The Pathophysiology of Afterload Mismatch and Ventricular Hypertrophy

Abstract

Afterload, easy to describe in words (but hard to measure), is the force against which the heart must contract in order to empty and generate cardiac output. Many common conditions including hypertension, aortic stenosis, and pulmonary hypertension increase left or right ventricular afterload, leading to the development of hypertrophy. Hypertrophy allows the heart to bear the increased load but unfortunately does so with pathologic costs to the patient. Hypertrophy leads to chamber dysfunction, heart failure, and increased mortality. The difficulties in measuring afterload, the transduction of afterload into hypertrophy, and the mechanisms by which hypertrophy is a double-edged sword, causing both compensation and decompensation, are discussed.