1. (D) Wenckebach, or type I second-degree AV block, is characterized on ECG by progressive lengthening of the PR interval until there is a nonconducted P wave. The magnitude of PR lengthening declines with each beat, so the RR intervals characteristically shorten prior to the dropped beat. It is almost always caused by abnormal conduction across the AV node, and the QRS complex is usually of normal duration.

2. (C) Aortic stenosis is most likely to be associated with angina pectoris, syncope, and exertional dyspnea. Exertional syncope is caused by either systemic vasodilation in the presence of fixed or inadequate cardiac output, an arrhythmia, or both. Syncope at rest is most frequently a result of a transient ventricular tachyarrhythmia.

3. (C) Common findings in infective endocarditis include petechiae, Roth’s spots, Osler’s nodes, Janeway lesions, splinter hemorrhages, stroke, and infarction of viscera, or extremities. Many of the complications are thought to be embolic but may include vasculitis. Autopsy studies reveal that many systemic emboli go unrecognized. Brain, lung, coronary arteries, spleen, extremities, gut, and eyes are common locations for emboli.

4. (B) The slow channel for calcium assumes considerable importance in the region of the sinus node and AV node. For verapamil, this results in both antiarrhythmic and negative inotropic effects. Different classes of calcium channel blockers have differential effects on these slow channels, explaining the different clinical properties of the various calcium channel blocking drugs.

5. (D) Pericarditis secondary to transmural infarction is very common and most cases appear within 4 days. The most common manifestation of pericarditis is a friction rub along the left sterna border. It is evanescent, lasting only a few days. The pain is usually perceived by the patient to be different than that of the infarct. It is worsened by inspiration, swallowing, coughing, or lying down. It frequently is associated with a low-grade fever.

6. (A) Positively inotropic is the best description of the effect of calcium ions on the myocardium.contraction coupling, and in possible drug effects and heart failure.)

7. (C) In the past, there was concern that rigorous drug treatment would harm the fetus. Studies now show benefit in controlling pressure with drugs, but ACE inhibitors are contraindicated because they might cause renal abnormalities in the fetus. Women who develop hypertension during pregnancy havea higher risk of developing hypertension in later life.

8. (E) There is a possible indication (but not an obligation) to insert a temporary pacemaker if a new LBBB occurs. If LBBB and a Mobitz type II AV block occur, there is general agreement on the usefulness of pacing. Temporary pacemaker is not required for first-degree block. For second-degree block of the Wenckebach type (usually with an inferior infarction), pacing is only required if symptoms of bradycardia and hypotension cannot be controlled medically. The necessity for temporary pacing during an acute myocardial infarction (AMI) does not necessarily indicate that permanent pacing will be required.

9. (D) Pulmonary hypertension is associated with an increased intensity of the second heart sound, which coincides with the end of the T wave on ECG. It is the pulmonic component of the second heart sound that is increased. Pulmonary stenosis can cause dyspnea on exertion but auscultation will reveal a systolic murmur and decreased second heart sound (pulmonic component). As well, there may be prominent a waves in the jugular

venous pulse, a right ventricular heave, an ejection click, and a right ventricular fourth heart sound. When signs and symptoms are apparent, the pulmonary hypertension is usually moderate to severe.

10. (D) The patient most likely has PSVT, since the tachycardia terminates after carotid sinus massage (CSM). CSM increases vagal tone (parasympathetic) which decreases AV nodal conduction and terminates AV node re-entry arrhythmias. Sinus tachycardia differs from PSVT tachycardia in that it does not start or stop abruptly. In PSVT, the QRS is usually narrow without clearly discernible P waves.A wide QRS in PSVT can result from a preexisting bundle branch block, or a functional bundle branch block secondary to the tachycardia. This can make the distinction from a ventricular arrhythmia quite difficult.

11. (D) In the absence of critical CAD, angina pectoris occurs most frequently with aortic stenosis.AMI is usually due to associated atherosclerotic coronary occlusion.

12. (E) Nitroglycerine is usually used in the setting of severe pulmonary congestion with adequate blood pressure. With significant hypotension, inotropic agents are generally administered prior to nitroglycerine.

