INTRODUCTION: A decline in the acceleration of the heart rate (HR, heart rate turbulence, HRT) after a ventricular premature capture is associated with increased mortality in patients suffering from coronary artery disease. The physiological properties of HRT have not been evaluated in a large human cohort. METHODS: In 95 healthy individuals, HRT parameters onset (TO) and slope (TS) as well as the turbulence timing (TT) were calculated from 24-hour Holter ECGs. With the help of a simple, linear, weighted regression model, gender specific differences of TO and TS were compared. A multiple linear regression model served to evaluate the influence of age and the basic HR preceding the ventricular premature contraction (VPC) on HRT. RESULTS: The median of TT is present in regression line #5. We discovered that, in men and women, TO is reduced as basic HR rises (p<0.01). In contrast, analysis of TS showed a divergence: in men, TS declines as basic HR increases. However, basic HR modifies TS in women to some extent (p<0.01). A multiple, linear regression model revealed a decrease of HRT with increasing age in men. CONCLUSIONS: The acceleration of HR after a ventricular premature beat occurred within the first 11 beats in more than 75% of our healthy individuals. An increased HR prior to VPC affects HRT in men. Increasing age leads to an attenuation of HRT in men and to a reduction of TO in women. These results emphasise the significance of the physiological properties of HRT when using HRT for risk stratification, especially in elderly patients.
INTRODUCTION: A decline in the acceleration of the heart rate (HR, heart rate turbulence, HRT) after a ventricular premature capture is associated with increased mortality in patients suffering from coronary artery disease. The physiological properties of HRT have not been evaluated in a large human cohort. METHODS: In 95 healthy individuals, HRT parameters onset (TO) and slope (TS) as well as the turbulence timing (TT) were calculated from 24-hour Holter ECGs. With the help of a simple, linear, weighted regression model, gender specific differences of TO and TS were compared. A multiple linear regression model served to evaluate the influence of age and the basic HR preceding the ventricular premature contraction (VPC) on HRT. RESULTS: The median of TT is present in regression line #5. We discovered that, in men and women, TO is reduced as basic HR rises (p<0.01). In contrast, analysis of TS showed a divergence: in men, TS declines as basic HR increases. However, basic HR modifies TS in women to some extent (p<0.01). A multiple, linear regression model revealed a decrease of HRT with increasing age in men. CONCLUSIONS: The acceleration of HR after a ventricular premature beat occurred within the first 11 beats in more than 75% of our healthy individuals. An increased HR prior to VPC affects HRT in men. Increasing age leads to an attenuation of HRT in men and to a reduction of TO in women. These results emphasise the significance of the physiological properties of HRT when using HRT for risk stratification, especially in elderly patients.