Complications Associated with Cardiomyopathy

A number of complications can develop as a result of having cardiomyopathy. The most common are arrhythmia and congestive heart failure. Other complications include blood clots, heart block and pulmonary hypertension. Medications and implantable devices can help in treating some of these problems.


The abnormality of the heart muscle in cardiomyopathy can sometimes interfere with the normal electrical activity of the heart. In the affected parts of the heart muscle, the electrical impulse can be disrupted. This can lead to arrhythmias in which the heart beats too slow (bradycardia), too fast (tachycardia) or erratically. If left untreated, tachycardias can become fibrillations, which can be life threatening. With fibrillations, the heart beats so fast and chaotically that it loses the ability to pump blood through the body. This may cause the heart to stop beating and go into cardiac arrest. All forms of cardiomyopathy are susceptible to arrhythmia, but with certain forms of cardiomyopathy the risk of sudden cardiac death is higher. Early identification of high-risk patients allows for preventative treatment with anti-arrhythmic medications or an implantable defibrillator.

Blood Clots

With dilated, restrictive and left ventricular non-compaction cardiomyopathy, there is an increased risk of blood clots forming in the heart because of slower than normal blood flow through the heart. Blood clots can block blood flow to the brain or other organs leading to a stroke. Anticoagulant medications (blood thinners) may be prescribed to reduce this risk.

Congestive Heart Failure

Heart failure is a common feature of all late-stage cardiomyopathies. The muscles of the heart become too weak or too stiff to pump enough blood for the body to function. When this happens, fluid can build up in the lungs or in the rest of the body causing difficulties in breathing, swelling, poor appetite, exercise intolerance and gastro-intestinal distress. If left untreated, heart failure can progress and a heart transplant may be required.

Heart Block

This can occur when the heart’s normal electrical system does not function properly and the electrical impulse traveling within the heart slows down or is blocked. This affects the way that the heart contracts. Heart block can occur in a small number of people with dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and with some forms of infiltrative restrictive cardiomyopathy. In patients where the heartbeat becomes too slow, a pacemaker may be recommended.

Pulmonary Hypertension

Pulmonary hypertension is abnormally high blood pressure in the arteries of the lungs. When the heart is weakened it requires higher pressure to fill the left chamber (ventricle) of the heart. As a result, pressure in the lungs can rise. Pulmonary hypertension is more of a risk with restrictive cardiomyopathy, but some patients with other forms of advanced cardiomyopathy also can develop pulmonary hypertension.

Evaluation and Diagnosis


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