Acute psychological stress and the propensity to ventricular arrhythmias -Evidence for a linking mechanism

Aims This study was designed to test the hypothesis that acute psychologica l stress is capable of inducing an increase in the dispersion of repolariza tion in patients with underlying coronary artery disease. Methods and Results Twenty four patients undergoing elective coronary angio graphy were studied, 17 with significant coronary artery disease and seven with normal coronary arteries. Following coronary angiography they were sub jected to a series of timed cognitive tests, well known to induce acute psy chological stress. An individual's perception of stress was assessed by Vis ual analogue scales. Serial ECGs were recorded during the cognitive tests a nd QT, QRS and JT intervals measured from which QT, QRS and JT dispersion w ere calculated. Psychological stress was reported by the seven patients wit h normal coronaries and 14 of the 17 with coronary artery disease. In patie nts who experienced stress a marked increase in QT dispersion, reflecting J T dispersion, was observed in those with coronary artery disease (F=22.4, P =0.0001) but not in those without. At baseline there was no difference in Q T dispersion between those with and without coronary artery disease (27-57 ms, 17-53 ms, P greater than or equal to 0.5). Conclusion Acute psychological stress induces an increase in QT dispersion in patients with underlying coronary artery disease due to changes in JT di spersion (rather than QRS dispersion). This suggests that psychological str ess modifies the dispersion of repolarization through ischaemia related cha nges in action potential duration. (Eur Heart J 2000; 21: 1023-1028) (C) 20 00 The European Society of Cardiology.