High density mapping of inappropriate sinus tachycardia further looks into potential mechanisms

Figures

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  Fig. 1. Activation map during the first ablation procedure. Areas of earliest activation (in red) were rather diffuse, located along the sinus node area, crista terminalis and anterior parts of the superior vena cava (the window of activation scale is restricted to around 10 ms for better delineation of the earliest sources).

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  Fig. 2. Activation maps during the second ablation procedure. Areas of earliest activation (in red) were much more localized, initially located at the arcuate ridge (A), then slightly inferior (B) and then at the infero-lateral part for the tricuspid annulus (C), together with changing rates and P wave morphologies (see text) (the window of activation scale is similarly restricted to 10 ms). Note that automatic annotation with the Rhythmia system sometimes led to apparently inconsistent maps due to the recording of large number of points, some being incorrectly annotated (points of different colors in areas with the same activation time). But due to the high number of points, only the “dominant” local activation time is depicted as a background color on the map, avoiding the need to check and reannotate all points in case of clear mechanism.

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  Fig. 3. Baseline 12-lead ECG 3 months after the second procedure, as recorded just before treadmill, showing low right atrial rhythm.