A technique for continuously analyzing atrial frequency characteristics of AF from the surface ECG has been developed and validated.

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Recurring patterns from preprocedural 1-minute recordings of ECG TQ intervals were significant predictors of CA 6-month outcome.

ObjectiveTo assess the effect of catheter ablation on atrial fibrillation (AF) symptoms and quality of life (QoL).MethodsPatients with AF scheduled for ablation were recruited. Pulmonary vein isolation (PVI) was performed and complex fractionated atrial electrogram (CFAE)±linear ablation undertaken in patients in AF despite PVI. QoL and AF symptoms were assessed using SF-36 V2 and Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaires before and 3 months after ablation. Change in QoL scores after ablation was correlated with clinical parameters and the extent of ablation. Magnitude of QoL change was compared between AFEQT and SF-36 physical component summary (PCS) and mental component summary (MCS) scores and correlated with arrhythmia outcome.Results80 patients were studied. Summative and individual health scores for both AFEQT (51.5±22.0 vs 81.3±18.2; p<0.01) and SF-36 (PCS 43.3±10.5 vs 47.9±11.3; p<0.01 and MCS 45.0±11.5 vs 51.5±9.4; p<0.01) improved significantly in patients who maintained sinus rhythm after ablation, but not in those with recurrent AF. Improvement in AFEQT (25.4±19) was significantly greater than change in PCS (6.8±6.4; p<0.01) and MCS (8.5±7.9; p<0.01) scores and correlated more closely with arrhythmia outcome (AFEQT r=0.55; PCS r=0.26; MCS r=0.30).ConclusionsPatients who maintained sinus rhythm after ablation had a significant improvement in AF symptoms and QoL; however, no improvement was observed in patients with recurrent AF. QoL change after ablation did not correlate with baseline clinical parameters or ablation strategy. AF specific QoL scales are more responsive to change and correlate better with ablation outcome.

HighlightsIndividual posterior ECG leads better reflect left atrial activity compared to V1.Surface dominant AF frequency (DAF) calculated using principal component analysis.Modified 12-lead ECG (including posterior leads) compared to standard 12-lead ECG.Surface DAF from modified ECG did not correlate stronger with left atrial activity.Lead V1 dominant in AF principal component from both ECG configurations.

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Our group has described previously the identification of arrhythmogenic pulmonary veins by rapid local electrical activations during atrial fibrillation. We have now investigated an algorithm for automated computer detection of this phenomenon from catheter electrodes in the upper pulmonary veins and assessed its performance in identifying arrhymogenic veins. Ten patients with persistent atrial fibrillation scheduled for pulmonary vein isolation at this hospital were studied. Electrogram recordings in the upper pulmonary veins were recorded and analyzed. Arrhythmogenic veins were identified by focal activity during sinus rhythm at electrophysiological studies. Recordings were visually assessed by a cardiologist for the presence of rapid repetitive electrical activations during atrial fibrillation. An index of rapid repetitive electrical activity (RREA index), the ratio of the number of activations with cycle lengths in the range 50 ms to 100 ms to the number of activations with cycle lengths in the range 100 ms to 200 ms, was devised to describe the extent of such activity automatically. The index was assessed as a predictor of arrhythmogenic veins. Electrograms from 19 upper pulmonary veins were recorded. Rapid activity was evident in 15 veins by visual manual assessment. The mean (range) automatic RREA index was 0.07 (0 to 0.16) for those identified as having no such activity manually, and 0.83 (0.22 to 1.68) for those identified with rapid activity (p<0.0001). With a threshold of RREA index in the range 0.17 to 0.21, the identification of veins with rapid firing was exactly the same as for manual assessment. Eleven upper pulmonary veins were identified as arrhythmogenic during electrophysiological study, and the identification of these veins by both manual and automatic assessment of rapid repetitive electrical activations gave a sensitivity of 100% (11/11) and specificity of 50% (4/8). A technique for automatic characterization of electrogram cycle length has been demonstrated and could be used online as a tool for identifying candidate sites for pulmonary vein isolation in patients despite persistent atrial fibrillation.

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