MOC Questions

Cardiology Review® Online, December 2006, Volume 23, Issue 12

The following questions can assist candidates for the Maintenance of Certification Exam in Cardiovascular Disease in preparing for this test. We hope you find this helpful and welcome your feedback.

Preparing for the American Board of Internal Medicine Maintenance of Certification

Questions

1. A 55-year-old man with a medical history significant for ischemic cardiomyopathy presents complaining of worsening dyspnea secondary to congestive heart failure. Despite optimal medical management he remains in New York Heart Association (NYHA) Class III heart failure. Two years ago an implantable cardioverter-defibrillator (ICD) was placed. As part of his workup, he is evaluated for possible device upgrade to a biventricular pacemaker. All of the following are true concerning cardiac resynchronization therapy (CRT), except:

a) Ventricular dysynchrony has been associated with an increased mortality in heart failure.

b) 15% of patients who receive CRT will show no improvement.

c) Optimal candidates for CRT have a dilated cardiomyopathy (ischemic or nonischemic), a left ventricular (LV) ejection fraction ≤0.35, a QRS complex Ž120 ms, are in sinus rhythm, and are NYHA functional class III or IV despite maximal medical therapy for heart failure.

d) CRT is achieved by placing a pacemaker lead in the coronary sinus in order to pace the LV free wall.

e) Most patients who qualify for CRT also qualify for an ICD.

2. A 20-year-old college student with no medical history is referred to your cardiology office after his primary care physician noticed a systolic murmur during a pre-athletics physical exam. He reports occasional chest discomfort with strenuous exercise and 1 previous episode of exercise-induced syncope. Physical exam reveals a harsh, nonradiating midsystolic murmur which increases in intensity with Valsalva and decreases with handgrip. The carotid upstroke is brisk. Electrocardiogram (EKG) reveals LV hypertrophy and inferolateral Q waves. Upon further investigation, the patient reveals that a cousin had died suddenly while playing sports at age 25. Which of the following is true concerning this patient’s most likely condition:

a) Surgery improves symptoms and reduces the risk of sudden cardiac death.

b) Nitrates and diuretics improve symptoms and are first-line therapy in treatment.

c) Beta-blockers should be avoided in patients with obstruction.

d) Sudden cardiac death is most frequent in older patients without the familial form of the disease.

e) Intracoronary septal injection of alcohol has been proposed as a treatment option.

3. A 42-year-old woman with a history of active breast cancer presents with acutely worsening dyspnea. Physical exam reveals tachycardia, hypotension, elevated jugular venous pressure, and distant heart sounds. An EKG shows electrical alternans. Pulsus paradoxus is performed and is 20 mm Hg. A chest x-ray reveals a large cardiac silhouette. A two-dimensional echocardiogram confirms a large pericardial effusion with tamponade physiology. All the following are true concerning cardiac tamponade, except:

a) Pulsus paradoxus can be seen in other conditions, such as chronic obstructive pulmonary disease (COPD).

b) Cardiac catheterization will show diastolic equilibration of pressures within the heart.

c) The most specific echocardiographic finding of tamponade is LV collapse.

d) Mechanical ventilation with positive airway pressure should be avoided in patients with tamponade, because this further reduces cardiac output.

e) Electrical alternans is an EKG beat-to-beat change in the QRS axis secondary to swinging of the heart within the fluid-filled pericardium.

4. A 46-year-old man with medical history significant for diabetes and hypertension is brought to the emergency room complaining of acute substernal chest pressure, nausea, and diaphoresis. An initial EKG shows 2 mm of ST elevation inferiorly. The patient is given 3 sublingual nitroglycerin tablets for persistent chest pain. His blood pressure subsequently drops from 140/82 to 96/64 mm Hg. A right-sided EKG is performed and confirms RV infarction. All of the following are true concerning RV infarction, except:

a) Nitrates and other preload-reducing medications should be avoided.

b) A proximal right coronary artery (RCA) occlusion is almost always the cause.

c) In patients with shock, mortality is low when compared with patients in shock from LV myocardial infarctions (MIs).

d) Clear lung fields, hypotension, and elevated jugular venous pressure is often seen in RV infarctions.

e) Aggressive intravenous fluids are critical to preventing shock.

