Impact of atrio-biventricular pacing to poor left-ventricular function after CABG

Aims: The relation between acute postoperative management of epicardial pacing and haemodynamic status in patients with poor left-ventricular function after coronary artery bypass grafting (CABG) demonstrates the importance of synchronous ventricular activation and contraction during the vulnerable early postoperative period. Methods: in 22 patients (mean age - 69.3 +/- 5.4 years) with poor left-ventricular function (ejection fraction 29.8 +/- 4.8), we compared the postoperative haemodynamic parameters between atrio-biventricular, atrio-monoventricular and atrial pacing 3 - 24 hours after elective coronary artery revascularisation. Temporary epicardial pacing electrodes were placed on the right atrium and the paraseptal region of the left and right ventricle. The ventricular pacing modus was confirmed by surface electrocardiogram (EGG). We used overdrive rate pacing. Results: In patients with left bundle branch block, atrio-left-ventricular and atrio-biventricular pacing increased cardiac index and decreased wedge pressure. Atrial pacing and atrio-right-ventricular pacing decreased cardiac index. In contrast, atrio-right-ventricular and atrio-biventricular pacing increased cardiac index in patients with right bundle brunch block. Conclusion: Atrio-biventricular pacing increased cardiac index and decreased wedge pressure compared with AAI pacing. In patients with wall-motion abnormalities and impaired cardiac conduction, a site-specific pacing therapy can help to optimize postoperative haemodynamics and reduce the application of inotropic substances.