Abstract 11832: Carotid Sinus Massage Can Obviate the Need for Tilt Table Testing in Patients With Undiagnosed Vasodepressor Syncope

Abstract

Introduction: Head-up tilt table (HUTT) testing is typically utilized for patients with syncope where the diagnosis is unclear but suspicion of a vasovagal etiology. Carotid sinus massage (CSM) can be used to elicit a vasopressor response though typically used to diagnose carotid sinus hypersensitivity. The usual protocol of HUTT consists of baseline CSM, 30-mins of HUTT, a repeat of CSM, and drug infusion. This is time-consuming and tedious. Hypothesis: CSM has a high predictive value for a vasodepressor response and may prevent the need for the completion of the HUTT protocol. Methods: Consecutive patients with clinical suspicion of vasovagal syncope underwent HUTT. Protocol consisted of baseline CSM in the supine posture, 30-mins of HUTT at 60 degrees, repeat CSM, and infusion of isoproterenol infusion from 1 to 3 mcg/min. Beat-to-beat blood pressure (BP) monitoring was performed non-invasively and standard cuff BP monitoring every minute. Positive tilt was defined as a drop in BP by more than 20 mmHg with reproducible symptoms (correlation to clinical symptoms). Results: 55 consecutive patients with a history of syncopal episode(s) underwent HUTT. 46 were females and 9 were male with a mean age of 54.4 ± 17.4 years old. They presented symptoms suggestive of a vasovagal etiology but were not diagnostic. 12 out of 55 (21.8%) patients had a positive reproducible response with supine CSM. 11 out of 12 of these patients subsequently had a positive result with protocol completion. This provided a positive predictive value (PPV) of 92%. 36 out of 55 (65.5%) patients had a negative response to CSM. All 36 had a negative result on completion of the HUTT protocol. This provided a negative predictive value (NPV) of 100%. 7 out of 55 (12.7%) patients had a “borderline” positive supine CSM. All 7 had a positive result with the completion of the HUTT protocol. Of note, these patients became positive only with isoproterenol infusion. Conclusions: CSM in the supine posture has a high PPV and NPV in eliciting a possible vasodepressor etiology. A full HUTT protocol may be only required in a patient who presents with a “borderline” CSM response in the supine posture. Therefore, CSM may easily be performed at the bedside with a monitor and a BP apparatus obviating the need for the full HUTT protocol.