5. Concerning the acute care of acute MI patients all the following are true, except:

a) In patients with a non-ST-elevation MI (NSTEMI), in whom an early intervention is planned, clopidogrel in addition to aspirin should be given upon admission.

b) Glycoprotein IIb/IIIa inhibitors may be started at time of percutaneous intervention in patients with NSTEMI.

c) Angiotensin-converting enzyme inhibitors should be initiated in all patients with LV dysfunction as soon as possible if not contraindicated.

d) Tight glucose control using intravenous (IV) insulin has been shown to increase mortality in patients who are not in diabetic ketoacidosis during the preinfarction period.

e) Atropine is the medication of choice for high-grade atrioventricular block during an acute MI.

6. A 62-year-old woman with history of chronic renal insufficiency, diabetes, and hypertension is to undergo elective coronary angiography for evaluation of exertional chest pain. Her current medications include metformin, hydrochlorothiazide, and lisinopril. All of the following would reduce her risk of developing contrast-induced nephropathy, except:

a) Discontinuation of her metformin 3 days prior to the procedure and until her renal function returns to normal.

b) Use of acetylcysteine prior to the procedure.

c) Sodium bicarbonate IV fluids started 3 hours prior to the procedure.

d) Avoidance of diuretics periprocedure.

e) Use of a high-osmolar contrast agent.

Staphylococcus aureus

7. A 38-year-old man with history of IV drug use is admitted to the hospital for fevers of 102º and pleuritic chest pain. Physical exam reveals a holosystolic murmur at the left sternal border, but is otherwise unremarkable. Multiple sets of blood cultures are positive for . A chest x-ray shows multilobar infiltrates. Transthoracic echocardiogram is performed showing moderate-severe tricuspid regurgitation, but no vegetation. Concerning a diagnosis of infective endocarditis (IE) in this patient, all of the following are true, except:

a) Based on the modified Duke criteria, this patient has 1 major and 2 minor criteria giving the patient a possible diagnosis of IE.

b) Transesophageal echocardiogram would be useful to better evaluate the tricuspid regurgitation and look for a vegetation.

c) The tricuspid valve is the most common site of IE in IV drug users.

d) The pulmonic valve is a rare site of endocarditis.

e) The chest x-ray abnormality is most likely secondary to septic pulmonary emboli.

8. You are called by the intensive care unit nurse to evaluate a patient who is complaining of increasing shortness of breath. The patient was admitted 4 days ago for an acute anterior wall MI and underwent percutaneous intervention of her right coronary artery. Upon your arrival the patient is in severe respiratory distress. Her heart reveals a very loud early systolic murmur heard in the apex as well as at the base, and a sternal heave is felt. She has bilateral pleural rales. She has elevated jugular venous pressure. The most likely diagnosis is:

a) Acute stent rethrombosis.

b) Ventricular septal rupture.

c) Pericardial tamponade.

d) Posteromedial papillary muscle rupture.

e) Pulmonary embolism with acute tricuspid regurgitation.

9. Which of the following about exercise treadmill stress testing (ETT) is correct:

a) Exercise treadmill stress testing is most useful in patients with a low pretest probability of coronary heart disease.

b) Exercise treadmill stress testing is useful in determining need for surgery in patients with severe symptomatic aortic stenosis.

c) Exertional hypotension is a normal response to exercise secondary to vasodilation.

d) Exercise treadmill stress testing should not be performed in patients with a recent

myocardial infarction.

e) Overall sensitivity and specificity of ETT is 68% and 77%, respectively, in intermediate pretest probability patients.

10. Which of the following about sudden cardiac death and ICDs is true:

a) In patients with a history of MI and ejection fraction ≤30%, but no history of ventricular arrhythmias, prophylactic implantation of an ICD is indicated.

b) The majority of patients who have out-of-hospital cardiac arrest survive to make it to the hospital.

c) Electrolyte abnormalities are the most frequent cause of sudden cardiac death.

d) The long QT syndrome is a contraindication to implantation of an ICD.

