N – compared with a normal heart value.

Coronary artery disease producing ischemic cardiomyopathy is the most common cause of left ventricular systolic dysfunction. Non-ischemic cardiomyopathies may resolve within the twelve months of the onset of symptoms in approximately 30% of cases.

Beyond one year, patients with both ischemic and nonischemic disease suffer frequent hospitalization and are an increased risk of premature death. Dietary indiscretion in sodium intake and medication noncompliance can worsen symptoms and lead to hospitalization. Progressive pump failure and malignant arrhythmias are the most common causes of death among heart failure patients.