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ABIM Cardiology practice questions

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Question 1Coronary Artery Disease

A 58-year-old man with stable angina uses sublingual nitroglycerin as needed. He asks whether he can start sildenafil. Which of his current or proposed medications is absolutely contraindicated with nitrates?

  1. Sildenafil Correct answer.
  2. Metoprolol
  3. Atorvastatin
  4. Lisinopril

Explanation

Phosphodiesterase-5 inhibitors block cGMP breakdown while nitrates increase cGMP production, so the combination can cause profound and refractory hypotension. Nitrates should be withheld for at least 24 hours after sildenafil or vardenafil and 48 hours after tadalafil.

Question 2Coronary Artery Disease

A 62-year-old man presents 90 minutes after the onset of STEMI to a hospital with an on-site catheterization laboratory and an experienced interventional team. Which reperfusion strategy is most appropriate?

  1. Primary PCI Correct answer.
  2. Medical therapy alone
  3. Fibrinolysis
  4. Urgent CABG

Explanation

Primary PCI is the preferred reperfusion strategy for STEMI when it can be delivered promptly by an experienced team, and it is superior to fibrinolysis when performed within the recommended time window. Fibrinolysis is reserved for situations in which timely PCI is unavailable and there is no contraindication.

Question 3Coronary Artery Disease

Which mechanism best describes the antiplatelet effect of aspirin in coronary artery disease?

  1. Glycoprotein IIb/IIIa receptor inhibition
  2. Direct thrombin inhibition
  3. Irreversible COX-1 acetylation Correct answer.
  4. Reversible P2Y12 receptor blockade

Explanation

Aspirin irreversibly acetylates platelet cyclooxygenase-1, blocking thromboxane A2 synthesis for the lifespan of the platelet. This distinguishes it from reversible P2Y12 inhibitors and from agents that target other steps in platelet activation or coagulation.

Question 4Coronary Artery Disease

A 55-year-old man is discharged after NSTEMI. His LDL cholesterol is 130 mg/dL on atorvastatin 20 mg daily, and he is adherent. What is the most appropriate lipid-lowering adjustment?

  1. Add ezetimibe and stop the statin
  2. Switch to a fibrate
  3. Continue the current regimen
  4. Intensify to atorvastatin 80 mg Correct answer.

Explanation

After acute coronary syndrome, high-intensity statin therapy is recommended for all patients regardless of baseline LDL, targeting at least a 50% reduction and an LDL below 70 mg/dL. Atorvastatin 40-80 mg or rosuvastatin 20-40 mg are standard high-intensity choices.

Question 5Coronary Artery Disease

Which description is most consistent with typical angina pectoris?

  1. Sharp pain that lasts hours and worsens with inspiration
  2. Brief, pinpoint stabbing pain
  3. Tearing pain that radiates to the back
  4. Exertional substernal pressure eased by rest Correct answer.

Explanation

Typical angina is substernal discomfort precipitated by exertion or emotional stress and relieved within minutes by rest or nitroglycerin. Pleuritic, tearing, or sharply localized brief pain is atypical and suggests other diagnoses.

Question 6Coronary Artery Disease

A 60-year-old man with stable angina and prior myocardial infarction has no contraindications to any antianginal drug. Which agent is the most appropriate first-line therapy?

  1. Ranolazine
  2. Beta blocker Correct answer.
  3. Nicorandil
  4. Ivabradine

Explanation

Beta blockers reduce myocardial oxygen demand and are first-line antianginal therapy, with additional mortality benefit after myocardial infarction and in left ventricular dysfunction. Other agents are added when beta blockers are insufficient or contraindicated.

Question 7Coronary Artery Disease

A 60-year-old man presents 3 hours after the onset of chest pain. His initial high-sensitivity troponin is normal. What is the most appropriate next step?

  1. Repeat troponin at 24 hours
  2. No further sampling is needed
  3. Repeat hs-troponin at 3 hours Correct answer.
  4. Repeat troponin at 72 hours

Explanation

High-sensitivity troponin may be normal very early after symptom onset, so serial sampling at 0 and 1-3 hours is used to detect the required rise or fall. A single early normal value does not exclude myocardial infarction.

