Abnormal P-wave axis and myocardial ischemia development during mental stress.

Exposure to psychological stress has been associated with the development of sustained arrhythmias. Acute changes in atrial electrophysiology may serve as intermediate phenotypes for stress-induced atrial arrhythmia such as atrial fibrillation. We examined if acute mental stress was associated with the development of abnormal P-wave axis (aPWA) and the role played by stress-induced myocardial ischemia. A total of 359 patients (mean age = 56 ± 9.9 years; 62% men; 43% white) with stable coronary heart disease and normal baseline P-wave axis (between 0° and 75°) were studied. All patients underwent mental stress testing (speech task). A total of 46 (13%) patients developed abnormal P-wave axis during either stress or recovery (stress: n = 43, 12%; recovery: n = 12, 3%). A rise in heart rate during mental stress was associated with an increased risk of an abnormal P-wave axis (per 5-unit increase: OR = 1.37, 95%CI = 1.03, 1.30). Myocardial ischemia induced by mental stress was associated with an increased risk of aPWA in women (OR = 5.2, 95%CI = 1.7, 15.6) and not in men (OR = 0.1, 95%CI = 0.01, 1.01), p-interaction = 0.004). In conclusion, in a sizable proportion of patients, acute mental stress results in the development of an abnormal P-wave axis, and this phenomenon is related to increases in heart rate and, among women, mental stress-induced ischemia. Our data suggest that acute psychological stress can promote adverse transient electrical changes in the atria that may predispose to AF.