Cardiovascular (Dysrhythmias, MI) Critical Care

ANS: D The statins have been found to lower low-density lipoproteins (LDLs) more than other types of lipid-lowering drugs. Nicotinic acid is used for adjunctive treatment of hyperlipidemia. Nitroglycerin is prescribed for angina Table 13-4

A patient has elevated blood lipids. The nurse anticipates which classification of drugs to be prescribed for the patient? a. Bile acid resins b. Nicotinic acid c. Nitroglycerin d. Statins

ANS: A A history of the patients use of sildenafil citrate (Viagra) or similar medications taken for erectile dysfunction is necessary to know when considering NTG administration. These medications potentiate the hypotensive effects of nitrates; thus, concurrent use is contraindicated. It is also important to determine whether the patient has any food or drug allergies.

A patient has been prescribed nitroglycerin in the ED for chest pain. In taking the health history, the nurse will be sure to verify whether the patient has taken medications prior to admission for: a. Erectile dysfunction b. Prostate enlargement c. Asthma d. Peripheral vascular disease

ANS: B Atropine is used to increase the heart rate by decreasing the vagal tone. It is indicated for patients with symptomatic bradycardia.

A 74-year-old patient is admitted to the coronary care unit with an inferior wall myocardial infarction and develops symptomatic bradycardia with premature ventricular contractions every third beat (trigeminy). The nurse knows to prepare to administer which drug? a. Amiodarone b. Atropine c. Lidocaine d. Magnesium

A. Adenosine is the drug of choice for SVT. It slows the conduction through the AV node and interrupts AV node reentrant electrical conduction. It does not treat rhythms involve the SA or AV node, such as in A flutter, A fib, or A tachy, or V tach.

A nurse is preparing to administer Adenosine. Which dysrhythmia is the patient most likely experiencing? a. Supraventricular Tachycardia b. Atrial flutter c. Ventricular Tachycardia d. Atrial fibrillation

ANS: C Lidocaine is an antidysrhythmic drug that suppresses ventricular ectopic activity.

A patient develops frequent ventricular ectopy. The nurse prepares to administer which drug? a. Adenosine b. Atropine c. Lidocaine d. Magnesium

ANS: B First-degree atrioventricular 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 has a sinus rhythm and a heart rate of 72 beats/min. The nurse determines that the PR interval is 0.24 seconds. The most appropriate intervention by the nurse would be to a. notify the health care provider immediately. b. document the finding and monitor the patient. c. give atropine per agency dysrhythmia protocol. d. prepare the patient for temporary pacemaker insertion.

ANS: A, B, D Administer atropine, 0.5 mg IV every 3 to 5 minutes to a total dose of 3 mg for symptomatic bradycardia. Transcutaneous pacing is also indicated for symptomatic bradycardia unresponsive to atropine. Epinephrine is considered as well. Lidocaine is contraindicated in bradycardia because it can depress conduction, which would be detrimental with a heart rate of 39 beats/min.

A patient is admitted to the critical care unit with bradycardia at a heart rate of 39 beats/min and frequent premature ventricular contractions. Upon assessment, you note that she is lethargic and has complained of dizziness for the past 12 hours. Which of the following are acceptable treatments for symptomatic bradycardia? (Select all that apply.) a. Atropine b. Epinephrine c. Lidocaine d. Transcutaneous pacemaker

ANS: A Medical treatment of AMI is aimed at relieving pain, providing adequate oxygenation to the myocardium, preventing platelet aggregation, and restoring blood flow to the myocardium through thrombolytic therapy or acute interventional therapy such as angioplasty. Since interventional cardiology is not available, thrombolytic therapy is indicated. Oxygen saturation should be maintained at higher levels to ensure adequate oxygenation to the heart muscle. An elevated heart rate increases oxygen demands and should be avoided. Diuresis is not indicated with this scenario.

A patient is admitted to the emergency department with clinical indications of an acute myocardial infarction. Symptoms began 3 hours ago. The facility does not have the capability for percutaneous coronary intervention. Given this scenario, what is the priority intervention in the treatment and nursing management of this patient? a. Administer thrombolytic therapy unless contraindicated b. Diurese aggressively and monitor daily weight c. Keep oxygen saturation levels at least 88% d. Maintain heart rate above 100 beats/min

ANS: C Myocardial remodeling is a process mediated by angiotensin II, aldosterone, catecholamine, adenosine, and inflammatory cytokines, which causes myocyte hypertrophy and loss of contractile function in the areas of the heart distant from the site of infarctions. ACE inhibitors (Vasotec, Monopril) reduce the incidence of remodeling.

A patient is admitted with an acute myocardial infarction (AMI). The nurse knows that an angiotensin- converting enzymes (ACE) inhibitor should be started within 24 hours to reduce the incidence of which process? a. Myocardial stunning b. Hibernating myocardium c. Myocardial remodeling d. Tachycardia

ANS: A, B, C, D All are potential complications of AMI.

