Day-to-day reproducibility of mental stress-induced abnormal left ventricular function response in patients with coronary artery disease and its relationship to autonomic activation

Background Mental stress (MS) results in left ventricular (LV) dysfunction in approximately half of the patients with symptomatic coronary artery dise ase (CAD) and is an adverse prognostic sign. The reproducibility of various MS tasks in inducing LV dysfunction and its relationship to autonomic acti vation in patients with CAD are not known. We studied the reproducibility o n different days of 3 commonly used MS tasks on LV ejection fraction (LVEF) , heart rate, blood pressure, and rate-pressure product and the relationshi p of reproducibility to autonomic activation as determined by heart rate va riability in patients with chronic stable angina. Methods and Results. Ten patients with CAD and exercise-induced ischemia wh o had abnormal LVEF responses to at least one MS task from a battery of MS tasks (mental arithmetic, anger recall, and color Stroop test) while underg oing continuous ambulatory Holter and LV function monitoring underwent a se cond MS testing 4 to 8 weeks later, with no change in clinical status or ca rdiac medications in the interim. Autonomic tone was determined from indexe s of heart rate variability (high frequency [HF] for parasympathetic activi ty and low frequency [LF] and low frequency/high frequency ratio [LF/HF] fo r sympathetic activity). MS tasks resulted in a small increase in heart rat e (P < .0001), a modest increase in systolic blood pressure (P < .0001) and the rate-pressure product (P < .0001), and a small but statistically signi ficant increase in LF (P < .002) and LF/HF (P < .0001), but no change in HP compared with baseline. These changes were highly reproducible over the 2 studies. With a fall in LVEF of 5% or greater considered as indicative of a n MS-positive task, anger recall was the most effective and reproducible MS task in inducing LV dysfunction, MS-positive tasks were associated with a greater increase in systolic blood pressure (P =.005), Anger recall resulte d in a trend toward a higher increase in systolic blood pressure (P =.08) t han the other MS tasks. In MS tasks with inconsistent LVEF responses in the 2 studies (LV dysfunction present in one study but not in the other), ther e was significant parasympathetic withdrawal (P =.02) in MS-negative tasks but no difference in sympathetic activation. On the other hand, in MS tasks with consistent LV dysfunction on both. occasions, there was no difference in parasympathetic or sympathetic activation, MS-positive tasks were not a ccompanied by chest pain or ST depression. Conclusions. Of the commonly used MS tasks, anger recall produces LV dysfun ction with the highest frequency and is the most reproducible task when ret ested 4 to 8 weeks later in patients with CAD. These data are relevant for planning studies of the effects of therapeutic interventions on MS-induced LV dysfunction.