and peaked T waves on a client's ECG? A. Sodium B. Potassium C. Magnesium D. Chloride
11. B T waves may become tall and peaked; inverted (negative); or flat as a result of myocardial ischemia, potassium or calcium imbalances, medications, or autonomic nervous system effects.
12. Which actions are responsibilities of the monitor technician? Select all that apply. A. Report client rhythm and significant changes to the nurse. B. Notify the health care provider of any pertinent changes. C. Print routine ECG strips for each monitored client. D. Apply battery-operated transmitter leads to clients. E. Watch the bank of cardiac monitors on a client care unit. F. Interpret rhythm strips for each monitored client.
12. A, C, E, F Most acute care facilities have monitor technicians who are specially educated in ECG monitoring and rhythm interpretation. Their responsibilities include: watching a bank of monitors on a unit; printing ECG rhythm strips routinely and as needed; interpreting rhythms; and reporting the client's rhythm and significant changes to the nurse. The nurse would be responsible for notifying the cardiac health care provider (HCP) of changes, and the nurse or a qualified AP would apply the leads to a monitored client.
13. Which would be the best method for the nurse to confirm a report from the monitor technician about a change in a monitored client's heart rate? A. Count QRS complexes in a 6-second strip and multiply by 10. B. Analyze the ECG rhythm strip using an ECG caliper. C. Assess the client's heart rate directly by checking the apical pulse. D. Request that the monitor technician run an ECG strip for a minute.
13. C The best and most direct method of checking the client for a change in heart rate is to assess the apical pulse for a full minute. All of the other responses are indirect methods and do not include assessing the client which is the most important action in this situation.
14. What is the first step when the nurse analyzes a client's ECG rhythm strip? A. Analyze the P waves B. Determine the heart rate C. Measure the QRS complex D. Assess for ST-segment elevation
14. B Analysis of an ECG rhythm strip requires a systematic approach using an eight-step method. The first step is to determine the heart rate. This is commonly accomplished by use of the 6-second strip method. Normal heart rate is 60-100 per minute. Less than 60 is bradycardia and more than 100 is tachycardia. Analyzing P waves is the 3rd step; measuring the QRS duration is 5th; and measuring the PR interval is the 4th step.
15. Which questions would the nurse use to assess a client's P wave on an ECG rhythm strip? Select all that apply. A. Do all P waves look similar? B. Are P waves present? C. Does one P wave follow each QRS complex? D. Are P waves occurring regularly? E. Are the P waves greater than 0.20 second? F. Are P waves smooth, rounded, and upright?
15. A, B, D, F Ask these five questions when analyzing P waves: Are P waves present?; Are the P waves occurring regularly?; Is there one P wave for each QRS complex?; Are the P waves smooth, rounded, and upright in appearance; or are they inverted?; and Do all P waves look similar?
16. Which criteria support the nurse's assessment that a client's ECG rhythm strip shows a normal sinus rhythm (NSR)? A. PR interval is 0.24 second. B. Atrial and ventricular rates are 58 beats/min. C. Atrial and ventricular rates are regular. D. P waves are present before every QRS complex. E. QRS duration is consistent at 0.08 second. F. Atrial and ventricular rates are 82 beats/min.
16. C, D, E, F Normal sinus rhythm (NSR) is the rhythm originating from the sinoatrial (SA) node (dominant pacemaker) that meets these ECG criteria: Rate: atrial and ventricular rates of 60 to 100 beats/min; Rhythm: atrial and ventricular rhythms regular; P waves: present, consistent configuration, one P wave before each QRS complex; PR interval: 0.12 to 0.20 second and constant; and QRS duration: 0.06 to 0.10 second and constant.
17. What is the priority action for the nurse when the monitor technician states that a client's telemetry monitor shows a rhythm that appears as a wandering or fuzzy baseline? A. Check to see if the client has a do-not-resuscitate order. B. Assess the client to differentiate artifact from an actual lethal rhythm. C. Immediately obtain a 12-lead ECG to assess the actual rhythm. D. Ask the assistive personnel (AP) to take a set of vital signs on the client.