A patient is admitted with an acute myocardial infarction (AMI). The nurse monitors for which potential complications? (Select all that apply.) a. Cardiac dysrhythmias b. Heart failure c. Pericarditis d. Ventricular rupture

ANS: C In unstable angina, some blood continues to flow through the affected coronary artery; however, flow is diminished related to partial occlusion. The pain in unstable angina is more severe, may occur at rest, and requires more frequent nitrate therapy. Complete occlusion would result in MI. A fatty streak within the intima of a coronary artery leads to CAD (fibrotic plaques, which may or may not rupture and result in a thrombus). Vasospasms of a coronary artery cause variant or prinzmetal angina, which occur at rest in the absence of precipitating factors or CAD

A patient is admitted with the diagnosis of unstable angina. The nurse knows that the physiological mechanism present is most likely which of the following? a. Complete occlusion of a coronary artery b. Fatty streak within the intima of a coronary artery c. Partial occlusion of a coronary artery with a thrombus d. Vasospasm of a coronary artery

ANS: A To be eligible for thrombolysis, the patient must be symptomatic for less than 6 hours.

A patient presents to the ED complaining of severe substernal chest pressure radiating to his left shoulder and back that started about 12 hours ago. The patient delayed coming to the ED since he was hoping the pain would go away. The patients 12-lead ECG shows ST-segment depression in the inferior leads. Troponin and CK-MB are both elevated. The hospital does not have the capability for percutaneous coronary intervention. Thrombolysis is one possible treatment. Based on these data, the nurse understands that? a. The patient is not a candidate for thrombolysis. b. The patients history makes him a good candidate for thrombolysis. c. Thrombolysis is appropriate for a candidate having a nonQ wave MI. d. Thrombolysis should be started immediately.

A. Pacemaker insertion is indicated for 2nd degree AV block type II (as in this scenario) and 3rd degree AV block.

A patient presents to the ED with symptoms of MI. The ECG shows randomly missing QRS complexes after the P wave. What therapeutic intervention would the nurse anticipate? a. Emergent pacemaker insertion b. Emergent percutaneous coronary intervention c. Emergent thrombolytic therapy d. Immediate coronary artery bypass graft surgery

ANS: A The goals of management of AMI are to dissolve the lesion that is occluding the coronary artery and to increase blood flow to the myocardium. Options include emergent percutaneous intervention, such as angioplasty, emergent coronary artery bypass graft surgery, or thrombolytic therapy if the patient has been symptomatic for less than 6 hours. Insertion of a pacemaker is indicated for 2nd degree AV block type II, 3rd degree AV block

A patient presents to the emergency department (ED) with chest pain that he has had for the past 2 hours. He is nauseous and diaphoretic, and his skin is dusky in color. The electrocardiogram shows ST elevation in leads II, III, and aVF. Which therapeutic intervention would the nurse question? a. Emergent pacemaker insertion b. Emergent percutaneous coronary intervention c. Emergent thrombolytic therapy d. Immediate coronary artery bypass graft surgery

ANS: B LVADs are capable of partial to complete circulatory support for short- to long-term use. At present, the LVAD is therapy for patients with terminal heart failure. It would provide better management than medical therapy alone. The IABP is for short-term management of acute heart failure.

A patient was admitted in terminal heart failure and is not eligible for transplant. The family wants everything possible done to maintain life. Which procedure might be offered to the patient for this condition to increase the patients quality of life? a. Intraaortic balloon pump (IABP) b. Left ventricular assist device (LVAD) c. Nothing, because the patient is in terminal heart failure d. Nothing additional; medical management is the only option

ANS: B The nurse will need to avoid giving nitrates to the patient because nitrate administration is contraindicated in patients who are using sildenafil because of the risk of severe hypotension caused by vasodilation. The other home medications should also be documented and reported to the health care provider but do not have as immediate an impact on decisions about the patient's treatment.

A patient who is being admitted to the emergency department with intermittent chest pain gives the following list of daily medications to the nurse. Which medication has the most immediate implications for the patient's care? a. captopril b. sildenafil (Viagra) c. furosemide (Lasix) d. warfarin (Coumadin)

ANS: A, B, D The initial pain of AMI is treated with morphine sulfate IV. Nitroglycerin may be given to reduce the ischemic pain of AMI. NTG increases coronary perfusion because of its vasodilatory effects. Oxygen administration is important for assisting the myocardial tissue to continue its pumping activity and for repairing the damaged tissue around the site of the infarct. Dopamine causes more intense contractions of the heart which increase oxygen demand.

Identify the priority interventions for managing symptoms of an acute myocardial infarction (AMI) in the ED. (Select all that apply). a. Administration of morphine b. Administration of nitroglycerin (NTG) c. Dopamine infusion d. Oxygen therapy

ANS: D In first-degree block, P and QRS waves are consistent in shape. P waves are small and rounded. A P wave precedes every QRS complex, which is followed by a T wave. PR interval is prolonged and is greater than 0.20 seconds. QRS complex and QT/QTc measurements are normal. Normal sinus rhythm (NSR) reflects normal conduction of the sinus impulse through the atria and ventricles. Atrial and ventricular rates are the same and range from 60 to 100 beats per minute. Rhythm is regular or essentially regular. PR interval is 0.12 to 0.20 seconds.

