Changes in ventricular repolarization duration during typical daily emotion in patients with Long QT syndrome

Intense emotions are known triggers of sudden cardiac death. However, the effect of typical daily emotion on repolarization has not been examined. We examined whether QT interval changes as a function of typical daily emotion in patients at risk for cardiac events in the context of emotion.

We studied 161 patients (n = 114 females; mean age, 35 years) with the congenital form of the Long QT Syndrome during daily activities. Each day for 3 days, a 12-hour Holter recording was completed. Patients were paged ten times per day at random times and rated the intensity of 16 prespecified emotions during the preceding 5 minutes. Measurements of QT interval and interbeat intervals were synchronized with emotion ratings.

Low Arousal Positive Affect was associated with significant increases in QT interval corrected for heart rate (using Fridericia's QTc) (p < .001), whereas higher arousal Activated Positive Affect (p < .001) and Activated Negative Affect (p < .01) were associated with significant decreases in QTc. Changes in QTc as a function of daily emotion ranged from 5-ms increases to 11-ms decreases. High-frequency heart rate variability (vagal tone) was positively correlated with QTc (p < .001). The effects of each positive emotion variable on QTc were greater in LQT2 than LQT1 patients (p < .001).

Ventricular repolarization duration (QTc) changes dynamically as a function of daily emotion. These changes are relatively small and do not constitute a risk in themselves. In the context of other risk factors, however, they may contribute to ventricular arrhythmias in vulnerable populations.