Centrifugal Wave Front Propagation Speed for Localizing the Origin of Ventricular Arrhythmias: Investigation Using a New Ultra-High-Resolution Mapping System.

OBJECTIVES: The aim of this study was to assess the use of wave front propagation speed on a right ventricular map for determining the earliest activation site as the origin of outflow tract ventricular arrhythmias (VAs).

BACKGROUND: VAs with centrifugal right ventricular outflow tract (RVOT) activation can be from an RVOT focus or a focus outside the RVOT.

METHODS: This prospective observational study included 23 patients with idiopathic outflow tract VAs. Mapping of the RVOT was performed using a new ultra-high-resolution electroanatomic mapping system. The wave front propagation speed was estimated from the area surrounded by a propagated wave front at 5, 10, 15, and 20 ms after the earliest activation.

RESULTS: VAs disappeared following ablations in the RVOT in 15 patients (RVOT origin). The remaining 8 patients had VAs of non-RVOT origin determined by ablation success at another site or ablation failure. The areas surrounded by a propagated wave front were significantly smaller in VAs of RVOT origin than non-RVOT VAs at 5 ms (1.0 [0.7 to 1.1] cm2  vs. 2.2 [1.6 to 4.4] cm2 ), 10 ms (1.9 [1.4 to 2.2] cm2 vs. 4.5 [3.2 to 5.8] cm2 ), 15 ms (3.2 [2.3 to 4.4] cm2 vs. 7.1 [6.3 to 9.8] cm2 ), and 20 ms (5.0 [3.0 to 6.6] cm2 vs. 9.8 [9.3 to 14.8] cm2 ). A propagated area of <5.0 cm2 at 15 ms predicted RVOT VAs with 87% sensitivity, 100% specificity, and 91% predictive accuracy.

CONCLUSIONS: VAs with slow wave front propagation speed on the right ventricular map indicate an RVOT origin.