Interpret the following rhythm: a. Normal sinus rhythm b. Sinus rhythm with second-degree A V block c. Complete heart block d. Sinus rhythm with first-degree A V block

ANS: A, C, E One complication of atrial fibrillation is thromboembolism. The blood that collects in the atria is agitated by fibrillation, and normal clotting is accelerated. Small thrombi, called mural thrombi, begin to form along the walls of the atria. These clots may dislodge, resulting in pulmonary embolism or stroke. The ineffectual contraction of the atria results in loss of atrial kick. If too many impulses conduct to the ventricles, atrial fibrillation with rapid ventricular response may result and compromise cardiac output. Ashman beats are not clinically significant. No recognizable or discernible P waves are present; therefore, PR interval is absent.

The nurse is caring for a patient who has atrial fibrillation. Sequelae that place the patient at greater risk for mortality/morbidity include which of the following? (Select all that apply.) a. Stroke b. Ashman beats c. Pulmonary emboli d. Prolonged PR interval e. Decreased cardiac output

ANS: B Also called a Mobitz I or Wenckebach phenomenon, second-degree AV block type I is represented on the ECG as a progressive lengthening of the PR interval until there is a P wave without a QRS complex. Second-degree AV block type II (Mobitz II) is a more critical type of heart block that requires early recognition and intervention. There is no progressive lengthening of the PR interval, which remains the same throughout with the exception of the dropped beat(s). Third-degree block is often called complete heart block because no atrial impulses are conducted through the AV node to the ventricles. In complete heart block, the atria and ventricles beat independently of each other because the AV node is completely blocked to the sinus impulse and it is not conducted to the ventricles. One hallmark of third-degree heart block is that the P waves have no association with the QRS complexes and appear throughout the QRS waveform.

Interpret the following rhythm: a. First-degree A V block b. Second-degree AV block Mobitz I (Wenckebach phenomenon) c. Second-degree A V block Mobitz II d. Third-degree A V block (complete heart block)

ANS: C Second-degree AV block type II (Mobitz II) is a more critical type of heart block that requires early recognition and intervention. "If some P's don't get through, then you have Type II". Treatment: pacemaker or atropine; transcutaneous or transvenous pacing for emergent treatment

Interpret the following rhythm: a. First-degree AV block b. Second-degree AV block Mobitz I (Wenckebach phenomenon) c. Second-degree AV block Mobitz II d. Third-degree AV block (complete heart block)

B. The impulse from the SA node quickly reaches the atrioventricular (AV) node located in the area called the AV junction, between the atria and the ventricles. Here the impulse is slowed to allow time for ventricular filling during relaxation or ventricular diastole. The AV node has pacemaker properties and can discharge an impulse if the SA node (not the ventricle) fails. The electrical impulse is then rapidly conducted through the bundle of His to the ventricles (not the SA node) via the left and right bundle branches.

One of the functions of the atrioventricular (AV) node is to: a. pace the heart if the ventricles fail. b. slow the impulse arriving from the SA node. c. send the impulse to the SA node. d. allow for ventricular filling during systole.

ANS: D Stenosis of the left mainstem artery is considered unacceptable for percutaneous intervention.

Percutaneous coronary intervention is contraindicated for patients with lesions in which coronary artery? a. Right coronary artery b. Left coronary artery c. Circumflex d. Left main coronary artery

ANS: A, B, C, D Vasovagal response; medications such as digoxin or AV nodal blocking agents, including calcium channel blockers and beta-blockers; myocardial infarction; normal physiological variant in the athlete; disease of the sinus node; increased intracranial pressure; hypoxemia; and hypothermia may cause sinus bradycardia. Hyperthyroidism is a cause of sinus tachycardia.

Sinus bradycardia is a symptom of which of the following? (Select all that apply.) a. Calcium channel blocker medication b. Beta-blocker medication c. Athletic conditioning d. Hypothermia e. Hyperthyroidism

ANS: C Reassess the patient frequently. Check for return of pulse, spontaneous respirations, and blood pressure.

The code team has just defibrillated a patient in ventricular fibrillation. Following CPR for 2 minutes, what is the next action to take? a. Administer amiodarone. b. Administer lidocaine. c. Assess rhythm and pulse. d. Prepare for transcutaneous pacing.

ANS: A *Atrial fibrillation* arises from multiple ectopic foci in the atria, causing chaotic quivering of the atria and ineffectual atrial contraction. The atrial rate may be as high 700 and no discernible P waves can be identified, resulting in a wavy baseline and an extremely irregular ventricular response. - *Atrial flutter* arises from a single irritable focus in the atria. The atrial focus fires at an extremely rapid, regular rate, between 240 and 320 beats per minute. The P waves are called flutter waves and may have a sawtooth appearance. The ventricular response may be regular or irregular based on how many flutter waves are conducted through the AV node. - *Atrial flutter with rapid ventricular response* occurs when atrial impulses cause a ventricular response greater than 100 beats per minute. - A *junctional escape rhythm* is a ventricular rate between 40 and 60 beats per minute with a regular rhythm. P waves may be absent, inverted, or follow the QRS complex. If a P wave is present before the QRS complex, the PR interval is shortened less than 0.12 milliseconds. QRS complex is normal.

The nurse is reading the cardiac monitor and notes that the patients heart rhythm is *extremely irregular* and there are no discernible P waves. The ventricular rate is 90 beats per minute, and the patient is hemodynamically stable. The nurse realizes that the patients rhythm is: a. atrial fibrillation. b. atrial flutter. c. atrial flutter with rapid ventricular response. d. junctional escape rhythm.

