Myocardial performance during hemorrhagic shock in the pancreatectomized dog

Abstract

Myocardial performance was evaluated in nine pancreatectomized and 12 nonpancreatectomized dogs by measuring left ventricular pressure (LVP), maximal dP/dt (max dP/dt), left ventricular end-diastolic pressure (LVEDP), pulmonary arterial pressure (PAP), aortic pressure (AoP), and lead II of the electrocardiogram during standardized hemorrhagic shock. Cardiac output (CO) and hematocrit were determined before hemorrhage, after 4 h of oligemia, when postinfusion mean blood pressure declined to 60 mmHg. Left ventricular function curves were obtained, by varying preload, in control dogs and 2 h after reinfusion of the shed blood in those dogs subjected to shock. Both groups of dogs showed identical responses to the shock procedure. In the immediate postinfusion period, LVP, max dP/dt, LVEDP, and mean blood pressure returned to near-control values, while PAP was significantly elevated. The postinfusion decline (after 60-90 min) in AoP was accompanied by a similar reduction in LVEDP. Left ventricular performance in hemorrhagic shock did not differ significantly from that seen in control dogs. In addition, there was no electrocardiographic indication of myocardial ischemia. The data indicate that terminal hemorrhagic shock need not be accompanied by myocardial depression whether or not the pancreas is intact.