Temporary Epicardial Cardiac Resynchronisation.

Patients with poor left ventricular (LV) function are at higher risk of complications after cardiac surgery, compared to patients with preserved LV function. The higher complication rates also lead to prolonged Cardiac Intensive Care (CITU) admissions for monitoring and multi-organ support.

The investigators hypothesise that BiV pacing will reverse cardiac dyssynchrony and improve target organ perfusion. This will be significantly reduced the post operative requirement for Level 3 CITU care.

This study will compare 48 hours of temporary biventricular (BiV) pacing to enhance cardiac function against standard post-operative pacing, in patients with poor LV function undergoing cardiac surgery. Temporary biventricular (BiV) pacing will be achieved with the addition of a third pacing electrode attached to the left ventricle. Using a pulmonary arterial catheter the interventricular (VV) delay will be adjusted to yield the maximum cardiac output at constant heart rate- sequential BiV pacing. A pilot study conducted at the University Hospital of Wales (UHW) showed that this approach is likely to be successful.

The primary endpoint of the study will be the mean duration of Level 3 CITU care required by patients after cardiac surgery. Secondary endpoints will include: haemodynamic improvement with BiV pacing; post-operative renal function; atrial fibrillation (AF)/ ventricular arrhythmias; post operative inotropic requirements and changes in biomarkers- NT Pro BNP and Troponin T.

Inclusion criteria

• Coronary disease scheduled for surgical revascularisation. Ejection fraction <35% (simpson's method.)

Exclusion criteria

• Permanent pacemaker or implantable defibrillator. Dialysis dependent renal failure. Permanent atrial fibrillation.