Aging, autonomic function, and the perception of angina.

Objective: To determine the effects of age and autonomic function on the perception of angina.
Design: Prospective evaluation of the relations between anginal perceptual threshold, autonomic function, and systolic blood pressure in patients with symptomatic coronary artery disease. Statistical analysis was by non-parametric techniques.
Setting: Cardiology departments of a district general hospital and a post-graduate teaching centre.
Subjects: 82 non-diabetic men with typical exertional angina and coronary artery disease confirmed by arteriography (n = 64) or a history of Q wave infarction (n = 18).
Main Outcome Measures: Age, anginal perceptual threshold, autonomic function, and blood pressure. Anginal perceptual threshold was defined as the time from onset of 0.1 mV ST depression to the onset of angina during treadmill stress testing. Autonomic function was measured as the ratio of peak heart rate during the Valsalva manoeuvre to the minimum rate after release.
Results: Anginal perceptual threshold showed a weak but significant correlation with age, with older patients tending to have a longer interval between the onset of ST depression and the onset of angina. Comparison of patients in the upper and lower quartile age ranges showed a difference of 50 seconds between median threshold measurements. Blood pressure and heart rate responses to the Valsalva manoeuvre also correlated with age, but neither variable correlated with the anginal perceptual threshold.
Conclusions: In non-diabetic men with coronary artery disease the perception of angina tends to deteriorate with advancing age. The mechanism is unclear but is not attributable solely to alterations in blood pressure or autonomic function.