17. B Artifact is interference seen on the monitor or rhythm strip, which may look like a wandering or fuzzy baseline. It can be caused by client movement, loose or defective electrodes, improper grounding, or faulty ECG equipment such as broken wires or cables. Some artifacts can mimic lethal dysrhythmias such as ventricular tachycardia (with toothbrushing) or ventricular fibrillation (with tapping on the electrode). Assess the client to differentiate artifact from actual lethal rhythms! Do not rely only on the ECG monitor.
18. Which actions would the nurse take when the monitor technician states that a client's telemetry ECG signal transmission is not very clear? Select all that apply. A. Ensure that the gel on each electrode is moist and fresh. B. Clean the skin and clip hairs if necessary. C. Abrade the skin by rubbing briskly with a rough washcloth. D. Make sure that the skin is free of lotion or any other substance. E. Clean the skin with povidone-iodine before applying electrodes. F. Check to be sure that electrodes are not placed over scar tissue.
18. A, B, D, F The clarity of continuous ECG monitor recordings is affected by skin preparation and electrode quality. To ensure the best signal transmission and decrease skin impedance, clean the skin and clip hairs if needed. Make sure that the area for electrode placement is dry. The gel on each electrode must be moist and fresh. Attach the electrode to the lead cable and then to the contact site. The contact site should be free of any lotion, tincture, or other substance that increases skin impedance. Electrodes cannot be placed on irritated skin or over scar tissue.
19. Which conditions would the nurse suspect when a client's telemetry ECG rhythm strip shows ST elevation of 1.5 mm (1.5 small blocks)? Select all that apply. A. Pericarditis B. Hypokalemia C. Myocardial infarction D. Ventricular hypertrophy E. Endocarditis F. Hyperkalemia
19. A, C, F ST elevation may indicate problems such as myocardial infarction, pericarditis, and hyperkalemia. ST depression is associated with hypokalemia, myocardial infarction, or ventricular hypertrophy. Endocarditis is an infection of the endocardium and usually affects the heart valves.
2. Which normal heart rates does the nurse expect to be initiated by the primary pacemaker of the heart (SA Node) in clients when the heart rate is regular? Select all that apply. A. 55 beats/min B. 62 beats/min C. 74 beats/min D. 86 beats/min E. 98 beats/min F. 110 beats/min
2. B, C, D, E The SA node is the heart's primary pacemaker. It can spontaneously and rhythmically generate electrical impulses at a rate of 60 to 100 beats/min and therefore has the greatest degree of automaticity (pacing function). Heart rates less than 60 beats/min are bradycardias and heart rates greater than 100 beats/min are tachycardias.
20. What does the nurse determine is the client's heart rate when assessing a 6-second telemetry ECG strip with five QRS complexes? A. 30 beats/min, bradycardia B. 40 beats/min, bradycardia C. 50 beats/min, bradycardia D. 60 beats/min, normal
20. C The most common method is to count the number of QRS complexes in 6 seconds and multiply that number by 10 to calculate the rate for a full minute. This client has five QRS complexes in a 6-second strip. So, 5 times 10 equals 50 beats/min, which is a bradycardia.
21. Which signs and symptoms would the nurse expect to assess in a client with sinus tachycardia? Select all that apply. A. Fatigue B. Shortness of breath C. Decreased oxygen saturation D. Decreased blood pressure E. Anginal pain F. Widened QRS complexes
21. A, B, C, D, E For clients with sinus tachycardia, assess for fatigue, weakness, shortness of breath, orthopnea, decreased oxygen saturation, increased pulse rate, and decreased blood pressure. Also assess for restlessness and anxiety from decreased cerebral perfusion and for decreased urine output from impaired renal perfusion. The client may also have anginal pain and palpitations. The ECG pattern may show T-wave inversion or ST-segment elevation or depression (not wide QRS complexes) in response to myocardial ischemia.
22. What does the nurse suspect when assessing a client's telemetry ECG strip and noting a wide distorted QRS complex of 0.14 second followed by a P wave? A. Delayed time of the impulse through the ventricles B. Problem with speed set on the ECG telemetry monitor C. Wide but normal complex with no cause for concern D. Premature ventricular complex followed by atrial contraction
22. D Premature ventricular complexes (PVCs), also called premature ventricular contractions, result from increased irritability of ventricular cells and are seen as early ventricular complexes followed by a pause. They appear as widened QRS complexes and sometimes the P waves follow the QRS complexes. They may be all the same shape (unifocal) or different shapes (multifocal). PVCs are common and increase with age.
