Heart failure is defined as an inability of the heart to pump sufficient blood to meet the body's demands, arising from depressed systolic contraction and/or impaired diastolic relaxation, most commonly due to ischemic heart disease. The body's compensatory neurohormonal response—mediated by the sympathetic nervous system, renin-angiotensin system, and antidiuretic hormone, and reinforced by the Frank-Starling mechanism (increased preload increases contractile force)—is adaptive for hemorrhage or dehydration but paradoxically worsens heart failure by promoting fluid and sodium retention, elevated filling pressures, and edema. This is a concept within cardiology, relating preload, afterload, and contractility theory to the pathophysiologic classification (systolic vs. diastolic, left- vs. right-sided) and staged management of a chronic disease state.
Heart failure is defined as an inability of the heart to pump sufficient blood to meet the body's demands, arising from depressed systolic contraction and/or impaired diastolic relaxation, most commo…