Etiology of Heart Failure

           There are many causes of myocardial injury that can result in clinically apparent Heart Failure. However, in considering the etiology of cardiac dysfunction it is useful to subdivide patients into those with abnormal systolic function and those with preserved systolic function. Among patients with abnormal systolic function, defined as ejection fraction < 40%, approximately two thirds will have an ischemic cardiomyopathy (ICM), usually resulting from prior myocardial infarction (MI).

The causes of nonischemic cardiomyopathy (NICM) in patients with systolic dysfunction are more varied and are shown in table below. Some 80% of patients with reduced left ventricular ejection fraction (LVEF) will have had a prior hospitalization for Heart failure. The mostcommon presentation for patients with systolic dysfunction is slowly progressive fluid accumulation.

              In Heart Failure patients with PSF, the underlying disease processes are distinct. Most disorders leading to Heart Failure with PSF affect myocardial relaxation leading to high cardiac filling presures. The most common causes are hypertension, diabetes, obesityand occasionally coronary artery disease (CAD). In addition, Heart Failure with PSF is more common in female and patients >65 years of age. Atrial Fibrillation (AF) and chronic renal insufficiency are frequent comorbidities. rare causes of Heart failure with PSF are shown in table below. Although they can have more commonly present with acute pulmonary edema and hypertension.