Question 8Coronary Artery Disease

A 64-year-old woman has angina at rest, a normal ECG, and two high-sensitivity troponin values that remain below the upper reference limit. What is the most likely diagnosis?

  1. STEMI
  2. NSTEMI
  3. Stable angina
  4. Unstable angina Correct answer.

Explanation

Unstable angina is defined by ischemic symptoms at rest, new-onset severe angina, or rapidly accelerating angina without a rise in cardiac biomarkers. A positive troponin would reclassify the event as NSTEMI, and persistent ST elevation would indicate STEMI.

Question 9Coronary Artery Disease

A 58-year-old man with stable CAD undergoes elective PCI with a drug-eluting stent. He has no separate indication for anticoagulation and is at low bleeding risk. Which antithrombotic regimen is most appropriate?

  1. Aspirin alone indefinitely
  2. Dual antiplatelet therapy for 1 month, then aspirin
  3. Triple therapy with aspirin, clopidogrel, and warfarin for 12 months
  4. Dual antiplatelet therapy for 6 months, then a single agent Correct answer.

Explanation

For stable CAD treated with a drug-eluting stent, 6 months of dual antiplatelet therapy is standard, with duration shortened for high bleeding risk or extended for high ischemic risk. Triple therapy is reserved for patients who have a separate indication for anticoagulation.

Question 10Coronary Artery Disease

A 66-year-old man with an inferior STEMI becomes hypotensive. He has elevated jugular venous pressure and clear lung fields. Which initial intervention is most appropriate?

  1. Nitroglycerin infusion
  2. Furosemide infusion
  3. Fluid bolus Correct answer.
  4. Metoprolol infusion

Explanation

Inferior STEMI with hypotension, elevated jugular venous pressure, and clear lungs suggests right ventricular infarction, which is preload dependent. Volume loading is the first step, whereas nitrates and diuretics can precipitate profound hypotension.

Question 11Coronary Artery Disease

A 55-year-old man's chest pain has resolved. His ECG shows deep, symmetric T-wave inversions in leads V2 and V3 without Q waves, and troponin is mildly elevated. What is the most appropriate next step?

  1. Pericardiocentesis
  2. Exercise treadmill stress testing
  3. Discharge with NSAIDs
  4. Urgent coronary angiography Correct answer.

Explanation

This Wellens pattern in a pain-free patient signals critical proximal LAD stenosis and impending anterior infarction. Urgent angiography is indicated, and stress testing can provoke occlusion and should be avoided.

Question 12Coronary Artery Disease

A patient has ST elevation in leads II, III, and aVF. Which artery is most commonly the culprit?

  1. Right coronary artery Correct answer.
  2. Left circumflex artery
  3. Left anterior descending artery
  4. Left main coronary artery

Explanation

Leads II, III, and aVF view the inferior wall, which is most often supplied by the right coronary artery. Circumflex occlusion can also cause inferior ST elevation but is a less common culprit.

Question 13Coronary Artery Disease

A 50-year-old woman has recurrent rest angina at night with transient ST elevation. Coronary angiography shows no obstructive disease, and symptoms resolve with nitroglycerin. Which long-term therapy is most appropriate?

  1. Calcium channel blocker plus nitrate Correct answer.
  2. As-needed nitroglycerin without daily therapy
  3. Beta blocker monotherapy
  4. High-dose aspirin

Explanation

Vasospastic angina is treated with calcium channel blockers and long-acting nitrates, and smoking cessation is essential. Beta blockers may worsen coronary spasm and are generally avoided as monotherapy.

Question 14Coronary Artery Disease

A 60-year-old man had an anterior MI 6 weeks ago. He now has fever, pleuritic chest pain, and a pericardial effusion. Which timing best fits this syndrome?

  1. 1 to 3 days after infarction
  2. 6 to 12 months after infarction
  3. 2 to 10 weeks after infarction Correct answer.
  4. 5 to 10 days after infarction

Explanation

Dressler syndrome is a post-MI autoimmune pericarditis that typically appears 2-10 weeks after infarction with fever, pleuritic pain, and effusion. Early post-MI pericarditis occurs within the first few days and has a different mechanism.

Question 15Coronary Artery Disease

Which mechanism of action describes ranolazine?

  1. Blocks the If current in the SA node
  2. Antagonizes beta-1 receptors
  3. Blocks L-type calcium channels
  4. Inhibits the late sodium current Correct answer.

