Feasibility and Safety of High‐Power Settings for Electrical Isolation of the Superior Vena Cava Using a Catheter Capable of Local Impedance and Contact Force Monitoring

Figures

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  FIGURE 1. Ultra‐high resolution activation and voltage maps of the SVC and upper RA during sinus rhythm. In patients with a conduction block line (red arrow, upper panel), point‐by‐point RF delivery was performed circumferentially along the line connecting the open ends of the conduction block line. In patients without a conduction block line (lower panel), circumferential SVCI was performed at approximately 1 cm above the earliest activation site (white arrow). The red tags indicate the ablation sites. The blue tags indicate the sites where phrenic nerve stimulation was observed by high‐output pacing (10 V) on the posterolateral wall of the SVC. RA, right atrium; RF, radiofrequency; SVCI, superior vena cava isolation.

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  FIGURE 2. The analysis of the time to reach 90%. The rate of change in the time‐dependent change in the measured LI was assessed, and the time to reach a 90% decay in the peak dY/dT, where Y indicates the LI value, was expressed as the “time to a 90% decay”.

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  FIGURE 3. The ablation area of the SVC was analyzed. A total of 1 402 points were evaluated in this study. The superior vena cava (SVC) was circumferentially divided into 8 segments (A–H).

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  FIGURE 4. The details of the impedance at each location segment. This figure shows the details of the impedance at each location segment. All parameters except for the initial GI drop showed significantly different values at each location segment. The LI drop and % LI drop were highest at the posteroseptal area and lowest at the anterolateral area. On the other hand, GI drop and % GI drop were highest at the septal area and lowest at the posterolateral area (initial LI, ohm).

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  FIGURE 5. The comparison of the time course of LI‐related parameters and GI‐related parameters at each location segment of the SVC. This figure shows the comparison of the time course of LI‐related parameters and GI‐related parameters at each location segment of the SVC (A; impedance drop, B; %impedance drop). At all segments, the LI‐related parameters changed more gradually than the GI‐related parameters.