What is dilated cardiomyopathy?

Updated: Mar 02, 2021
  • Author: Vinh Q Nguyen, MD, FACC; Chief Editor: Gyanendra K Sharma, MD, FACC, FASE  more...
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Dilated cardiomyopathy is a progressive disease of heart muscle that is characterized by ventricular chamber enlargement and contractile dysfunction. The right ventricle may also be dilated and dysfunctional. Dilated cardiomyopathy is the third most common cause of heart failure and the most frequent reason for heart transplantation.

Dilated cardiomyopathy is 1 of the 3 traditional classes of cardiomyopathy, along with hypertrophic and restrictive cardiomyopathy. However, the classification of cardiomyopathies continues to evolve, based on the rapid evolution of molecular genetics as well as the introduction of recently described diseases.

Multiple causes of dilated cardiomyopathy exist, one or more of which may be responsible for an individual case of the disease (see Etiology). All alter the normal muscular function of the myocardium, which prompts varying degrees of physiologic compensation for that malfunction.

The degree and time course of malfunction are variable and do not always coincide with a linear expression of symptoms. Persons with cardiomyopathy may have asymptomatic left ventricular (LV) systolic dysfunction, LV diastolic dysfunction, or both. When compensatory mechanisms can no longer maintain cardiac output at normal LV filling pressures, the disease process is expressed with symptoms that collectively compose the disease state known as chronic heart failure (CHF).

Continuing ventricular enlargement and dysfunction generally leads to progressive heart failure with further decline in LV contractile function. Sequelae include ventricular and supraventricular arrhythmias, conduction system abnormalities, thromboembolism, and sudden death or heart failure–related death.

Cardiomyopathy is a complex disease process that can affect the heart of a person of any age, but it is especially important as a cause of morbidity and mortality among the world's aging population. It is the most common diagnosis in persons receiving supplemental medical financial assistance via the US Medicare program.

Nonpharmacologic interventions are the basis of heart failure therapy. Instruction on a sodium diet restricted to 2 g/day is very important and can often eliminate the need for diuretics or permit the use of reduced dosages. Fluid restriction is complementary to a low-sodium diet. Patients may be enrolled in cardiac rehabilitation involving aerobic exercise.

For patient education information, see the Heart Center, as well as Congestive Heart Failure.

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