Answers

1: b

Cardiac resynchronization therapy aims to reverse the deleterious effects of dysynchronous ventricular contraction that frequently occurs in advanced heart failure. Up to one third of advanced heart failure patients have a left bundle branch block (LBBB). Heart failure patients with a LBBB have a worse prognosis than patients without LBBB. In patients with LBBB, depolarization in the left ventricle is abnormal, proceeding from the anterior septum through the LV myocardium to the inferior and lateral LV walls. As a result, LV contraction is dysynchronous, with the interventricular septum contracting before the LV free wall. In CRT, a pacemaker lead-in passed through the coronary sinus with the goal of pacing the LV free wall. Unfortunately, up to 30% of patients do not improve with CRT. Current investigations indicate that QRS duration may not be the optimal indicator of dysynchrony, and instead echocardiographic evidence of dysynchrony may provide a superior indicator of those who will benefit from CRT.

Circulation

Gregoratos G, Abrams J, Epstein AE, et al. ACC/AHA/NASPE 2002 guideline update for implantation of cardiac pacemakers and antiarrhythmia devices: summary article: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines (ACC/AHA/NASPE Committee to Update the 1998 Pacemaker Guidelines). . 2002;106:2145-2161.

2: e This patient has a classic presentation for hypertrophic cardiomyopathy (HCM). This heterogeneous disease affects all age groups, but is a significant cause of sudden cardiac death in young people. Sudden cardiac death is most commonly seen in younger patients with the familial form of the disease. Patients with HCM usually have asymmetric LV hypertrophy of the basal interventricular septum. This septal hypertrophy can lead to subaortic obstruction. Surgical resection of the basal septum improves symptoms but does not alter the risk of sudden cardiac death. Beta blockers and verapamil are first-line agents for symptom treatment. Nitrates and diuretics should be avoided given the risk of reducing preload in the setting of a significant obstruction. Intracoronary injection of ethanol has been proposed as a method of creating a controlled infarction of the septum thereby relieving the obstruction. In patients at increased risk for sudden cardiac death, ICD placement should be encouraged.

N Engl J Med

Spirito P, Seidman CE, McKenna WJ, Maron BJ. Medical progress: the management of hypertrophic cardiomyopathy. . 1997;336:775-785.

3: c This patient has cardiac tamponade most likely secondary to metastatic breast cancer to the pericardium. Pulsus paradoxus is defined as an inspiratory systolic fall of blood pressure greater than 10 mm Hg. Other causes include massive pulmonary embolism, hemorrhagic shock, and COPD. Echocardiogram is necessary to confirm and/or diagnose tamponade. Right ventricular collapse is not sensitive but if seen, is specific for tamponade. Right atrial collapse is more sensitive but less specific. Other echocardiogram findings include mitral inflow patterns, which frequently show significant respiratory variation correlating with pulsus paradoxus. Emergent pericardiocentesis is indicated in all patients with signs and symptoms of cardiac tamponade in order to prevent intravascular collapse.

N Engl J Med

Spodick DH. Current concepts: acute cardiac tamponade. . 2003;349:684-690.

4: c Right ventricular (RV) infarctions are commonly seen in the setting of an inferior wall acute MI. Almost all RV MIs are caused by the occlusion of a proximal RCA prior to the marginal branches. The SHOCK registry taught us that despite the younger age and lower incidence of comorbidities in RV infarction patients, the mortality rate in patients with cardiogenic shock was similar to patients with LV infarction. Preload-reducing medications such as nitrates should be avoided in these patients, and often a drop in blood pressure after nitro administration is the first indication that a RV MI is present.

J Am Coll Cardiol

Jacobs AK, Leopold JA, Bates E, et al. Cardiogenic shock caused by right ventricular infarction: A report from the SHOCK registry. . 2003;41:1273-1279.

5: d The Diabetic Insulin-Glucose Infusion in Acute MI (DIGAMI) trial showed a 29% lower 1-year mortality rate in patients with diabetes who had tight glycemic control using IV insulin. The largest benefit was seen in patients who had no prior insulin therapy. The mortality benefit persisted after long-term follow-up (mean follow-up 3.4 years).

J Am Coll Cardiol

Malmberg K, Ryden L, Efendic S, et al. Randomized trial of insulin-glucose infusion followed by subcutaneous insulin treatment in diabetic patients with acute myocardial infarction (DIGAMI study): effects on mortality at 1 year. . 1995;26:57-65.

6: e Contrast-induced nephropathy is a transient rise in the serum creatinine occurring frequently after contrast administration. It is the third most common cause of in-hospital acute renal failure. Risk factors for developing contrast-induced nephropathy include underlying renal disease, diabetes, concominant use of metformin, dehydration, use of diuretics, and use of high-osmolar contrast agents. Studies have shown mild prevention with infusion of acetylcysteine secondary to reduction of free radicals, as well as alkalinization of the urine using bicarbonate infusions.