ANS: D Ventricular fibrillation (VF) is a chaotic rhythm characterized by a quivering of the ventricles, which results in total loss of cardiac output and pulse. VF is a life-threatening emergency, and the more immediate the treatment is, the better the survival will be. VF produces a wavy baseline without a PQRST complex. Because a loose lead or electrical interference can produce a waveform similar to VF, it is always important to immediately assess the patient for pulse and consciousness. *The next action if VF was confirmed is to DEFIB*

The nurse is talking with the patient when the monitor alarms and shows a wavy baseline without a PQRST complex. The nurse should: a. defibrillate the patient immediately. b. initiate basic life support. c. initiate advanced life support. d. assess the patient and the electrical leads.

ANS: D Sinus bradycardia may be a normal heart rhythm for some individuals such as athletes, or it may occur during sleep. Assess for hemodynamic instability related to the bradycardia. *If patient is symptomatic --> atropine. If atropine is not effective in increasing heart rate, then transcutaneous pacing, dopamine infusion, or epinephrine infusion may be administered*. Atropine is avoided for treatment of bradycardia associated with hypothermia.

The nurse is working on the night shift when she notices sinus bradycardia on the patients cardiac monitor. The nurse should: a. give atropine to increase heart rate. b. begin transcutaneous pacing of the patient. c. start a dopamine infusion to stimulate heart function. d. assess for hemodynamic instability.

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 are multifocal or that the R-on-T phenomenon is occurring.

The nurse notes that a patient's heart 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 fibrillation (VF) is a life-threatening emergency, and the more immediate the treatment, the better the survival will be. VF produces a wavy baseline without a PQRST complex. Because a loose lead or electrical interference can produce a waveform similar to VF, it is always important to immediately *assess patient for pulse and consciousness*. If no pulse is present, provide emergent basic and advanced life-support interventions, including defibrillation.

The nurse notes the following rhythm on the heart monitor. The patient is unresponsive and not breathing. The nurse should a. treat with intravenous amiodarone or lidocaine. b. provide emergent basic and advanced life support. c. provide electrical cardioversion. d. ignore the rhythm because it is benign.

ANS: C First-degree AV block is a common dysrhythmia in the elderly and in patients with cardiac disease. As the normal conduction pathway ages or becomes diseased, impulse conduction becomes slower than normal and ECG shows prolonged PR intervals . It is well tolerated. No treatment is required. Continue to monitor the patient and the rhythm. A transcutaneous pacemaker would be indicated in Mobitz II or 3rd degree AV block. Atropine for Wenckebach I and 3rd degree

The nurse notices that the patient has a first-degree AV block. Everything else about the rhythm is normal. The nurse should: a. prepare to place the patient on a transcutaneous pacemaker. b. give the patient atropine to shorten the PR interval. c. monitor the rhythm and patients condition. d. give the patient an antiarrhythmic medication.

ANS: B Ventricular tachycardia (VT) is a rapid, life-threatening dysrhythmia originating from a single ectopic focus in the ventricles. Determine whether the patient has a pulse. *If NO pulse is present*, provide emergent basic and advanced life-support interventions, including defibrillation. If a *pulse is present and patient is hemodynamically stable*, the patient can be treated with intravenous *amiodarone or lidocaine*. Cardioversion is used as an emergency measure in patients who become hemodynamically unstable but continue to have a pulse. It also may be used in nonemergency situations, such as when a patient has asymptomatic VT.

The nurse notices ventricular tachycardia on the heart monitor. When the patient is assessed, the patient is found to be unresponsive with no pulse. The nurse should: a. treat with intravenous amiodarone or lidocaine. b. begin cardiopulmonary resuscitation and advanced life support. c. provide electrical cardioversion. d. ignore the rhythm since it is benign.

ANS: D The absence of P waves, wide QRS, rate greater than 150 beats/min, 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.

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

ANS: C In first-degree AV block, a P wave precedes every QRS complex, which is followed by a T wave indicating complete conduction. It is represented on the ECG as a prolonged PR interval. Second-degree heart block refers to AV conduction that is intermittently blocked. Therefore, some P waves are conducted and some are not. Third-degree block is often called complete heart block because no atrial impulses are conducted through the AV node to the ventricles.

The nurse understands that in a third-degree AV block: a. every P wave is conducted to the ventricles. b. some P waves are conducted to the ventricles. c. none of the P waves are conducted to the ventricles. d. the PR interval is prolonged.

ANS: A Pacemakers can be operated in a demand mode or a fixed rate (asynchronous) mode. The demand mode paces the heart when no intrinsic or native beat is sensed. For example, if the rate control is set at 60 beats per minute, the pacemaker will only pace if the patients heart rate drops to less than 60. The fixed rate mode paces the heart at a set rate, independent of any activity the patients heart generates. *The fixed rate mode may compete with the patients own rhythm and deliver an impulse on the T wave (R-on-T phenomenon), with the potential for producing ventricular tachycardia or fibrillation. The demand mode is safer and is the mode of choice.*

The patient has a permanent pacemaker inserted. The provider has set the pacemaker to the demand mode at a rate of 60 beats per minute. The nurse realizes that: a. the pacemaker will pace only if the patients intrinsic heart rate is less than 60 beats per minute. b. the demand mode often competes with the patients own rhythm. c. the demand mode places the patient at risk for the R-on-T phenomenon. d. the fixed rate mode is safer and is the mode of choice.

