Heart Failure and Dysrhythmias PDF

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Practice questions to prepare for pathophysiology exams on heart failure and dysrhythmias....

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Chapter 19: Heart Failure and Dysrhythmias: Common Sequelae of Cardiac Diseases Test Bank MULTIPLE CHOICE 1. Left-sided heart failure is characterized by a. pulmonary congestion. b. decreased systemic vascular resistance. c. jugular vein distention. d. peripheral edema.

ANS: A Left-sided heart failure is characterized by pulmonary congestion and edema. Right-sided heart failure is characterized by congestion in the systemic venous system that increases systemic vascular resistance. Jugular vein distention is a classic sign of right-sided heart failure. Peripheral edema is seen in right-sided failure. REF: Pg. 414 2. The therapy that most directly improves cardiac contractility in a patient with systolic heart failure is a. afterload reduction. b. β-antagonist agents. c. preload reduction. d. digitalis.

ANS: D Digitalis may be used for symptom management of heart failure. Cardiac glyco‐ sides directly inhibit the sodium-potassium pump present in the cell membrane of all cells. The intracellular changes allow more calcium to remain in the cell, thus strengthening myocardial contraction. Contractility is not improved through afterload reduction. Beta-blockers inhibit the effects of sympathetic activation and have the potential to reduce cardiac output. Preload reduction is not the therapy of choice in improving cardiac contractility.

REF: Pg. 418 3. Hypertrophy of the right ventricle is a compensatory response to a. aortic stenosis. b. aortic regurgitation. c. tricuspid stenosis. d. pulmonary stenosis.

ANS: D Right ventricular hypertrophy is the direct result of pulmonary disorders that increase pulmonary vascular resistance and impose a high afterload on the right ventricle. Aortic stenosis does not lead to right ventricular hypertrophy. Aortic regurgitation is not associated with right ventricular hypertrophy. Hypertrophy of the right ventricle is not a compensatory response to tricuspid stenosis. REF: Pg. 411 4. The common denominator in all forms of heart failure is a. poor diastolic filling. b. reduced cardiac output. c. pulmonary edema. d. tissue ischemia.

ANS: B The common manifestation of all forms of heart failure is the failure of the heart to pump blood adequately. The clinical presentation may differ depending on which ventricle fails (left or right, or both). Poor diastolic filling is not seen in all forms of heart failure. Pulmonary edema is seen in left-sided failure. Tissue ischemia is directly related to myocardial infarction, which may induce heart failure. REF: Pg. 413 5. a.

Cor pulmonale refers to

biventricular failure. b. left ventricular hypertrophy secondary to lung disease. c. right ventricular hypertrophy secondary to pulmonary hypertension. d. right ventricular failure secondary to right ventricular infarction.

ANS: C Pulmonary disorders that result in increased pulmonary vascular resistance impose a high afterload on the right ventricle. The resultant right ventricular hypertrophy known as cor pulmonale may progress to right ventricular failure as the lung disease worsens. Biventricular failure is most often the result of primary left ventricular failure that progresses to the right. Cor pulmonale is not associat‐ ed with left ventricular hypertrophy. Only 3% of MIs occur in the right ventricle. REF: Pgs. 416-417 6.

Lusitropic impairment refers to

a. poor contractile force. b. impaired diastolic relaxation. c. altered action potential conduction rate. d. altered automaticity.

ANS: B Lusitropic impairment refers to an energy-requiring process that removes free calcium ions from the cytoplasm by pumping them back into the sarcoplasmic reticulum and across the cell membrane into the extracellular fluid. Ischemia interferes with this process in the active phase of diastolic relaxation. Poor contractile force is not associated with lusitropic impairment. The conduction rate is not associated with the energy-requiring process known as lusitropy. Auto‐ maticity is not a factor in lusitropy. REF: Pg. 410 7. First-degree heart block is characterized by a. prolonged PR interval. b. absent P waves.

c. widened QRS complex. d. variable PR interval.

ANS: A First-degree block is generally identified by a prolonged PR interval (more than 0.20 second) on ECG. P waves are not absent in first-degree heart block. A widened QRS complex is associated with a particular dysrhythmia, but not firstdegree heart block. A variable PR interval is found in type I second-degree block. REF: Pg. 426 8. Second-degree heart block type I (Wenckebach) is characterized by a. absent P waves. b. lengthening PR intervals and dropped P wave. c. constant PR interval and dropped QRS complexes. d. no correlation between P waves and QRS complexes.