23. Which causes would the nurse recognize as leading to increased atrial irritability and premature atrial contractions (PACs) in a client's myocardium? Select all that apply. A. Caffeine intake B. Anxiety C. Syncope D. Stress in life E. Infection F. Pulmonary hypotension
23. A, B, D, E The causes of atrial irritability that can lead to PACs include: stress; fatigue; anxiety; inflammation; infection; intake of caffeine, nicotine, or alcohol; and drugs such as epinephrine, sympathomimetics, amphetamines, digoxin, or anesthetic agents. PACs may also result from myocardial ischemia, hypermetabolic states, electrolyte imbalance, or atrial stretch.
24. Which dysrhythmia does the nurse consider life threatening because it causes the ventricles to quiver and results in the absence of cardiac output for a client? A. Asystole B. Ventricular tachycardia C. Atrial fibrillation D. Ventricular fibrillation
24. D Ventricular fibrillation (VF) is a cardiac dysrhythmia that results from electrical chaos in the ventricles; impulses from many irritable foci fire in a totally disorganized manner so that ventricular contraction cannot occur; there is no cardiac output or pulse and therefore no cerebral, myocardial, or systemic perfusion. This rhythm is rapidly fatal if not successfully terminated within 3 to 5 minutes. Ventricular tachycardia and asystole are also life-threatening dysrhythmias. With atrial fibrillation there is loss of the atrial contribution to cardiac output, but the ventricles are usually still putting out adequate cardiac output.
25. Which nursing actions have priority when a client with acute supraventricular tachycardia (SVT) is to be administered adenosine by the health care provider? Select all that apply. A. Have injectable beta-blocker drugs at the bedside. B. Give the drug slowly over 1-2 minutes. C. Ensure that emergency equipment is at the bedside. D. Follow the drug injection with a normal saline bolus. E. Monitor the client for bradycardia, nausea, and vomiting. F. Prepare for synchronized cardioversion after giving the adenosine.
25. C, D, E Adenosine is used to terminate the acute episode and is given rapidly (over several seconds) followed by a normal saline bolus. Side effects of adenosine include significant bradycardia with pauses, nausea, and vomiting. Beta blockers would not be given because they would cause increased bradycardia. The purpose of the drug is to terminate the dysrhythmia so cardioversion is not necessary.
26. Which risk factors for atrial fibrillation would the nurse monitor for in client? Select all that apply. A. Peripheral vascular disease B. Hypertension C. Chronic obstructive pulmonary disease D. Diabetes mellitus E. Excessive alcohol intake F. Mitral valve disease
26. B, D, E, F Risk factors for atrial fibrillation include hypertension (HTN), previous ischemic stroke, transient ischemic attack (TIA) or other thromboembolic event, coronary heart disease, diabetes mellitus, heart failure, obesity, hyperthyroidism, chronic kidney disease, excessive alcohol use, and mitral valve disease. This dysrhythmia also increases with age.
27. When a client has been in atrial fibrillation for 3 days and is scheduled for an elective cardioversion, what priority teaching does the nurse provide to the client? A. Consume potassium-rich food sources such as bananas. B. Report muscle tremors or weakness to the health care provider. C. Get up slowly when getting out of bed or a chair. D. Watch for any sign of bleeding and report this to your health care provider.
27. D When the onset of AF is greater than 48 hours, the client must take anticoagulants for at least 3 weeks (or until the INR is 2 to 3) before the elective cardioversion to prevent clots from moving from the heart to the brain or lungs. Teaching the client to monitor for bleeding and reporting this to the primary health care provider (HCP) are essential when a client is prescribed an anticoagulant drug.
28. Which actions are essential nursing care for a client immediately after elective cardioversion? Select all that apply. A. Administer oxygen. B. Assess vital signs and level of consciousness. C. Provide sips of water or ice chips. D. Monitor for dysrhythmias. E. Maintain an open airway. F. Document the results of the cardioversion.