ANS: A, B, C This patient is showing signs and symptoms of an acute exacerbation of heart failure. Dobutamine and nesiritide are medications administered for acute short-term management; mechanical assist with an intraaortic balloon pump also may be warranted.

The patient has been in chronic heart failure for the past 10 years. He has been treated with beta-blockers and angiotensin-converting enzyme inhibitors as well as diuretics. His symptoms have recently worsened, and he presents to the ED with severe shortness of breath and crackles throughout his lung fields. His respirations are labored and arterial blood gases show that he is at risk for respiratory failure. Which of the following therapies may be used for acute, short-term management of the patient? (Select all that apply). a. Dobutamine b. Intraaortic balloon pump c. Nesiritide (Natrecor) d. V entricular assist device

ANS: C Pericardiocentesis, or needle aspiration of pericardial fluid, is performed to alleviate the pressure around the heart.

The patient has pulseless electrical activity (PEA). The doctor decides that the cause of the PEA is pericardial tamponade. What is the most appropriate treatment for pericardial tamponade? a. Atropine b. Chest tube placement c. Pericardiocentesis d. Transcutaneous pacemaker

ANS: B Atrial fibrillation and flutter are dysrhythmias common after cardiac surgery.

The patient has undergone open chest surgery for coronary artery bypass grafting. One of the nurses responsibilities is to monitor the patient for which common postoperative dysrhythmia? a. Second degree heart block b. Atrial fibrillation or flutter c. V entricular ectopy d. Premature junctional contractions

ANS: B Sinus tachycardia results when the SA node fires faster than 100 beats per minute. Sinus tachycardia is a normal response to stimulation of the sympathetic nervous system. Sinus tachycardia is also a normal finding in children younger than 6 years. Both atrial and ventricular rates are greater than 100 beats per minute, up to 160 beats per minute, but may be as high as 180 beats per minute. Sinus tachycardia is regular or essentially regular. PR interval is 0.12 to 0.20 seconds. QRS interval is 0.06 to 0.10 seconds. P and QRS waves are consistent in shape. P waves are small and rounded. A P wave precedes every QRS complex, which is then followed by a T wave. The fast heart rhythm may cause a decrease in cardiac output because of the shorter filling time for the ventricles. Lowering cardiac out further may complicate the situation. The dysrhythmia itself is not treated, but the cause is identified and treated appropriately. For example, if the patient has a fever or is in pain, the infection or pain is treated appropriately.

The patient is admitted with a fever and rapid heart rate. The patients temperature is 103 F (39.4 C).The nurse places the patient on a cardiac monitor and finds the patients atrial and ventricular rates are above 105 beats per minute. P waves are clearly seen and appear normal in configuration. QRS complexes are normal in appearance and 0.08 seconds wide. The rhythm is regular, and blood pressure is normal. The nurse should focus on providing: a. medications to lower heart rate. b. treatment to lower temperature. c. treatment to lower cardiac output. d. treatment to reduce heart rate.

ANS: A ST segment elevation and elevated cardiac enzymes are seen in Q wave MI. ST segment depression with normal cardiac enzymes is seen with unstable angina episode. ST segment depression with elevated total CPK is seen in non Q wave MI.

The patient is admitted with a suspected acute myocardial infarction (MI). In assessing the 12-lead electrocardiogram (ECG) changes, which findings would indicate to the nurse that the patient is in the process of an evolving Q wave myocardial infarction(MI)? a. ST-segment elevation on ECG and elevated CPK-MB or troponin levels b. Depressed ST-segment on ECG and elevated total CPK c. Depressed ST-segment on ECG and normal cardiac enzymes d. Q wave on ECG with normal enzymes and troponin levels

ANS: C Radiofrequency catheter ablation is a method of interrupting a supraventricular tachycardia, a dysrhythmia caused by a reentry circuit, and an abnormal conduction pathway. Implantable cardioverter-defibrillator are used for primary or secondary prevention of lethal dysrhythmias (VT or VF) Permanent pacemaker insertion is for sinus node dysfunction, 2nd degree type II and 3rd degree AV blocks Temporary transvenous pacemaker placement for patients urgently waiting permanent pacemaker placement or to treat transient bradydysrhythmias. (has more complications than transcutaneous) p323

The patient is admitted with recurrent supraventricular tachycardia that the cardiologist believes to be related to an accessory conduction pathway or a reentry pathway. The nurse anticipates which procedure to be planned for this patient? a. Implantable cardioverter-defibrillator placement b. Permanent pacemaker insertion c. Radiofrequency catheter ablation d. Temporary transvenous pacemaker placement

ANS: C AV nodal blocking medications (beta-blockers, calcium channel blockers, and digoxin) and increased vagal tone may cause sinus exit block. Causes are explored, and prescribed medications may need to be adjusted or discontinued. If patients are symptomatic (HR less than 50, chest pain, syncope, SOB), significant numbers of pauses may require treatment, including temporary (including transcutaneous) and permanent implantation of a pacemaker.

