Premium
A Comparative Evaluation of a Minute Ventilation Sensing and Activity Sensing Adaptive‐Rate Pacemakers During Daily Activities
Author(s) -
LAU CHUPAK,
WONG CHEUKKIT,
LEUNG WINGHUNG,
CHENG CHUNHO,
LO CHIWING
Publication year - 1989
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1989.tb06156.x
Subject(s) - medicine , ventilation (architecture) , intensive care medicine , meteorology , physics
Most studies evaluating the rate response of adaptive‐rate pacemakers have been based on treadmill or bicycle exercise. These studies disregard the fact that few pacemaker recipients voluntarily undertake such activities. The rate responses of nine patients (mean age 62 years, range 33 79 years) with implanted minute ventilation sensing (Meta) pacemakers were studied. The indications for pacing were complete heart block (seven patients), six sinus syndrome (one patient), and five nodal disease (one patient). Significant improvement in maximum distance covered during a 12‐minute walking test was observed in the rate adaptive compared to the VVI pacing mode (989 ± 104 vs 921 ± 90 m. P < 0.02). The rate responses of this pacemaker during daily activities were recorded with telemetry during a variety of structured daily activities. The rate responses were also compared to those of an externally attached Activitrax pacemaker in each patient and to a group of ten age and sex matched volunteers. For less strenuous activities such as walking, descending stairs, washing, and bed making, both pacemakers achieved adequate rate responses compared to normal subjects. For more strenuous activities, the Activitrax pacemaker failed to achieve an adequate rate response. For example. the pacing rate achieved on ascending stairs was lower than that achieved on descending stairs (92 ± 3 vs 102 ± 3 bpm, P < 0.02). The direction of rate responses was more appropriate for the Meta pacemaker. Similar to the normal subjects, the maximum rate was reached before the end of an activity with the Activitrax pacemaker. A significant delay was observed with the Meta pacemaker and the rate response was achieved during the recovery period of some activities (e.g., maximum pacing rate was achieved at 45 ± 35 sec after ascending stairs with the Meta pacemaker). In conclusion, the Meta pacemaker improved submaximal exercise capacity. This study suggests the two different rate adaptive pacemakers differed in their proportionality and speed of rate responses.