Late arrhythmia recurrence after atrial fibrillation ablation: incidence, mechanisms and clinical implications

Background and objectives Catheter ablation of atrial fibrillation (AF) has become a well-established and widely used therapy, with pulmonary vein isolation (PVI) being the key modality of ablation. However, arrhythmia recurrences after PVI are common, with a relevant number of patients undergoing repeat ablation. Arrhythmia recurrence after PVI may vary regarding time point and mode of recurrence. While early arrhythmia recurrences of AF after PVI are mostly found to be the product of electrical reconnection of the pulmonary veins, the exact mechanisms of very late arrhythmia recurrence, occurring later than 12 months after successful PVI, remain unclear. This review provides an overview on the current evidence on time point and mechanisms of arrhythmia recurrence after PVI focussing on late arrhythmia recurrence. Recent findings The incidence of late arrhythmia recurrence after PVI can lie at a rate of up to 30% according to long-term follow-up studies. Mechanisms of recurrence include electrical reconnection of previously isolated pulmonary veins and development of atrial fibrosis. The use of cryoballoon ablation is likely to be more effective in reducing late arrhythmia recurrences compared to radiofrequency ablation. Novel scores such as the MB-LATER score or the APPLE score may become useful tools in predicting arrhythmia recurrence after PVI. Results and conclusion Late arrhythmia recurrence after PVI is common and leads to a relevant impairment of long-term success. Relevant data are currently limited and exact mechanisms of arrhythmia recurrence remain unclear. Further studies are needed to elucidate pathogenetic mechanisms of late arrhythmia recurrence after PVI in order to improve treatment strategies.

Implantation of a VDD implantable cardioverter-defibrillator lead via a persistent left superior vena cava

A persistent left superior vena cava (LSVC) represents a challenging congenital abnormality for transvenous cardiac device implantation. In the current case a secondary prophylactic VDD implantable cardioverter-defibrillator (ICD) implantation was planned in a 75-year-old woman presenting with ischemic cardiomyopathy and elevated stroke risk. Since no venous communication to the right side was identified intraoperatively, the lead was placed via the persistent LSVC. The far-field signal on the floating atrial dipole could be successfully blanked out, and appropriate device function with high and stable atrial sensing was demonstrated at follow-up.