Effect of dobutamine on ventriculoarterial coupling in acute regional myocardial ischemia in dogs. Seki, Kohzaburo, Kazuhiro Katayama, Hisanori Sakai, Takahito Yonezawa, Hideki Kunichika, Yasuhiko Saeki, Takashi Hiro, Masunori Matsuzaki. Second Department of Internal Medicine, Yamaguchi University School of Medicine, Yamaguchi, Japan
APStracts 2:0476H, 1995.
We assessed the effect of dobutamine on the left ventriculoarterial coupling during acute regional ischemia. We analyzed the end-systolic pressure volume relation (ESPVR) in anesthetized dogs using a conductance catheter. We calculated the slope (Ees) of ESPVR, the slope (Ea) of end-systolic pressure stroke volume relation, Ea/Ees and the ratio (work efficiency) of external work to pressure volume area at baseline, during ischemia induced by occlusion of left anterior descending coronary artery, during low-dose (1-3 [mu]g x min-1 x kg-1) and during high-dose (4-10 [mu]g x min-1 x kg-1) dobutamine infusions with ischemia. ESPVR shifted to the right without change of Ees during ischemia. Dobutamine caused dose -dependent increases in Ees but did not affect the intercept of ESPVR. During ischemia, Ea/Ees increased and work efficiency decreased. Low- dose dobutamine was associated with a return to control value for Ea/Ees and work efficiency. High-dose dobutamine increased both Ees and Ea but produced no further increase in Ea/Ees or work efficiency. Low-dose dobutamine would appear to be the preferable regimen to achieve the optimal ventriculoarterial coupling in acute regional ischemia associated with mismatched ventriculoarterial coupling and depressed left ventricular work efficiency.

Received 5 January 1995; accepted in final form 12 September
1995.
APS Manuscript Number H4-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95