Predictive factors for pacemaker implantation in patients receiving an implantable loop recorder for syncope remained unexplained after an extensive cardiac and neurological workup

• Published in: International journal of cardiology Vol. 168; no. 4; pp. 3450 - 3457
• Main Authors: Palmisano, Pietro, Accogli, Michele, Zaccaria, Maria, Luzzi, Giovanni, Nacci, Frida, Anaclerio, Matteo, Favale, Stefano
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 09.10.2013; Elsevier
• Subjects: Aged; Aged, 80 and over; Arrhythmias; Atrioventricular block; Biological and medical sciences; Bradycardia - diagnosis; Bradycardia - physiopathology; Bradycardia - therapy; Cardiac dysrhythmias; Cardiology. Vascular system; Cardiovascular; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Exercise Test - methods; Exercise Test - trends; Female; Follow-Up Studies; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Heart; Humans; Implantable loop recorder; Male; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neurologic Examination - methods; Neurologic Examination - trends; Neurology; Pacemaker; Pacemaker, Artificial - trends; Predictive Value of Tests; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Sinus arrest; Syncope - diagnosis; Syncope - physiopathology; Syncope - therapy; Unexplained syncope; Sinus arrest; Pacemaker; Unexplained syncope; Arrhythmias; Implantable loop recorder; Atrioventricular block; Heart; Prisoner; Carceral environment; Arrest; Arrhythmia; Atrioventricular bloc; Cardiovascular disease; Nervous system; Etiology; Syncope; Heart block; Heart disease; Cause; Neurological disorder; Cardiology; Human; Nervous system diseases; Consciousness impairment; Instrumentation therapy; Recorder; Implantation; Patient; Conduction disorder; Instrumental stimulation; Implanted; Legal aspect; Circulatory system; Predictive factor
• ISSN: 0167-5273; 1874-1754; 1874-1754
• DOI: 10.1016/j.ijcard.2013.04.179

Several previous implantable loop recorder (ILR) studies have shown bradyarrhythmic events requiring a pacemaker implantation in a significant proportion of patients with unexplained syncope (US). The aim of this observational, two-centre, study was to identify the predictive factors for pacemaker implantation in a population of patients receiving an ILR for US with suspected arrhythmic aetiology. Fifty-six patients (mean age 68years, 61% male) with a history of US and negative cardiac and neurological workup, who underwent ILR implantation, were enrolled. After the implantation, a follow-up visit was undertaken after symptomatic events or every 3months in asymptomatic subjects. The end-point of the study was the detection of a bradyarrhythmia (with or without a syncopal recurrence) requiring pacemaker implantation. After a median ILR observation of 22months, a clinically significant bradyarrhythmia was detected in 11 patients (20%), of which 9 cases related to syncopal relapses. In the multivariable analysis, three independent predictive factors for pacemaker implantation were identified: an age >75years (odd ratio [OR]: 29.9; p=0.035); a history of trauma secondary to syncope (OR: 26.8; p=0.039); and the detection of periods of asymptomatic bradycardia, not sufficient to explain the mechanism of syncope, during conventional ECG monitoring (through 24h Holter or in hospital telemetry), performed before ILR implantation (OR: 24.7; p=0.045). An advanced age, a history of trauma secondary to syncope, and the detection of periods of asymptomatic bradycardia during conventional ECG monitoring were independent predictive factors for bradyarrhythmias requiring pacemaker implantation in patients receiving an ILR for US.