Cardiomyopathy: Part One

Introduction

• Cardiomyopathy is the deterioration of the heart muscle (myocardium) often leading to heart failure.
• Common symptoms include shortness of breath and peripheral edema.

Types of Cardiomyopathy

1. Dilated Cardiomyopathy
   • Most common form.
   • The heart becomes weakened and enlarged, unable to pump blood efficiently.
   • Pathological change: Enlargement of all four cardiac chambers.
   • Causes: Often related to damage from toxic, metabolic, or infectious agents.
2. Hypertrophic Cardiomyopathy
   • Myocardium is hypertrophied without any obvious cause.
   • Leading cause of sudden cardiac death in all age groups.
   • Often involves asymmetric septal hypertrophy.
3. Restrictive Cardiomyopathy
   • Least common form.
   • The ventricular walls are rigid, hindering proper filling with blood.

Pathophysiology and Diagnosis

• Dilated Cardiomyopathy
  • Involves cardiomyocyte death and myocardial fibrosis.
  • Leads to impaired mechanical function, increased wall stress, and mechanical disadvantage.
  • Can cause atrioventricular valve regurgitation.
  • Diagnostic Tool: Echocardiography and BNP blood test.
• Hypertrophic Cardiomyopathy
  • Features asymmetric septal hypertrophy which may obstruct the left ventricular outflow.
  • Leads to diastolic dysfunction, exercise intolerance, and potentially sudden death.
  • Diagnostic Tool: Echocardiography and ECG.

Clinical Presentation

• Dilated Cardiomyopathy
  • Similar to biventricular heart failure.
  • Symptoms: Overfilling, leading to congestion in pulmonary and systemic circulations.
• Hypertrophic Cardiomyopathy
  • Symptoms: Dyspnea, angina, palpitations, lightheadedness, fatigue, syncope, and sudden cardiac death.
  • Can mimic congestive heart failure.

Treatment

• Dilated Cardiomyopathy
  • Treatment aims to decrease myocardial oxygen demand and relieve peripheral edema.
  • Medications include diuretics like spironolactone.
  • Important to control arrhythmias and prevent thrombosis.
  • Cardioverter defibrillator implantation may be recommended.
• Hypertrophic Cardiomyopathy
  • Medications: Beta-blockers, calcium channel blockers, and anti-arrhythmic drugs.
  • Surgical options: Myomectomy and septal ablation.
  • Antibiotic prophylaxis to prevent infective endocarditis.

Conclusion

• Cardiomyopathy involves complex pathophysiological changes and requires targeted diagnostic and treatment approaches.
• Both types discussed have unique challenges and risks, including heart failure and sudden cardiac death.