Utilizing Lead aVR QRS Morphology to Localize Abnormal Substrates in Arrhythmogenic Right Ventricular Cardiomyopathy

Q: What are the key findings of this study?

In patients with arrhythmogenic right ventricular cardiomyopathy, ECG lead aVR morphology was associated with epicardial scar distribution and right ventricular dysfunction, though post-ablation ventricular arrhythmia recurrence did not significantly differ based on right ventricular outflow tract scar involvement.

Q: What is the clinical evidence from this study?

Study design: Cohort. Population: Arrhythmogenic right ventricular cardiomyopathy (n=45). Intervention: Epicardial right ventricular outflow tract scar involvement (≥50%) vs. No epicardial right ventricular outflow tract scar involvement (<50%). Primary outcome: Post-ablation ventricular arrhythmia recurrence (p=0.249).

Q: What does this research mean for the field?

In patients with arrhythmogenic right ventricular cardiomyopathy, ECG lead aVR morphology and R/Q ratio identify right ventricular epicardial scar distribution and are associated with right ventricular dysfunction. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Chiao‐Chin Lee; Chin‐Yu Lin; Fa‐Po Chung; Yenn‐Jiang Lin; Shih‐Lin Chang; Li-Wei Lo; Yu‐Feng Hu; Ta‐Chuan Tuan; Tze‐Fan Chao; Jo‐Nan Liao; Ling Kuo; Ting‐Yung Chang; Chih‐Min Liu; Cheng‐I Wu; Shin‐Huei Liu; Ming-Jen Kuo; Guan‐Yi Li; Yu‐Shan Huang; Wen-Po Fan; Lo-Chieh Ling; Shih‐Ann Chen

doi:10.4070/kcj.2025.0547

Key result

In ARVC, lead aVR morphology is linked to epicardial scar distribution and RV dysfunction.

P=0.249
n=45

Why the study?

Accurate, noninvasive markers reflecting epicardial scar distribution and guiding ablation strategy in arrhythmogenic right ventricular cardiomyopathy remain limited.

Does ECG lead aVR morphology predict epicardial RVOT scar distribution and arrhythmic vulnerability in patients with ARVC?

Key Points

To evaluate whether QRS morphology and R/Q ratio in lead aVR can noninvasively reflect right ventricular epicardial scar distribution and guide ablation strategies in arrhythmogenic right ventricular cardiomyopathy.
Analyzed 45 patients (mean age 45.8±14.4 years, 35 male) with arrhythmogenic right ventricular cardiomyopathy undergoing endocardial and epicardial voltage mapping.
Categorized patients into the p-RVOT group (≥50% epicardial right ventricular outflow tract scar involvement, n=35) and n-RVOT group (<50% involvement, n=10).
Evaluated lead aVR morphologies (QR, QS, or R patterns), Q- and R-wave amplitudes, and R/Q cutoff via receiver operating characteristic analysis with 5,000 bootstrap resamples.
All n-RVOT patients exhibited a QR pattern (100.0%), whereas p-RVOT patients showed QR (48.6%), QS (37.1%), or R (14.3%) patterns (p=0.024), along with a significantly lower R/Q ratio (0.19±0.23 vs. 0.86±0.47, p<0.001).
An aVR R/Q ratio cutoff <0.582 identified epicardial RVOT scar with 93.3% sensitivity, 80% specificity, and an AUROC of 0.88 (bootstrap AUROC 0.887, 95% CI 0.714–1.000).
Patients with RVOT scar involvement presented larger total epicardial scar areas (22.08±16.53% vs. 11.09±6.97%, p=0.013) and more sustained ventricular arrhythmias (median 2 vs. 1, p=0.041), with R/Q ratio inversely correlating with scar-positive segments (ρ=−0.459, p=0.003).

Study Design

Type

Cohort (n=45)

Multicenter

No

Structured PICO

Does ECG lead aVR morphology predict epicardial RVOT scar distribution and arrhythmic vulnerability in patients with ARVC?

P

Population

45 patients with definite arrhythmogenic right ventricular cardiomyopathy and drug-refractory ventricular arrhythmias who underwent epicardial-endocardial mapping and catheter ablation.

E

Exposure

Electrocardiography (ECG) lead aVR morphology analysis (QR pattern, R pattern, QS pattern) and R/Q ratio measurement prior to ablation

C

Comparator

Comparison between patients with <50% epicardial right ventricular outflow tract (RVOT) scar involvement (n-RVOT group, n=10) and ≥50% epicardial RVOT scar involvement (p-RVOT group, n=35)

O

Outcome

Association of ECG lead aVR morphology and R/Q ratio with epicardial RVOT scar distributionsurrogate

Main Result

Absolute Event Rate: 42.9% vs 60%

p-value: p=0.249

Limitations

Retrospective single-center study with a relatively small sample size (n=45).
Scar distribution was assessed using a semi-quantitative approach (≥50% criterion) which is a pragmatic definition rather than a biologically validated cutoff.
Systemic left ventricle electroanatomic mapping was not routinely performed.
Genetic data were limited, preventing full assessment of genotype impact on scar distribution.
Comparisons of post-ablation ventricular arrhythmia recurrence may be underpowered due to the limited number of events.

Implication

In patients with ARVC, the R/Q ratio and morphology in ECG lead aVR provide a simple, noninvasive marker to predict epicardial RVOT scar distribution and right ventricular dysfunction, aiding in ablation procedural planning.

Abstract

Accurate, noninvasive markers reflecting epicardial scar distribution and guide ablation strategy in arrhythmogenic right ventricular cardiomyopathy remain limited.In this study, the R/Q ratio and morphology in electrocardiography (ECG) lead aVR were associated with right ventricular epicardial scar distribution and may help identify patients who require broader endocardial or epicardial ablation.These electrocardiographic indicators were also associated with right ventricular dysfunction and markers of arrhythmic vulnerability.Our findings suggest a simple ECG-based approach that may assist substrate characterization, procedural planning, and risk assessment.

Discussion

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Cite This Study

Lee et al. (2026) conducted a cohort in Arrhythmogenic right ventricular cardiomyopathy (n=45). Epicardial right ventricular outflow tract scar involvement (≥50%) vs. No epicardial right ventricular outflow tract scar involvement (<50%) was evaluated on Post-ablation ventricular arrhythmia recurrence (p=0.249). In patients with arrhythmogenic right ventricular cardiomyopathy, ECG lead aVR morphology was associated with epicardial scar distribution and right ventricular dysfunction, though post-ablation ventricular arrhythmia recurrence did not significantly differ based on right ventricular outflow tract scar involvement.

synapsesocial.com/papers/6a3d91e2408ebb922448b1cc https://doi.org/10.4070/kcj.2025.0547

Topics

AF ablation outcomes

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Utilizing Lead aVR QRS Morphology to Localize Abnormal Substrates in Arrhythmogenic Right Ventricular Cardiomyopathy

Key Points

Study Design

Structured PICO

Main Result

Limitations

Implication

Abstract

Discussion

Cite This Study

Topics

Utilizing Lead aVR QRS Morphology to Localize Abnormal Substrates in Arrhythmogenic Right Ventricular Cardiomyopathy

Key Points

Study Design

Structured PICO

Main Result

Limitations

Implication

Abstract

Discussion

Cite This Study

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