ANS: B Type I second-degree block is associated with progressively lengthening PR intervals until one P wave is not conducted and becomes a dropped beat. Second-degree block is not characterized by an absence of P waves. Type II second-degree block is associated with a consistent PR interval and dropped beats. The ECG of third-degree block shows regularly occurring P waves that are independent of the ventricular rhythm. REF: Pg. 426 9. Which dysrhythmia is thought to be associated with reentrant mechanisms? a. Second-degree AV block b. Sinus bradycardia c. Junctional escape d. Preexcitation syndrome tachycardia (Wolf-Parkinson-White syndrome)

ANS: D Reentry is a complex process in which a cardiac impulse continues to depolarize in a part of the heart after the main impulse has finished its path and the majority of the fibers have repolarized. Wolff-Parkinson-White syndrome is caused by accessory pathways that originate in the atria, bypass the AV node, and enter a site in the ventricular myocardium. This causes the ventricles to contract prema‐ turely, resulting in a reentrant tachycardia. Second-degree block is a conduction failure between the sinus impulse and its ventricular response. Sinus bradycardia is a slowed impulse generation by the sinus node. A junctional escape rhythm originates in the AV node. REF: Pg. 421 | Pgs. 427-428 10.

In which dysrhythmias should treatment be instituted immediately?

a. Asymptomatic sinus bradycardia at a heart rate of 50 beats/min b. Fever-induced tachycardia at 122 beats/min c. Premature atrial complexes occurring every 20 seconds d. Atrial fibrillation with a ventricular rate of 220 beats/min

ANS: D Atrial fibrillation is a completely disorganized and irregular atrial rhythm accompa‐ nied by an irregular ventricular rhythm of variable rate. Atrial fibrillation causes the atria to quiver rather than to contract forcefully. This allows blood to become stagnant in the atria and may lead to formation of thrombi. This condition requires resuscitation because of the reduction in cardiac output. The cause of the bradycardia should be investigated, but is not treated emergently when an individual is not exhibiting any symptoms. Fever-induced tachycardia will correct itself once the fever is lowered. Dysrhythmias are treated if they produce signifi‐ cant symptoms or are expected to progress to a more serious level. REF: Pg. 425 11. An abnormally wide (more than 0.10 second) QRS complex is characteristic of a. paroxysmal atrial tachycardia. b. supraventricular tachycardia. c.

junctional escape rhythm. d. premature ventricular complexes.

ANS: D The QRS of the premature complex is prolonged (greater than 0.10 second) and bizarre in appearance. Paroxysmal atrial tachycardia does not display a QRS complex that is greater than 0.10 seconds. Supraventricular tachycardia does not display a wide QRS complex. Escape rhythms may have a P wave that is inverted and located before, during, or after the QRS. REF: Pg. 425 12. A laboratory test that should be routinely monitored in patients receiving digitalis therapy is a. serum sodium. b. albumin level. c. serum potassium. d. serum calcium.

ANS: C Digitalis slows the heart rate through parasympathetic system activation and promotes sodium and water excretion through improved cardiac output to the kidney. Depletion of serum potassium (hypokalemia) may potentiate digitalis toxicity. Sodium and water excretion is activated through the parasympathetic system due to improved cardiac output to the kidneys. Albumin level is not affected by digitalis. Digitalis allows more calcium to remain in the cell through a slowing of the sodium-dependent calcium pump. REF: Pg. 418 13. After sitting in a chair for an hour, an elderly patient develops moderate lower extremity edema. His edema is most likely a consequence of a. arterial obstruction. b. isolated left-sided heart failure. c. right-sided heart failure. d.

peripheral vascular disease.

ANS: C The backward effects of right-sided heart failure are due to congestion in the systemic venous system and lead to lower extremity edema. Arterial obstruction is not associated with dependent edema of the lower extremities. Left-sided heart failure is associated with pulmonary symptoms. Edema may be associated with peripheral vascular disease, but dependent edema over a 1-hour period is related to right-sided heart failure. REF: Pg. 417 14. A patient is exhibiting severe dyspnea and anxiety. The patient also has bubbly crackles in all lung fields with pink, frothy sputum. This patient is most likely experiencing a. right-sided heart failure. b. cardiomyopathy. c. a medication reaction. d. acute cardiogenic pulmonary edema.

