Zeitschrift für Kardiologie
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Comparative Study
[Low pacing thresholds of ventricular pacemaker leads: not a marker for large R-wave amplitudes and high impedance values].
An optimal position of a ventricular pacing lead in the bottom or apex of the right ventricle is defined by low pacing thresholds and high R wave amplitudes. At similar pacing thresholds high pacing impedance additionally reduces the pacing current delivered by the pacemaker. Finding an optimal position for the pacing lead would be facilitated if locations with low pacing thresholds are usually associated with great R wave amplitudes and high pacing impedance. ⋯ In respect to impedance, neither the correlation with pacing threshold (r = 0.07) nor that with R wave amplitude (r = 0.18) was statistically significant. In conclusion, most patients had pacing thresholds < 0.5 V at 0.5 ms pulse duration and R wave amplitudes > 10 mV; fewer than 5% of the patients had pacing thresholds > 0.6 V or R wave amplitudes < 5 mV. Lead locations with low pacing thresholds are usually not associated with great R wave amplitudes or high impedance.