EXAGGERATED REACTIVITY TO MENTAL STRESS IS ASSOCIATED WITH EXERCISE-INDUCED MYOCARDIAL-ISCHEMIA IN AN ASYMPTOMATIC HIGH-RISK POPULATION

Background This study was done to determine whether cardiovascular rea ctivity to mental stress is associated with exercise-induced occult is chemia in an asymptomatic population at high risk for premature corona ry heart disease (CHD). Methods and Results One hundred fifty-two sibl ings of persons with premature CHD underwent mental stress testing. Ex ercise thallium tomography and 24-hour Holter monitoring were also per formed. Hemodynamic changes were monitored during both stressors. Sibl ings positive for exercise-induced ischemia were offered cardiac cathe terization, During mental stress, siblings with an abnormal exercise E CG and/or thallium scan (n=15) had greater maximal increases in systol ic blood pressure (SBP, P=.0004) and diastolic blood pressure (DBP, P= .05) and had greater heart rate variability in the normalized low freq uency domain of an analysis of Holter monitor recordings, compared wit h siblings without exercise-induced ischemia. Coronary arteriography c onfirmed coronary atherosclerosis in 85% of siblings with exercise-ind uced ischemia. Regression analyses showed that occult ischemia during exercise was a strong independent predictor of maximal change in SBP a nd DBP during mental stress. A multivariate logistic model demonstrate d that siblings with exercise-induced occult ischemia were 21 times mo re likely to be ''hot'' responders (top quartile of change in SBP and DBP) during mental stress. Conclusions An exaggerated cardiovascular r esponse to mental stress is associated with exercise-induced myocardia l ischemia in persons with preclinical coronary heart disease.