Detection of Epicardial Late Potentials by Endocardial Wide-Bipolar Mapping in a Case of Cardiac Sarcoidosis

Figures

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  Visual Summary. Detection of Epicardial Late Potentials by Endocardial Wide-Bipolar Mapping LV = left ventricular; VT = ventricular tachycardia.

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  Figure 1. ECG and Diagnostic Imaging (A) 12-lead ECG during ventricular tachycardia showing a heart rate of 167 beats/min, right bundle branch block pattern, inferior axis, and wide QRS complex tachycardia. (B) Contrast-enhanced cardiac CT demonstrating a thinned aneurysm on the posterolateral wall of the left ventricle (arrows). (C) FDG-PET showing abnormal tracer uptake in the left ventricle. CT = computed tomography; ECG = electrocardiogram; FDG-PET = fluorodeoxyglucose positron emission tomography.

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  Figure 2. Endocardial Mapping and Ablation (A) Left ventricular endocardial omnipolar isochronal late activation map (ILAM) acquired during right atrium pacing. The area enclosed by the white arrows indicates the left ventricular aneurysm. (B) Endocardial voltage map of the left ventricle acquired during right atrium pacing using omnipolar mapping with EnSite OT Near Field annotation. The white dashed arrows indicate sites where good pace maps for VT1 and VT2 were obtained. (C) Endocardial unipolar voltage map acquired during right atrium pacing. The aneurysmal region shows low voltage. (D) Endocardial wide-bipolar isochronal late activation map during right atrium pacing. The area enclosed by the white dashed circle (blue to purple, indicating a delay of >40 ms after the end of the QRS complex) is considered to reflect far-field late potentials originating from the epicardial side. VT = ventricular tachycardia.

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  Figure 3. Epicardial Mapping and Ablation (A) 12-lead ECG during VT showing a heart rate of 143 beats/min with QRS complexes in a right bundle branch block pattern and a superior axis configuration. (B) Epicardial isochronal late activation map (ILAM) during right ventricular apex (RVA) pacing. The area enclosed by the white arrows indicates the left ventricular aneurysm. Extensive isolated late potentials were observed on the epicardial surface of the LV aneurysm, with signals delayed by >40 ms from the end of the QRS complex (blue to purple). (C) Epicardial activation map of the clinical VT. Diastolic potentials were continuously recorded throughout the diastolic phase on the epicardial side of the left ventricular aneurysm, suggesting a 2-dimensional VT circuit localized to that area. (D) Successful ablation at the central portion of the isthmus. ECG = electrocardiogram; LV = left ventricular; VT = ventricular tachycardia.

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  Figure 4. Comparison of Omnipolar and Wide-Bipolar Mapping (A) Configuration of the Advisor HD Grid catheter. Each electrode is 1 mm in size with 3 mm interelectrode spacing. Wide-bipolar signals with 7 mm spacing were created by pairing electrodes such as A1 to A3 and A1 to C1. (B) Endocardial activation maps during right atrium pacing annotated by the last deflection. The upper panels show omnipolar mapping, and the lower panels show wide-bipolar mapping. Potentials delayed by more than 40 ms after the end of the QRS complex are displayed in blue to purple. (C) Comparison of electrograms between omnipolar (upper) and wide-bipolar (lower) mapping. In the inferior portion of the LV aneurysm, late potentials not seen with omnipolar mapping were observed as dull far-field late potentials (FFLPs) with wide-bipolar mapping (white arrow). (D) Epicardial late potential voltage map during right ventricular apex (RVA) pacing. The area enclosed by the white arrows indicates the LV aneurysm. The LP region is divided into a high-voltage LP area (purple) and a low-voltage LP area (red). LP = late potential; LV = left ventricular.