The Tilt Test-Induced REsponse in Closed-loop Stimulation (TIRECS) Study

Effects of Closed-loop Stimulation vs. DDD Pacing on Prevalence and Timing of Haemodynamic Variations and Clinical Prodromes Induced by Head-up Tilt Test in Patients With Refractory Cardioinhibitory Vasovagal Syncope. The TIRECS Study

Multicentre, prospective, double blinded, randomized study designed as an intrapatient comparison to evaluate the effects of the Biotronik Closed-loop Stimulation algorithm on prevalence and timing of haemodynamic variations and clinical prodromes induced by head-up tilt test in patients underwent pacemaker implantation for refractory cardioinhibitory vasovagal syncope.

A total of 30 patients with refractory cardioinhibitory vasovagal syncope receiving a Biotronik pacemaker with Closed-loop Stimulation (CLS) algorithm will be enrolled in the study. Two head-up tilt test (HUTT), one during DDD 60/min pacing with CLS algorith turned off (CLS-OFF) and the other during DDD-CLS pacing (CLS-ON), will be performed one week apart; patients will be randomly and blindly assigned to group A (n=15, first HUTT in CLS-ON mode) or B (n=15, first HUTT in CLS-OFF mode). During HUTT heart rate, blood pressure, and the incidence of clinical prodromes and syncope wil be recorded.

Inclusion Criteria:

• Refractory cardioinhibitory vasovagal syncope treated with permanent pacemaker;
• Pacemaker Biotronik with Closed-loop Stimulation algorithm
• Ability to perform a head up tilt test
• Completion of the 18th year of age

Exclusion Criteria:

• Contraindications to head up tilt test