Abstract
BACKGROUND: Heart rate turbulence (HRT) has recently been described as a strong, independent risk stratifier in postinfarct patients. To date, however, the incidence of false positive HRT findings in adults is unknown. Therefore, we performed a blinded, retrospective analysis of HRT in a prospectively collected database of 110 apparently healthy persons to determine the prevalence and clinical significance of abnormal HRT findings in healthy controls using previously published cut-off values. METHODS AND RESULTS: The study included 43 out of 110 apparently healthy adults, in whom a sufficient number of ventricular premature beats were available for HRT analysis on 24-hour Holter recordings. The HRT slope was dichotomized at 2.5 ms per R-R interval and HRT onset was dichotomized at 0% using previously established criteria to define an abnormal HRT analysis in postinfarct patients. Using these definitions, abnormal HRT results were found in 2 out of 43 controls (5%) for HRT slope and in 8 out of 43 controls (19%) for HRT onset without any cardiac deaths during 32 +/- 15 months follow-up. CONCLUSIONS: The incidence of false positive HRT results in healthy middle-aged volunteers is low for HRT slope (5%), but not for HRT onset (19%) when previously published cut-off values are used to define abnormal HRT results. Thus, HRT slope dichotomized at 2.5 ms per R-R interval, but not HRT onset dichotomized at 0%, may be used as a relatively specific tool for risk stratification in middle-aged persons.