Reduction in energy pacing thresholds by overlapping biphasic stimulation versus conventional bipolar pacing.
Overlapping biphasic (OLBI) stimulation is a new pacing waveform consisting of two simultaneous monophasic pulses of opposite polarities applied to a bipolar electrode. The goal of this prospective study was to compare, using conventional pacing leads, the acute energy pacing thresholds, measured at 0.5-ms pulse duration, associated with bipolar versus OLBI (mode 7 and mode 8) pulse delivery.


RESULTS
Thirty one leads were tested in 20 patients. Of these leads, 7 (23%) were implanted chronically, 12 (39%) were in atrial positions, and 19 (61%) in ventricular positions. Energy pacing thresholds were significantly lower (-25.6 +/- 25.6%, P = 0.005) in OLBI mode 8 (1.30 +/- 3.96 microJ) compared to bipolar (1.55 +/- 4.37 microJ) pacing, regardless of the pacing site or length of service of the leads. In contrast, OLBI mode 7, which has an anodal component, at the tip electrode was associated with higher energy pacing thresholds (3.65 +/- 6.48 microJ; +358.3 +/- 219.4%, P = 0.002).


CONCLUSIONS
Mode 8 OLBI pacing is associated with lower acute energy pacing thresholds when used with bipolar leads in contact with the myocardium. OLBI pacing may increase pacemaker longevity by reducing long-term energy consumption.
Lazarus
A
A
Association Cardiologie Val d'Or, Saint Cloud, France. Alazarusl@aol.com
Taskiran
M
M
Ritter
P
P
Gras
D
D
Cazeau
S
S
Mugica
J
J
D001145:Arrhythmias, Cardiac / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004567:Electrodes, Implanted; D006801:Humans; D010138:Pacemaker, Artificial; D011446:Prospective Studies