13. (A) Aventricularseptal defect is considered a relatively high-risk lesion for infective endocarditis. Mitral valve prolapse with regurgitation, asymmetric septal hypertrophy, and pure mitral stenosis are considered an intermediate risk. Atrial septal defects of the secundum type are considered low risk.

14. (A) Themyxoma is a solitary globular or polypoid tumor varying in size from that of a cherry to a peach. About 75% are found in the left atrium, and most of the remainder in the right atrium. The clinical presentation is with one or more of the classical triad of constitution symptoms (fatigue, fever, anemia), embolic events, or obstruction of the valve orifice.

15. (A) Diltiazem and verapamil may be of help in both acute paroxysms of atrial flutter and chronic management. The other choices have no effect on the AV node to slow down flutter, and atropine accelerates AV conduction. At times, catheter ablation of the flutter pathway is required in chronic atrial flutter. Surgical ablation is reserved for cases where other surgical interventions are required.

16. (D) Contrast media used in cardiac catheterization may result in renal impairment. The group at highest risk includes diabetics with renal disease and those with preexisting renal failure. Good hydration is essential. Other manifestations of contrast media include nausea and vomiting (common), and anaphylactoid reactions characterized by low-grade fever, hives, itching, angioedema, bronchospasm, and even shock. Side effects are reduced with the use of new low osmolality contrast media.

17. (E) Pericarditis in clinical practice is commonly idiopathic and frequently assumed to be of possibleviral origin. Coxsackieviruses are a common cause, but herpesviruses are not. Although TB, rheumatic fever, and MI can cause pericarditis, they are unlikely in this case.

18. (C) Aortic dissection is a medical emergency requiring prompt attention. Other cardiac and pulmonary causes of chest pain can be quickly ruled out with ECG and CXR. CT scan of the chest is sensitive (93–100%) in ruling out dissection. Transesophageal echocardiography is equally as sensitive but not a transthoracic echo.

19. (B) Angina or infarction in young patients should prompt the physician to consider congenitalcoronary artery anomaly or congenital coronary artery aneurysm. Acquired coronary artery aneurysm can be caused by atherosclerosis, trauma, angioplasty, atherectomy, vasculitis, mycotic emboli, Kawasaki syndrome, or arterial dissection.

20. (D) This pulse is seen in aortic regurgitation. The pressure in diastole is usually 50 mm Hg or lower. This is known as a water hammer or Corrigan’s pulse. A bisferiens pulse (in the bisferiens wave form there are two pressure peaks) may be present as well. Systolic blood pressure is elevated.

21. (B) Digoxin toxicity may cause any dysrhythmia. Classically, dysrhythmias that are associated with increased automaticity and decreased AV conduction occur (i.e., paroxysmal atrial tachycardia with 2:1 block, accelerated junctional rhythm, or bidirectional ventricular tachycardia [torsade de pointes]). Sinus bradycardia and other bradyarrhythmias are very common. Slow atrial fibrillation with very little variationin the ventricular rate (regularization of the RR interval) may occur. This arrhythmia is likely slow atrial fibrillation. Symptoms of digitalis toxicity include anorexia, nausea, fatigue, dizziness, and visual disturbances. The presence of hypokalemia increases the likelihood of digitalis toxicity.

22. (B) Retention of fluid is complex and not due to any one factor, however, hormones may contribute.Growth hormone does not have fluid retaining properties. The exact mechanisms that initiate renal conservation of salt and water are not precisely understood, but may include arterial volume receptors sensing a decrease in the effective arterial blood volume. Aldosterone, renin, and vasopressin are generally increased in heart failure.

23. (A)

24. (D) In aortic stenosis, there is normal overall cardiac size, but dilatation of the proximal ascending aorta and blunt rounding of the lower left cardiac contour. Calcification of the valve is often difficult to determine on plain films. Although left atrial enlargement can occur, its presence on the CXR should raise other diagnostic possibilities, such as mitral valve disease.

25. (A) High urinary specific gravity, nocturia, and daytime oliguria occur in addition to low urinary sodium content in untreated CHF. These changes are the result of the activation of the renin-angiotensin-aldosterone system.

