Po-04-007 reproducibility of the acqmap composite map function for assesment of conduction velocity within the left atrium: a pilot study

Identifying targets for ablation beyond Pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF) remains challenging The AcQMap system (Acutus) composite map algorithm computes the speed and direction of the propagating wavefront. The number of wavefronts that have a conduction velocity (CV) less than a 0.3 m/s is counted and visualized on the 3D anatomy. This technology has the potential to identify areas of abnormal conduction within the patient’s individual left atrial (LA) substrate that may be important ablation targets The aim of this pilot study was to assess the reproducibility of LA conduction velocity assesment using composite map for individual patients undergoing AF ablation Data from 9 consecutive patients undergoing PVI for persistent AF were studied retrospectively. Conduction velocity of the LA was recorded for 5, 10 and 20 second intervals and graded 0 (normal), 1, 2 or 3 according to whether CV was abnormal for < 60, 70, 80 or 90 % of all activations at a given site A 42 segment model of the LA was used and CV in each segment graded by 3 observer consensus. There were no complications in any procedures Correlations between 5 and 10 second samples with 20 seconds for each patient are shown in figure 1a. Mean correlation was 79 and 90 % respectively. Correlation between serial 10 seconds samples was 83% (figure 1b) Of note there were 4 samples that correlated poorly with others for the patient. Closer inspection of the sample period demonstrated relative organisation (pseudo flutter) in the sample There were no specific LA sites where disagreement was noted between maps more frequently than others In this pilot study the composite map assessment of LA showed a high degree of reproducibility for recordings > 10 seconds and suggests 20 seconds to be the optimum duration