Cardiomyopathy | Pathophysiology and Implications (Nursing School Lessons)

Cardiomyopathy is a disease of the heart muscle, defined as an abnormality of heart muscle that leads to functional changes and impairment of cardiac output. Common causes include hypertension and heart failure, which make the heart work overtime, leading to ventricular muscle changes.

There are three main types: dilated, hypertrophic, and restrictive. Dilated cardiomyopathy involves enlarged and thinned ventricular walls, leading to decreased contractility. Hypertrophic cardiomyopathy features significantly thickened and stiff ventricular muscle, reducing the space for blood filling. Restrictive cardiomyopathy involves normal-sized but rigid walls that struggle to stretch and fill, leading to decreased stroke volume.

Cardiomyopathy symptoms mimic heart failure, including poor peripheral perfusion (decreased pulses, paleness), volume overload (JVD, pulmonary edema, shortness of breath, crackles in lungs), and an enlarged heart visible on imaging like echocardiograms or chest X-rays. A significantly enlarged heart can hinder breathing.

In most cases, there is no cure for cardiomyopathy, and management focuses on supportive care. This includes encouraging rest, clustering activities, minimizing stress, and treating hypertension with lifestyle changes (DASH diet, sodium restriction) and medications like ACE inhibitors or ARBs. Beta-blockers are particularly effective, decreasing the heart's workload and oxygen demand. In advanced stages, a ventricular assist device (LVAD) may be used as a bridge to heart transplant.