28. A, B, D, E, F Nursing care after cardioversion includes: maintaining a patent airway; administering oxygen; assessing vital signs and the level of consciousness; administering antidysrhythmic drug therapy, as prescribed; monitoring for dysrhythmias; assessing for chest burns from electrodes; providing emotional support; and documenting the results of cardioversion. Sips of water and ice chips would not be provided until the client's gag reflex returned.
29. Which client assessment takes priority when the nurse begins his or her shift? A. Client with chronic atrial fibrillation and ventricular rate of 72 beats/min B. Client with sinus tachycardia and occasional premature atrial contractions (PACs) C. Client with paroxysmal supraventricular tachycardia (PSVT) that terminated D. Client with atrial fibrillation and sustained rapid ventricular response
29. D The nurse would want to assess all four clients. However, the client with atrial fibrillation with sustained rapid ventricular response is at highest risk for decreased cardiac output and development of symptoms. Therefore this client would need to be assessed first.
3. Which waveform does the nurse recognize as atrial depolarization when a client is placed on a cardiac monitor? A. P wave B. PR segment C. QRS complex D. T wave
3. A Impulses from the sinus node move directly through atrial muscle and lead to atrial depolarization, which is reflected in a P wave on the electrocardiogram (ECG). Atrial muscle contraction should follow. The PR segment reflects impulses slowing down or being delayed in the AV node before proceeding to the ventricles. QRS complexes reflect ventricular depolarization and T waves reflect ventricular repolarization.
30. How does the nurse interpret a client's telemetry ECG strip that shows four successive premature ventricular contractions (PVCs)? A. The monitor is showing two PVC couplets in a row. B. This rhythm is ventricular asystole as seen in a dying heart. C. The client had an episode of nonsustained ventricular tachycardia (NSVT). D. The nurse must check the client for loose leads and artifact.
30. C Three or more successive PVCs in a row are usually called nonsustained ventricular tachycardia (NSVT). Two PVCs in a row make a couplet. Artifact appears as a fuzzy or wandering baseline. Ventricular asystole is generally described as a flat line although P waves may still be seen.
31. Which procedure would the nurse provide teaching about to a client who has chronic atrial fibrillation and is at increased risk for a stroke, but is not a candidate for anticoagulation? A. Radiofrequency catheter ablation (RCA) B. Left atrial appendage (LAA) occlusion C. Biventricular pacing D. Surgical maze procedure
31. B For clients who are at high risk for stroke and who are not candidates for anticoagulation, the left atrial appendage (LAA) occlusion device may be an option. The LAA is the most common site of blood clot development leading to the risk of stroke. Inserted percutaneously via the femoral vein, a device to occlude the LAA is delivered via a transseptal puncture. Radiofrequency catheter ablation (RCA) is an invasive procedure that may be used to destroy an irritable focus in atrial or ventricular conduction. Biventricular pacing is used with clients who have heart failure and conduction disorders. The surgical maze procedure is an open-chest surgical technique performed with coronary artery bypass grafting (CABG).
32. After calling for help, when the nurse finds a client in his or her room without a pulse, apneic and unconscious, which action should be taken next? A. Begin cardiac compressions. B. Establish IV access. C. Give supplemental oxygen. D. Defibrillate the client.
32. A The desired outcomes of collaborative care are to resolve VF promptly and convert it to an organized rhythm. Therefore, the priority is to defibrillate the client immediately according to ACLS protocol. If a defibrillator is not readily available, as would likely be the case in a client's room, high-quality CPR must be initiated and continued until the defibrillator arrives.
33. Which drug does the nurse prepare to administer to a client diagnosed with the dysrhythmia torsades de pointes? A. Calcium chloride B. Epinephrine C. Magnesium sulfate D. Adenosine
33. C Magnesium is used to treat the life-threatening ventricular tachycardia called torsades de pointes. Often a client with this dysrhythmia is hypomagnesemic which causes increased ventricular irritability. Adenosine treats PSVT; epinephrine increases atrial irritability and heart rate; and calcium chloride is used in cardiac resuscitation, arrhythmias, hypermagnesemia, calcium channel blocker overdose, and beta-blocker overdose.
