Closed Loop Stimulation: Therapy for Malignant Neurocardiogenic Syncope

Summary Vasovagal syncope (VVS) is often preceded by fluctuations in sympathetic activity and is frequently accompanied by sudden-onset bradycardia. Pacemaker therapy can compensate for the bradycardia and thus prevent loss of consciousness and related subsequent injury to the patient. Pacemakers with Closed Loop Stimulation (CLS) may be particularly effective because they adapt the pacing rate to the contraction dynamics of the right ventricle and can therefore intervene directly in the generation mechanism of the VVS. In this study, we examined 22 patients with malignant VVS (16 female, age 55.5 ± 17.3 years, range 17 − 77 years). Inos 2+ CLS pacemakers were implanted in 17 patients (nine female, age 63.0 ± 9.7 years) who were resistant to conventional β-blocker therapy. A head-up tilt test prior to implantation was used to classify the VVS as either syncope of the cardioinhibitory type IIa (n = 13) or IIb (n = 1), or as syncope of the vasodepressor type III (n = 3). Another tilt-table test was performed following a recovery period of at least one week after the pacemaker implantation. The patients' further disease progress in daily life regarding syncopal events was followed for a period of 4 − 48 months after the pacemaker implantation. The results from the tilttable examinations and daily life after pacemaker implantation suggest that type IIa and IIb syncope were prevented successfully by CLS pacing. In patients with VVS of type III, the symptoms could be alleviated and the prodromal phase extended; however, VVS could not be completely suppressed. None of the 17 patients reported VVS in daily life after the pacemaker implantation, and the quality of life improved for all patients.