Explanation

Ranolazine inhibits the late inward sodium current, reducing intracellular calcium overload and angina without lowering heart rate or blood pressure. It is used as add-on therapy for chronic angina.

Question 16Coronary Artery Disease

A 63-year-old woman has a 70% mid-LAD stenosis. Fractional flow reserve across the lesion is 0.75 after intracoronary adenosine. What is the most appropriate management?

  1. Perform PCI of the LAD lesion Correct answer.
  2. Repeat FFR after intracoronary nitroglycerin
  3. Proceed with CABG
  4. Defer intervention and continue medical therapy

Explanation

An FFR of 0.80 or less identifies a hemodynamically significant stenosis that benefits from revascularization. Values above 0.80 are generally managed medically.

Question 17Coronary Artery Disease

A 68-year-old man with diabetes has 70% distal left main stenosis and multivessel disease with a SYNTAX score of 30. Which revascularization strategy is most appropriate?

  1. Medical therapy alone
  2. Catheter-directed thrombolysis
  3. PCI with a drug-eluting stent
  4. Coronary artery bypass grafting Correct answer.

Explanation

CABG improves survival compared with PCI in left main disease, particularly with multivessel disease, diabetes, or a high SYNTAX score. PCI remains an alternative in selected patients with low anatomic complexity.

Question 18Coronary Artery Disease

A 42-year-old woman without atherosclerotic risk factors presents with spontaneous coronary artery dissection of the LAD. She is hemodynamically stable with no ongoing ischemia. What is the most appropriate management?

  1. Intravenous fibrinolysis
  2. PCI with drug-eluting stenting
  3. Urgent coronary artery bypass surgery
  4. Medical management alone Correct answer.

Explanation

Spontaneous coronary artery dissection in a stable patient without ongoing ischemia is generally managed conservatively because PCI can extend the dissection and carries high complication rates. Revascularization is reserved for ongoing ischemia, hemodynamic instability, or left main involvement.

Question 19Coronary Artery Disease

A 50-year-old woman is diagnosed with MINOCA after NSTEMI and angiography shows no obstructive coronary disease. What is the most appropriate next step?

  1. Intravenous fibrinolytic therapy
  2. Reassurance and anxiolytic therapy
  3. Cardiac MRI and vasospasm workup Correct answer.
  4. Referral for cardiac transplantation

Explanation

MINOCA requires evaluation for plaque disruption, coronary spasm, embolism, and noncoronary causes such as myocarditis, and cardiac MRI helps clarify the diagnosis. Routine fibrinolysis and transplantation referral are inappropriate in this setting.

Question 20Coronary Artery Disease

A 34-year-old man develops chest pain after cocaine use, with sinus tachycardia and blood pressure 175/100 mm Hg. Aspirin and nitroglycerin have been given. Which additional therapy is most appropriate?

  1. Routine fibrinolytic therapy for all patients
  2. Intravenous metoprolol as sole therapy
  3. Oral propranolol followed by fibrinolysis
  4. Benzodiazepines and a calcium blocker Correct answer.

Explanation

In cocaine-associated MI, benzodiazepines reduce sympathetic drive and calcium channel blockers relieve coronary vasospasm, while aspirin and nitrates are also used. Nonselective beta blockers are avoided because unopposed alpha stimulation can worsen vasospasm and hypertension.

Question 21Heart Failure and Cardiomyopathy

According to the universal definition of heart failure, which left ventricular ejection fraction (LVEF) defines heart failure with reduced ejection fraction (HFrEF)?

  1. An LVEF of 41% to 49%
  2. An LVEF of 50% or greater
  3. An LVEF of 40% or less Correct answer.
  4. Any LVEF in a patient with elevated filling pressures

Explanation

The universal definition separates heart failure by LVEF: HFrEF is an LVEF of 40% or less, heart failure with mildly reduced ejection fraction is 41% to 49%, and HFpEF is 50% or greater, each accompanied by symptoms or signs and supportive structural or functional abnormalities. The 40% threshold is the one used in the trials that established guideline-directed medical therapy for HFrEF.

