Measurement of Minute Ventilation with Different DDDR Pacemaker Electrode Configurations.

A rate responsive minute ventilation (VE) pacemaker was implanted in 49 patients (70.8 ± 40.0 years). A Chorus RM 7034 pacemaker was implanted in 43 patients and an Opus RM 4534 in six patients. Four sensor configurations 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 patients; and floating configuration (VDD single-pass lead) in 3 patients. The patients carried out 57 exercise tests in all with cardiopulmonary recording (CPX). Real VE and oxygen consumption (VO₂) were recorded by the CPX, the VE measured by the sensor (VE sensor) was recorded in the pacemaker memory. The mean correlation between VE and VE sensor was 0.90 ± 0.08 (P <0.001) and between VO₂ and VE sensor was 0.86 ± 0.10 (P <0.001). The mean correlation between VE and VE sensor by configuration 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 conclude that uniploar electrodes can be used in VDDR, AAIR, VVIR, or DDDR modes to measure VE. [ABSTRACT FROM AUTHOR]