A single-center trial of electrographic flow mapping and concomitant voltage mapping in sinus rhythm and atrial fibrillation (FLOW EVAL-AF)

Figures

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  Fig. 1. Diagram of FLOW EVAL-AF study procedure. Patients were mapped by bipolar voltage map and EGF map in their presenting rhythm. They then underwent PVI followed by either AF induction or cardioversion into the rhythm in which they did not present. They were lastly remapped in the new rhythm and cardioverted, if applicable

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  Fig. 2. Example LA and RA EGF maps from a single patient in AF where active sources were present and corresponding LA and RA EGF maps in SR. In the LA map, the source at D2 in AF (SAC 27.4%) converted to a sink where flow vectors come together from four orthogonal directions at D2 in SR. In the RA map, the source near D4 in AF (SAC 32.9%) converted to a sink near D3 in SR. In both cases, EGFC – visualized as purple flow vectors v. blue – is higher in SR v. AF

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  Fig. 3. Box-and-whisker plot of EGFC from all paired recording locations of patients in AF v. SR. In all but one case, median EGFC was higher in SR. A linear mixed effect model of this data demonstrated that the EGFC in the two rhythms were significantly different (P < 0.0001)

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  Fig. 4. Electrode-level comparison of EGFC in AF v. SR. a shows the distribution of electrodes by EGFC in each rhythm from all positionally paired maps of patients with EGF maps in both SR and AF. AF is shown in orange v. SR in blue. Low-contact electrodes were excluded. EGFC was 38% higher on average in SR v. AF (P < 0.0001). b shows a heatmap of the EGFC by spline number and electrode number of all pooled electrodes from the maps in a. Darker regions had higher EGFC and lighter regions had lower EGFC, normalized per rhythm. Though electrodes 1 and 8 in all splines tended to localize near regions with relatively low EGFC in both rhythms, the EGFC distributions otherwise did not align. Results were comparable among all individual patients and mapping positions. c shows a scatter plot of all positionally-aligned electrodes with good contact from patients with maps in both rhythms. No notable trends were observed

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  Fig. 5. EGF maps in AF and SR with corresponding basket positions and overlaid voltage map taken from the same rhythm. Moving clockwise, A spline is cyan, B spline is red, C and D splines are white, E spline is yellow, F spline is green, G spline is blue and H spline is pink. In AF, the A and B splines (view 1) start in a high voltage region (purple) for their first two electrodes and then move to low voltage (gray). The C and D splines descend and stay in a high voltage region for their first 6 electrodes (view 1) before electrodes 7 and 8 ascend into an unmapped (tan) region (view 3). By contrast, the E and F splines (view 2) predominantly pass through low-voltage areas except locally at F3, and the G and H splines (view 1) start in high voltage regions before descending into low-voltage and unmapped areas (view 3). In SR, splines A–D (views 1–2) predominantly pass through high EGFC regions, even at A4–A5 where the spline passes through the left-sided PVI lesion (red spheres). At electrodes 7–8, the splines ascend into a low-voltage region (view 3). By contrast, the E and F splines (view 2–3) mainly pass through low voltage except for a high voltage patch at E3/F3-E4/F5 (view 3).…

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  Fig. 6. EGFC versus Voltage. a Unipolar voltage was measured from the median f-wave amplitude at each electrode and plotted against local EGFC at the same electrode for the first recording in each atrium from each patient. SR is shown in blue v. AF in orange. An overall linear trendline was fit to the data (r = 0.389, P < 0.0001). b All voltage maps had their healthy voltage percent surface area plotted against the EGFC mean computed from the average of all concomitant EGFC maps in the same patient and rhythm. SR is shown in blue v. AF in orange; LA is shown as circles v. RA as diamonds. An overall linear trendline was fit to the data (r = 0.651, P < 0.0001)