Question 22Heart Failure and Cardiomyopathy

A 62-year-old man with chronic HFrEF (LVEF 30%) takes sacubitril/valsartan, carvedilol, and eplerenone. He is euvolemic, has no diabetes, and remains NYHA class II. Which addition would complete four-pillar guideline-directed medical therapy with proven mortality benefit?

  1. Ivabradine
  2. Digoxin
  3. Dapagliflozin Correct answer.
  4. Furosemide

Explanation

The four guideline-directed pillars for HFrEF are a renin-angiotensin system inhibitor (preferably sacubitril/valsartan), an evidence-based beta-blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor. SGLT2 inhibitors reduce cardiovascular death and heart failure hospitalization in HFrEF irrespective of diabetes status, so they are indicated in this patient without diabetes.

Question 23Heart Failure and Cardiomyopathy

A patient with HFrEF is to be switched from lisinopril to sacubitril/valsartan. How long must the ACE inhibitor be withheld before the first dose of sacubitril/valsartan?

  1. 12 hours
  2. 36 hours Correct answer.
  3. 24 hours
  4. No washout period is required

Explanation

Neprilysin inhibition and ACE inhibition both increase bradykinin availability, and giving them together markedly raises the risk of angioedema. A 36-hour washout after the last ACE inhibitor dose is therefore required before starting sacubitril/valsartan. ARBs do not carry this interaction and need no washout.

Question 24Heart Failure and Cardiomyopathy

Which condition most lowers measured natriuretic peptide concentrations relative to the true severity of heart failure?

  1. Advanced age
  2. Obesity Correct answer.
  3. Chronic kidney disease
  4. Atrial fibrillation

Explanation

Adipose tissue decreases natriuretic peptide synthesis and release and increases clearance, so obese patients can have BNP or NT-proBNP values that are lower than expected for their degree of filling pressure elevation. This reduces the sensitivity of standard diagnostic thresholds in obesity. Age, kidney disease, and atrial fibrillation all tend to raise natriuretic peptide levels.

Question 25Heart Failure and Cardiomyopathy

In patients with HFrEF who are in sinus rhythm, digoxin therapy has which of the following effects?

  1. It reduces heart failure hospitalizations without a clear mortality benefit Correct answer.
  2. It reverses left ventricular remodeling and prolongs survival
  3. It is preferred over beta-blockers for rate control in sinus rhythm
  4. It lowers all-cause mortality compared with placebo

Explanation

The DIG trial showed that digoxin reduced hospitalizations for worsening heart failure but did not reduce all-cause mortality. It is therefore used as adjunctive therapy for symptom control or rate control rather than as a mortality-reducing drug. Beta-blockers remain the preferred agents for rate control in HFrEF when tolerated.

Question 26Heart Failure and Cardiomyopathy

Furosemide produces its diuretic effect by blocking which transporter?

  1. The sodium-potassium ATPase in the proximal tubule
  2. The epithelial sodium channel in the collecting duct
  3. The sodium-chloride cotransporter in the distal convoluted tubule
  4. The sodium-potassium-2-chloride cotransporter in the thick ascending limb Correct answer.

Explanation

Loop diuretics inhibit the sodium-potassium-2-chloride cotransporter in the thick ascending limb of the loop of Henle, where roughly a quarter of filtered sodium is normally reabsorbed. Blocking this site also abolishes the medullary concentration gradient, which is why loop diuretics are the most potent diuretic class. Thiazides act at the sodium-chloride cotransporter of the distal convoluted tubule.

Question 27Heart Failure and Cardiomyopathy

A 74-year-old woman with HFpEF (LVEF 58%), obesity, and type 2 diabetes remains NYHA class II on furosemide and is euvolemic. Which addition has been shown to reduce heart failure hospitalization in this population?

  1. Sacubitril/valsartan
  2. Spironolactone
  3. Empagliflozin Correct answer.
  4. Digoxin

Explanation

SGLT2 inhibitors such as empagliflozin and dapagliflozin reduced the composite of cardiovascular death or heart failure hospitalization in trials of patients with HFmrEF and HFpEF, with benefit observed regardless of diabetes status. They are now recommended for these patients. Sacubitril/valsartan and spironolactone did not meet their primary endpoints in this population.

