What is the clinical evidence from this study?

Study design: Observational. Population: Idiopathic outflow tract ventricular arrhythmias (n=101). Intervention: Synthesized 18-lead ECG (V5R QRS morphology pattern). Primary outcome: Overall accuracy of predicting the precise origin of OT-VAs.

January 6, 2015Open Access

The QRS morphology pattern in V5R is a novel and simple parameter for differentiating the origin of idiopathic outflow tract ventricular arrhythmias

Q: What does this research mean for the field?

The QRS morphology pattern in the synthesized V5R lead can predict the precise origin of idiopathic outflow tract ventricular arrhythmias with an overall accuracy of 75%. Novelty: ClaimNovelty.METHODOLOGICAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Key Result

The QRS morphology pattern in the synthesized V5R lead predicted the precise origin of idiopathic outflow tract ventricular arrhythmias with an overall accuracy of 75%.

Study Design

Type

Observational (n=101)

Structured PICO

Does the QRS morphology pattern in the synthesized V5R lead accurately predict the origin of idiopathic outflow tract ventricular arrhythmias?

Population

101 patients with idiopathic outflow tract ventricular arrhythmias (OT-VAs), comprising 28 in a pacemapping study and 73 in a prospective validation cohort.

Intervention

Synthesized 18-lead ECG, specifically evaluating the QRS morphology pattern in the synthesized V5R lead.

Outcome

Accuracy of predicting the precise origin of OT-VAs using the V5R QRS morphology pattern.surrogate

The QRS morphology pattern in the synthesized V5R lead provides a simple and accurate method for differentiating the precise origin of idiopathic outflow tract ventricular arrhythmias.

Abstract

AIMS: There are many reports on the ECG characteristics of idiopathic outflow tract ventricular arrhythmias (OT-VAs) to predict their origin. However, differentiating near regions using 12-lead ECGs is still complicated. The synthesized 18-lead ECG derived from the 12-lead ECG can provide virtual waveforms of the right-sided chest leads (V3R, V4R, and V5R) and back leads (V7, V8, and V9). The aim of this study was to develop a simple and useful parameter for differentiating OT-VA origins using the 18-lead ECG. METHODS AND RESULTS: We studied 28 and 73 patients with idiopathic VAs in a pacemapping study and validation cohort, respectively. In the pacemapping study, several sites out of five different sites were paced in each patient: the anterior and posterior right ventricular OT (RVOT-ant and RVOT-post), right and left coronary cusps (RCC and LCC), and junction of both cusps (RLJ). The 18-lead ECGs during pacemapping among the five sites were compared for establishing a simple parameter to predict VA origins. A novel parameter using 18-lead ECGs was tested prospectively in 73 patients. In the pacemapping study, the dominant QRS morphology pattern in the synthesized V5R significantly differed among those sites (RVOT-ant:Rs, RVOT-post:rS, RCC:QS, RLJ:qR, and LCC:R). The patients in the validation cohort were divided into five groups depending on those QRS morphology patterns during VAs in the synthesized V5R. Each V5R QRS morphology pattern could predict a precise origin of the OT-VAs with an overall accuracy of 75%. CONCLUSION: The QRS morphology pattern in V5R was a simple and useful parameter for differentiating detailed OT-VA origins.