Failure of pacemaker therapy in a pediatric patient with neurally mediated complete heart block and syncope: A case report

Key Clinical Message Neurally mediated syncope (NMS) is a well‐known condition that can be subdivided into three subgroups: vasopressor type, cardioinhibitory type, and mixed type. While different degrees of sinus bradycardia occur at the time of syncope in all types, complete heart block is a rare event that can lead to pulselessness during syncope. We present a case of a 14‐year‐old girl with documented NMS before and after temporary pacemaker implantation, who had complete heart block during syncope. The patient's temporary pacemaker placement was ineffective in preventing syncope during a repeat head‐up tilt test, indicating that permanent pacing may not be effective in this patient. Midodrine, an alpha‐adrenergic agonist, was started, and the patient experienced complete control of syncope episodes without recurrence during a 2‐month follow‐up.