Benefit of Dual-chamber Pacing With Closed Loop Stimulation (CLS) in Tilt-induced Cardioinhibitory Reflex Syncope

Benefit of Dual-chamber Pacing With Closed Loop Stimulation (CLS) in Tilt-induced Cardioinhibitory Reflex Syncope. A Randomized Double-blind Parallel Trial.

The purpose of this study is to assess whether the Closed Loop Stimulation (CLS) in addition to the DDD pacing is effective in reducing syncopal recurrences. The study hypothesis is that DDD pacing with CLS stimulation is able to prevent syncopal recurrences completely or partially by transforming syncope in pre-syncope.

Inclusion Criteria:

Patients affected by clinical diagnosis of reflex syncope who meet all the following criteria:

• age >=40 years
• significant limitation of social and working life due to unpredictable or frequent syncope recurrences, ≥2 within the last year.
• type 2B cardio-inhibitory response to TT (according to the VASIS classification).
• Alternative therapies have failed or were not feasible.
• exclusion of other possible competitive causes of syncope.

Exclusion Criteria:

- Any other indication to IPG, implantable defibrillator (ICD), cardiac resynchronization therapy (CRT), according to current guidelines

Any cardiac dysfunctions possibly leading to loss of consciousness:

• overt heart failure;
• ejection fraction (LVEF) <40% (Echo-assessed within 3-month prior to study participation);
• myocardial infarction;
• diagnosis of hypertrophic or dilated cardiomyopathy;
• clinically significant valvular disease;
• sinus bradycardia <50 bpm or sinoatrial block;
• Mobitz I second-degree atrioventricular block;
• Mobitz II second or third-degree atrioventricular block;
• bundle-branch block;
• rapid paroxysmal supraventricular tachycardia or ventricular tachycardia;
• preexcited QRS complexes;
• prolonged QT interval;
• Brugada syndrome;
• arrhythmogenic right ventricular cardiomyopathy
• Symptomatic orthostatic hypotension diagnosed by standing BP measurement;
• Nonsyncopal loss of consciousness (eg, epilepsy, psychiatric, metabolic, drop-attack, cerebral transient ischemic attack, intoxication, cataplexy).
• Symptomatic cardioinhibitory carotid sinus hypersensitivity.