Treatment of Neurocardiogenic Syncope with Permanent Pacemaker Implantation

Neurocardiogenic syncope episodes are characteristically associated with sudden fall in arterial blood pressure and decrease in heart rate. The presence of bradycardia suggests that pacemaker implantation may prevent the syncopal episodes. Single-chamber VVI pacemaker does not prevent syncope and may increase the severity of the neurocardiogenic syncope because of the disruption of AV synchrony. Studies with dual-chamber pacemakers showed different results and studies with rate drop response pacemakers did not reveal that treatment of neurocardiogenic syncope with this pacemaker algorithm effectively prevent the episodes. The most im portant predictor of the failure of vasovagal syncope therapy with pacemaker implantation is the decrease in blood pressure prior to decrease in heart rate. In addition, the type of the syncope attacks that occurred spontaneously or were induced with head-upright tilt table test may not be in the same pathophysiologic pattern (cardioinhibitor, vasodepressor, mixed). Although pacemaker implantation for neurocardiogenic syncope does not prevent the presyncope attacks, it has been shown that these patients have better response to drugs and better quality of life. The beneficial effect of permanent pacemaker in neurocardiogenic syncope primarily occurs by providing persistence of consciousness, and by providing a valuable time to the patient during the initiation of attacks.