Frank-Starling curves in heart failure

Idealized family of Frank-Starling curves produced by worsening ventricular function in heart failure. In ventricles with normal cardiac performance, there is a steep and positive relationship between increased cardiac filling pressures (as estimated from the LVEDP or pulmonary capillary wedge pressure) and increased stroke volume or cardiac output (top curve). By comparison, during progression from mild to severe myocardial dysfunction, this relationship is right shifted (ie, a higher filling pressure is required to achieve the same cardiac output) and flattened so that continued increases in left heart filling pressures lead to minimal increases in cardiac output at the possible expense of pulmonary edema. The onset of mild heart failure results in an initial reduction in cardiac function (from point A to point B), a change that can be normalized, at least at rest, by raising the LVEDP via fluid retention (point C). Diuretic therapy reduces left ventricular filling pressure at the expense of mildly decreased cardiac output (moving from point C to point B). By comparison, normalization of stroke volume is not attainable in severe heart failure (bottom curve).