Dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a condition in which the heart becomes enlarged and cannot pump blood effectively. Symptoms vary from none to feeling tired, leg swelling, and shortness of breath. It may also result in chest pain or fainting. Complications can include heart failure, heart valve disease, or an irregular heartbeat.

Causes include genetics, alcohol, cocaine, certain toxins, complications of pregnancy, and certain infections. Coronary artery disease and high blood pressure may play a role, but are not the primary cause. In many cases the cause remains unclear. It is a type of cardiomyopathy, a group of diseases that primarily affects the heart muscle. The diagnosis may be supported by an electrocardiogram, chest X-ray, or echocardiogram.

In those with heart failure, treatment may include medications in the ACE inhibitor, beta blocker, and diuretic families. A low salt diet may also be helpful. In those with certain types of irregular heartbeat, blood thinners or an implantable cardioverter defibrillator may be recommended. Cardiac resynchronization therapy (CRT) may be necessary. If other measures are not effective a heart transplant may be an option in some.

During the last two decades, there has been an increase in the number of patients diagnosed, and DCM represents the most common form of cardiomyopathy in adults. The most recent figures indicate that about 3 per 1,000 men and 1 per 1,000 women are affected. It is associated with a substantial excess mortality compared with the general population, ranging from about a 32-fold higher mortality in the youngest adults with DCM to about a 2-fold increase in the oldest patients. It can also occur in children and is the most common type of cardiomyopathy in this age group.