34. When would the telemetry unit nurse use temporary transcutaneous pacing for a client? Select all that apply. A. Only when a client's ECG shows a bradydysrhythmia and the client is asymptomatic B. When a client's ECG strip shows atrial fibrillation with a rapid ventricular response C. Only as a temporary emergency measure until invasive pacing method can be started D. When a client is experiencing syncope, dizziness and fainting E. Only until the client's heart rhythm returns to normal F. When invasive pacing is not immediately available
34. C, E, F Transcutaneous pacing is used as an emergency measure to provide demand ventricular pacing in a profoundly bradycardic or asystolic client until invasive pacing can be used or the client's heart rate returns to normal. This method of pacing is painful and may require administration of pain and sedative medications for the client to tolerate the therapy. Transcutaneous pacing is used only as a temporary measure to maintain heart rate and perfusion until a more permanent method of pacing is used.
35. Which ECG strip pattern is evidence to the nurse that a client's temporary transvenous pacemaker has successfully depolarized the ventricles? A. A pacer spike followed by a QRS complex B. Two spikes followed by a QRS complex C. A pacer spike before and after the QRS complex D. No pacer spike but regular QRS complexes
35. A When a pacing stimulus is delivered to the heart, a spike (or pacemaker artifact) is seen on the monitor or ECG strip. When the pacer spike is followed by a QRS complex, this pattern indicates ventricular depolarization and is referred to as capture (the pacemaker successfully depolarized the ventricles).
36. Which statements about permanent pacemakers are accurate? Select all that apply. A. Permanent pacemakers are powered by lithium batteries that last over 20 years. B. Permanent pacemakers are available as pacemaker/defibrillator devices. C. Biventricular pacemakers allow synchronized depolarization of the ventricles. D. Permanent pacemakers are used to treat disorders such as complete heart block. E. A client with a new pacemaker should avoid lifting his or her arm over the head for at least 6 months. F. The pulse generator for a permanent pacemaker is usually implanted in the left subclavian area.
36. B, C, D, F The average life of lithium batteries that power permanent pacemakers is 10 years. A biventricular pacemaker may be used to coordinate contractions between the right and left ventricles. The electrophysiologist implants the pulse generator in a surgically made subcutaneous pocket at the shoulder in the right or left subclavicular area, which may create a visible bulge. Permanent pacemaker insertion is performed to treat conduction disorders that are not temporary, including complete heart block. Combination pacemaker/defibrillator devices are available. If the surgical incision is near either shoulder, advise the client to avoid lifting the arm over the head or lifting more than 10 lb for the next 4 weeks because this could dislodge the pacemaker wire.
37. Which are nursing responsibilities for the care of a client with a newly implanted permanent pacemaker? Select all that apply. A. Assess the implantation site for bleeding, swelling, redness, tenderness, or infection. B. Administer short-acting sedatives as needed and prescribed. C. Monitor the ECG rhythm strip to ensure that the pacemaker is working correctly. D. Observe for overstimulation of the chest wall, which might cause pneumothorax. E. Assess that the implantation site dressing is clean and dry. F. Teach the client about initial activity restrictions.
37. A, C, E, F After the procedure, monitor the ECG rhythm to check that the pacemaker is working correctly. Assess the implantation site for bleeding, swelling, redness, tenderness, and infection. The dressing over the site should remain clean and dry. The client should be afebrile and have stable vital signs. The electrophysiologist prescribes initial activity restrictions, which are then gradually increased. Observe for muscle contractions over the diaphragm that are synchronous with the heart rate. Pneumothorax is usually not a complication of pacemaker implantation. Sedative drugs are often given to clients receiving transcutaneous pacing but not for permanent pacemaker insertion.
38. Which important teaching points would the nurse discuss with a client who receives a new permanent pacemaker? Select all that apply. A. Report any pulse rate that is lower than the rate set on the pacemaker. B. Avoid sources of strong electromagnetic fields such as magnets. C. If the surgical incision is near the shoulder, be sure to perform daily range of motion. D. Carry a pacemaker identification card and wear a medical alert bracelet. E. Avoid tight clothing to prevent pressure over the pacemaker generator. F. It is safe to go through airport security because the pacemaker will not set off the alarms.
