MEASUREMENT OF MINUTE VENTILATION WITH DIFFERENT DDDR PACEMAKER ELECTRODE CONFIGURATIONS

A rate responsive minute ventilation (VE) pacemaker was implanted in 4 9 patients (70.8 +/- 40.0 years). A Chorus RM 7034 pacemaker was impla nted in 43 patients and an Opus RM 4534 in six patients. Four sensor c onfigurations were compared: atrial configuration (bipolar atrial lead ) in 34 patients; ventricular configuration (bipolar ventricular lead) in 6 patients; unipolar configuration (double unipolar leads) in 6 pa tients; and floating configuration (VDD single-pass lead) in 3 patient s. The patients carried out 57 exercise tests in all with cardiopulmon ary recording (CPX). Real VE and oxygen consumption (VO2) were recorde d by the CPX, the VE measured by the sensor (VEsensor) nas recorded in the pacemaker memory. The mean correlation between VE and VEsensor wa s 0.90 +/- 0.08 (P < 0.001) and between VO2 and VEsensor was 0.86 +/- 0.10 (P < 0.001). The mean correlation between VE and VEsensor by conf iguration type were as follows: atrial configuration = 0.89 +/- 0.08; ventricular configuration = 0.95 +/- 0.05; unipolar configuration = 0. 87 +/- 0.14; and floating configuration = 0.88 +/- 0.05. In conclusion , VE may be reliably measured using different electrode configurations . A study conducted in a larger population should allow one to conclud e that uniploar electrodes can be used in VDDR, AAIR, VVIR, or DDDR mo des to measure VE.