Cardiomyopathy or enlargement of the heart is responsible for 10,000 deaths and 46,000 hospitalizations each year in the United States according to Marilyn Weigner, MD and James Morgan,MD in their UptoDate article "Causes of Dilated Cardiomyopathy." This condition involves enlargement of the left ventricle of the heart and impairment of the ejection of blood from the heart. This impairment frequently leads to heart failure also called congestive heart failure. There are multiple reasons for an enlarged heart.
Idiopathic
Idiopathic cardiomyopathy represents approximately 50 percent of all cases of cardiomyopathy. In these cases, no reason for the enlargement of the heart can be found. In about five percent of cases, a genetic or familial relationship is identified, says the book "The Principles and Practice of Medicine."
Ischemic
According to Dr. Weigner and Morgan, ischemic cardiomyopathy represents 50 to 75 percent of patients with heart failure caused by an enlarged heart. Most patients with ischemic disease have known coronary artery disease and many have had heart attacks. Heart attacks or myocardial infarctions lead to cardiac cell death and the increase in pressure from circulating blood in the system on non-functioning heart muscle causes the heart to dilate.
Inflammatory
Inflammatory changes caused by viral illness or Lyme disease can cause cardiomyopathy. Viruses such as the Coxsackie virus, influenza virus, cytomegalovirus and HIV can actually live in the heart cells if an adequate immune response does not eliminate the virus. The virus will cause inflammatory changes and destroy heart muscle.
Lyme disease which patients acquire through tick bites can cause an inflammatory response if the virus infects the heart. Heart muscle dysfunction can occur but the cardiomyopathy usually proves transient and treatment with antibiotics can improve heart muscle function, says Drs. Weigner and Morgan.
Toxins
Alcoholic cardiomyopathy results from the excessive use of alcohol and its effects on cardiac cells, says Drs. Weigner and Morgan. Not everyone who drinks excessively develops an enlarged heart but at this time individual susceptibility remains elusive to detection. If caught early, abstinence can lead to a significant improvement in overall heart function.
Cocaine and some chemotherapy drugs can also alter and destroy cardiac cells. Doxorubicin or Adriamycin is a potent antitumor drug but it is toxic to the heart in a patient who receives a large enough cumulative dose, says the book "Idiopathic cardiomyopathy represents approximately 50 percent of all cases of cardiomyopathy. In these cases, no reason for the enlargement of the heart can be found. In about five percent of cases, a genetic or familial relationship is identified, says the book "The Principles and Practice of Medicine." Chronic cocaine use leads to multiple ischemic events in the heart and subsequent areas of scarring which lead to cardiomyopathy.
References
- UptoDate: Causes of Dilated Cardiomyopathy
- "The Principles and Practice of Medicine": John Stobo, MD, David Hellmann, MD, Paul Ladenson, MD, Brent Petty, MD, Thomas Traill, FRCP. 1996
