Author + information
- Received September 13, 2018
- Revision received January 29, 2019
- Accepted January 31, 2019
- Published online March 27, 2019.
- Jayaprakash Shenthar, MD, DMa,b,∗ (, )
- Mukund Aravind Prabhu, MD, DMa,b,
- Bharatraj Banavalikar, MD, DMa,b,
- David G. Benditt, MDa,b and
- Deepak Padmanabhan, MD, DMa,b
- aElectrophysiology Unit, Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bangalore, Karnataka, India
- bUniversity of Minnesota Medical School, Minneapolis, Minnesota
- ↵∗Address for correspondence:
Prof. Jayaprakash Shenthar, Electrophysiology Unit, Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, 9th Block Jayanagar, Bannerghatta Road, Bangalore 560069, India.
Objectives This study sought to determine the cause of recurrent syncope and clinical outcomes by using the head up tilt test (HUTT) and an insertable loop recorder (ILR) in patients with structural heart disease (SHD) and negative electrophysiology study (EPS) results.
Background Patients with syncope and SHD with negative EPS findings have a low risk of sudden cardiac arrest. Nevertheless, the cause of recurrent syncope and the outcomes in these patients are not well characterized.
Methods and Results This prospective study evaluated syncope patients with SHD and negative EPS results by using HUTT (with sublingual nitroglycerine [NTG] provocation as needed) and ILR. A total of 41 SHD patients (27 patients [66%] had coronary arterial disease, and 14 patients [34.15%] had dilated cardiomyopathy with mean EF of 42% ± 4.8% [range 30% to 49%]) were included. HUTT findings were positive in 25 patients (61%) in group A and negative in 16 patients (39%) in group B. An ILR was implanted in 21 of 25 group A patients (84%) and in 12 of 16 group B patients (75%), and they were followed for 15 ± 8 months. During follow-up, 17 of 21 patients (81%) in group A and 5 of 12 patients (41.7%) in group B had ILR evidence consistent with reflex syncope. One group B patient had documented atrioventricular block and underwent pacemaker implantation. There were no malignant ventricular arrhythmias or deaths on follow-up.
Conclusions Reflex syncope is the most common cause of syncope and accounts for approximately 60% of cases in patients with SHD, negative EPS results, left ventricular systolic dysfunction with left ventricular EF >30%, and not in heart failure.
Dr. Benditt is supported in part by a grant from the Dr. Earl E. Bakken Family for Heart-Brain research; and is a consultant for and holds equity in Medtronic Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received September 13, 2018.
- Revision received January 29, 2019.
- Accepted January 31, 2019.
- 2019 American College of Cardiology Foundation
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