Exaggerated reactivity to mental stress is associated with exercise-induced myocardial ischemia in an asymptomatic high-risk population.

Abstract

This study was done to determine whether cardiovascular reactivity to mental stress is associated with exercise-induced occult ischemia in an asymptomatic population at high risk for premature coronary heart disease (CHD). One hundred fifty-two siblings of persons with premature CHD underwent mental stress testing. Exercise thallium tomography and 24-hour Holter monitoring were also performed. Hemodynamic changes were monitored during both stressors. Siblings positive for exercise-induced ischemia were offered cardiac catheterization. During mental stress, siblings with an abnormal exercise ECG and/or thallium scan (n=15) had greater maximal increases in systolic blood pressure (SBP, P=.0004) and diastolic blood pressure (DBP, P=.05) and had greater heart rate variability in the normalized low frequency domain of an analysis of Holter monitor recordings, compared with siblings without exercise-induced ischemia. Coronary arteriography confirmed coronary atherosclerosis in 85% of siblings with exercise-induced ischemia. Regression analyses showed that occult ischemia during exercise was a strong independent predictor of maximal change in SBP and DBP during mental stress. A multivariate logistic model demonstrated that siblings with exercise-induced occult ischemia were 21 times more likely to be "hot" responders (top quartile of change in SBP and DBP) during mental stress. An exaggerated cardiovascular response to mental stress is associated with exercise-induced myocardial ischemia in persons with preclinical coronary heart disease.