Pathologies of the heart and its blood vessels. Almost all cardiovascular disorders eventually progress to serious debilitating stages characterized by heart failure (reduced pumping function), dysrhythmias (abnormal electrical rhythms), and sudden death. Coronary atherosclerosis, a disease causing obstruction of the arteries that supply nutrient blood to heart muscle, is the leading cause of cardiovascular mortality. Hypertension (high blood pressure) is another important cause. Valvular heart disease, cardiomyopathies (disease of heart muscle), and congenital heart disease are less common.