Application of the dual sequence method to estimate the baroreflex sensitivity in patients with dilated cardiomyopathy

This study aims to estimate the spontaneous baroreflex sensitivity (BRS) with two different methods in patients with dilated cardiomyopathy (DCM). The new Dual Sequence Method (DSM) contains the analysis of spontaneous fluctuations of systolic blood pressure (SEP) and the corresponding beat-to-beat intervals (BBI) of heart rate (HR). Bradycardic as well as tachycardic fluctuations were considered for synchronized and a three beats shifted BBI-sequence. Whereas the established Z-coefficient method investigates the statistical dependence between SEP and HR values. The BRS and the number of fluctuations with a slope >5 msec/mmHg calculated by the DSM are significant lower (p<0.05) in DCM patients than in controls. Thus, the DSM leads in contrast to the Z-coefficient method to an improved precision in characterizing DCM patients.