A novel approach for effective superior vena cava isolation using the CARTO electroanatomical mapping system

Figures

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  FIGURE 1. One of the cases of our ablation protocol (block type). A, We set the first lower threshold to the value of 1800/LAT to optimize visualization of the spontaneous RA‐SVC conduction block. In this case, the LAT is 232 ms, and we set the first lower threshold of 1800/232 ≒ 8 (%). RF application is delivered to the area where the white line does not appear but the SVC is not isolated. B, The lower threshold is 5% and increases to 13%, and a new gap appears. C, SVC isolation is successfully achieved through the additional ablation to the new gap. LAT, local activation time

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  FIGURE 2. One of the cases of our ablation protocol (nonblock type). A, We set the first lower threshold of 22 (%). RF application is delivered to the area where the white line does not appear but the SVC is not isolated. B, The lower threshold is 5% and increases to 27%, and a new gap appears. RF application is delivered to the new gap but the SVC is not isolated. C, The lower threshold is 5% and increases to 32%, SVC isolation is successfully achieved through the additional ablation to the new gap

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  FIGURE 3. The representative cases of the block type and nonblock type. The block group requires fewer RF deliveries for SVC isolation than the nonblock group. RF application on the phrenic nerve is not required to achieve SVC isolation in the block group. Moreover, the size of the isolated area in the block group is larger than that in the nonblock group

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  FIGURE 4. The representative case of RA‐SVC reconduction with isoproterenol. This is the case of the RA‐SVC reconduction with isoproterenol. Upper panels (without isoproterenol): Spontaneous conduction block (type U) appears, and RF application is delivered to the gap of the white line. Lower panels (with isoproterenol): RA‐SVC reconduction occurs with isoproterenol, and the former spontaneous conduction block disappears at the septal to posterior wall. SVC is successfully isolated by an additional RF application to the new gap