The effect of dual-chamber closed-loop stimulation on syncope recurrence in healthy patients with tilt-induced vasovagal cardioinhibitory syncope: a prospective, randomised, single-blind, crossover study

Background The closed-loop stimulation (CLS) pacemaker algorithm is a system that permanently monitors the contractile state of the myocardium and converts the intrinsic information into rate regulation. The role that the CLS algorithm plays in the prevention of syncope recurrences still remains unclear. The aim of our prospective, randomised, single-blind, crossover study was to evaluate the effect of dual-chamber CLS in the prevention of syncope recurrence in patients with refractory vasovagal syncope (VVS) and a cardioinhibitory response to head-up tilt test (HUT) during a 36months follow-up. Method sand results We studied 50 patients (mean age 535.1; 33 male) with the indication for permanent dual-chamber cardiac pacing for HUT-induced vasovagal cardioinhibitory syncope. They were randomised after 1month of stabilisation period to CLS algorithm features programmed OFF or ON for 18months each, using a crossover design. The number of syncopal and presyncopal episodes during active treatment was lower than those registered during no treatment (n syncopal episodes: 2 vs 15; p=0.007; n presincopal episodes: 5 vs 30; p=0.004). Lead parameters remained stable over time, and there were no lead-related complications. Conclusions Based on these 36months follow-up data, it is concluded that dual-chamber CLS is an effective algorithm for preventing syncope recurrences in healthy patients with tilt-induced vasovagal cardioinhibitory syncope.