Which classification of cardiomyopathy often results in reduced contractility?

Dilated cardiomyopathy is characterized by an enlarged heart and decreased contractility, meaning the heart's ability to pump blood effectively is impaired. This condition often results from the dilation of the heart chambers, particularly the left ventricle, which negatively impacts the heart's ability to contract and eject blood. Over time, the weakening of the heart muscle leads to heart failure symptoms, as the heart can no longer maintain adequate blood circulation for the body's needs.

In contrast, hypertrophic cardiomyopathy typically involves abnormal thickening of the heart muscle, which may obstruct blood flow and alter cardiac function but does not primarily lead to reduced contractility. Restrictive cardiomyopathy involves rigidity of the heart walls that limits filling, leading to heart failure with preserved contractility in many cases. Arrhythmogenic cardiomyopathy is characterized by the replacement of heart muscle with fatty or fibrous tissue, which can lead to rhythm abnormalities, but it does not primarily lead to a loss of contractility like dilated cardiomyopathy does. Therefore, dilated cardiomyopathy is the classification that most commonly results in reduced contractility.