Temporary A-V sequential pacing using transluminal pacing electrodes

A case is presented which describes the initiation of atrialventricular (A-V) sequential pacing using atrial epicardial wires and an in situ transluminal ventricular pacing probe. A 68year-old female with a permanent A-V sequential pacemaker was scheduled for elective aortocoronary bypass. Following sternotomy, pacing function was converted to ventricular pacing (WI) with the use of electrocautery. A Chandler® V-pacing probe was introduced through a Paceport® (American Edwards) pulmonary artery catheter and with a paced increase in ventricular rate, the cardiac output increased from 2.8 to 3.2 L · min^-1. At the conclusion of cardiopulmonary bypass the patient was in sinus rhythm at a rate of 67 · min^-1 and was paced to a faster rate using bipolar atrial epicardial wires. The patient subsequently developed intermittent heart block so temporary A-V sequential pacing was established using atrial epicardial wires and the in situ ventricular pacing probe. Pacing was achieved at routine generator output settings of seven milliamps (mA) for both atrium and ventricle and at an A-V interval of 0.120 sec. This resulted in an immediate increase in cardiac output from 3.3 to 4.1L- min^-1. The compatability of these two pacing systems offers an increased margin of safety in cardiac surgery patients requiring atrial pacing, who are at risk for developing postoperative heart block.