P wave height during incremental exercise in patients with chronic airway obstruction.
We examined changes in P wave height in lead 2 of an ECG obtained during progressive exercise in 23 patients with COPD, and measured both P wave changes and pulmonary hemodynamics during exercise at a constant workload corresponding to approximately 50 to 60 percent of VO2 max in nine patients. The P wave response to exercise (delta P/delta VO2, %/ml/min), estimated by the relationship between percentage of change in P wave height and VO2, was significantly greater (p less than 0.01) in 15 patients who had a decrease in PaO2 with exercise (group A) than eight patients who did not have a fall in PaO2 with exercise (group B). There was a significant negative correlation between change in PaO2 and change in P wave height from rest to maximal exercise (r = -0.68, p less than 0.001). Oxygen therapy in nine patients in group A reduced the increase in P wave height during exercise. Furthermore, change in P wave height from rest to exercise correlated significantly with that of mean pulmonary artery pressure (r = 0.75, p less than 0.01). These results suggest that increase in P wave height during exercise in COPD patients is related partly to oxygen desaturation during exercise, and continuous measurement of P wave change may be useful for noninvasively predicting the pulmonary vascular pressure response to exercise.
Hida
W
W
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Taguchi
O
O
Kikuchi
Y
Y
Ohe
M
M
Shirato
K
K
Takishima
T
T
D000368:Aged; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D008168:Lung / Q000098:blood supply*; D008173:Lung Diseases, Obstructive / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption