Case studies on the effect of exercise and hot water submersion on intracardiac temperature and the performance of a pacemaker which varies pacing rate based on temperature.
The effectiveness of using blood temperature change as an indicator to automatically vary heart rate physiologically was evaluated in 3 patients implanted with Model Sensor Kelvin 500 (Cook Pacemaker Corporation, Leechburg, PA, USA) pacemakers. Each patient performed two block-randomized treadmill exercise tests: one while programmed for temperature-based, rate-modulated pacing and the other while programmed without rate modulation. In 1 pacemaker patient and 4 volunteers, heart rates were recorded during exposure to a hot water bath. Blood temperature measured at 10 sec intervals and pacing rate measured at 1 min intervals were telemetered to a diagnostic programmer and data collector for storage and transfer to a computer. Observation comments and ECG-derived heart rates were manually recorded. The temperature-based pacemaker was shown to respond promptly not only to physical exertion but also to emotionally caused stress and submersion in a hot bath. These events cause increased heart rate in the normal heart. Using a suitable algorithm to process the measurement of blood temperature, it was possible to produce appropriate pacing rates in paced patients.
Fearnot
N E
NE
Hillenbrand Biomedical Engineering Center, Purdue University, West Lafayette, IN 47907.
Kitoh
O
O
Fujita
T
T
Okamura
H
H
Smith
H J
HJ
Calderini
M
M
D000368:Aged; D001494:Baths; D001790:Blood Physiological Phenomena; D001831:Body Temperature; D004562:Electrocardiography; D004867:Equipment Design; D005260:Female; D006339:Heart Rate; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D005082:Physical Exertion; D013315:Stress, Psychological / Q000503:physiopathology; D013821:Thermometers; D014867:Water
D014867:Water