Cardiovascular Medicine Flashcards

A 58-year-old man with hypertrophic obstructive cardiomyopathy (HOCM) presents with worsening dyspnea and near-syncope. Echo shows a resting LVOT gradient of 65 mmHg. He is on maximal doses of metoprolol. Which of the following interventions is MOST appropriate as the next step?

Answer: Add disopyramide to his current regimen

Disopyramide is a class IA antiarrhythmic with potent negative inotropic properties that reduces dynamic LVOT obstruction in HOCM. It is guideline-recommended as an add-on to beta-blockers when symptoms persist. Digoxin increases contractility and worsens obstruction. Amlodipine causes vasodilation and reflex tachycardia, exacerbating the gradient. Dobutamine dramatically worsens LVOT obstruction and is contraindicated.

A 72-year-old woman with chronic heart failure with reduced ejection fraction (HFrEF, EF 30%) on optimal medical therapy develops symptomatic bradycardia (HR 42 bpm) requiring dose reduction of her carvedilol. Her NT-proBNP is markedly elevated. Which of the following best explains the mortality benefit of ivabradine in this clinical context?

Answer: It reduces heart rate via I(f) current inhibition without negative inotropy

Ivabradine selectively inhibits the funny current (I(f)) in the sinoatrial node, reducing heart rate without affecting myocardial contractility or vascular tone — a critical distinction in HFrEF where negative inotropy is harmful. This allows heart rate reduction when beta-blocker titration is limited by bradycardia or hypotension. It does not block beta receptors, does not cause venodilation, and does not prolong QT.

A 45-year-old man with no cardiac history is found to have a PR interval of 320 ms and Mobitz type I (Wenckebach) block on a routine ECG. He is asymptomatic. EP study reveals the block is infranodal (His-Purkinje). What is the most appropriate management?

Answer: Permanent pacemaker implantation

Although Wenckebach block is classically considered benign and nodal, infranodal Wenckebach (below the bundle of His) is pathological and carries a high risk of progression to complete heart block, warranting permanent pacemaker implantation per ACC/AHA guidelines. Infranodal conduction disease does not respond to atropine (which acts at the AV node). Observation alone is inappropriate given the risk of sudden complete block. Flecainide has no role here.

A 61-year-old woman with longstanding rheumatoid arthritis presents with progressive dyspnea. Echo shows a mean mitral valve gradient of 8 mmHg, valve area of 1.3 cm², and pulmonary artery systolic pressure (PASP) of 62 mmHg. She is NYHA Class III. Mitral valve morphology is heavily calcified and subvalvular apparatus is fused. What is the preferred intervention?

Answer: Mitral valve replacement (MVR)

PBMV is the preferred intervention for symptomatic mitral stenosis with favorable valve morphology (pliable, non-calcified, minimal subvalvular disease — Wilkins score ≤8). This patient has heavily calcified valves with fused subvalvular apparatus, making PBMV high-risk for MR and unlikely to succeed. MVR is the guideline-recommended intervention for symptomatic severe MS with unfavorable anatomy. TMVR for native mitral stenosis remains investigational. Diuretics alone are insufficient for NYHA Class III symptoms with hemodynamically significant MS.

A 38-year-old male marathon runner collapses during a race. He is resuscitated from ventricular fibrillation. ECG after resuscitation shows epsilon waves and T-wave inversions in leads V1–V4. Cardiac MRI reveals fibrofatty infiltration of the right ventricular free wall. Genetic testing confirms a desmoplakin mutation. Which of the following is the most important determinant guiding ICD implantation in this condition?

Answer: History of sustained ventricular arrhythmia or aborted sudden cardiac death

In arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), ICD implantation is a Class I indication for survivors of sustained VT/VF or aborted sudden cardiac death — this patient clearly qualifies. While RVEF <45%, desmosomal mutations, and EP inducibility are risk factors used in risk stratification for primary prevention, a prior cardiac arrest is the strongest and most definitive indication for ICD regardless of other variables. Mutation alone without documented arrhythmia is insufficient for Class I ICD indication.

A 55-year-old man with type 2 diabetes and chronic kidney disease (eGFR 28 mL/min) has a recent STEMI with residual EF of 35%. He is initiated on guideline-directed medical therapy. Which agent from the following list provides BOTH cardiovascular mortality reduction AND slowing of CKD progression in this patient population, independent of glycemic control?

Answer: Empagliflozin (SGLT2 inhibitor)

SGLT2 inhibitors (e.g., empagliflozin, dapagliflozin) have demonstrated cardiovascular mortality reduction in patients with HFrEF (EMPEROR-Reduced, DAPA-HF) and nephroprotective effects (EMPA-KIDNEY, CREDENCE) independent of glucose lowering. They are now guideline-recommended in HFrEF with or without diabetes. Sitagliptin showed neutral CV effects (TECOS) with no renal benefit. GLP-1 agonists reduce MACE but lack robust HF and CKD benefit in this specific population. Pioglitazone causes fluid retention and worsens HF — it is contraindicated in this setting.