The V6R/V4R Index: A Novel ECG Parameter for Identifying Idiopathic Ventricular Arrhythmias Originating From the Aortic Cusp.

Authors

Yoshihisa Naruse, Kohki Nakamura, Kanae Hasegawa, Toshihiko Tsuji, Machiko Miyoshi, Tatsuhiro Kataoka, Hideyuki Aoki, Yoshinori Okazaki, Shigeto Naito, Hiroshi Tada, and other members of the V6R/V4R Study Group

Published in

Journal of cardiovascular electrophysiology. Jul 08, 2026. Epub Jul 08, 2026.

Abstract

Radiofrequency catheter ablation within the aortic cusp can eliminate left ventricular outflow tract (LVOT) ventricular arrhythmias (VAs). However, in a significant proportion of cases, successful ablation requires targeting the aorto-mitral continuity, the endocardium just below the left ventricular summit, and/or the mitral annulus. This study aimed to identify electrocardiographic (ECG) indices useful for differentiating VAs originating from the aortic cusp from those arising outside the cusp among LVOT-VAs.
This retrospective study included 159 idiopathic VAs (79 in the derivation cohort and 80 in the validation cohort) successfully ablated from the LVOT. Based on the site of VA origin, VAs were classified into cusp (n = 125) and non-cusp (n = 34) groups. Detailed PVC morphologies were compared between the two groups.
In the derivation cohort (mean age 60 ± 16 years, 43 men), the ratio of R-wave amplitude in lead V6 to that in lead V4 was significantly higher in the cusp group than in the non-cusp group (0.64 [0.56-1.00] vs. 0.32 [0.24-0.40], p < 0.001). Receiver operating characteristic curve analysis showed that a V6R/V4R amplitude index > 0.55 predicted cusp-origin VAs with 0.80 sensitivity and 0.88 specificity (area under the curve, 0.865; 95% confidence interval [CI], 0.762-0.967). In the validation cohort, the sensitivity and specificity of a V6R/V4R amplitude index > 0.55 for predicting cusp origin were 84% and 82%, respectively.
The V6R/V4R index is a simple and practical ECG criterion for distinguishing VAs originating from the aortic cusp from those arising outside the cusp among LVOT-VAs, with high accuracy.

PMID:
42418805
Bibliographic data and abstract were imported from PubMed on 09 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.