Question 28Heart Failure and Cardiomyopathy

A 62-year-old man with HFrEF (LVEF 30%) is in sinus rhythm at 82 beats/min and remains symptomatic despite metoprolol succinate 200 mg daily, sacubitril/valsartan, eplerenone, and dapagliflozin. He is euvolemic. Which agent is most appropriate to add?

  1. Ivabradine Correct answer.
  2. Amiodarone
  3. Diltiazem
  4. Digoxin

Explanation

Ivabradine inhibits the If current in the sinoatrial node and is indicated for symptomatic HFrEF with LVEF 35% or less in sinus rhythm with a resting heart rate of 70 beats/min or higher despite maximally tolerated beta-blockade. This patient meets each of those criteria. It is ineffective in atrial fibrillation and does not lower blood pressure.

Question 29Heart Failure and Cardiomyopathy

A 58-year-old self-identified Black man with HFrEF (LVEF 25%), NYHA class III, remains symptomatic and euvolemic on sacubitril/valsartan, carvedilol, spironolactone, and dapagliflozin. Which addition has been shown to reduce mortality in this population?

  1. Hydralazine plus isosorbide dinitrate Correct answer.
  2. Digoxin
  3. Amlodipine
  4. Ivabradine

Explanation

The combination of hydralazine and isosorbide dinitrate improved survival in self-identified Black patients with NYHA class III or IV HFrEF already treated with standard therapy, and it is recommended as add-on therapy in this group. The benefit reflects combined preload reduction and nitric oxide–mediated effects rather than blood pressure lowering alone.

Question 30Heart Failure and Cardiomyopathy

A 66-year-old man with HFrEF (LVEF 25%) on sacubitril/valsartan, carvedilol, and spironolactone 25 mg daily has a potassium of 5.6 mEq/L and stable renal function. He is euvolemic. What is the most appropriate next step?

  1. Stop spironolactone permanently and refer for renal artery evaluation
  2. Continue the current regimen unchanged and recheck potassium in three months
  3. Hold the MRA and add a potassium binder Correct answer.
  4. Discontinue sacubitril/valsartan and switch to hydralazine with isosorbide dinitrate

Explanation

Potassium above 5.5 mEq/L warrants holding the mineralocorticoid receptor antagonist while contributors such as dietary potassium, potassium supplements, NSAIDs, and worsening renal function are addressed. Adding a potassium binder allows the MRA to be restarted, which matters because these drugs carry a mortality benefit and should not be abandoned permanently. Potassium should be rechecked within about a week of any adjustment.

Question 31Heart Failure and Cardiomyopathy

A 68-year-old woman with nonischemic HFrEF (LVEF 30%) in sinus rhythm has a QRS duration of 160 ms with left bundle branch block. She remains NYHA class III after three months of optimized medical therapy. Which intervention is most likely to reduce her mortality?

  1. Referral for evaluation for an implantable left ventricular assist device
  2. Cardiac resynchronization therapy with a defibrillator Correct answer.
  3. Escalation of diuretic therapy with close outpatient follow-up
  4. An implantable cardioverter-defibrillator implanted without a resynchronization lead

Explanation

Cardiac resynchronization therapy is indicated for symptomatic HFrEF with LVEF 35% or less, sinus rhythm, and a QRS duration of 150 ms or more with left bundle branch block despite optimized medical therapy, and it improves survival in this group. When the LVEF is 35% or less, a combined defibrillator device is generally implanted. A defibrillator alone does not correct dyssynchrony or improve pump function.

Question 32Heart Failure and Cardiomyopathy

A 78-year-old man with HFpEF (LVEF 55%) and marked left ventricular thickening has grade 3 myocardial uptake on technetium-99m pyrophosphate scintigraphy. Serum and urine immunofixation and the serum free light chain ratio are all normal. Which diagnosis is most likely?

  1. Fabry disease with left ventricular hypertrophy
  2. Sarcomeric hypertrophic cardiomyopathy
  3. Light-chain (AL) cardiac amyloidosis
  4. Transthyretin cardiac amyloidosis Correct answer.

Explanation

Grade 2 or 3 myocardial uptake on bone-seeking scintigraphy combined with the absence of a monoclonal protein by serum and urine immunofixation and a normal free light chain ratio is diagnostic of transthyretin cardiac amyloidosis without the need for biopsy. A monoclonal protein would instead mandate tissue confirmation to exclude AL amyloidosis, because that diagnosis requires urgent different treatment.

