CHEMOREFLEXSENSITIVITY AND BAROREFLEXSENS ITIVITY AMONG PATIENTS WITHSURVIVED SUDDEN CARDIAC DEATH

Introduction. To evaluate patients with an increased risk of sudden ca rdiac death the analysis of ventricular late potentials, heart rate va riability and baroreflexsensitivity is helpful. However, the predictio n of malignant arrhythmic events cannot be performed with sufficient a ccuracy. For a better identification of high risk patients other metho ds are necessary. In this study the impact of the chemoreflexsensitivi ty for the prediction of ventricular tachyarrhythmias was investigated . Methods. Out of 44 patients included in the study, 23 were survivors of sudden cardiac death (SCD). Seven patients suffered from sustained monomorphic ventricular tachycardias, 14 had no arrhythmic events in their prior history. For the investigation of the baroreflexsensitivit y (BRS) systolic blood pressure was augmented by Norfenefrin (Novadral ) and the resulting increase of RR-intervals was measured in the surfa ce-EGG. For determination of the chemoreflex-sensitivity (ChRS) the ra tio of the RR-interval-shift and the blood pressure shift during a 5-m in inhalation of oxygen with a nose mask was formed. Results. Patients with aborted SCD showed significantly decreased values for the ChRS c ompared to those patients without an arrhythmic event in their prior h istory (2.49 +/- 1.86 vs. 6.75 +/- 6.79 mm Hg, p < 0.001). In contrast , for the BRS no significant differences could be found (5.23 +/- 3.95 vs. 5.34 +/- 3.10 mm Hg, p = n. s.). Patients with aborted sudden car diac death and inducible tachyarrhythmias during the electrophysiologi c study showed significantly lower values of BRS and ChRS compared to patients without inducibility. Conclusion. As a new method for identif ication of patients with an increased risk of sudden cardiac death the analysis of chemoreflex-sensitivity seems feasable and indicates an i ncreased arrhythmic risk with a high sensitivity. The predictive impac t has to be corroborated in larger patient collectives by prospective studies.