Pulmonary vein isolation (PVI) is the cornerstone of ablation for paroxysmal atrial fibrillation (AF). However, success rates from AF ablation are not as high as would be hoped and this body of work focussed on improving outcomes from this procedure. Late PV reconnection following PVI is very common and is strongly associated with atrial tachyarrhythmia (AT) recurrence. The primary study of this work involved a randomised controlled trial comparing standard care with a strategy of early repeat

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... lectrophysiology study, irrespective of symptoms, to assess for and treat PV reconnection. Patients were followed-up for 12 months with daily ECG monitoring using a portable monitor. This study demonstrated a reduction in AT recurrence and burden and an improvement in quality-of-life in the repeat study group. At present, a 3-month blanking period following PVI is recommended, during which AT recurrences are not deemed indicative of procedure failure. In a secondary study, the relationship between episodes of AT recorded within this 3-month blanking period and PV reconnection was studied. Early recurrence beyond 4 weeks after PVI was associated with PV reconnection, whereas recurrence within the first 4 weeks was not. Force-Time Integral is a commonly-used ablation lesion quality marker but has limitations. Ablation Index is a novel marker incorporating power along with contact force and time in a weighted formula. In a further study, the relationship between Ablation Index and late PV reconnection was examined. Reconnected segments had significantly lower minimum Ablation Index values than non-reconnected segments, and higher values were required to avoid reconnection in anterior/roof segments compared to posterior/inferior segments. In the final part of the work, the relationship between sites of acute PV reconnection that underwent re-ablation and sites of late reconnection was studied, as the effectiveness of such re-ablation is unclear. No difference was found in the rates of late reconnection between areas with and w [...]