Hemodynamic changes during off-pump CABG surgery.

OBJECTIVES

The purpose of this study was to assess the patients' hemodynamics during off-pump coronary artery bypass graft (OPCABG) surgery.

METHODS

Continuous monitoring of the mean systemic arterial pressure (SAP), mean pulmonary arterial pressure (PAP), mixed venous oxygen saturation (SvO(2)) and cardiac output index (COI) was done on 55 patients undergoing complete OPCAB revascularization. Hemodynamic changes were recorded at the completion of the anastomosis before releasing coronary snaring and stabilization and compared to baseline.

RESULTS

The mean age of the patients was 66.4+/-9.2 years, and on average 3.3+/-0.8 grafts per patient were performed. The average SAP drop after manipulations was -8.3+/-16.9 mmHg for the left anterior descending artery (LAD), -13.5+/-19.6 mmHg for the diagonal artery (DG), -14.6+/-13 mmHg for the optuse marginal artery (OM), and -14.2+/-13.5 mmHg for the right coronary artery. This was significant for all territories (P<0.01). The PAP significantly increased in all territories except OM (LAD: 3.7+/-6.3 mmHg, DG: 4.3+/-8.6 mmHg, OM: 1.1+/-7.2 mmHg, posterior descending artery: 2.7+/-5.6 mmHg; P<0.05). Variations in COI were significant in all territories (P<0.01) but more significantly in LAD and DG territories (-15+/-3% and -13+/-9%, respectively). The SvO(2) variations were <10% for all territories and reached only borderline significance (P=0.05) in all territories except OM. All these hemodynamic changes were well tolerated by all patients.

CONCLUSIONS

Manipulation of the beating heart during OPCABG surgery brings significant fluctuations in the patients' hemodynamics. Mean PAP increase and COI drop were more significant during manipulation of the anterior territories suggesting a more severe diastolic restrictive disease during anterior wall manipulation.