What is Cardiomyopathy? (Article -02)

Heart muscle problems – Cardiomyopathy

Many cardiac disorders (including coronary artery disease, valvular heart disease, viral infections, diabetes, kidney failure, and a variety of inflammatory diseases) can cause a weakness of the cardiac muscle, mostly affecting the ventricles. Weakening of the heart muscle is called cardiomyopathy. 

Cardiomyopathy takes two basic forms: dilated cardiomyopathy, and hypertrophic cardiomyopathy. 

Dilated cardiomyopathy occurs when the ventricle (generally the left ventricle) becomes dilated, and the ventricular muscle weak and relatively flaccid. As a result, the pumping action of the ventricle becomes weak; the amount of blood pumped with each heart beat drops; and the body’s organs do not receive their full quotient of blood.  Probably the best measure of the severity of a person’s dilated cardiomyopathy is the left ventricular ejection fraction (LVEF), a measure of the percentage of the left ventricle’s volume that is ejected with each heart beat. Normally, the LVEF is greater than 50%. Patients generally experience a reduction in exercise capacity as the LVEF approaches 40%, and often experience symptoms at rest (weakness, fatigue, shortness of breath) when the LVEF is in the 20 - 30% range. 

As dilated cardiomyopathy progresses, symptoms of shortness of breath, weakness, fatigue, and leg swelling worsen. The propensity to develop life-threatening arrhythmias (ventricular tachycardia and ventricular fibrillation) also increases as the LVEF drops. The mainstay of therapy is drug treatment: digitalis, diuretics, ACE inhibitors and beta blockers are commonly used. For many patients, a new breed of pacemakers that synchronize and optimize ventricular contraction can improve both symptoms and survival.Various types of cardiac assist devices (essentially, implantable pumps) are also progressing rapidly.

Hypertrophic cardiomyopathy (HCM) is a primary disease of the myocardium (the muscle of the heart) in which a portion of the myocardium is hypertrophied (thickened) without any obvious cause, creating functional impairment of the cardiac muscle. It is a leading cause of sudden cardiac death in young athletes.