The patient is admitted with sinus pauses causing periods of loss of consciousness. The patient is asymptomatic, awake and alert, but fatigued. He answers questions appropriately. When admitting this patient, the nurse should first: a. prepare the patient for temporary pacemaker insertion. b. prepare the patient for permanent pacemaker insertion. c. assess the patients medication profile. d. apply transcutaneous pacemaker paddles.

ANS: D Ventricular tachycardia (VT) is a rapid, life-threatening dysrhythmia originating from a single ectopic focus in the ventricles. It is characterized by at least three PVCs in a row. VT occurs at a rate greater than 100 beats per minute, but the rate is usually around 150 beats per minute and may be up to 250 beats per minute. Depolarization of the ventricles is abnormal and produces a widened QRS complex. The patient may or may not have a pulse. Determine whether the patient has a pulse. If no pulse is present, provide emergent basic and advanced life-support interventions, including defibrillation. If a pulse is present and the blood pressure is stable, the patient can be treated with intravenous amiodarone or lidocaine.

The patient is alert and talking when the nurse notices the following rhythm. The patients blood pressure is 90/44 mm Hg. The nurse should a. defibrillate immediately. b. begin basic life support. c. begin advanced life support. d. treat with intravenous amiodarone or lidocaine.

ANS: C Digitalis toxicity is a major cause of this rhythm, and further digitalis doses should not be given until a digitalis level is obtained. Other causes of Mobitz I include AV nodal blocking drugs, acute inferior wall myocardial infarction or right ventricular infarction, ischemic heart disease, and excess vagal response. This type of block is usually well tolerated and no treatment is indicated unless the dropped beats occur frequently.

The patient is asymptomatic but is diagnosed with second-degree heart block Mobitz I. The patient is on digitalis medication at home. The nurse should expect that: a. the patient has had an anterior wall myocardial infarction. b. the physician will order the digitalis to be continued in the hospital. c. a digitalis level would be ordered upon admission. d. the patient will require a transcutaneous pacemaker.

ANS: A Adenosine is the initial drug of choice for the diagnosis and treatment of supraventricular dysrhythmias. Adenosine has an onset of action of 10 to 40 seconds and duration of 1 to 2 minutes; therefore, it is administered rapidly.

The patient is diagnosed with abrupt onset of supraventricular tachycardia (SVT). The nurse prepares which medication that has a short half-life and is recommended to treat symptomatic SVT? a. Adenosine b. Amiodarone c. Diltiazem d. Procainamide

ANS: A The peak of the T wave through the downslope of the T wave is considered the vulnerable period, which coincides with partial repolarization of the ventricles. *If a PVC occurs during the T wave, ventricular tachycardia may occur*. When the R wave of PVC falls on the T wave of a normal beat, it is referred to as the R-on-T phenomenon. PVCs may occur in healthy individuals and usually do not require treatment. The nurse must determine if PVCs are increasing in number by evaluating the trend. If PVCs are increasing, the nurse should evaluate for potential causes such as electrolyte imbalances, myocardial ischemia or injury, and hypoxemia. Runs of nonsustained ventricular tachycardia may be a precursor to development of sustained ventricular tachycardia. Because the stimulus depolarizes the ventricles in a slower, abnormal way, the QRS complex appears widened and has a bizarre shape. *The QRS complex is often wider than 0.16 seconds.*

The patient is having premature ventricular contractions (PVCs). The nurses greatest concern should be: a. the proximity of the R wave of the PVC to the T wave of a normal beat. b. the fact that PVCs are occurring, because they are so rare. c. if the number of PVCs are decreasing. d. if the PVCs are wider than 0.12 seconds.

ANS: A, C, D Treatments include transcutaneous or transvenous pacing and implanting a permanent pacemaker. Atropine reduces vagal tone, but that is not a cause of complete heart block (as it is with second degree). It is important to note that the only treatment is pacing. Amiodarone IV is used to suppress ventricular dysrhythmia and is not used to treat third-degree heart block.

The patient is in third-degree heart block (complete heart block) and is symptomatic. The treatment for this patient is which of the following? (Select all that apply.) a. transcutaneous pacemaker. b. atropine IV . c. temporary transvenous pacemaker. d. permanent pacemaker. e. amiodarone IV .

ANS: A Coronary artery bypass graft surgery is indicated for significant left main coronary occlusion (>50%). p. 319

The patient presents to the ED with severe chest discomfort. He is taken for cardiac catheterization and angiography that shows 80% occlusion of the left main coronary artery. Which procedure will be most likely followed? a. Coronary artery bypass graft surgery b. Intracoronary stent placement c. Percutaneous transluminal coronary angioplasty (PTCA) d. Transmyocardial revascularization

ANS: D If an abnormal P wave cannot be visualized on the ECG but the QRS complex is narrow, the term supraventricular tachycardia (SVT) is often used. Treatment is directed at assessing the patients tolerance of the tachycardia. If the rate is higher than 150 beats per minute and the patient is symptomatic, emergent synchronized cardioversion is considered. If the patient is not symptomatic, treatment includes adenosine, Beta- blockers, calcium channel blockers, and amiodarone. Atropine is used in the treatment of bradycardia. If atropine is not effective in increasing heart rate, then transcutaneous pacing is implemented.

