Potential role of body surface ECG mapping for localization of atrial fibrillation trigger sites

Catheter ablation has revolutionized the clinical management of atrial fibrillation (AF) by offering a curative treatment option for this highly prevalent arrhythmia. Ablation therapy is aimed at electrical isolation of the pulmonary veins (PVs) as a means to prevent rapidly firing focal activation within the PVs from penetrating into the left atrium (LA) and initiate reentrant wavelet propagation. However, non-PV AF trigger sites may be present and lead to unsuccessful ablation or post-ablation AF recurrences. Infrequent trigger firing and the difficulty or inability to induce focal trigger activity in the electrophysiology laboratory limits invasive catheter-based mapping of non-PV trigger sites. Identification of AF trigger sites using the surface electrocardiogram (ECG) P wave morphology is feasible but conventional 12-lead scalar recordings do not offer the resolving power to provide discrete regional localization to potentially target catheter ablation. The present paper includes a review of preliminary clinical data on the use of a 65-lead ECG mapping system (Resolution Medical, Inc) for the non-invasive localization of AF trigger sites. This method utilizes a unique previously developed reference database of 34 mean paced P wave integral map patterns which are each specific to activation arising from a discrete segment in the LA and right atrium (RA). Trigger site localization is obtained by matching the P wave integral map morphology of a premature atrial contraction (PAC) with the reference database of 34 mean paced P wave integral map patterns.