What is the appropriate management for a 38-year-old male presenting with chest discomfort, cough, and shortness of breath, with EKG findings suggestive of hypertrophic cardiomyopathy (HCM) and a computed tomography (CT) scan showing bilateral pleural effusions?

Management of Suspected Hypertrophic Cardiomyopathy with Bilateral Pleural Effusions

This patient requires immediate echocardiographic confirmation of HCM, evaluation of left ventricular outflow tract obstruction, assessment of the pleural effusions' etiology, and initiation of beta-blocker therapy if symptomatic obstruction is confirmed. 1

Immediate Diagnostic Workup

Confirm HCM Diagnosis

• Transthoracic echocardiography (TTE) is the gold standard and must be performed immediately to confirm left ventricular hypertrophy, assess for asymmetric septal hypertrophy, evaluate left ventricular outflow tract obstruction (LVOTO), and assess diastolic function 1
• The EKG findings of downsloping pattern in V5, V6, II, III, and aVF are consistent with HCM, as 75-95% of phenotypic HCM patients have abnormal ECGs showing LVH and repolarization changes 1
• If TTE is inconclusive, cardiac MRI (CMR) is indicated to definitively establish the diagnosis and assess the magnitude and distribution of hypertrophy 1

Evaluate for Dynamic Obstruction

• Exercise echocardiography is reasonable if resting gradient is <50 mm Hg to detect and quantify exercise-induced dynamic LVOTO, which could explain his dyspnea with work 1
• The sharp reproducible chest pain along the left axillary line suggests a musculoskeletal component, but angina from microvascular ischemia is common in HCM 1

Address the Pleural Effusions

• The bilateral pleural effusions are likely secondary to heart failure from either LVOTO or diastolic dysfunction, both common in HCM 2, 3
• Thoracentesis should be considered if effusions are moderate-to-large to rule out alternative etiologies (infection, malignancy) and provide symptomatic relief
• The positive D-dimer with negative CT for PE appropriately excludes pulmonary embolism but does not explain the effusions

Initial Medical Management

Symptomatic Treatment

• Beta-blockers are first-line therapy for symptomatic HCM patients with dyspnea or chest pain 1
• Start with a non-vasodilating beta-blocker and titrate to resting heart rate <60-65 bpm (up to maximum recommended doses) 1
• Use with caution given potential conduction disease suggested by EKG findings 1

Alternative if Beta-Blockers Fail or Are Contraindicated

• Verapamil (starting low dose, titrating up to 480 mg/day) is recommended for patients who don't respond to or cannot tolerate beta-blockers 1, 4
• However, verapamil should be used with extreme caution if high resting gradients (>100 mm Hg) or severe dyspnea at rest are present, as it can be potentially harmful 1
• Diltiazem is a reasonable alternative calcium channel blocker 1

Medications to AVOID

• Discontinue any vasodilators (ACE inhibitors, ARBs, dihydropyridine calcium channel blockers) or digoxin, as these worsen LVOTO 1
• Avoid high-dose diuretics, though cautious use of low-dose diuretics may help with volume overload symptoms from the pleural effusions 1

Risk Stratification for Sudden Cardiac Death

Mandatory Arrhythmia Screening

• 24-hour Holter monitoring is required in the initial evaluation to detect ventricular tachycardia and identify ICD candidacy 1
• This is critical given his age (38 years), as HCM is an important cause of sudden cardiac death in young adults 3
• Repeat Holter monitoring every 1-2 years is reasonable for ongoing surveillance 1

Additional Risk Assessment

• Assess for major SCD risk factors: family history of sudden death, syncope, massive LVH (≥30 mm), and nonsustained VT 1, 3
• The patient denies family history of premature CAD, but specifically inquire about sudden cardiac death in relatives

Coronary Artery Disease Evaluation

• Coronary angiography (invasive or CT) is indicated given his chest discomfort, even with low-to-intermediate CAD likelihood, to assess for concomitant coronary disease 1
• This is particularly important if surgical myectomy becomes necessary, as coronary anatomy must be defined preoperatively 1

Follow-Up Imaging and Monitoring

• Repeat TTE in 3-6 months after initiating medical therapy to assess response and gradient reduction 1
• If symptoms persist despite optimal medical therapy with beta-blockers or calcium channel blockers, consider escalation to disopyramide, mavacamten (cardiac myosin inhibitor), or septal reduction therapy at a comprehensive HCM center 1
• CMR with late gadolinium enhancement may be considered if SCD risk stratification remains inconclusive after conventional risk factor assessment 1

Critical Pitfalls to Avoid

• Do not dismiss symptoms as anxiety or musculoskeletal pain without confirming HCM diagnosis and excluding high-risk features 2, 5
• Do not start diuretics aggressively without first establishing whether obstruction is present, as volume depletion worsens LVOTO 1
• Do not delay ICD placement if high-risk features are identified, as this is the only proven therapy to prevent sudden cardiac death 3
• The patient's residence in a group home suggests possible developmental or psychiatric comorbidities—ensure medication adherence strategies are in place 1