The patients heart rate is 165 beats per minute. His cardiac monitor shows a rapid rate with narrow QRS complexes. The P waves cannot be seen, but the rhythm is regular. The patients blood pressure has dropped from 124/62 to 78/30. His skin is cold and diaphoretic and he is complaining of nausea. The nurse prepares the patient for: a. administration of beta-blockers. b. administration of atropine. c. transcutaneous pacemaker insertion. d. emergent cardioversion.

ANS: B The normal intrinsic rate for the AV node and junctional tissue is 40 to 60 beats per minute, but rates can accelerate. An *accelerated* junctional rhythm has a rate between *60 and 100* beats per minute, and the rate for *junctional tachycardia* is greater than 100 beats per minute. *If P wave precedes QRS -> it is inverted or upside down; the P wave may not be visible, or it may follow the QRS*. If a P wave is present before the QRS, the PR interval is shortened less than 0.12 milliseconds. Atrial fibrillation arises from multiple ectopic foci in the atria, causing chaotic quivering of the atria and ineffectual atrial contraction. The AV node is bombarded with hundreds of atrial impulses and conducts these impulses in an unpredictable manner to the ventricles.

The patients heart rate is 70 beats per minute, but the P waves come after the QRS complex. The nurse correctly determines that the patients heart rhythm is: a. a normal junctional rhythm. b. an accelerated junctional rhythm. c. a junctional tachycardia. d. atrial fibrillation.

ANS: A Junctional escape rhythm occurs when the dominant pacemaker, the SA node, fails to fire. The normal heart rate of the AV node is 40 to 60 beats per minute, so the AV node rate has neither increased nor decreased. An *increased SA node rate would override the AV node.*

The patients heart rhythm shows an inverted P wave with a PR interval of 0.06 seconds. The heart rate is 54 beats per minute. The nurse recognizes the rhythm as a junctional escape rhythm, and understands that the rhythm is due to the: a. loss of sinus node activity. b. increased rate of the A V node. c. increased rate of the SA node. d. decreased rate of the A V node.

ANS: A This patient is having PVCs secondary to bradycardia. Atropine is a first-line drug for bradycardia. Administer atropine, 0.5 mg IV every 3 to 5 minutes to a total dose of 3 mg.

The patients monitor shows bradycardia (heart rate of 40 beats/min) and frequent premature ventricular contractions (PVCs) with a measured blood pressure of 85/50 mm Hg. The nurse anticipates the use of which drug? a. Atropine 0.5 to 1 mg intravenous push b. Dopamine dripcontinuous infusion c. Lidocaine 1 mg/kg intravenous push d. Transcutaneous pacemaker

ANS: C A successful angioplasty procedure is one in which the stenosis is reduced to less than 50% of the vessel lumen diameter, although most clinicians aim for less than 20% final diameter stenosis.

The patients wife asks the nurse if the angioplasty will remove all the buildup in the vessel walls so that the patient will be healthy again. The nurse explains: a. The operation will remove all of the plaque, and if your husband exercises and diets he will be free of cardiac problems. b. The surgery will remove all the buildup, but it will reaccumulate and he will probably need this surgery again this time next year. c. The best outcome will be if 20% to 50% of the diameter of the vessel can be restored. Your husband will need to diet and exercise carefully to avoid further cardiac risk. d. The surgeon will only be able to get 5% to 10% of the plaque, but this will bring about marked relief of your husbands symptoms.

ANS: B Stents are inserted to optimize the results of other treatments for acute vessel closure (percutaneous transluminal coronary angioplasty, atherectomy, fibrinolytics) and to prevent restenosis.

The patients wife is confused about the scheduling of a stent insertion. She says that she thought the angioplasty was surgery to fix her husbands heart problem. The nurse explains to her: a. The angioplasty was a failure, and so this procedure has to be done to fix the heart vessel. b. The stent is inserted to enhance the results of the angioplasty, by helping to keep the vessel open and prevent it from closing again. c. This procedure is being done instead of using clot-dissolving medication to help keep the heart vessel open. d. The stent will remove any clots that are in the vessel and protect the heart muscle from damage.

ANS: A Hypothermia decreases the metabolic rate by 6% to 7% for every decrease of 1 C in temperature; decreased metabolic rate may protect neurological function. Induced hypothermia to a core body temperature of 32o C to 34o C for 12 to 24 hours may be beneficial in reducing neurological impairment after cardiac arrest.

What is the major reason for using a treatment to lower body temperature after cardiac arrest to promote better neurological recovery? a. Hypothermia decreases the metabolic rate by 7% for each decrease of 1 C. b. Lower body temperatures are beneficial in patients with low blood pressure. c. Temperatures of 40 C may reduce neurological impairment. d. The lower body temperature leads to decreased oxygen delivery.

ANS: C When an electrical signal is aimed directly at the positive electrode, an upright inflection is visualized. If the impulse is going away from the positive electrode, a negative deflection is seen; and if the signal is perpendicular to the imaginary line between the positive and negative poles of the lead, the tracing is equiphasic, with equally positive and negative deflection.