26. (D) Orthostatic hypotension (systolic dropping by 20 mm or more) is particularly common in the elderly and in diabetics because of autonomic neuropathy. Management includes avoidance of precipitating factors, simple adaptive maneuvers, volume expansion, and pharmacologic agents.

27. (E)

28. (C) Management of acute viral or idiopathicpericarditis includes analgesia (usually aspirinevery 3–4 hours initially) and rest if the painis severe. Occasionally, nonsteroidalanti-inflammatory drugs (NSAIDs) are required(e.g., ibuprofen or indomethacin). Carefulobservation for increasing effusion and tamponadeare essential. The classic findings ofcardiac tamponade include arterial hypotensionand pulsusparadoxus.

29. (B) Diastolic dysfunction is an important causeof heart failure in the elderly. It is commonlyassociated with a history of hypertension anddiabetes. Normal ejection fraction

and aorticsclerosis rule out either systolic or valvularheart disease as causes. In HOCM there isnonconcentric hypertrophy.

30. (A) Acute rupture of an atherosclerotic plaque is now recognized as the most common causeof ST-elevation MI. Pericarditis has diffuse ST elevation in multiple leads and aortic stenosis does cause angina but not ST elevation.

31. (D) S. epidermidisis still the most frequent early and late cause of endocarditis in patients with prosthetic heart valves. The other organisms are seen less frequently in late prosthetic valve endocarditis.

32. (D) This man has acute coronary syndrome (ACS) until proven otherwise. The ECG is the most useful initial investigation since it identifies individuals with ST-segment elevation who may be candidates for either thrombolysis or primary angioplasty (PCI). The troponins are important in diagnosing myocardial necrosis. The other investigations may be important in looking for alternate causes of chest pain once ST-elevation MI has been ruled out.

33. (C) Essential hypertension is the most likely diagnosis. Asecondary cause for hypertension is found in only 10% of patients, with 90% labeled as essential. Current recommendations for initial workup of a hypertensive patient include serum chemistry (glucose, potassium, creatinine), urinalysis, and ECG.

34. (B) The PR interval of the first two complexes is normal at 0.20 seconds. The QRS duration is 0.16 seconds. The third P wave is nonconducted. This cycle recurs in the remainder of the strip. This is second-degree heart block of the Mobitz type II variety. Note the wide QRS. When this type of heart block develops, either de novo or in the course of an AMI, a cardiac pacemaker is usually recommended, as the incidence of complete heart block is high in this situation.

35. (D) The ST is depressed in leads II, III, aVF, and V4–V6. These nonspecific abnormalities do not indicate significant coronary heart disease, especially in an apprehensive young patient. Further evaluations should be guided by clinical circumstances.

37. (E) The underlying rhythm is a regular sinus rhythm with a rate of 85 beats/min. The sinus rhythm is interrupted frequently by bursts of irregular ventricular, premature beats. The sinus rhythm is uninterrupted as can be determined by plotting the PP intervals, which are regular. The rhythm may be termed a chaotic ventriculararrhythmia or ventricular tachycardia. Its gross irregularity is unusual. Antiarrhythmic therapy is usually not indicated for nonsustained VT in the setting of thrombolytic treatment.

38. (A) No atrial activity is detected. The ventricular rate is slightly irregular. Beat number 4 is a ventricular premature contraction. The T waves are tall and markedly peaked. This type of T wave is characteristic of hyperkalemia, as is absence of visible atrial activity. The potassium level was 8.2 mmol/L.

39. (A) Sudden death, defined as death within 1 hour of onset of symptoms, is usually caused by cardiac disease in middle-aged and elderly patients, but in younger age groups noncardiac causes predominate. There is a bimodal distribution in the population, with the first peak before 6 months of age (sudden infant death syndrome). The most common coronary artery finding is extensive chronic coronary atherosclerosis, although acute syndromes do occur.

40. (B) Over 90% of hypertensives in the general population have essential hypertension. Only about 60% of hypertensives are very sensitive to salt. About 20% of hypertensives have low-renin essential hypertension. This is more common in Blacks. Male sex, Black race, youth, smoking, DM, excess alcohol ingestion, hypercholesterolemia, more severe hypertension, and evidence of end-organ damage are among the factors that suggest a poor prognosis.