[Short-term heart rate turbulence analysis versus variability and baroreceptor sensitivity in patients with dilated...

New methods for the analysis of arrhythmias and their hemodynamic consequences have been applied in risk stratification, particularly to patients after myocardial infarction. This study investigates the suitability of shortterm heart rate turbulence (HRT) in comparison to heart rate and blood pressure variability as well as baroreceptor sensitivity analyses to characterize the regulatory differences in patients with dilated cardiomyopathy (DCM) and healthy controls. In this study, 30 minutes data from noninvasive continuous blood pressure and ECG of 37 DCM patients and 167 controls under standard resting conditions were analyzed. The results showed highly significant differences between DCM patients and controls in heart rate and blood pressure variability as well as baroreceptor sensitivity parameters. Applying a combined heart rate-blood pressure trigger, in 24.3% (9) of the DCM patients and in 11.3% (19) of the controls ventricular premature beats were detected. This fact demonstrates the constricted applicability of short-term HRT analyses. However, the HRT parameters showed significant differences in this subgroup with ventricular premature beats (Turbulence Onset: DCM: 1.80+/-2.72, CONTROLS: -4.34+/-3.10, p<0.001; Turbulence Slope: DCM: 6.75+/-5.50, CONTROLS: 21.30+/-17.72, p = 0.021). Considering all (including HRT) parameters in the subgroup with ventricular beats, a discrimination rate between DCM patients and controls of 88.0% was obtained (max. 6 parameters). In comparison, in the total group this rate was 86.3% (without HRT parameters). The comparable classification rates and the high correlations between heart rate turbulence and variability and baroreflex parameters point to a more universal applicability of the last-mentioned methods.