Background: The purpose of this study is to investigate the effects of cardiac displacement, regional ischemia and reperfusion to hemodynamics in four main settings of our technique on the beating heart coronary bypass.

Methods: Thirty-one patients operated on the beating heart between October and December 2001 were included in this study. Heart rate (HR), mean systemic arterial pressure (MAP), central venous pressure (CVP), mean pulmonary arterial pressure (MPAP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO) were measured during position, ischemia, reperfusion and at the end of the operation in anterior, lateral, posterior and inferior settings and compared to baseline values.

Results: There were statistically significant reductions in MAP (except anterior position) and CO measırements compared to baseline in all position and ischemic settings. The CVP, MPAP, PCWP, HR (except lateral ischemia, posterior position and ischemia) increased according to the baseline in all position and ischemic settings. Variations were more significant during the manipulation of the posterior territories. All these hemodynamic changes returned to baseline with reperfusion (except HR in inferior), though HR, CVP, MPAP, PCWP remained increased in the anterior setting. Heart rate was the single variable that remained high, all hemodynamic parameters returned to baseline at the end of the operation.

Conclusions: Hemodynamic changes occur in all settings during beating heart coronary bypass. But all of these changes are transient and well tolarated by the patients.

Keywords : Coronary artery bypass, beating heart, hemodynamics