100+ Free Internal Medicine Board Practice Questions

Explanation: According to the ACC/AHA guidelines, for patients with ST-segment elevation myocardial infarction (STEMI) presenting to a non-PCI-capable hospital, primary PCI is preferred if it can be performed within 120 minutes of first medical contact. If the expected time to primary PCI exceeds 120 minutes, immediate fibrinolytic therapy (unless contraindicated) should be administered within 30 minutes of arrival, followed by routine transfer for angiography and rescue PCI if needed.

Explanation: Guideline-directed medical therapy (GDMT) for HFrEF (Stage C) consists of four pharmacological pillars: an ARNI (sacubitril-valsartan preferred over ACEi/ARB), an evidence-based beta-blocker (bisoprolol, carvedilol, or metoprolol succinate), a mineralocorticoid receptor antagonist (MRA, e.g., spironolactone), and an SGLT2 inhibitor (dapagliflozin or empagliflozin). Since she is on sub-maximal therapy and stable, transitioning to an ARNI and initiating an MRA and SGLT2i is indicated to reduce mortality and hospitalization.

Explanation: This patient has a CHA2DS2-VASc score of at least 3 (hypertension 1, diabetes 1, age 65-74 1). Note that chronic kidney disease is not itself a CHA2DS2-VASc component (it is added in the modified R2CHA2DS2-VASc score). In patients with nonvalvular atrial fibrillation and a CHA2DS2-VASc score >= 2 in men (or >= 3 in women), oral anticoagulation is indicated. DOACs (such as apixaban, rivaroxaban, dabigatran, or edoxaban) are preferred over warfarin due to a lower risk of intracranial hemorrhage and superior or non-inferior efficacy, and apixaban is well tolerated even in mild-to-moderate CKD (eGFR > 30).

Explanation: Fibromuscular dysplasia (FMD) typically affects young females and involves the mid-to-distal renal artery ('string of beads' appearance). For patients with hypertension resistant to medical therapy or with renal dysfunction, revascularization is indicated. The preferred procedure for FMD is percutaneous transluminal angioplasty (PTA) without stenting. Stenting is reserved for dissection or vessel rupture.

Explanation: The clinical presentation (pleuritic chest pain relieved by sitting forward, post-viral) and ECG findings (diffuse ST elevation, PR depression, aVR PR elevation) are diagnostic of acute pericarditis. First-line therapy consists of high-dose NSAIDs (e.g., ibuprofen 600-800 mg TID or aspirin 750-1000 mg Q8H for post-MI patients) tapered over 1-2 weeks, combined with colchicine (0.5-0.6 mg daily or BID for 3 months) to reduce recurrence rates.

Explanation: This patient has symptomatic, severe aortic stenosis (valve area < 1.0 cm², mean gradient >= 40 mmHg, classic symptoms of dyspnea and lightheadedness). Symptomatic severe AS has a poor prognosis without intervention (2-year survival < 50%). Intervention (either Surgical Aortic Valve Replacement [SAVR] or Transcatheter Aortic Valve Replacement [TAVR]) is a Class I indication. TAVR is preferred in older patients or those at high surgical risk.

Explanation: Exertional syncope, a family history of sudden cardiac death in a young relative, and a systolic murmur that increases with Valsalva (decreases venous return/preload, reducing LV size and increasing outflow obstruction) and decreases with passive leg raise (increases preload, widening the outflow tract) point to Hypertrophic Obstructive Cardiomyopathy (HOCM). AS and MR murmurs behave opposite to HOCM during these maneuvers (they soften with Valsalva).

Explanation: According to the AHA and ESC guidelines, infective endocarditis prophylaxis is only recommended for patients at the highest risk of adverse outcomes from IE undergoing dental procedures that involve manipulation of gingival tissue or perforation of the oral mucosa. High-risk conditions include: prosthetic cardiac valves, prosthetic material used for valve repair, prior history of IE, unrepaired cyanotic congenital heart disease, and cardiac transplant recipients who develop valvulopathy. Mitral valve prolapse (even with regurgitation) does not fall into these categories, so prophylaxis is not recommended.

Explanation: This patient presents with classic nephrotic syndrome (anasarca, proteinuria > 3.5 g/day, hypoalbuminemia, hyperlipidemia). The presence of serum antibodies against the M-type phospholipase A2 receptor (PLA2R) is highly specific (approximately 70-80% sensitive and > 95% specific) for primary (idiopathic) membranous nephropathy, which is the most common cause of nephrotic syndrome in non-diabetic white adults.

Explanation: The renal biopsy shows Class IV lupus nephritis (diffuse proliferative lupus nephritis), which carries a high risk of progression to end-stage renal disease (ESRD) if untreated. The standard induction therapy for proliferative lupus nephritis (Class III or IV) consists of immunosuppression with either mycophenolate mofetil (MMF) or intravenous cyclophosphamide (low-dose Euro-Lupus regimen or high-dose NIH regimen), combined with intravenous methylprednisolone pulses followed by high-dose oral prednisone.