38. A, B, D, E The client would inform airport personnel of the pacemaker before passing through a metal detector and show them the pacemaker identification card. The metal in your pacemaker will trigger the alarm in the metal detector device. Instruct the client to avoid lifting the arm over the head or lifting more than 10 lb for the next 4 weeks because this could dislodge the pacemaker wire. Teach the client to report any pulse rate lower than that set on the pacemaker. Tell clients to avoid sources of strong electromagnetic fields, such as magnets and telecommunications transmitters. Carry a pacemaker identification card provided by the manufacturer and wear a medical alert bracelet at all times.
39. Which safety precaution must be taken before defibrillating a client with ventricular fibrillation (VF)? A. Make sure that the defibrillator is set on the synchronous mode. B. Be sure to hyperventilate the client before the defibrillation. C. Command all health care team members to stand clear of the client's bed. D. Disconnect the monitor leads to prevent electrical shocks to the client.
39. C Before defibrillation, loudly and clearly command all personnel to clear contact with the client and the bed and check to see they are clear before the shock is delivered. This safety measure prevents health care team members from receiving a shock when the client is defibrillated. Synchronous mode is used for cardioversion. Disconnection of the monitor leads would prevent assessing the effectiveness of the defibrillation shock. Hyperventilation of the client will not keep the health care team safe.
4. How would the nurse best interpret the electrocardiogram (ECG) of a younger athletic client which shows sinus bradycardia with a rate of 54 beats/min? A. It is the body's attempt to compensate for a decreased stroke volume by decreasing heart rate. B. The sinus bradycardia provides an adequate stroke volume that is associated with cardiac conditioning. C. The client has a rapid filling rate that lengthens diastolic filling time and leads to decreased cardiac output. D. This is a common finding in healthy adults of all ages and would be considered a normal finding.
4. B Well-conditioned athletes with bradycardia have a hypereffective heart in which the strong heart muscle provides an adequate stroke volume and a low heart rate to achieve a normal cardiac output. This is not a common finding in adults of all ages, but an indicator of dysrhythmia in older adults. Decreasing heart rate in most adults results in decreased cardiac output.
40. For which cardiac dysrhythmia(s) would an automatic external defibrillator (AED) instruct the nurse to immediately defibrillate an unconscious client at an outpatient clinic? Select all that apply. A. Paroxysmal supraventricular tachycardia B. Pulseless electrical activity C. Ventricular fibrillation D. Pulseless ventricular tachycardia E. Nonsustained ventricular tachycardia F. Atrial fibrillation with rapid ventricular response
40. C, D Defibrillation shocks are recommended by AEDs only for ventricular fibrillation and pulseless ventricular tachycardia.
41. What effect does the nurse expect a Class IV drug to have on a client's cardiac conduction system? A. Slow the flow of calcium into the cell during depolarization to depress automaticity B. Stabilize membranes to decrease myocardial contractility C. Decrease heart rate and conduction velocity D. Lengthen the absolute refractory period and prolong repolarization
41. A Class IV antidysrhythmics slow the flow of calcium into the cell during depolarization, thereby depressing the automaticity of the sinoatrial (SA) and atrioventricular (AV) nodes, decreasing the heart rate, and prolonging the AV nodal refractory period and conduction. Calcium channel blockers, such as verapamil hydrochloride and diltiazem hydrochloride, are Class IV drugs. They are used to treat supraventricular tachycardia (SVT) and atrial fibrillation (AF) to slow the ventricular response.
42. Which descriptions are characteristics of Class III antidysrhythmic drugs? Select all that apply. A. Increase force of contraction B. Lengthen absolute refractory period C. Include hypertension as a side effect for some drugs D. Include bradycardia as a side effect for some drugs E. Prolong QT interval F. Prolong repolarization
42. B, D, F Class III antidysrhythmics lengthen the absolute refractory period and prolong repolarization and the action potential duration of ischemic cells. Class III drugs include amiodarone and ibutilide and are used to treat or prevent ventricular premature beats, VT, and VF. Bradycardia is a side effect with sotalol and amiodarone. Hypertension is not a side effect of these drugs.
