What is cardiomyopathy?
The word cardiomyopathy means heart muscle disease. In medicine, it is the collection of diseases of heart muscle (myocardium) in which the abnormal myocardium is associated with mechanical and/or electrical dysfunction, usually with ventricular hypertrophy It is currently classified according to dysfunction:
- Dilated cardiomyopathy: Dilation and contraction impairment in one or both ventricles.
- Hypertrophic cardiomyopathy: Enlarged right ventricle (occasionally the left), usually from a genetic cause.
- Restrictive cardiomyopathy: Non-dilated ventricles that still have abnormal ventricular filling.
- Arrhythmogenic right ventricular cardiomyopathy/dysplasia: A genetic disease of the right ventricle that causes arrhythmias.
- Cirrhotic cardiomyopathy: Associated with alcoholism.
- Cardiomyopathy-unclassified: Include left ventricular noncompaction (congenital tissue structure abnormality); and stress-induced cardiomyopathy (e.g., “broken heart syndrome”).
There are cardiomyopathies due to specific cardiac disorders, such as hypertension or aortic stenosis. There are also normal variations, such as “athlete’s heart,” which is structural change from intense training.
Cardiac Dysfunction from Cardiomyopathy
Systolic dysfunction: When systole, the contractile portion of the heart rhythm which propels blood from the heart, is weakened in cardiopathy, there is a reduction in cardiac output (specifically, the left ventricular ejection fraction, one of the measurable parameters in determining the severity of the dysfunction). This reduction in systolic function evokes compensation with left ventricular enlargement in attempt to create a larger pump; and a more sensitive response to stretch, which is part of the normal reflex dynamics of the heart.
Diastolic dysfunction: In cardiomyopathy that affects diastole, the relaxation (refilling) portion of the heart rhythm, there is abnormal filling and an elevated filling pressure. Diastolic dysfunction occurs with or without systolic dysfunction.
Signs and Symptoms:
- Clinical presentations of cardiomyopathy include
- dyspnea on exertion
- nocturnal dyspnea and orthopnea (dyspnea when lying flat)
- elevated jugular venous pressure
- abnormal lung sounds (rales)
- edema in the legs
Complications of Cardiomyopathy
The heart is a singular organ and the quintessential vital organ: dysfunction of it has morbidity and mortality implications. Heart failure can cause prolonged, debilitating illness when symptomatic and can result in death after crossing a crucial threshold of dysfunction. Heart failure, when asymptomatic, can result in sudden cardiac death.