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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Cardiovasc. Med. | doi: 10.3389/fcvm.2019.00154

Cardiovascular autonomic dysfunction is the most common cause of syncope in paced patients

 Ekrem Yasa1,  Fabrizio Ricci2, Hannes Holm1, Torbjörn Persson3, Olle Melander1,  Richard Sutton4,  Artur Fedorowski1 and  Viktor Hamrefors1*
  • 1Department of Clinical Sciences, Faculty of Medicine, Lund University, Sweden
  • 2Department of Neuroscience, Imaging and Clinical Sciences, G. d'Annunzio University of Chieti and Pescara, Italy
  • 3Department of Cardiology, Skåne University Hospital, Sweden
  • 4National Heart and Lung Institute, Faculty of Medicine, Imperial College London, United Kingdom

Introduction: Syncope and orthostatic intolerance in paced patients constitute a common clinical dilemma. We, thus, aimed to determine the aetiology of syncope and/or symptoms of orthostatic intolerance in paced patients.

Methods: Among 1705 patients with unexplained syncope and/or orthostatic intolerance that were investigated by cardiovascular autonomic tests, including Valsalva manoeuvre, active standing, carotid sinus massage, and tilt-testing, 39 patients (2.3 %; age 65.6 years; 39 % women) had a cardiac implantable electronic device (CIED). We explored past medical history, diagnoses found during cardiovascular autonomic tests, and the further clinical workup, in case of negative initial evaluation.

Results: An aetiology was identified during cardiovascular autonomic tests in 36 of the 39 patients. Orthostatic hypotension (n=16; 41%) and vasovagal syncope (n=12; 31%) were the most common diagnoses. There were no cases of pacemaker dysfunction. The original pacing indications followed guidelines (sick-sinus-syndrome in 16, atrioventricular block in 16, atrial fibrillation with bradycardia in five). Twenty-two of the 39 patients (56 %) had experienced syncope prior to the original CIED implantation. Orthostatic hypotension was diagnosed in seven (32%) and vasovagal syncope in nine (41%) of these patients. Of the 17 patients that had not experienced syncope prior to the original CIED implantation, nine patients (53 %) were diagnosed with orthostatic hypotension and vasovagal syncope was diagnosed in three (18%). Of the 39 patients, two had implantable cardioverter-defibrillators to treat malignant ventricular arrhythmias diagnosed after syncopal episodes.

Conclusion: Cardiovascular autonomic tests reveal the aetiology of syncope and/or orthostatic intolerance in the majority of paced patients. The most common diagnosis was orthostatic hypotension (40 %) followed by vasovagal syncope (30%), whereas there were no cases of pacemaker dysfunction. Our results emphasize the importance of a complete diagnostic work-up, including cardiovascular autonomic tests, in paced patients that present with syncope and/or orthostatic intolerance.

Keywords: Pacemaker (IMD), pacing, Syncope - etiology, Orthostatic Intolerance, Cardiovascular autonomic tests

Received: 04 Aug 2019; Accepted: 09 Oct 2019.

Copyright: © 2019 Yasa, Ricci, Holm, Persson, Melander, Sutton, Fedorowski and Hamrefors. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: MD, PhD. Viktor Hamrefors, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, 202 13, Sweden,