Complications

The risk of complications from an enlarged heart depends on the part of the heart that is enlarged and the cause.

Complications of an enlarged heart can include:

• Heart failure. An enlarged left ventricle, one of the most serious types of enlarged heart, increases the risk of heart failure. In heart failure, your heart muscle weakens, and the ventricles stretch (dilate) to the point that the heart can't pump blood efficiently throughout your body.
• Blood clots. Having an enlarged heart may make you more susceptible to forming blood clots in the lining of your heart. If clots enter your bloodstream, they can block blood flow to vital organs, even causing a heart attack or stroke. Clots that develop on the right side of your heart may travel to your lungs, a dangerous condition called a pulmonary embolism.
• Heart murmur. For people whose hearts are enlarged, two of the heart's four valves — the mitral and tricuspid valves — may not close properly because they become dilated, leading to a backflow of blood. This flow creates sounds called heart murmurs. Although not necessarily harmful, heart murmurs should be monitored by your doctor.
• Cardiac arrest and sudden death. Sometimes an enlarged heart can lead to disruptions in your heart's beating rhythm. Heart rhythms that are too slow to move blood or too fast to allow the heart to beat properly can result in fainting or, in some cases, cardiac arrest or sudden death.