Effects of mental stress on coronary epicardial vasomotion and flow velocity in coronary artery disease: Relationship with hemodynamic stress responses

OBJECTIVES This study examines the prevalence and hemodynamic determinants of mental stress-induced coronary vasoconstriction in patients undergoing d iagnostic coronary angiography. BACKGROUND Decreased myocardial supply is involved in myocardial ischemia t riggered by mental stress, but the determinants of stress-induced coronary constriction and flow velocity responses are not well understood. METHODS Coronary vasomotion was assessed in 76 patients (average age 59.9 /- 10.4 years; eight women). Coronary flow velocity responses were assessed in 20 of the 76 patients using intracoronary Doppler flow. Repeated angiog rams were obtained after a baseline control period, a 3-min mental arithmet ic task and administration of 200 mug intracoronary nitroglycerin. Arterial blood pressure (BP) and heart rate assessments were made throughout the pr ocedure. RESULTS Mental stress resulted in significant BP and heart rate increases ( p < 0.001). Coronary constriction (>0.15 mm) was observed in 11 of 59 patie nts with coronary artery disease (CAD) (18.6%). Higher mental stress presse r responses were associated with more constriction in diseased segments (r Delta SBP = -0.26, r Delta DBP = -0.30, r Delta MAP = -0.29; p's < 0.05) bu t not with responses in nonstenotic segments. The overall constriction of d iseased segments was not significant (p > 0.10), whereas a small but signif icant constriction occurred in nonstenotic segments (p = 0.04). Coronary fl ow velocity increased in patients without CAD (32.2%; p = 0.008), but not i n patients with CAD (6.4%5 p = ns). Cardiovascular risk factors were not pr edictive of stress-induced vasomotion in patients with CAD. Coronary vasoco nstriction in angiographically diseased arteries varies with hemodynamic re sponses to mental arousal. CONCLUSIONS Coronary flow responses are attenuated in CAD patients. Thus, c ombined increases in cardiac demand and concomitant reduced myocardial bloo d supply may contribute to myocardial ischemia with mental stress. (J Am Co ll Cardiol 2001;37:1359-66) (C) 2001 by the American College of Cardiology.