ANS: D Acute cardiogenic pulmonary edema is a life-threatening condition requiring immediate treatment. It is associated with left ventricular failure that severely impairs gas exchange, and produces dramatic signs and symptoms including anxiety, severe dyspnea, an upright posture to breathe effectively, and pink frothy sputum. Right-sided heart failure produces systemic venous congestion. Car‐ diomyopathy is not associated with bubbly crackles and pink frothy sputum. A medication reaction is not the reason for the patient to exhibit severe dyspnea, anxiety, bubbly crackles, and frothy sputum. REF: Pg. 415 15. A patient with pure left-sided heart failure is likely to exhibit a. jugular vein distention. b. pulmonary congestion with dyspnea. c. peripheral edema. d.

hepatomegaly.

ANS: B Left-sided heart failure is most often associated with left-ventricular infarction and systemic hypertension. The ineffective pumping of the left ventricle results in an accumulation of blood within the pulmonary circulation. As a result, pulmonary congestion with dyspnea is an expected finding. Jugular vein distention is more often associated with right-sided failure. Peripheral edema is associated with right-sided failure. Hepatomegaly is not seen in pure left-sided edema. REF: Pg. 414 16. Beta-blockers are advocated in the management of heart failure because they a. increase cardiac output. b. reduce cardiac output. c. enhance sodium absorption. d. reduce blood flow to the kidneys.

ANS: B Beta-blockers are advocated in the management of heart failure to inhibit the cardiac effects of sympathetic activation. These drugs are negative inotropes and have the potential to reduce cardiac output. The goal with the use of betablockers in heart failure is to reduce cardiac output. Beta-blockers do not affect sodium reabsorption. Angiotensin II and aldosterone enhance sodium and water reabsorption by the kidney, contributing to an elevated blood volume. REF: Pg. 411 17. A patient with heart failure who reports intermittent shortness of breath during the night is experiencing a. orthopnea. b. paroxysmal atrial tachycardia. c. sleep apnea. d. paroxysmal nocturnal dyspnea.

ANS: D Dyspnea that occurs at night is known as paroxysmal nocturnal dyspnea. Orthopnea is known as dyspnea when lying down. Intermittent shortness of breath at night is not known as paroxysmal atrial tachycardia. Sleep apnea is an absence of breathing during sleep. REF: Pg. 414 18. Low cardiac output to the kidneys stimulates the release of _____ from juxtaglomerular cells. a. aldosterone b. norepinephrine c. angiotensinogen d. renin

ANS: D When cardiac output is reduced, juxtaglomerular cells in the kidney release renin and initiate the renin-angiotensin-aldosterone cascade leading to salt and water retention by the kidney. Aldosterone is not released from juxtaglomerular cells. Norepinephrine is not released by cells within the kidney. Angiotensin is not involved in the process of cellular release within the kidneys. REF: Pg. 410 19. Patients with structural evidence of heart failure who exhibit no signs or symptoms are classified into which New York Heart Association heart failure class? a. Class I b. Class II c. Class III d. Class IV

ANS: A Patients who have structural heart disease but no signs or symptoms of heart failure are placed in Class I of the NYHA Classes. Class II patients have current

or previous symptoms of heart failure. Class III patients have current or previous symptoms of heart failure, such as dyspnea or fatigue. Class IV patients have advanced structural heart disease and marked symptoms at rest. REF: Pg. 417 20. The majority of tachydysrhythmias are believed to occur because of a. triggered activity. b. enhanced automaticity. c. defective gap junctions. d. reentry mechanisms.

ANS: D Reentry is thought to be the culprit in most tachydysrhythmias. Reentry is a complex process in which a cardiac impulse continues to depolarize in a part of the heart after the main impulse has finished its path. Triggered activity occurs when an impulse is generated during or just after repolarization. Alterations in automaticity create electrolyte imbalances. Defective gap junctions are not related to tachydysrhythmias. REF: Pg. 421 21. A patient who reports dizziness and who has absent P waves, wide QRS complexes, and a heart rate of 38 beats/min on an ECG is most likely in which rhythm? a. Third-degree heart block b. Junctional tachycardia c. Ventricular escape rhythm d. Sinus bradycardia

ANS: C A ventricular escape rhythm originates in the Purkinje fibers, has a rate of 15 to 40 beats/minute, and is characterized by a wide QRS complex. An important clue to identifying escape rhythms is the absence of normal P waves and PR intervals. The rhythm involved in third-degree heart block includes regularly occurring P waves. Junctional tachycardia has a heart rate between 70 to 140

beats/minute. P waves are preceding, following, or buried in the QRS complex. Sinus bradycardia has a normal pattern on the ECG, but with a rate of less than 60 beats/minute. REF: Pg. 423 22. A patient is diagnosed with heart failure with normal ejection fraction. This patient is most likely characterized by a(n) a. elderly woman without a previous history of MI. b. middle-aged man with a previous history of MI. c. young female athlete with cardiomegaly. d. young sedentary male with a high-stress job.

