Ventricular Function

1954 Circulation  
of the heart has been studied in the dog with a complete circulation with the continuous registration of cardiac output, and atrial and arterial pressures. From this data ventricular function curves were constructed. In any given physiologic state there was a consistent and reproducible correlation between atrial pressure and ventricular stroke work on the same side. The classically conceived descending limb did not occur in the normal heart. The concept of a family of Starling or ventricular
more » ... ng or ventricular function curves adds a third dimension to the adaptive capacity of the heart as put forth by Frank and Starling. STARLING'S LAW of the heart states "that the energy of contraction, however measured, is a function of the length of the muscle fibers" prior to contraction.' Starling deduced this law from his own and also from the prior studies of Frank on isolated heart and heart-lung preparations.2'4 Both its validity and significance in the presence of an intact circulation have been questioned.5-" Many investigations of this matter in the presence of a complete circulation have been either inadequate or misleading largely because of the following: (1) stroke volume or cardiac output and not stroke work has been used as the measure of the "energy of contraction"; (2) attempts have been made to correlate right sided filling pressure with left ventricular stroke work; (3) attempts have been made to correlate filling pressure with ventricular work per minute instead of per stroke, and (4) perhaps most important, it has not been generally appreciated that a single Starling curve cannot always satisfactorily explain the observed phenomena; for any given heart there is a series or family of curves. From the
doi:10.1161/01.cir.9.5.706 pmid:13161102 fatcat:gfyuazocrnhetjfk4ct5kknexi