Author + information
- Received March 5, 2018
- Revision received April 16, 2018
- Accepted April 19, 2018
- Published online September 17, 2018.
- Jackson J. Liang, DO∗,
- Benjamin A. D’Souza, MD∗,
- Brian P. Betensky, MD,
- Erica S. Zado, PA-C,
- Benoit Desjardins, MD, PhD,
- Pasquale Santangeli, MD, PhD,
- William W. Chik, MD, PhD,
- David S. Frankel, MD,
- David J. Callans, MD,
- Gregory E. Supple, MD,
- Mathew D. Hutchinson, MD,
- Sanjay Dixit, MD,
- Robert D. Schaller, DO,
- Fermin C. Garcia, MD,
- David Lin, MD,
- Michael P. Riley, MD, PhD and
- Francis E. Marchlinski, MD∗ ()
- Cardiovascular Division, Electrophysiology Section, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
- ↵∗Address for correspondence:
Dr. Francis E. Marchlinski, Cardiovascular Division, Electrophysiology Section, Hospital of the University of Pennsylvania, 9 Founders Pavilion, 3400 Spruce Street, Philadelphia, Pennsylvania 19104.
Objectives This study sought to characterize septal substrate in patients with nonischemic left ventricular cardiomyopathy (NILVCM) undergoing ventricular tachycardia (VT) ablation.
Background The interventricular septum is an important site of VT substrate in NILVCM.
Methods The authors studied 95 patients with NILVCM and VT. Electroanatomic mapping using standard bipolar (<1.5 mV) and unipolar (<8.3 mV) low-voltage criteria identified septal scar location and size. Analysis of unipolar voltage was performed and scars quantified using graded unipolar cutoffs from 4 to 8.3 mV were correlated with delayed gadolinium-enhanced cardiac magnetic resonance (DE-CMR), performed in 57 patients.
Results Detailed LV endocardial mapping (mean 262 ± 138 points) showed septal bipolar and unipolar voltage abnormalities (VAs) in 44 (46%) and 79 (83%) patients, most commonly with basal anteroseptal involvement. Of the 59 patients in whom the septum was targeted, bipolar and unipolar septal VAs were seen in 36 (61%) and 54 (92%). Of the 35 with CMR-defined septal scar, bipolar and unipolar septal VAs were seen in 18 (51%) and 31 (89%). In 12 patients without CMR septal scar, 6 (50%) had isolated unipolar septal VAs on electroanatomic mapping, a subset of whom the septum was targeted for ablation (44%). In the graded unipolar analysis, the optimal cutoff associated with magnetic resonance imaging septal scar was 4.8 mV (sensitivity 75%, specificity 70%; area under the curve: 0.75; 95% confidence interval: 0.60 to 0.90).
Conclusions Septal substrate by unipolar or bipolar voltage mapping in patients with NILVCM and VT is common. A unipolar voltage cutoff of 4.8 mV provides the best correlation with DE-CMR. A subset of patients with septal VT had normal DE-CMR or endocardial bipolar voltage with abnormal unipolar voltage.
↵∗ Dr. Liang and Dr. D’Souza contributed equally to this work and are joint first authors.
The 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 March 5, 2018.
- Revision received April 16, 2018.
- Accepted April 19, 2018.
- 2018 American College of Cardiology Foundation
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