A new insight into the anatomical ablation approach at R-L ILT for VAs with a left ventricular summit origination: electrophysiological characteristics and catheter ablation

Figures

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  Fig. 1. Twelve-lead surface ECGs of 9 patients in this study. Group 1(NO.1–3): Earliest activation site(EAS) at RVOT/PSC region; Group 2(NO.4–6): EAS at right-left subvalvular interleaflet triangle(R-L ILT); Group 3(NO.7–9): EAS at GCV/AIV region. LPSC: Left pulmonary sinus cusp; RVOT: Right ventricular outflow tract; GCV/AIV: Great cardiac vein/anterior interventricular vein; R-L ILT: Right-left subvalvular interleaflet triangle

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  Fig. 2. Stepwise mapping and ablation algorithm. PSC: Pulmonary sinus cusp; RVOT: Right ventricular outflow tract; GCV/AIV: Great cardiac vein/anterior interventricular vein; ILT: Right-left Subvalvular interleaflet triangle; ASC: Aortic sinus cusp; EAS: Earliest activation site

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  Fig. 3. Mapping and ablation results of VA with EAS observed in RVOT region. A detailed mapping of both ROVT septal (B) and LPSC(A) was performed first. EAS was observed at LPSC(-30ms) and a presystolic potential was recorded at LPSC. The result of pace mapping at EAS (C) was poor with a different QRS morphology at lead I, V2 and V3. A ablation attempt was performed at EAS and a transient effective result was observed. Then a detailed mapping of LVOT was performed. The EAS of LVOT located at the region of RCC adjacent to LCC (D) with local preceding time of 16ms. The mapping of epicardial region of LV summit was failed as the mapping catheter and ablation catheter couldn’t reach the distal part of GCV. A poor pace mapping (G) and activation mapping (F) results were observed at R-L ILT. The ablation attempt was performed at RCC target but failed. Finally the VAs was successfully ablated at R-L ILT. The anatomical feature of RVOT and LVOT was illustrated in figure G and H. The target of R-L ILT was close to the EAS of LPSC with a distance of 12ms. The Fluoroscopy and 3D anatomic construction showed that the successful ablation site was at the R-L ILT (G-I). LPSC: Left pulmonary sinus cusp;…

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  Fig. 4. Anatomical features of EAS between endocardial and epicardial region of VAs successfully ablated in R-L ILT. Detailed activation mapping of RVOT (A), GCV (B), ASC (C) and R-L ILT (D) was performed during procedure. The EAS located in RVOT septal region with an acceptable pace mapping result and a preceding time of 39ms (A). A first attempt was performed in ROVT target but was not effective. An ablation attempt was also not effective in GCV target. The VA was finally successfully ablated in R-L ILT. The intracardiac echocardiography(ICE) was utilized in this case to validate the precise location of the catheter location (G and H). CartoSound 3-dimensional anatomic construction indicated a successful ablation site at the R-L ILT (G, H). The grey colored 3-D anatomic reconstructions represent the ASC. The green part represents the right coronary cusp (RCC). The brown part represents the left coronary cusp (LCC). The pink part represents the non-coronary cusp (NCC). The anatomical relationship of endocardial and epicardial targets were illustrated in figure I and J. The distance between R-L ILT target and ROVT EAS was 14.4 mm (I). The distance between R-L ILT target and GCV target…

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  Fig. 5. Presystolic potential at R-L ILT region with a EAS observed in R-L ILT A-F: Activation mapping results of two cases. EAS located in R-L ILT and a presystolic potential were recorded in both cases. H-I: The VAs were successfully ablated in R-I ILT in both cases and the anatomical feature of targets in different region were showed. G and I: Presystolic potential of EAS AT R-L ILT with different morphology were also observed in the other two cases of group 2. R-L ILT: Right-left subvalvular interleaflet triangle; EAS: Earliest activation site

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  Fig. 6. Bipolar potential characteristic for different groups. Examples of bipolar potential at R-L ILT target for each group were showed in this figure. Presystolic potential was not found in Cases A (group 1), case B and case C (group 3). In case D-F (group 2), presystolic potential with different morphology of EAS at R-L ILT were observed (red arrow)

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  Fig. 7. Illustrative Diagram Demonstrating Anatomy of the ventricular outflow tracts and an ablation approach at R-L ILT. The anatomy of R-L ILT had been illustrated in the figure A. The R-L ILT (yellow star) had a close relationship with RVOT septal and LV summit (Blue area). CartoSound 3-dimensional anatomic construction indicated a successful ablation site at the R-L ILT (Figure C). The grey colored 3-D anatomic reconstructions represent the ASC. The green part represents the right coronary cusp (RCC). The brown part represents the left coronary cusp (LCC). The pink part represents the non-coronary cusp (NCC). RVOT: Right ventricular outflow tract; ASV: aortic sinus of Valsalva; RL-ILT: Right-left subvalvular interleaflet triangle