What makes your cat’s heart tick? A cat’s four-chambered heart is a complex, synchronized network of electrical circuits woven through the cardiac muscle. The heart is the pump at the center of the circulatory system. This system delivers vital oxygen to the tissues in the body and carries wastes from the tissues back to the lungs to be exhaled. Problems with this vital pump include abnormal: 1) blood flow (heard as a murmur), as in congenital defects, 2) heart muscle function termed, cardiomyopathies; and 3) electrical signals in the heart muscle (e.g.: atrial fibrillation), causing uncoordinated contractions of the heart. Indications that your cat may have a heart problem include: hiding, exercise intolerance, cold extremities, weakness, collapse, and/or changes in breathing patterns; cats with heart disease rarely cough.