[Ergospirometric findings in respiration- and QT-controlled pacemakers].
This study used ergospirometry with quantification of gas exchange parameters to analyze the beneficial effects of two sensors for rate responsive pacing: QT-interval and minute ventilation (MV). Bicycle exercise testing was performed with modulating VVIR pacing modes in random sequence. Rate responsiveness effected a mean increase of exercise tolerance of 31.1% in the QT group and 22.6% in the MV group. With both systems maximal oxygen uptake increased by 29.4% (QT) and 28.3% (MV). Oxygen consumption at the anaerobic threshold was improved by 28.3% (QT) and 32.1% (MV). The increase of cardiopulmonary parameters achieved by rate responsiveness was significant (p < 0.05) without significant difference in comparison between both groups. Despite the initially delayed rate increase at the onset of exercise mediated by the QT-interval, the programmed upper rate limit was satisfactorily attained by both principles. Thus, both sensors--minute ventilation and QT-interval--provide an adequate rate modulation in response to exercise and a marked improvement of cardiopulmonary work capacity.
Sigmund
M
M
Medizinische Klinik I, RWTH Aachen.
van Erckelens
F
F
Reupcke
C
C
Heiermann
B
B
Hanrath
P
P
D015308:Anaerobic Threshold; D001919:Bradycardia / Q000503:physiopathology* / Q000628:therapy; D004562:Electrocardiography; D005080:Exercise Test; D006327:Heart Block / Q000503:physiopathology* / Q000628:therapy; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D010138:Pacemaker, Artificial; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012804:Sick Sinus Syndrome / Q000503:physiopathology* / Q000628:therapy; D013147:Spirometry
Spiroergometrische Befunde bei atmungs- und QT-gesteuerten Schrittmachern.