Noninvasive Cardiac Electrical Activity Mapping Systems: Current Available Options

Figures

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  Fig. 1.. Timeline of the principal development in ECGi history. ECGi, electrocardiographic imaging.

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  Fig. 2.. ECGi mapping performed with the CardioInsight system, LAO projection. Panels from left to right, up to down: (1) VT potential map providing a snapshot of unipolar activation. In gray the reconstruction of the LAD artery (indicated by the green arrow), a LV medio-apical calcification (indicated by the red arrow) and the LV epicardial catheter (indicated by the blue arrow). (2) Voltage map during atrial pacing showing a medio-apical and inferior scar; the scar is represented by voltages lower than 1 mV in red and non-purple colors, whereas normal voltages are displayed in purple. (3) VT directional activation map showing directional vectors of local activations. (4) VT activation map (first activation in red and latest in blue). The three maps combined suggest a reentry macrocircuit with a large epicardial exit area including the medio-basal antero-lateral LV wall. Legend: LAO, left anterior oblique; LAD, left anterior descending; LV, left ventricle; STAR, stereotactic arrhythmia radioablation; VT, ventricular tachycardia.

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  Fig. 3.. Comparison between invasive mapping (A) and noninvasive mapping performed by the VIVO system (B), both in PA projection. The maps show ventricular premature depolarization originating from the RVOT posterior wall (as highlighted by the red circles). The image shows a local activation map, with the earliest activation shown in red and the latest in blue or purple. In this case the correlation appears satisfactory despite in this region the noninvasive system is known to have a suboptimal resolution. Legend: PA, posteroanterior; RVOT, right ventricular outflow tract; VPD, ventricular premature depolarization.