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Lead I R‐wave amplitude to differentiate idiopathic ventricular arrhythmias with left bundle branch block right inferior axis originating from the left versus right ventricular outflow tract
Author(s) -
Xie Shuanglun,
Kubala Maciej,
Liang Jackson J.,
Hayashi Tatsuya,
Park Jaeseok,
Padros Irene Lucena,
Garcia Fermin C.,
Santangeli Pasquale,
Supple Gregory E.,
Frankel David S.,
Zado Erica S.,
Lin David,
Schaller Robert D.,
Dixit Sanjay,
Callans David J.,
Nazarian Saman,
Marchlinski Francis E.
Publication year - 2018
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/jce.13747
Subject(s) - ventricular outflow tract , medicine , cardiology , left bundle branch block , right bundle branch block , endocardium , electrocardiography , heart failure
Differentiation of right versus left ventricular outflow tract (RVOT vs. LVOT) arrhythmia origin with left bundle branch block right inferior axis (LBRI) morphology is relevant to ablation planning and risk discussion. Our aim was to determine if lead I R‐wave amplitude is useful for differentiation of RVOT from LVOT arrhythmias with LBRI morphology. Methods The R‐wave amplitude in lead I was measured in a retrospective cohort of 75 consecutive patients with LBRI pattern ventricular arrhythmias (VAs) successfully ablated from the RVOT ( n = 54), LVOT ( n = 16), or the anterior interventricular vein (AIV; n = 5). The optimal R‐wave threshold was identified and diagnostic indices were compared with the previously reported transitional zone (TZ) index and V2S/V3R index. Results An R‐wave amplitude greater than or equal to 0.1 mV predicted LVOT origin with 75% sensitivity and 98.2% specificity. In comparison, the TZ and V2S/V3R indices had 50% and 68.8% sensitivity, and 75.9% and 88.9% specificity, respectively, for predicting LVOT origin. The area under the curve (AUC) was 0.85 for lead I R‐wave amplitude, 0.87 for V2S/V3R, and 0.72 for the TZ index. Of 36 cases with QS in lead I, 30 (83.3%) were from the anterior RVOT, three (8.3%) from the LVOT, and three (8.3%) from the AIV. Conclusion The presence of R‐wave amplitude in lead I (≥0.1 mV) is a simple and useful criterion to identify LVOT cusp or endocardium focus in LBRI arrhythmias. A QS pattern in lead I suggests an origin in the anterior RVOT, or less commonly the adjacent LV summit.