Background: Although psychological stress is known to favor ventricular arrhythmic events, there is no evidence that stress management intervention decreases ventricular electrical instability in implantable cardioverter-defibrillator (ICD) patients. The aim of the study was to determine whether cognitive behavioral therapy (CBT) results in a decrease of arrhythmic events requiring ICD intervention through an improvement in sympathovagal balance.
Methods: Of 253 consecutive ICD patients (age 59 +/- 10 years, 64 men), 70 were randomly assigned to CBT (n = 35) or conventional medical care (n = 35). Measures of heart rate variability, psychological well-being, and quality of life were assessed at baseline, 3 months, and 1 year. The primary outcome was appropriate ICD shock.
Results: Although, it was not statistically different, the number of patients requiring shocks was less in the CBT group than in the conventional treatment group. At 3 months, among patients without antiarrhythmic drugs, none of the subjects in the CBT group had experienced arrhythmic events requiring ICD intervention, as compared with 4 in the control group (P < .05). At 12 months, there was no difference in the number of arrhythmic events requiring therapy between the CBT group versus the control group. Among heart rate variability indexes, daytime pNN 50 and nocturnal SDNN improved significantly in the CBT group, as compared with the control group.
Conclusions: By decreasing anxiety and possibly improving sympathovagal balance, cognitive behavior therapy may decrease the propensity for ventricular arrhythmias in ICD patients. However, these effects appear to be limited over time.