Improving hemodynamics by atrial pacing during off-pump bypass surgery.

BACKGROUND

To avoid hemodynamic deterioration during tilting of the heart in off-pump surgery, we perform atrial pacing. We describe hemodynamic evaluation of this simple maneuver.

METHODS

Eleven consecutive patients (8 men, 3 women; age, 68.14 +/- 10.3 years; left ventricular ejection fraction, 51.17% +/- 18.6%) admitted for coronary artery bypass grafting were equipped with a PiCCO catheter (Pulsion Medical Systems, Munich, Germany) for monitoring of cardiac output (CO), cardiac index (CI), stroke volume (SV), heart rate (HR), and systemic vascular resistance. In addition, mean and systolic arterial pressure (RRm, RRs) as well as left atrial pressure (LAP) were monitored. During the procedure, temporary pacemaker wires were installed, and hemodynamic monitoring was performed before and after atrial pacing. All procedures were performed with the same standardized offpump technique.

RESULTS

All patients survived the procedure without inotropic support. In all cases a branch of the circumflex artery was grafted. The number of grafts per patient was 2.7. There was a statistically significant increase in RRs (11.12 mm Hg), RRm (9.72 mm Hg), HR (31.6 beats/min), CO (1.09 L/min), and CI (0.61 L/min per m2) (P <.005). SV decreased statistically significantly (11.8 mL, P <.005) as did LAP (6 mm Hg, P < .05).

CONCLUSIONS

Atrial pacing increases intraoperative RRs, RRm, CO, and CI and decreases SV and LAP significantly, thus offering stable hemodynamics during off-pump surgery. In the last 400 consecutive off-pump coronary artery bypass grafting procedures, there was only 1 (0.25%) conversion to cardiopulmonary bypass.