43. Which beta-blocker drug approved for treating dysrhythmias is also a Class III antidysrhythmic drug? A. Sotalol B. Esmolol C. Propranolol D. Acebutolol
43. A Sotalol hydrochloride is an antidysrhythmic agent with both noncardioselective beta-adrenergic blocking effects (Class II) and action potential duration prolongation properties (Class III). It is an oral agent that may be used for the treatment of documented ventricular dysrhythmias such as VT that are life threatening.
5. To determine if a client has a pulse deficit, what procedure would the nurse follow? A. Assess the apical and radial pulses for a full minute and calculate the difference. B. Check the client's blood pressure and subtract the diastolic from the systolic pressure. C. Take the client's pulse rate while supine, then in a standing position. D. Assess the radial pulse for a minute, have the client rest, then check the radial pulse again.
5. A Pulse deficit is the difference between the apical and peripheral (e.g., radial) pulses. If the apical pulse differs from the radial pulse rate, a pulse deficit exists and indicates that the heart is not pumping adequately to achieve optimal perfusion to the body. The difference between systolic and diastolic pressures is the pulse pressure. When a client's blood pressure and pulse are taken first lying down and then sitting or standing, that is orthostatic vital signs.
6. Which ECG waveforms and intervals are the normal measurements or positions? Select all that apply. A. PR interval 0.12-0.20 second B. QRS complex 0.06-0.10 second C. PR segment isoelectric line D. QT interval less than half of the R to R interval E. U wave follows T wave if present F. TP segment one block above isoelectric line
6. A, B, C, D, E All of these statements are correct except F. The TP segment should return to and be located on the isoelectric line.
7. Which definition best describes the electrophysiologic property called automaticity of myocardial pacemaker cells? A. The ability of atrial and ventricular muscle cells to shorten their fiber length in response to electrical stimulation, causing sufficient pressure to push blood forward through the heart B. The ability to send an electrical stimulus from cell membrane to cell membrane C. The ability of nonpacemaker heart cells to respond to an electrical impulse that begins in pacemaker cells D. The ability of cardiac cells to generate an electrical impulse spontaneously and repetitively
7. D The electrophysiologic properties of specialized myocardial cells regulate heart rate and rhythm and possess unique properties: automaticity, excitability, conductivity, and contractility. Automaticity (pacing function) is the ability of cardiac cells to generate an electrical impulse spontaneously and repetitively. Excitability is the ability of nonpacemaker heart cells to respond to an electrical impulse that begins in pacemaker cells. Conductivity is the ability to send an electrical stimulus from cell membrane to cell membrane. Contractility is the ability of atrial and ventricular muscle cells to shorten their fiber length in response to electrical stimulation, causing sufficient pressure to push blood forward through the heart.
8. To best perform a 12-lead ECG on a client, how does the nurse place the leads on the client? A. Four leads are placed on the limbs and four are placed on the chest. B. The negative electrode is placed on the left arm and the positive electrode is placed on the right leg. C. Four leads are placed on the limbs and six are placed on the chest. D. The negative electrode is placed on the right arm and the positive electrode is placed on the left leg.
8. C The 12-lead ECG provides 12 views of the electrical activity of the heart. There are six unipolar (or V) chest leads, determined by the placement of the chest electrode. The four limb electrodes are placed on the extremities which provide the 12 views. Positioning of the electrodes is crucial in obtaining an accurate ECG. Comparisons of ECGs taken at different times will be valid only when electrode placement is accurate and identical at each test. In many cases, a surgical marker is used to assure consistent placement of the leads.
9. Where will the nurse place the leads on a client for a five-lead continuous monitoring system? Select all that apply. A. Right arm electrode just below the right clavicle B. Left arm electrode just below the left clavicle C. Right leg electrode on the highest palpable rib, on the right midclavicular line D. Left leg electrode on the lowest palpable rib, on the left midclavicular line E. Fifth electrode placed to obtain one of the six chest leads F. Left arm electrode just above the left clavicle
9. A, B, D, E If the monitoring system provides five electrode cables, place the electrodes as follows: right arm electrode just below the right clavicle; left arm electrode just below the left clavicle; right leg electrode on the lowest palpable rib, on the right midclavicular line; left leg electrode on the lowest palpable rib, on the left midclavicular line; and fifth electrode placed to obtain one of the six chest leads.