Question 33Heart Failure and Cardiomyopathy

Peripartum cardiomyopathy is defined by left ventricular systolic dysfunction presenting within which time frame?

  1. Last month of pregnancy to five months postpartum Correct answer.
  2. First trimester of pregnancy through the time of delivery
  3. Delivery through the first two weeks after birth
  4. Conception through twelve months after delivery in any patient

Explanation

Peripartum cardiomyopathy is heart failure due to left ventricular systolic dysfunction (LVEF under 45%) that develops in the last month of pregnancy or within five months after delivery, with no other identifiable cause of heart failure. Most cases are diagnosed in the first month postpartum. The left ventricle is not necessarily dilated at presentation.

Question 34Heart Failure and Cardiomyopathy

A 64-year-old woman with HFrEF (LVEF 30%), NYHA class III, has a hemoglobin of 12.8 g/dL, ferritin of 80 ng/mL, and transferrin saturation of 18%. What is the most appropriate treatment for her iron deficiency?

  1. Oral ferrous sulfate 325 mg three times daily
  2. Transfusion of packed red blood cells
  3. Intravenous ferric carboxymaltose Correct answer.
  4. Subcutaneous erythropoietin

Explanation

Absolute iron deficiency in heart failure is defined as ferritin below 100 ng/mL, or ferritin 100 to 299 ng/mL with transferrin saturation below 20%, and intravenous iron improves symptoms and reduces heart failure hospitalizations in symptomatic HFrEF. Oral iron is poorly absorbed in this setting, partly because of gut congestion and elevated hepcidin. Erythropoiesis-stimulating agents and transfusion are not indicated for this degree of anemia.

Question 35Heart Failure and Cardiomyopathy

A 70-year-old man admitted with decompensated HFrEF receives intravenous furosemide 40 mg as a bolus followed by an infusion of 5 mg/h. Over the next six hours his urine output is 180 mL and he remains congested. What is the most appropriate next step?

  1. Proceed directly to urgent ultrafiltration
  2. Switch to oral furosemide 80 mg twice daily
  3. Increase the infusion rate and add oral metolazone Correct answer.
  4. Add intravenous albumin and continue the current infusion rate

Explanation

An inadequate response to a loop diuretic usually reflects distal sodium reabsorption escaping loop blockade and warrants a higher loop dose plus sequential nephron blockade with a thiazide such as metolazone. This combination must be monitored closely for hypokalemia, hyponatremia, and worsening renal function. Ultrafiltration is reserved for patients who fail these pharmacologic measures.

Question 36Heart Failure and Cardiomyopathy

A 66-year-old man is admitted with decompensated HFrEF (LVEF 20%) and atrial fibrillation with a ventricular rate of 140 beats/min. Blood pressure is 105/68 mmHg and he has rales and elevated jugular venous pressure. Which agent is the most appropriate for rate control?

  1. Intravenous diltiazem
  2. Intravenous digoxin Correct answer.
  3. Intravenous verapamil
  4. Oral dronedarone for rate control

Explanation

Non-dihydropyridine calcium channel blockers are negative inotropes and potent vasodilators, so they can precipitate cardiogenic shock in decompensated HFrEF and should be avoided. Digoxin, or amiodarone when a beta-blocker cannot be used, is a reasonable choice for rate control in this setting while the precipitant is treated. The underlying cause of decompensation must also be addressed.

Question 37Heart Failure and Cardiomyopathy

A 45-year-old man with hypertrophic cardiomyopathy has a maximal left ventricular wall thickness of 32 mm. He has no symptoms, no family history of sudden cardiac death, and no ventricular tachycardia on a 14-day monitor. What is the most appropriate management?

  1. Implantable cardioverter-defibrillator Correct answer.
  2. Alcohol septal ablation
  3. Observation with annual Holter monitoring
  4. Septal myectomy

Explanation

A maximal left ventricular wall thickness of 30 mm or more is itself a major risk factor for sudden cardiac death in hypertrophic cardiomyopathy and is sufficient to justify implantation of a cardioverter-defibrillator. Septal reduction therapies are indicated for drug-refractory obstruction with symptoms, neither of which is present here. The decision should still incorporate the patient's values and the estimated risk.

