What is cardiomyopathy?
Cardiomyopathy is a serious disease of the muscles of the heart, where they become enlarged, flabby, and weak, severely reducing the heart’s ability to pump blood effectively. The heart may also be dilated (stretched out of shape) due to the loss of effective “recoil” contraction after it has relaxed open to accommodate the inflow of blood into its chambers. The inability to contract causes poor pump action and the backup of blood, with some degree of pooling, in the lungs and other vital organs. This leads to accumulation of the fluid in the lungs, liver, kidney and legs, among other parts. Most patients with dilated cardiomyopathy end up with heart failure. The rhythm of the heartbeat may also be disrupted to a dangerous degree.
What is the incidence of ICM?
About 50,000 Americans have idiopathic cardiomyopathy (ICM). ICM is prevalent among young people unlike many other forms of heart diseases, and is by far the leading indication for heart transplantation, closely followed by cardiomyopathy from end-stage coronary heart disease, where even coronary bypass surgery can no longer be done. The disease is usually progressive, and in many cases, it gets worse rapidly.
What causes cardiomyopathy?
The muscle damage could be caused by coronary artery disease, such as heart attacks (the ischemic type). Most cardiomyopathies (the non-ischemic variety, which is subclassified as dilated, hypertrophic and restrictive) are called idiopathic, where the cause of the damage is unknown. However, there are some factors which have been implicated, among them are: diabetes, poor diet, lack of exercise, smoking, excessive alcohol intake, illegal drugs (i.e. cocaine), infections (usually viral) leading to inflammation of the heart muscles (myocarditis), toxins (like cobalt, once used in beers), some pregnancies, and uncommonly, heredity. Some prescription medications and particular anti-cancer agents (like doxorubicin and daunorubicin) have caused cardiomyopathy too in some patients.
What are the symptoms?
Dilated cardiomyopathy may be present for years without symptoms. However, in due course, the heart gradually weakens and enlarges. The symptoms and signs are those of congestive heart failure: progressive shortness of breath, fatigue, weakness, coughing spells, especially when lying down, or, after physical exertion, a sense of drowning due to lung congestion, edema (swelling) of the feet and legs, abnormal weight gain from fluid retention. Advanced stages of cardiomyopathy can cause severe heart failure, with chest and/or abdominal pains, and serious arrhythmia (irregularity of the heartbeat), which can be life-threatening. Sudden deaths have been reported among these cases.
How is the diagnosis made?
In the majority of cases, an astute clinician can make a tentative diagnosis based on the patient’s medical history and physical examination. However, it behooves the attending physician to differentiate this from various other heart conditions that cause heart failure. In general, the following are done: chest X-ray, electrocardiogram and echocardiogram. The more specific tests which may be needed include radionuclide ventriculogram and/or cardiac catheterization.
What is the treatment for cardiomyopathy?
Early diagnosis of cardiomyopathy is not easy; many patients are seen when they are at the beginning or already have full-blown heart failure, in the advanced stage of the disease. The principle of treatment is to control the symptoms of heart failure, manage causal or complicating factors (like alcohol intake, smoking, etc.) to minimize the progression of the disease. Weight control and dietary changes, especially salt restriction, is a beneficial part of therapy. There is no cure for cardiomyopathy. For those who are under 60 years of age, otherwise healthy, and who satisfy the other criteria for heart transplantation, this procedure is the only viable alternative.
What is the prognosis of cardiomyopathy?
The disease is progressive and as time goes by, the heart continues to enlarge and get weaker, and the efficiency of the cardiac pumping diminishes. As a consequence, some individuals with this disease are unable to do even simple physical activities, such as walking, and, in severe cases, even talking long sentences without being short of breath. Some luckier patients, who are disciplined and under regular medical care, remain fairly stable for years. Since patients are usually seen in their advanced stage of cardiomyopathy, about 50 percent with dilated heart live five years, and about 25 percent survive 10 years, after the diagnosis of heart failure is made.
How beneficial is heart transplant?
Survival is greatly improved with cardiac transplantation. About 75 percent of these patients live five years or longer after the transplant. Unfortunately, there is a scarcity of heart donors (only about 2000 per year in the US) and those who satisfy the criteria have to wait for months or years, many of them dying before the donors’ hearts are available. A few, somehow, have improved while waiting, and are taken off the transplant list.
What are LVADs?
These are left ventricular assist devices (LVADs) — small implanted mechanical pumps — that are used as a “bridge” to heart transplantation. They are temporary pumps that circulate blood, partly taking over the work of the failing heart, allowing the heart to “rest a little,” while waiting for a donor’s heart.
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Philip S. Chua, MD, FACS, FPCS, Cardiac Surgeon Emeritus in Northwest Indiana and chairman of cardiac surgery from 1997 to 2010 at Cebu Doctors University Hospital, where he holds the title of Physician Emeritus in Surgery, is based in Las Vegas, Nevada. He is a Fellow of the American College of Surgeons, the Philippine College of Surgeons, and the Denton A. Cooley Cardiovascular Surgical Society. He is the chairman of the Filipino United Network – USA, a 501(c)(3) humanitarian foundation in the United States. Email: [email protected]