ANS: A Heart failure with normal ejection fraction is particularly likely to develop in the elderly, in women, and in those without a history of MI. A middle-aged man with a previous history of MI may have heart failure, but the older woman fits the criteria of heart failure with normal ejection fraction. A young female athlete with car‐ diomegaly may experience heart failure, but is not the normal patient profile for this condition. A young sedentary male with a high-stress job may experience heart failure, but this patient does not fit the normal profile for this condition. REF: Pg. 409 23. Increased preload of the cardiac chambers may lead to which patient symptom? a. Decreased heart rate b. Decreased respiratory rate c. Edema d. Excitability

ANS: C Preload reduces glomerular filtration resulting in fluid conservation, or edema. Increased preload may lead to an increased, not decreased, heart rate. In‐ creased preload may lead to shortness of breath and an increased respiratory rate. Increased preload may lead to fatigue, not excitability, as the heart works

harder to circulate blood. REF: Pg. 411 MULTIPLE RESPONSE 24. Which statement is true about the incidence of heart failure? (Select all that apply.) a. Heart failure affects about 2 million Americans. b. Heart failure is the fastest-growing cardiac disorder. c. There are more than 400,000 new cases of heart failure diagnosed each year in the United States. d. The increasing incidence and hospitalization rates of heart failure reflect the aging population in the United States. e. The incidence of heart failure is 10 per 1000 population after age 65.

ANS: B, D, E Heart failure is the fastest growing cardiac disorder at this time. The incidence and hospitalization rates associated with heart failure are reflective of the aging population in the United States. The incidence of heart failure is 10 per 1000 population in people over 65. Heart failure affects about 5.7 million Americans. More than 550,000 new cases of heart failure are diagnosed in the United States each year. REF: Pg. 409 25. Right-sided heart failure is usually a consequence of (Select all that apply.) a. elevated right ventricular afterload. b. right ventricular infarction. c. tricuspid valve defects. d. congenital anomalies.

ANS: A, B Because the right and left ventricles function in tandem, left-ventricular failure

eventually increases the workload on the right ventricle. Consequently, the right ventricle may fail causing infarction. Pulmonary disorders create a high afterload on the right ventricle and may cause a progression to right ventricular failure. Tricuspid valve defects are not the cause of right-sided heart failure. Congenital anomalies are not generally associated with right-sided failure. REF: Pgs. 415-417 26. A patient has heart failure with a normal ejection fraction. Which findings are most likely found in this patient? (Select all that apply.) a. High cardiac output b. Pulmonary congestion c. Edema d. Ejection fraction greater than 50% e. Ejection fraction less than 45%

ANS: B, C, D Pulmonary congestion is a hallmark sign of heart failure. Edema is also a hallmark sign of heart failure. An ejection fraction greater than 50% indicates a normal ejection fraction. Low cardiac output, not high cardiac output, is a sign of heart failure. An ejection fraction of less than 45% indicates an abnormal ejection fraction. REF: Pg. 410 27. The most common causes of heart failure are (Select all that apply.) a. myocardial ischemia. b. hypertension. c. dilated cardiomyopathy. d. high-fat diet. e. urinary retention.

ANS: A, B The most common causes of heart failure are myocardial ischemia from coronary

artery disease, followed by hypertension. Dilated cardiomyopathy is less com‐ mon cause of heart failure. A high-fat diet can contribute to coronary artery disease, which is a contributor to heart failure, but a high-fat diet is not one of the most common causes of heart failure. Urinary retention is not a common cause of heart failure. REF: Pg. 409 28. A patient with forward effects of heart failure may present with which symptoms? (Select all that apply.) a. Impaired memory b. Mental fatigue c. Stupor d. Confusion e. Aggression

ANS: A, B, D The forward effects of heart failure cause inadequate perfusion of the brain and may lead to restlessness, mental fatigue, confusion, anxiety, impaired memory, generalized fatigue, activity intolerance, and lethargy. Stupor is not a symptom of the forward effects of heart failure. Aggression is not a symptom of the forward effects of heart failure. REF: Pg. 414 29. Dysrhythmias are significant since they (Select all that apply.) a. are an indicator of life span. b. can indicate an underlying disorder. c. can impair venous return. d. increase the severity of heart murmurs. e. can impair cardiac output.

ANS: B, E Dysrhythmias can be indicative of an underlying pathophysiologic disorder.

Dysrhythmias can impair normal cardiac output and lead to serious patient complications. Dysrhythmias are not an indicator ...