Dilated Cardiomyopathy (DCM) - Treatment & Management

1. General / Supportive Measures

• Sodium and fluid restriction to manage volume overload
• Alcohol cessation - direct cardiotoxin; abstinence can lead to partial or full recovery in alcoholic DCM
• Avoidance of other cardiotoxins (cocaine, certain chemotherapy agents)
• Exercise: Submaximal aerobic exercise is desirable in stable patients to prevent deconditioning and maintain psychological health. However, rest and exercise avoidance are specifically recommended in:
  • Active myocarditis
  • Peripartum cardiomyopathy
  • Desmosomal or lamin A/C (LMNA) mutation carriers (high arrhythmia risk)

2. Pharmacological Treatment (Heart Failure Medications)

A. ACE Inhibitors / ARBs / ARNi

• ACEi: Ramipril or perindopril 5 mg/day - reduce afterload, improve remodeling
• ARB (if ACEi-intolerant): e.g., candesartan, valsartan
• ARNI (Sacubitril/Valsartan): Preferred over ACEi/ARB in stable symptomatic patients with HFrEF - superior outcomes for mortality and hospitalization

B. Beta-Blockers

• Bisoprolol 5-10 mg/day or Carvedilol 12.5-25 mg twice daily (or metoprolol succinate)
• Reduce mortality, improve EF, prevent sudden cardiac death
• Also used prophylactically in gene-positive asymptomatic family members

C. Mineralocorticoid Receptor Antagonists (MRA)

• Spironolactone or eplerenone for symptomatic heart failure (NYHA class II-IV)
• Reduce mortality and hospitalizations

D. SGLT2 Inhibitors

• Dapagliflozin or empagliflozin - now part of the "quadruple therapy" for HFrEF regardless of diabetes status; shown to reduce CV death and worsening HF

E. Diuretics

• Loop diuretics (furosemide, bumetanide) for volume overload and symptom relief
• Do not reduce mortality but essential for quality of life and congestion management

F. Ivabradine

• In patients with sinus rhythm, resting HR ≥70 bpm, and LVEF ≤35% despite maximally tolerated beta-blocker - reduces hospitalizations

3. Anticoagulation

• Indicated for patients with atrial fibrillation or echocardiographic evidence of left atrial/left ventricular mural thrombus
• Preferred agent: Direct oral anticoagulants (DOACs) (e.g., rivaroxaban, apixaban)
• Alternative: Warfarin (INR target 2.0-3.0)

4. Device Therapy

Implantable Cardioverter-Defibrillator (ICD)

• Primary prevention of sudden cardiac death from ventricular arrhythmia
• Preferred over antiarrhythmic drugs for prevention
• Indicated in LVEF ≤35% with NYHA Class II-III on optimal medical therapy for ≥3 months
• Especially important in LMNA, FLNC, and desmosomal gene mutations (very high arrhythmia burden)

Cardiac Resynchronization Therapy (CRT)

• For patients with LVEF ≤35% + wide QRS (≥150 ms, LBBB morphology) + symptomatic HF (NYHA II-IV)
• CRT-D (with defibrillator) preferred in most eligible patients
• Improves symptoms, functional class, and mortality

5. Advanced Heart Failure Therapies

6. Management of Specific DCM Subtypes

7. Arrhythmia Management

• Ventricular arrhythmias: ICD + beta-blockers; amiodarone as adjunct if ICD shocks are frequent
• Atrial fibrillation: rate control (beta-blocker, digoxin) or rhythm control + anticoagulation
• LMNA mutations: early ICD implantation even at higher EF thresholds due to life-threatening conduction disease and ventricular arrhythmias

8. Family Screening

• When a pathogenic variant is identified, cascade genetic testing of first-degree relatives is recommended
• Asymptomatic gene-positive relatives: 12-lead ECG + 2D echocardiogram at intervals
• Early initiation of ACEi/beta-blocker in gene-positive relatives being studied (Goldman-Cecil Medicine)

9. Monitoring & Follow-Up

• Serial echocardiography to track LVEF and chamber dimensions
• BNP/NT-proBNP levels predict survival and hospitalization risk
• Symptom-limited exercise testing with respiratory gas analysis (VO2 max) - useful for functional status and transplant listing criteria
• Ambulatory ECG monitoring for arrhythmia detection

Emergency Management (ED)

• Oxygen supplementation
• Avoid IV fluids (worsens pulmonary edema)
• IV diuretics (furosemide) for acute congestion
• Inotropes (dobutamine) in cardiogenic shock
• Mechanical ventilation if severe respiratory failure
• Cardiology consult mandatory; ICU admission for hemodynamically unstable patients

• Goldman-Cecil Medicine International Edition, Vol. 2 (Chapter 47, p. 514)
• Tintinalli's Emergency Medicine: A Comprehensive Study Guide (p. 875-876)
• Robbins & Kumar Basic Pathology (p. 371)