Temporary transcoronary pacing by coated guidewires

Abstract

Relevant bradycardias during percutaneous coronary intervention (PCI) are a rare event, but they require immediate therapy by temporary pacing. However, transvenous pacing is associated with frequent and severe complications. Therefore, we wanted to evaluate the safety and reliability of trans-coronary pacing by means of a PCI guidewire. Coronary pacing was applied to 70 consecutive patients undergoing PCI. Pacing was performed before and after PCI in a unipolar setting using standard guidewires as a cathode and a skin electrode as an anode. Both were connected to an external pacemaker. Coronary pacing (maximum output at 10 V, impulse duration 2.5 ms) was effective in 60 of 70 patients (85.7%). Successful pacing was achieved in the LAD and diagonal branches in 90% (27 of 30 Pts.), in the LCX and marginal branches 84.2% (16 of 19 Pts.) and in the RCA in 81% (17 of 21 Pts.). Pacing thresholds were comparable in all vessels within a range of 1-10 V averaging 6.6 +/- 2.3 V before and 6.6 +/- 2.2 V after PCI. The impedance ranged from 190-544 Omega with mean pacing impedance for coronary pacing of 424 Omega before and 416 Omega after PCI, respectively. Significant bradycardias during PCI occurred in 7 cases (10%). In three cases (4.3%) temporary coronary pacing became necessary at a maximum pacing duration of 3 min. There were no severe side effects. Coronary spasm occurred in 3 cases (4.3%) after pacing and was promptly reversible after intracoronary application of nitroglycerine. It is concluded that coronary pacing is a safe and feasible method for the treatment of bradycardias during PCI. It avoids additional venous puncture under hemodynamically unstable conditions and subsequent transvenous pacing, which is accompanied by potentially severe complications and additional costs.