Happiness and Stress Alter Susceptibility to Cardiac Events in Long QT Syndrome

Objective: We sought to determine whether the circumstances preceding an arrhythmic event differed from those preceding a prior control occasion in patients with Long QT Syndrome (LQTS), a well-characterized genetic disorder that puts affected individuals at risk for sudden cardiac death. Methods: Thirty-eight patients (89% female) with LQTS completed a "case-crossover interview" in which each patient served as his/her own control by reporting on circumstances preceding an arrhythmic event (syncope, aborted cardiac arrest, or defibrillator discharge) and preceding a control occasion (the next-to-last birthday). On average the interview was conducted 17 months after the cardiac event and control occasion. Results: During the 24-hour period preceding the cardiac event compared to the day before the control occasion, psychological stress was elevated, peak happiness was reduced, and peak exertion was not significantly different. Rated for the 6-month intervals preceding the event and control occasions, none of these three variables was significantly associated with events. Conclusions: Happiness is associated with a reduction in the 24-hour risk of cardiac events in patients with LQTS, with stress having an opposite effect. To our knowledge, this is the first report indicating that positive emotion may have a protective effect on life-threatening ventricular arrhythmias. This study lends further support to the role of emotions in influencing cardiac events in arrhythmia-prone patients.