Role of loop recorder and pacemaker implantation in vasovagal syncope

Abstract

Given that vasovagal syncope is characterized by a benign prognosis, therapy should be aimed at preventing associated trauma and improving the quality of life rather than prolonging life expectancy. Therefore, according to the European guidelines, only selected patients have to be specifically treated: those suffering from highly recurrent vasovagal syncope, individuals in whom syncope onset is not preceded by prodromal symptoms or recognized triggers, patients suffering from associated severe trauma, and persons engaged in risky jobs. Several studies have shown that in both older and pediatric patients with unexplained syncope, with or without structural heart disease the use of an implantable loop recorder (ILR) yields more complete diagnosis than does conventional testing. The European Society of Cardiology (ESC) guidelines on the management of syncope and the European Heart Rhythm Association guidelines on the use of implantable and external electrocardiographic loop recorders provide a class I indication for the use of ILR in patients with infrequent (i.e., with less than monthly frequency) unexplained syncope of possible arrhythmic origin or in high-risk patients when all other investigations prove inconclusive. A recent study also suggests the use of ILR in selected patients with recurrent vasovagal syncope and asystolic response before embarking on pacemaker (PM) implantation. ESC guidelines on syncope and cardiac pacing identify a class IIa indication for PM implantation in patients older than 40 years with vasovagal syncope, with recurrent and unpredictable syncope and documented symptomatic pause(s) resulting from sinus arrest or atrioventricular block. However, guidelines acknowledge that “in patients with reflex syncope, cardiac pacing should be the last choice and should be given to highly selected patients, that is, those with relatively old age, affected by severe forms of reflex syncope, with a history of recurrent syncope and frequent injuries, probably due to a lack of prodromal symptoms. The fact that pacing is effective in some patients with reflex syncope does not mean that it is also always necessary. It must be emphasized that the decision to implant a PM needs to be undertaken in the clinical context of a benign condition (in terms of mortality), which frequently affects young patients.