Unipolar voltage mapping in right ventricular cardiomyopathy: pitfalls, solutions and advantages

Figures

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  Figure 1. Examples of adjustment of the WOI. The automatically and manually adjusted WOI UV values are shown. *In this unipolar EGM, the near-field is completely obscured within the far-field signal caused by RV pacing, and therefore, the unipolar amplitude cannot be determined. EGM, electrogram; RV, right ventricle; UV, unipolar voltage; WOI, window-of-interest.

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  Figure 2. Ratio between endo- and epicardial voltages among three epicardial fat categories. The median (IQR) ratio between endo- and epicardial voltages for UV on the left and BV on the right. The ratio is more towards 1 among the different fat categories (especially <2.7 mm) for UV compared with BV. BV, bipolar voltage; UV, unipolar voltage.

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  Figure 3. Correlation between endo- and epicardial UV and BV in two fat categories. The correlation between endo- and epicardial UV (top) and BV (bottom) in points with epicardial FT <1 mm (left) and epicardial FT ≥2.8 mm (right) is much better for UV. BV, bipolar voltage; FT, fat thickness; UV, unipolar voltage.

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  Figure 4. Example of the importance of adjusting the WOI and the role of epicardial UV mapping. Endocardial and epicardial mapping during RV pacing in a patient with arrhythmogenic right ventricular cardiomyopathy in modified right anterior oblique view. (A) Endocardial UV map using the automatic WOI on the left and the UV map after adjusting the WOI on the right, clearly demonstrating the underestimation of scar using the automatic WOI. (B) Epicardial BV map. (C) Adjusted epicardial UV map. (D) Epicardial FT map, based on CT. Notable, UV (see C) is less influenced by the thick epicardial fat layer at the apex, compared with BV (see B). BV, bipolar voltage; CT, computed tomography; FT, fat thickness; UV, unipolar voltage; WOI, window-of-interest.