Premium
Isolated very low QRS voltage predicts response to tilt‐table testing in patients with neurally mediated syncope
Author(s) -
Blendea Dan,
McPherson Craig A.,
Pop Sorin,
Anton Florin P.,
Crisan Sorin,
Ruskin Jeremy N.
Publication year - 2019
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.13815
Subject(s) - medicine , presyncope , cardiology , qrs complex , lead (geology) , diastole , anesthesia , heart rate , blood pressure , geomorphology , geology
Background A number of patients with neurally mediated syncope (NMS) have isolated QRS complexes of very low voltage (≤0.3 mV) in the frontal plane leads on the 12‐lead electrocardiogram (ECG). Hypothesis The aim of this study was to assess the importance of QRS voltage in predicting response to tilt‐table testing (TTT) in patients with suspected NMS. Methods We included 216 patients (age: 49 ± 20 years, 103 men) with suspected NMS who had either a positive or negative response to TTT ( n = 91 TTT+, and n = 125 TTT−). The QRS voltage was measured in mV on 12‐lead ECGs performed within 3 days of the TTT. The lowest QRS voltage (QRSmin), as well as the voltage in each of the 12 leads was also determined. Results Very low voltage (QRSmin ≤ 0.3 mV) in the frontal leads was significantly more prevalent in the TTT+ group than in the TTT− group (74 vs 22%, respectively; P < .001). Patients in the TTT+ group had significantly lower QRSmin when compared to patients in the TTT− group. QRSmin predicted a positive tilt‐table test in a multivariate model that also included patient gender, height, history of presyncope, QRS duration, and left ventricular end‐diastolic diameter indexed to height. ROC analysis showed that QRSmin of ≥0.3 mV discriminated between TTT+ and TTT− patients with a sensitivity of 78% and specificity of 68%. Conclusion Isolated very low QRS voltage in the frontal leads predicts a positive response to TTT in patients with suspected NMS.