Background: The risk of new-onset atrial fibrillation (AF) is associated with acute episodes of sadness, anxiety, anger, and stress. Antidepressants (ADs) may help stabilize emotional lability and, as a result, abnormal autonomic consequences of emotional stress that may lead to AF. Laboratory studies of changes in left atrial electrophysiology during mental stress may help to understand the role of ADs on investigating atrial arrhythmia.
Hypothesis: ADs are associated with blunted mental stress changes in left atrial electrophysiology as measured via P-wave terminal force in lead V1 (PTFV1) which is risk marker of future AF and CVD death.
Methods: We studied 228 subjects with stable coronary heart disease submitted to a laboratory-based mental (speech task) stress test, and serial 12-lead digital ECG’s at rest, stress, and recovery (500 Hz sampling frequency). PTFV1, was calculated as the product of the duration (ms) and depth (μV) of the downward deflection (terminal portion) of the median P-wave in lead V1. The change in PTFV1 from rest to stress was the primary outcome, and antidepressant use was the main exposure. Multivariable linear regression models were performed to adjust for sociodemographic, CVD risk factors, and BP/heart rate changes with stress.
Results: The mean age (SD) was 64 (9) years; 77% were men and 66% white; 43 patients (19%) reported using ADs. The mean negative PTFV1 at rest was - 2,876 ± 2,534 μV*ms; this worsened (became more negative) with stress (-3,250 ± 2,719 μV*ms, p=0.01). ADs were associated with a blunted, or less negative, PTFV1 change with stress (B= 467 μV*ms, p=0.048) despite multivariable adjustment. In subgroup analysis, patients not taking ADs experienced an acute change in PTFV1 [mean change= -461, 95%CI= (-135, -787); p=0.01. Patients taking ADs did not show any change with stress [mean change= -6.0, 95%CI=(-657, 669); p=0.99]. The interaction between groups was statistically significant (p<0.05).
Conclusion: In subjects with CAD, PTFV1 worsens with acute mental stress, but only in those who are not taking ADs. ADs may have a psychophysiological stabilizing effect, although further research in randomized studies are needed.