Okumura Y, Watanabe I, Nakai T, Ohkubo K, Kofune T, Ashino S, Kofune M, Nagashima K, Hiro T, Hirata A, Nikaido M, Hirayama A. A quantitative and qualitative analysis of the virtual unipolar electrograms from non-contact mapping of right or left-sided outflow tract premature ventricular contractions/ventricular tachycardia origins.
J Interv Card Electrophysiol 2010;
30:17-25. [PMID:
21161574 DOI:
10.1007/s10840-010-9522-4]
[Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 10/05/2010] [Indexed: 11/29/2022]
Abstract
OBJECTIVE
This study was conducted to examine the virtual unipolar electrogram configuration of right/left outflow tract (OT) premature ventricular contraction (PVC)/ventricular tachycardia (VT) origins obtained from a non-contact mapping system (NCMS).
METHODS
The subjects consisted of 30 patients with OT-PVCs/VT who underwent NCMS-guided ablation. We evaluated the virtual unipolar electrograms of the origin on 3D right ventricular (RV)-OT isochronal maps.
RESULTS
Successful ablation was achieved from the RV in 20 patients (RVOT group), and it failed in 10 (non-RVOT group: including left-sided/pulmonary artery/deep RVOT foci). On the virtual unipolar electrograms, the earliest activation (EA) preceded the QRS onset by 11.2 ± 2.6 ms in the RVOT group and by 7.4 ± 10.5 ms in the non-RVOT group (P = 0.138). The negative slope of the electrogram at the EA site (EA slope(5)), quantified by the virtual unipolar voltage amplitude 5 ms after the EA onset, was significantly steeper in the RVOT group than in the non-RVOT group (0.66 ± 0.52 mV vs. 0.14 ± 0.17 mV, P = 0.005). Cutoff values for the EA-to-QRS onset time and EA slope(5) of ≥ 8 ms and >0.3 mV, respectively, completely differentiated the RVOT group from the non-RVOT group. A lesser EA slope(5) was associated with a greater radiofrequency energy delivery required to terminate RVOT-PVCs/VT.
CONCLUSIONS
These demonstrate the importance of the virtual unipolar electrograms from OT-PVC/VT origins obtained with the NCMS. The virtual EA predicts both successful and potentially difficult ablation sites from the RV side.
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