Restrictive cardiomyopathy, the rarest form of cardiomyopathy, is a condition in which the walls of the lower chambers of the heart (the ventricles) are abnormally rigid and lack the flexibility to expand as the ventricles fill with blood.
The pumping or systolic function of the ventricle may be normal but the diastolic function (the ability of the heart to fill with blood) is abnormal. Therefore, it is harder for the ventricles to fill with blood, and with time, the heart loses the ability to pump blood properly, leading to heart failure.
Someone in the prime of their life -- a professional sports star, teen athlete, marathon runner, or other seemingly healthy person -- isn't supposed to collapse and die from heart disease. But it occasionally happens, making sudden cardiac arrest front-page news.
The rare nature of sudden cardiac arrest among the young is precisely what makes it so attention-grabbing. According to the Cleveland Clinic, sudden cardiac death kills 1 in 100,000 to 1 in 300,000 athletes under age 35, more often males...
The size of the heart may remain normal with restrictive cardiomyopathy. In some cases, restrictive cardiomyopathy may be confused with constrictive pericarditis, a condition in which the layers of the pericardium (the sac that surrounds the heart) become thickened, calcified, and stiff.
A myocardial biopsy, or biopsy of the heart muscle, occasionally is done to determine the cause of cardiomyopathy. During a myocardial biopsy, a small tissue sample is taken from the heart and examined under a microscope to examine the cause of the symptoms.