N Engl J Med

Barrett BJ, Parfrey PS. Preventing nephropathy induced by contrast medium. . 2006;354:379-386.

7: a Infective endocarditis (IE) is a common and well-described disease with a high morbidity and mortality. The diagnosis of IE is based on multiple factors and not 1 single test. In many cases the diagnosis is obvious, but in many others the diagnosis can be a challenge. The modified Duke criteria have simplified the diagnosis process. A definite diagnosis can be made with the presence of 2 major criteria, or 1 major and 3 minor criteria, or 5 minor criteria. There are 3 major criteria: pathologic specimen (eg, biopsied vegetation), positive blood cultures for IE with typical organisms or persistent bacteremia, and last, evidence of endocardial involvement either by echocardiogram or the presence of a new valvular regurgitation. Minor criteria include a predisposing cardiac condition or IV drug abuse, fevers, vascular phenomena (eg, septic emboli), immunologic phenomena (eg, glomerulonephritis), and microbiologic evidence not meeting the major criteria. Based on this, this patient has 2 major criteria, a new valvular regurgitation, as well as bacteremia with a usual pathogen, S aureus. This patient also has 3 minor criteria, IV drug use, fevers, and septic pulmonary emboli. Based on these criteria this patient would be classified as a definite case of IE. Transesophageal echocardiogram would be helpful to further evaluate the tricuspid valve to confirm the presence of a vegetation, but is not needed to make the diagnosis.

N Engl J Med

Mylonakis E, Calderwood SB. Infective endocarditis in adults. . 2001;345:1318-1330.

8: d

Papillary muscle rupture is a life-threatening complication of acute MIs that accounts for 5% of deaths in MI patients. Rupture usually occurs 2 to 7 days after infarction. Rupture of the posteromedial papillary muscle is more common than rupture of the anterolateral papillary muscle because the latter has a dual blood supply from both the left anterior descending artery and the circumflex, while the former is fed solely by the posterior descending artery. The diagnosis is made by the presence of acute decompensating mitral regurgitation with subsequent right heart overload and confirmed with emergent echocardiogram. Treatment consists of acute afterload reduction with nitroprusside and/or intra-aortic balloon pump counterpulsation as well as emergent surgical repair.

Heart

Greaves SC. Role of echocardiography in acute coronary syndromes. . 2002;88:419-425.

9: e Exercise treadmill stress testing, also known as exercise EKG testing, is frequently used to aid in diagnosing coronary artery disease (CAD) in patients who have intermediate pretest probability of CAD. In a large meta-analysis of patients who underwent both angiography and ETT the overall sensitivity and specificity of ETT was 68% and 77%, respectively, in intermediate pretest probability patients. Exercise treadmill stress testing is most useful in diagnosing patients who fall into the intermediate pretest probability category. Severe symptomatic aortic stenosis is an absolute contraindication to ETT. Exertional hypotension is a concerning finding during ETT that indicates an increased risk of coronary events and often is an indicator of left main disease or multivessel CAD. Exercise treadmill stress testing can be performed in patients with a recent MI. Submaximal ETT can be performed to risk-stratify patients after a recent MI prior to discharge from the hospital, especially if they did not undergo percutaneous intervention.

Circulation

Gianrossi R, Detrano R, Mulvihill D, et al. Exercise-induced ST depression in the diagnosis of coronary artery disease. A meta-analysis. . 1989;80(1):87-98.

10: a Implantable cardioverter-defibrillators have been shown to reduce sudden death secondary to cardiac causes. The second Multicenter Automatic Defibrillator Implantation Trial (MADIT II), a primary prevention trial, enrolled 1232 patients with a history of CAD, a history of a MI, and an ejection fraction of ≤30% to either receive an ICD or conventional medical therapy. Mortality in the ICD group was 14.2% compared with 19.8% in the control group after an average of 20 months of follow-up. The majority of sudden cardiac deaths are a result of ischemic heart disease. Despite many advances in emergency care, the majority of patients die before arrival to the hospital. The long QT syndrome is a strong indication for the prophylactic implantation of an ICD.

N Engl J Med

Dimarco JP. Medical progress: implantable cardioverter-defibrillators. . 2003;349:1836-1847.