A case report on the usefulness of combining online continuous wavelet transform analysis with a novel real-time phase mapping system during nonparoxysmal atrial fibrillation catheter ablation

Figures

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  Figure 1. Frame advance of representative atrial fibrillation wave dynamics at left inferior pulmonary vein antrum. Of the 5-second phase map movie, the activation sequence of the representative episodes during 400 ms (40 ms × 10 consecutive time windows) is depicted in frame advance. The numbers on each movie screen indicate 41 bipolar electrograms (1–32 are physical bipolar, 33–41 are virtual bipolar). The green square at the top of each screen shows the reliability of ExTRa Mapping (Nihon Kohden, Tokyo, Japan). The color is determined according to the number of rejected bipolar electrograms owing to their low quality: blue, 0; green, 1; yellow, 2–4; orange, 5–10; red, 11–16; and gray, ≥17. The colors change in real time on the screen, informing the operator of the reliability of ExTRa Mapping. The nonpassively activated ratio was only adopted when the reliability was high enough, such as blue, green, and yellow. White lines indicate the head of the wavefront. The wavefront traveled from the northwest to the southeast (from 1 to 10) on the screen. This activation sequence appeared intermittently and repeatedly during the phase map movie. M = multiple wavelets; NP = nonpassive activation;…

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  Figure 2. Continuous wavelet transform analysis results and phase map movie screen at left inferior pulmonary vein antrum during atrial fibrillation (AF) before pulmonary vein isolation. Left panel: Recordings from the top are electrocardiography lead II and physical bipolar electrograms recorded from the 20-pole spiral-shaped catheter (HD1-2 to HD13-20). The numbers in parentheses are the numbers 1–32, assigned to the physical bipolar electrograms. The second column shows the pseudo-frequency (PF), and the third column shows the coefficient of variation (CV). The sweep speed was 25 mm/s. Right panel: Phase map movie screen where the indications of the numbers on the screen are the same as those in Figure 1. The meaning of the green-colored square at the top of the phase map movie screen is the same as in Figure 1. The red star on the northwest side of the screen was the estimated AF driver location. The red arrow indicates the direction of the wave from the AF driver to the phase map movie screen. In both panels, the red open circle is the highest stable PF (sPF = PF with CV <10)1 at 6.5 Hz, and the orange open circle is the second-highest sPF at 6.4 Hz. Other abbreviations as in Figure 1.

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  Figure 3. The placement of the 20-pole spiral-shaped mapping catheter at the left inferior pulmonary vein antrum in a 3-dimensional (3D) electroanatomical mapping image. The estimated location of the atrial fibrillation (AF) driver is shown in the 3D electroanatomical image of the patient. The number next to the 20-pole spiral-shaped catheter in the image indicates the electrode number. Red star indicates the estimated AF driver location. The red arrow indicates the direction of the AF wave from the AF driver. Adjusting the spiral 20-pole electrode catheter placement more posteriorly may have resulted in a higher nonpassively activated ratio on ExTRa Mapping (Nihon Kohden, Tokyo, Japan).