The association between acute mental stress and abnormal left atrial electrophysiology

Background: Acute stress may trigger atrial fibrillation (AF), but the underlying mechanisms are unclear. We examined if acute mental stress results in abnormal left atrial electrophysiology as detected by more negative deflection of P-wave terminal force in lead V-1 (PTFV1), a well-known marker of AF risk. Methods and results: We examined this hypothesis in 422 patients (mean age = 56 +/- 10 years; 61% men; 44% white) with stable coronary heart disease who underwent mental (speech task) stress testing. PTFV1 was defined as the duration (milliseconds) times the value of the depth (mu V) of the downward deflection (terminal portion) of the P-wave in lead V-1 measured on digital electrocardiograms (ECG). Electrocardiographic left atrial abnormality was defined as PTFV1 <= -4000 mu V*ms. Mean PTFV1 values during stress and recovery were compared with rest. The percentage of participants who developed left atrial abnormality during stress and recovery was compared with the percentage at rest. Compared with rest, PTFV1 became more negative during mental stress (mean change = -348,95% CI=[-515,-182]; P< 0.001) and no change was observed at recovery (mean change = 12, 95% CI =[-148, 172]; P = 0.89). A larger percentage of participants showed left atrial abnormality on ECGs obtained at stress (n = 163, 39%) and recovery (n = 142, 34%) compared with rest (n = 127, 30%). Conclusion: Acute mental stress alters left atrial electrophysiology, suggesting that stressful situations promote adverse transient electrical changes to provide the necessary substrate for AF.