The heart is a muscular organ which contracts in order to pump blood to the lungs and throughout the rest of the body. Although athletes can have larger than normal hearts that are not a medical problem, there are situations in which the heart can become too large. A dangerously enlarged heart is typically a sign of a serious underlying problem with the cardiovascular system.
Identification
As a general rule, a person's heart is considered to be unusually large if it causes a cardiothoracic ratio of more than 0.50, DownloadHeart.us explains. This means that the heart is larger than half of the diameter of the inner portion of the rib cage. An enlarged heart, also known as cardiomegaly, can be detected on an X-ray and is sometimes an incidental finding on imaging tests that are performed to examine organs and tissue other than the heart.
Symptoms
In many cases, an enlarged heart will cause no symptoms, especially early in the course of the condition. During this time, the heart is still functioning normally. Patients may develop symptoms, however, if the enlarged heart is unable to effectively beat and pump blood. This can cause shortness of breath and other breathing difficulties, the Mayo Clinic states, as well as dizziness, a chronic cough and edema. An enlarged heart can also result in an irregular heart beat. Over time, enlarged hearts can become weak and fail or grow so large that they block the flow of blood to the aorta.
Types
There are two different ways in which a heart can become dangerously enlarged. Dilated cardiomyopathy, the American Heart Association explains, is when the chambers inside the heart become larger, causing the heart muscle to become stretched and weak. Patients can also develop a dangerously enlarged heart due to hypertrophic cardiomyopathy. This is caused by the muscular portion of the heart becoming larger, leading to thickened heart walls.
Causes
A number of different things can cause a heart to become dangerously large, the Mayo Clinic reports. High blood pressure can cause the heart to become larger so that it can pump more strongly. Patients with congenital heart defects, arrythmias or problems with their heart valves may develop an enlarged heart as the organ attempts to compensate for its deficient pumping ability. Anemia and hyperthyroidism can also cause the heart to become enlarged. Finally, hemochromatosis and amyloidosis can cause thickening of the heart muscle due to deposition of iron and abnormal proteins, respectively.
Treatment
Because cardiomegaly is usually a symptom of another underlying disorder, treatment often hinges on correcting the health condition that made the heart enlarge. For example, patients who have high blood pressure may take medications that lower their blood pressure; in other cases, surgery to correct a problem with a heart valve or an arrythmia may be necessary. Medications can also be taken to help prevent the condition from progressing. Patients who have a weakened heart can take medications such as digoxin and dopamine to increase the strength of the heart. If the heart is becoming enlarged due to pumping too hard, drugs such as beta blockers and calcium channel blockers can reduce the force with which the heart pumps. In severe cases, a heart transplant may be needed.