When assessing the 12-lead electrocardiogram (ECG) or a rhythm strip, it is helpful to understand that the electrical activity is viewed in relation to the positive electrode of that particular lead. When an electrical signal is aimed directly at the positive electrode, the inflection will be: a. negative. b. upside down. c. upright. d. equally positive and negative.

ANS: A, C, D, E, B This order will result in rapid defibrillation without endangering hospital staff.

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 hands-free, multifunction defibrillator pads on the patient's chest. e. Check the location of other staff and call out "all clear."

ANS: B Adenosine must be given over 1 to 2 seconds to be effective. The RN should hold the diltiazem until discussing it with the health care provider. The treatment for *asystole is immediate CPR*. The synchronizer switch should be "off" when defibrillating

Which action by a new registered nurse (RN) who is orienting to the telemetry unit indicates a good understanding of the treatment of heart dysrhythmias? a. Prepares defibrillator settings at 360 joules for a patient whose monitor shows asystole. b. Injects IV adenosine (Adenocard) over 2 seconds to a patient with supraventricular tachycardia 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: C Continued chest pain suggests that the thrombolytic therapy is not effective and that other interventions such as percutaneous coronary intervention may be needed. Bruising is a possible side effect of thrombolytic therapy, but it is not an indication that therapy should be discontinued. *The decrease of the ST-segment elevation indicates that thrombolysis is occurring and perfusion is returning to the injured myocardium*. An increase in troponin levels is expected with reperfusion and is related to the washout of cardiac biomarkers into the circulation as the blocked vessel is opened.

Which information about a patient who has been receiving thrombolytic therapy for an acute myocardial infarction is most important for the nurse to communicate to the health care provider? a. An increase in troponin levels from baseline b. A large bruise at the patient's IV insertion site c. No change in the patient's reported level of chest pain d. A decrease in ST-segment elevation on the electrocardiogram

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 are also abnormal, they are not likely to be the etiology of the patient's PVCs and do not require immediate correction

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 of 243 mg/dL c. Serum sodium of 134 mEq/L b. Serum chloride of 92 mEq/L d. Serum potassium of 2.9 mEq/L

ANS: B, C, The head of the bed must not be elevated more than 30 degrees, and the patient should be instructed to keep the affected leg straight. Bed rest is 6 to 8 hours in duration, unless a vascular hemostatic device is used. The nurse observes the patient for bleeding or swelling at the puncture site and frequently assesses adequacy of circulation to the involved extremity.

Which nursing interventions would be appropriate after angioplasty? (Select all that apply.) a. Elevate the head of the bed by 45 degrees for 6 hours b. Assess pedal pulses on the involved limb every 15 minutes for 2 hours c. Monitor the vascular hemostatic device for signs of bleeding d. Instruct the patient bend his/her knee every 15 minutes while the sheath is in place

ANS: A Sinus arrhythmia is a cyclical change in heart rate that is associated with respiration. The *heart rate increases slightly during inspiration and slows slightly during exhalation because of changes in vagal tone*. The ECG tracing demonstrates an alternating pattern of faster and slower heart rate that changes with the respiratory cycle. *Interval measurements are normal*. This rhythm is tolerated well, and no treatment is required.

Which of the following is true about a patient diagnosed with sinus arrhythmia? a. The heart rate varies, dependent on vagal tone and respiratory pattern. b. Immediate treatment is essential to prevent death. c. Sinus arrhythmia is not well tolerated by most patients. d. PR and QRS interval measurements are prolonged.

ANS: C Transcutaneous (external noninvasive) cardiac pacing is used during emergencies to treat symptomatic bradycardia (hypotension, altered mental status, angina, pulmonary edema) that has not responded to atropine. This patient is symptomatic. Asystole is treated with BLS and ACLS. Unstable SVT is treated with cardioversion.

Which rhythm would be an emergency indication for the application of a transcutaneous pacemaker? a. Asystole b. Bradycardia (heart rate 40 beats/min) normotensive and alert c. Bradycardia (heart rate 50 beats/min) with hypotension and syncope d. Supraventricular tachycardia (heart rate 150 beats/min), hypotensive

ANS: C Acute myocardial infarction is death (tissue necrosis) of the myocardium that is caused by lack of blood supply from the occlusion of a coronary artery and its branches.

While instructing a patient on what occurs with a myocardial infarction, the nurse plans to explain which process? a. Coronary artery spasm. b. Decreased blood flow (ischemia). c. Death of cardiac muscle from lack of oxygen (tissue necrosis). d. Sporadic decrease in oxygen to the heart (transient oxygen imbalance).

ANS: D Third-degree AV block: no atrial impulses are conducted through the AV node to the ventricles. The atria and ventricles beat independently of each other because the AV node is completely blocked to the sinus impulse and it is not conducted to the ventricles. P-P and R-R intervals regular but not associated with each other. *P waves have no association with the QRS complexes and appear throughout the QRS waveform*. QRS followed by T wave/ Treatment for this is Transcutaneous or Transvenous pacing and implanting a permanent pacemaker.

a. First-degree AV block b. Second-degree AV block Mobitz I (Wenckebach phenomenon) c. Second-degree A V block Mobitz II d. Third-degree A V block (complete heart block)