Dilated, or congestive, cardiomyopathy is more common and occurs due to enlarging and stretching of the heart cavity, weakening the heart so it doesn’t pump normally.
The heart muscle becomes weak and too flexible, preventing it pumping blood efficiently around the body. Because the heart is stretched or dilated, the valves may not close very well and may become leaky. Breathlessness results as fluid builds up in the lungs, congesting them. This is called left heart failure. There may also be right heart failure, where fluid accumulates in the tissues and organs of the body, usually the legs and ankles, and the liver and abdomen. Disruption of the heart’s electrical rhythm also often occurs.
The cause of the condition is unknown in many cases, but it can be caused by infection with a virus, auto-immune diseases such as rheumatoid arthritis, excessive consumption of alcohol or, rarely, as a result of pregnancy – peri-partum cardiomyopathy.
Shortness of breath, palpitations, tiredness, swollen ankles and angina are common symptoms. Blood clots often form because the blood is flowing more slowly through the heart. These clots may break free and move to the lungs causing pulmonary emboli or to the brain causing a stroke.
Treatment may include anti-clotting drugs to prevent emboli, and medication to prevent arrhythmias and help the heart to work more efficiently. Any underlying cause should be identified and treated too. In severe cases a heart transplant may be necessary.