Question 38Heart Failure and Cardiomyopathy

A 42-year-old woman presents with complete atrioventricular block and an LVEF of 40%. Cardiac PET shows patchy fluorodeoxyglucose uptake with a matching perfusion defect, and mediastinal lymph node biopsy demonstrates noncaseating granulomas. What is the most appropriate management?

  1. Observation with repeat PET imaging in six months
  2. Immunosuppression alone with repeat PET in three months
  3. Immunosuppression plus implantation of an ICD Correct answer.
  4. Referral for cardiac transplantation

Explanation

Cardiac sarcoidosis with conduction disease and left ventricular dysfunction warrants anti-inflammatory therapy plus assessment for an implantable cardioverter-defibrillator, because granulomatous myocardial infiltration creates a substantial risk of ventricular arrhythmia and sudden death. Immunosuppression alone does not reliably eliminate that arrhythmic risk, and the scarring often persists after inflammation resolves.

Question 39Heart Failure and Cardiomyopathy

A 60-year-old man with a history of mediastinal radiation has HFpEF with preserved natriuretic peptide elevation. Which echocardiographic finding most favors constrictive pericarditis over restrictive cardiomyopathy?

  1. Respirophasic septal shift with preserved or elevated annular velocities Correct answer.
  2. Biatrial enlargement with normal ventricular wall thickness
  3. Markedly reduced lateral mitral annular velocity
  4. Left ventricular wall thickness of 18 mm with apical sparing on strain imaging

Explanation

In constrictive pericarditis, the tethered annulus moves normally, yielding preserved or even elevated mitral annular velocities with the medial velocity equal to or greater than the lateral velocity, alongside respirophasic septal shift and preserved longitudinal strain. In restrictive cardiomyopathy the myocardium itself is diseased, so annular velocities are typically markedly reduced. These features help avoid misclassifying the two conditions, which have very different treatments.

Question 40Heart Failure and Cardiomyopathy

A 58-year-old man with an anterior myocardial infarction has a blood pressure of 78/50 mmHg, cardiac index of 1.6 L/min/m2, wedge pressure of 24 mmHg, and lactate of 4.2 mmol/L despite norepinephrine. Which intravenous agent is most appropriate to add?

  1. Esmolol to reduce myocardial oxygen demand
  2. Furosemide alone at a higher dose
  3. Dobutamine Correct answer.
  4. Milrinone, because beta-receptors are already blocked

Explanation

In cardiogenic shock with low cardiac output despite vasopressor support, an inotrope is added, and dobutamine is the usual first-line choice because it increases contractility and cardiac output while its vasodilatory effect is modest. Milrinone is a reasonable alternative in patients on chronic beta-blockade, but it is a vasodilator with a long half-life and can worsen hypotension. Diuretics alone do not restore perfusion in shock.

Question 41Arrhythmias and Conduction Disorders

A 28-year-old with palpitations has a regular narrow-complex tachycardia at 180 bpm, and P waves are not visible. Which mechanism is most likely?

  1. Sinus tachycardia
  2. Ventricular tachycardia
  3. Atrial fibrillation
  4. AVNRT Correct answer.

Explanation

A regular narrow-complex tachycardia with no visible P waves is most commonly AVNRT, a reentrant circuit within the AV node. Ventricular tachycardia is typically wide, atrial fibrillation is irregular, and sinus tachycardia usually shows P waves and a gradual onset.

Question 42Arrhythmias and Conduction Disorders

Which ECG pattern defines third-degree AV block?

  1. Progressive PR prolongation with dropped QRS complexes
  2. Intermittent dropped beats with constant PR
  3. Irregularly irregular rhythm without P waves
  4. Independent atrial and ventricular rhythms Correct answer.

Explanation

Third-degree AV block is defined by complete dissociation of atrial and ventricular activity, so P waves and QRS complexes have no fixed relationship. The atrial rate exceeds the ventricular escape rate, and the PR interval varies randomly.

Question 43Arrhythmias and Conduction Disorders

Which finding is characteristic of typical atrial flutter on ECG?

