Presence of low voltage area predicts atrial tachyarrhythmia inducibility with atrial burst pacing after pulmonary vein isolation

Background Induction of atrial fibrillation (AF)/atrial tachycardia (AT) by atrial burst pacing following ablation procedure may reflect the presence of residual substrates in the atria that maintain AF. However, the relation between the inducibility and left atrial low voltage area (LVA) has not been established. Methods Fifty-nine patients (65 years old, 43 males) with persistent AF who underwent pulmonary vein isolation (PVI)-based ablation were studied. All patients underwent left atrial voltage mapping during sinus rhythm and atrial burst pacing after PVI. Atrial burst pacing was performed with 30-beat at an amplitude of 10V from the ostium of the coronary sinus; increasing from 240 to 320 ppm in steps of 20 ppm or failure to 1:1 atrial capture. Inducibility was defined as AF/AT lasting more than 5 minutes following burst pacing. Left atrial LVA and other co-variates were analyzed with regard to burst pacing positivity. Results AF/AT was induced by burst pacing in 23 patients (39%). Univariate analysis revealed that past history of stroke, CHADS2 score and presence of left atrial LVA were significantly associated with the inducibility of AF/AT. Multivariate analysis revealed that only the presence of LVA was associated with the inducibility (OR 1.5: per 10% increase; p=0.04). We focused on the relationship between the extent of LVA and burst positivity. AF/AT inducibility increased as low voltage area increased, and it was as high as 72.7% when low voltage area was more than 20% (P<0.05). Interestingly, induced arrhythmia type was AT rather than AF when low voltage area was more than 20%. Conclusions Presence of left atrial LVA is an independent predictor of atrial tachyarrhythmia inducibility after PVI in patients with persistent AF. A large amount of low voltage area is related to AT inducibility rather than AF. Extent of LVA and burst positivity Funding Acknowledgement Type of funding source: None

Pacing the PV after isolation/1

This case considers pulmonary vein capture with exit block and intermittent far-field atrial capture