You may know cardiomyopathy as a type of heart disease. But its actually more than that. Cardiomyopathy is really a group of diseases affecting the heart muscle. There are several kinds of cardiomyopathies, and each one has its own set of possible causes and outcomes. One of the common characteristics of cardiomyopathies is that the heart muscle becomes bigger and sometimes weaker. In many cases, cardiomyopathy can lead to heart failure and possibly the need for a heart transplant.