  1. Narrow QRS with a delta wave
  2. Sawtooth flutter waves in inferior leads Correct answer.
  3. Grouped beating with progressive PR lengthening
  4. Irregularly irregular rhythm with fibrillatory baseline

Explanation

Typical atrial flutter produces sawtooth flutter waves, best seen in the inferior leads, with an atrial rate near 300 bpm. The ventricular response is often regular at 150 bpm with 2:1 AV block.

Question 44Arrhythmias and Conduction Disorders

A hemodynamically stable patient has a regular narrow-complex tachycardia. What is the appropriate first intervention?

  1. Immediate synchronized cardioversion
  2. Vagal maneuvers Correct answer.
  3. IV amiodarone bolus
  4. Oral metoprolol

Explanation

In a hemodynamically stable patient with a regular narrow-complex tachycardia, vagal maneuvers are the first step because they increase AV nodal refractoriness and can terminate AVNRT or AVRT. Adenosine is used if vagal maneuvers fail; cardioversion is reserved for instability.

Question 45Arrhythmias and Conduction Disorders

Which ECG abnormality is most characteristic of moderate-to-severe hyperkalemia?

  1. Delta waves
  2. Peaked T waves Correct answer.
  3. Prolonged QT interval
  4. Sawtooth flutter waves

Explanation

Hyperkalemia classically produces peaked, narrow-based T waves, and more severe elevations can widen the QRS and produce a sine-wave pattern. These changes reflect altered myocardial repolarization and conduction.

Question 46Arrhythmias and Conduction Disorders

Which ECG measurement is prolonged in congenital long QT syndrome?

  1. QT interval Correct answer.
  2. P wave duration
  3. QRS duration
  4. PR interval

Explanation

Congenital long QT syndrome is characterized by prolongation of the QT interval, which reflects delayed ventricular repolarization and predisposes to torsades de pointes. The corrected QT is used because the raw QT varies with heart rate.

Question 47Arrhythmias and Conduction Disorders

A 72-year-old man with hypertension and diabetes has new nonvalvular atrial fibrillation. His CHA2DS2-VASc score is 3. What is the recommended antithrombotic therapy?

  1. No antithrombotic therapy
  2. Aspirin alone
  3. Dual antiplatelet therapy
  4. Oral anticoagulation Correct answer.

Explanation

A CHA2DS2-VASc score of 3 in a man is a strong indication for oral anticoagulation to reduce stroke risk in nonvalvular atrial fibrillation. Aspirin or dual antiplatelet therapy is not equivalent to anticoagulation for stroke prevention.

Question 48Arrhythmias and Conduction Disorders

A patient with known Wolff-Parkinson-White syndrome presents with rapid irregular wide-complex tachycardia consistent with pre-excited atrial fibrillation. Which therapy is most likely to accelerate conduction over the accessory pathway?

  1. Procainamide infusion
  2. Synchronized cardioversion
  3. IV verapamil Correct answer.
  4. Ibutilide infusion

Explanation

In pre-excited atrial fibrillation, AV nodal blocking drugs such as verapamil can increase antegrade conduction over the accessory pathway and precipitate ventricular fibrillation. Procainamide or ibutilide can slow accessory pathway conduction, and synchronized cardioversion is used if the patient is unstable.

Question 49Arrhythmias and Conduction Disorders

A 70-year-old with syncope has an ECG showing intermittent dropped QRS complexes without progressive PR prolongation. What is the most appropriate definitive management?

  1. Long-term oral amiodarone
  2. Catheter ablation of the AV node
  3. Permanent pacemaker implantation Correct answer.
  4. Reassurance and outpatient follow-up

Explanation

Mobitz II second-degree AV block is characterized by intermittent dropped QRS complexes without progressive PR prolongation and carries a high risk of progression to complete heart block. Permanent pacemaker implantation is therefore the definitive management, even if the patient is temporarily asymptomatic.

Question 50Arrhythmias and Conduction Disorders

A patient with QT prolongation develops polymorphic ventricular tachycardia with a twisting axis. What is the first-line pharmacologic treatment?

  1. IV adenosine
  2. IV verapamil
  3. Oral flecainide
  4. IV magnesium sulfate Correct answer.

Explanation

Torsades de pointes is a polymorphic ventricular tachycardia associated with QT prolongation, and IV magnesium sulfate is the first-line pharmacologic treatment. Correction of electrolytes and removal of QT-prolonging drugs are also essential.