Types of Cardiomyopathy
Dilated Cardiomyopathy: Dilated cardiomyopathy is the most common type of the disease. It mostly occurs in adults aged 20 to 60. Men are more likely than women to have this type of cardiomyopathy. Dilated cardiomyopathy affects the hearts ventricles and atria. These are the lower and upper chambers of the heart, respectively. The disease often starts in the left ventricle, the heart is main pumping chamber. The heart muscle begins to dilate (stretch and become thinner). This causes the inside of the chamber to enlarge. The problem often spreads to the right ventricle and then to the atria as the disease gets worse. When the chambers dilate, the heart muscle does not contract normally. Also, the heart can not pump blood very well. Over time, the heart becomes weaker and heart failure can occur. Symptoms of heart failure include fatigue (tiredness); swelling of the ankles, feet, legs, and abdomen; and shortness of breath. Dilated cardiomyopathy also can lead to heart valve problems, arrhythmias, and blood clots in the heart.
Hypertrophic Cardiomyopathy: Hypertrophic cardiomyopathy can affect people of any age. About 1 out of every 500 people has this type of cardiomyopathy. It affects men and women equally. This type of cardiomyopathy occurs when the walls of the ventricles (usually the left ventricle) thickens. Despite this thickening, the ventricle size often remains normal. Hypertrophic cardiomyopathy may block blood flow out of the ventricle. When this happens, the condition is called obstructive hypertrophic cardiomyopathy. In some cases, the septum thickens and bulges into the left ventricle. In both cases, blood flowing out of the left ventricle is blocked.
As a result, the ventricle must work much harder to pump blood out to the body. Symptoms can include chest pain, dizziness, shortness of breath, or fainting. Hypertrophic cardiomyopathy also can affect the hearts mitral valve, causing blood to leak backward through the valve. Sometimes the thickened heart muscle does not block blood flow out of the left ventricle. This is called nonobstructive hypertrophic cardiomyopathy. The entire ventricle may become thicker, or the thickening may happen only at the bottom of the heart. The right ventricle also may be affected. In both types (obstructive and non-obstructive), the thickened muscle makes the inside of the left ventricle smaller, so it holds less blood. The walls of the ventricle also may stiffen. As a result, the ventricle is less able to relax and fill with blood.
Restrictive Cardiomyopathy: Restrictive cardiomyopathy tends to mostly affect older adults. In this type of the disease, the ventricles become stiff and rigid. This is due to abnormal tissue, such as scar tissue, replacing the normal heart muscle. As a result, the ventricles can not relax normally and fill with blood, and the atria become enlarged. Over time, blood flow in the heart is reduced. This can lead to problems such as heart failure or arrhythmias.
Arrhythmogenic Right Ventricular Dysplasia: Arrhythmogenic right ventricular dysplasia (ARVD) is a rare type of cardiomyopathy. ARVD occurs when the muscle tissue in the right ventricle dies and is replaced with scar tissue. This process disrupts the hearts electrical signals and causes arrhythmias. Symptoms include palpitations and fainting after physical activity. ARVD usually affects teens or young adults. It can cause SCA in young athletes. Fortunately, such deaths are rare.