Paradoxical elevation of threshold to angina pectoris by cold pressor test in men with significant coronary artery disease.
Patients with coronary artery disease (CAD) have angina pectoris at varying levels of myocardial oxygen demand. Fluctuations in coronary blood supply due to dynamic changes in coronary vasomotor tone are believed to be responsible for this variation in angina threshold. Cutaneous cold application produces an inappropriate increase in coronary vascular resistance in patients with CAD. To assess the effect of a coronary vasoconstrictor stimulus during exercise (when there are competitive stimuli for coronary dilatation), 16 men with documented CAD and angina underwent 2 exercise tolerance tests, 1 performed for control purposes and the other during cold application (hand and forearm immersed in ice). The cold pressor test elicited an increase in systolic blood pressure at rest (134 vs 159 mm Hg, p less than 0.02) at the end of stage I (145 vs 165 mm Hg, p less than 0.02) and at peak exercise (154 vs 166 mm Hg, p less than 0.05). The diastolic pressure was similarly increased during cold pressor exercise test, but the heart rate showed little or no change. Most patients (11 of 16) tolerated equal or greater double products (heart rate X systolic pressure X 10(-3) at angina (17 vs 20, p less than 0.02), 1-mm ST-segment depression (16 vs 18, p less than 0.05) and peak exercise (18 vs 20, p less than 0.08) during cold pressor exercise test as compared with the baseline exercise test, without a reduction in exercise capacity.(ABSTRACT TRUNCATED AT 250 WORDS)
Nesto
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RW
Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts.
Lamas
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GA
Barry
J
J
D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000175:diagnosis*; D001794:Blood Pressure; D003080:Cold Temperature; D003326:Coronary Circulation; D003327:Coronary Disease / Q000175:diagnosis*; D003331:Coronary Vessels / Q000503:physiopathology; D004562:Electrocardiography; D005080:Exercise Test; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption; D014655:Vascular Resistance