In a worst-case scenario, cardiomyopathy can lead to heart failure and death. Less severe effects of cardiomyopathy should serve as warning signs that you need to seek treatment from your doctor. Cardiomyopathy can cause swelling in the legs, feet, or abdomen. It can also lead to a change in the pattern of your heartbeats as well as heart palpitations. Sometimes cardiomyopathy can cause blood clots.