Prognostic significance of ventricular arrhythmia modified by ability to adapt to stressful situations

BACKGROUND: Ventricular arrhythmia is a risk factor for myocardial infarction and mortality but many individuals with this abnormality live long and healthy lives. The aim of this study is to analyse the prognostic significance of frequent and complex ventricular arrhythmia in men who differed regarding ability to adapt to a stressful situation. DESIGN: Prospective cohort study. METHODS: The serial Color Word Test is a semi-experimental way to assess how individuals behave in a stressful encounter. This test was included in the prospective cohort study 'Men born in 1914' together with 24-h ambulatory electrocardiographic recordings at a baseline examination in 1982/83. Behaviour in the test was categorized as either adaptive or maladaptive. Behaviour in the test and occurrence of ventricular arrhythmia at baseline were analyzed in relation to incidence of myocardial infarction and mortality during approximately 14 years of follow-up. RESULTS: Multivariate analyses showed that ventricular arrhythmia was not associated with the incidence of myocardial infarction or all-cause mortality in the presence of an adaptive behaviour. Ventricular arrhythmia together with a maladaptive behaviour was associated with the incidence of myocardial infarction [relative risk (RR) 2.43; 95% confidence interval (CI) 1.37 to 4.31] and with all-cause mortality (RR 1.56; 95% CI 1.01 to 2.41) during follow-up. CONCLUSIONS: A maladaptive behaviour in a stressful encounter makes men with electrocardiographically detected ventricular arrhythmias more vulnerable and thereby exposed to an increased risk of a future myocardial infarction and overall mortality.