Cardiomyopathy, in general, refers to a disease of the heart muscle or myocardium. In this condition, the heart doesn’t pump blood effectively.
In some cases, it leads to irregular heartbeats (arrhythmias). This is a progressive ailment, and patients may develop life-threatening heart failure later in their lives. Among the two types, namely, ischemic cardiomyopathy and non-ischemic cardiomyopathy, the non-ischemic type is less common.
Non-ischemic cardiomyopathy is not related to coronary artery disease unlike ischemic cardiomyopathy. Non-ischemic cardiomyopathy is mainly of three types such as hypertrophic cardiomyopathy, dilated cardiomyopathy, and restrictive cardiomyopathy.
Hypertrophic cardiomyopathy develops with the increase in the size of the heart’s left ventricle. This occurs due to abnormal enlargement of the muscle fibers of the heart. Due to the increased muscle mass, the wall separating the two ventricles increases in size and blocks the blood flow from the left ventricle. This does not allow the heart to relax correctly between the beats. Eventually, the left ventricle fills with less blood, and in turn, limits the amount of blood being pumped by the heart in each beat.
This type of non-ischemic cardiomyopathy is rare and is inherited in most cases. It can affect men and women of all ages. This is also known to be associated with aging and hypertension. Some of the symptoms of this condition include shortness of breath, chest pain, dizziness, and fainting. The symptoms can develop both in childhood and adulthood.
Some patients suffering from hypertrophic cardiomyopathy may also experience cardiac arrhythmias, which may lead to sudden death.
According to a data synthesis report on hypertrophic cardiomyopathy published by The Journal of the American Medical Association, this is a genetic disease with an annual mortality rate of approx. 1 % and with a normal life expectancy. The journal also outlines some of the treatment options, depending upon the specific condition of the patient. The septal myotomy-myectomy is established as a standard care for patients with severe refractory symptoms and outflow obstruction. Alcohol septal ablation and pacing may be used as alternatives to surgery, depending upon the conditions of patients. Drug treatment is another option. Moreover, the implantable cardioverter-defibrillator is used for high risk patients to prevent sudden occurrence of death. However, The Journal of the American Medical Association also concludes that due to the complex clinical expression and natural history of hypertrophic cardiomyopathy, it still remains a focal point of cardiovascular specialists for more investigation and research.
In this condition, the cavity of the heart is enlarged and stretched due to the damaged heart muscles. This weakens the heart’s capability to pump blood properly. A journal article published by UCLA School of Medicine characterizes dilated cardiomyopathy as increase in the internal dimensions of the left ventricle without an appropriate increase in the wall thickness of ventricles. This is the most frequent form of non-ischemic cardiomyopathy. The various causes of dilated cardiomyopathy may include any ischemic heart disease with decreased blood flow to the heart, viral infections, chronic exposure to alcohol and chemotherapy drugs, and dietary deficiencies.
Cardiac transplantation has been established as treatment option to improve the life expectancy of the patients suffering from this type of non-ischemic cardiomyopathy. Another preliminary study report published by The New England Journal of Medicine outlines that administration of human growth hormone to the patients suffering from dilated cardiomyopathy reduces the size of the left ventricular chamber and increases the myocardial mass, thereby resulting in improved blood flow and pumping of the heart.
In this form, the muscles of the ventricles lose their flexibility and the blood filling in them between the heartbeats is affected. The wall thickness of the left ventricles remains normal in this case. This is the least common form of non-ischemic cardiomyopathy. Restrictive cardiomyopathy is usually related to other conditions such as amyloidosis (collection of protein fibers in the heart muscle), sarcoidosis (formation of small inflammatory masses in certain organs) and hemochromatosis (excessive iron in the body). The symptoms may include difficulty in breathing and fatigue.
References