A new mapping method to estimate exit sites of ventricular arrhythmias using intracardiac echocardiography and M‐mode for catheter ablation

Figures

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  Fig. 1. A. The shell of the ventricle is constructed using an ICE probe positioned in the right ventricle. B. The M-mode interrogation line is available using two-dimensional echocardiography. Arrow; M-mode interrogation line. LV; left ventricle, RV; right ventricle.

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  Fig. 2. A. The M-mode beam is swept to the mapped point. B. M-mode echocardiography at the mapped point is shown, and the electrocardiogram is recorded below the ultrasound image. The QRS-c-time was measured using this image. Circle; mapped point, Arrow; onset of the contraction, SR; sinus rhythm, PVC; premature ventricular contraction, other abbreviations as Fig. 1.

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  Fig. 3. A. The twelve-lead electrocardiogram of the PVCs is shown. B, C. Activation map (B) and contraction map (C) of a representative patient. The earliest site of the PVCs was the anterior MA. In the contraction mapping, all labeled points were annotated manually as in the QRS-c-time using the activation mapping mode. The contraction mapping determined a similar site as the activation mapping.

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  Fig. 4. An example of an electrocardiogram of the PVCs (A), activation map (B), and contraction map (C) in Patient 2 are shown.

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  Fig. 5. The M-mode swept to the inferior LV revealed that the QRS-c-time was 50 ms. The local activation time at that site was 22 ms before the onset of the QRS. SR; sinus rhythm, PVC; premature ventricular complex, LV; left ventricle.

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  Fig. 6. There was a significantly strong correlation between the local activation time and QRS-c-time.