Assessment of contractility changes in humans by transoesophageal echocardiography: the peak-systolic pressure end-systolic diameter relationship (PSPESDRS).
The peak-systolic pressure end-systolic diameter relationship (PSPESDRS) was determined in ten healthy subjects under general anaesthesia by using the radial artery pressure tracing (peak-systolic pressure) and transoesophageal 2d-and m-mode echocardiography (left ventricular diameters) without blocking of autonomic reflexes. Left ventricular load was changed by injection of a single intravenous dose of 0.2 mg nitroglycerin (NTG). Linear regression analysis showed a close linear relationship during the pressure decrease between peak-systolic pressures and end-systolic diameters. During infusion of dobutamine 5 micrograms/kg/min there was also a close linear relationship during pressure decrease with increased slope and unchanged Do (D0 = diameter at theoretical pressure zero). Values taken during pressure returning to control level were shifted leftward indicating transient increased contractility. We conclude, that the PSPESDRS can reliably be measured in humans without autonomic blockade during the decrease of arterial pressure after NTG, where reflex changes in inotropy are not yet present. This relationship increases in slope with dobutamine, reflecting the increased contractile state.
D001794:Blood Pressure / Q000187:drug effects; D004280:Dobutamine; D004452:Echocardiography / Q000379:methods; D004947:Esophagus; D006339:Heart Rate / Q000187:drug effects; D006352:Heart Ventricles / Q000033:anatomy & histology; D006801:Humans; D009200:Myocardial Contraction; D005996:Nitroglycerin
D004280:Dobutamine; D005996:Nitroglycerin