Afterload sensitivity of nonlinear end-systolic pressure-volume relation vs preload recruitable stroke work in conscious dogs.
The observations in vivo of a non-linear, afterload-sensitive end-systolic pressure-volume relation (ESPVR) and a linear, load-insensitive preload recruitable stroke work (PRSW) relation may be reconciled by considering the PRSW as a product of both the ventricular ESPVR and the arterial elastance (Ea). We obtained pressure-volume data from eight conscious dogs. The ESPVR was nonlinear, and its trajectory was afterload-dependent. The PRSW was linear and load-independent. Arterial elastance changed with both acute reductions in preload and steady-state changes in afterload. The PRSW relation thus describes both myocardial function and ventricular-arterial interaction and is a useful index of cardiovascular performance in patients.
McClain
L C
LC
Department of Surgery, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298, USA.
Wright
L D
LD
Bose
R K
RK
Spratt
J A
JA
Maier
G W
GW
D000818:Animals; D001158:Arteries / Q000502:physiology; D001794:Blood Pressure; D003326:Coronary Circulation; D004285:Dogs; D004548:Elasticity; D005260:Female; D006321:Heart / Q000502:physiology*; D006334:Heart Function Tests; D008297:Male; D009200:Myocardial Contraction; D013318:Stroke Volume; D013599:Systole; D016276:Ventricular Function