The implantable Holter allows correlations between ECG and symptoms, though does not monitor arterial pressure or cerebral perfusion. The ISSUE classification was developed from the analysis of implantable Holter records in attempt to identify the pathophysiologic mechanisms of syncope. This patient’s ECG was a typical Class IA recording, including acceleration of sinus rate, followed by bradycardia and, finally, a long sinus pause. These observations, made in typical circumstances (in this case a meal) strongly suggest a vagal mechanism. Whether cardiac pacing is indicated for patients suffering from major, recurrent, vagally-mediated syncope, is controversial. It is now clear that pacing cannot be expected to be effective when the mechanism of syncope is vasodilatation, and loss of consciousness is due to a fall in arterial pressure. It seems, therefore, appropriate to strictly reserve pacing for patients who develop profound bradycardia. The identification of the culpable mechanism is, therefore, a critical stage of the diagnosis-making process, as well as indispensable information to plan the therapy. Furthermore, the results of tilt-table or ATP tests are weakly correlated with the implantable Holter records obtained at the time of a spontaneous episode of syncope. It does not seem appropriate, therefore, to recommend the implantation of a pacemaker for vagally-mediated syncope after the observation of a long pause during tilt-table testing. Finally, the implantable Holter serves to either confirm or exclude a bradycardia during a vagally-mediated episode. By selecting patients who present with long sinus pauses or prolonged, complete atrioventricular block, the yield of implanting a pacemaker appears.