Usefulness of unipolar epicardial ventricular electrogram for triggering of intraaortic balloon counterpulsation during off-pump coronary artery bypass surgery in patients with hemodynamic instability complicating acute coronary syndromes.

During off-pump coronary artery bypass graft (CABG) surgery for patients requiring preoperative intraaortic balloon counterpulsation (IABP) support, errors in timing of IABP during mobilization of the heart can induce unstable hemodynamic conditions. We applied a simple technique for triggering IABP accurately during off-pump CABG: one end of an epicardial pacemaker wire is placed on the surface of the left ventricle, and the other end is linked to one of the precordial V leads. This technique provided an exact detection of R-wave potentials in any position of the heart during the off-pump CABG procedure.