Pulmonary vein isolation using the cryoballoon: is “real-time” really important?

Excerpt

Pulmonary vein isolation (PVI) using the cryoballoon (CB) has seen widespread clinical acceptance with robust randomized data supporting its long-term efficacy [1]. A subset of patients will experience recurrent atrial fibrillation (AF) commonly attributed to electrical pulmonary vein (PV) reconnection [2, 3]. During CB PVI, a spiral mapping catheter (Achieve, Medtronic Inc., Minneapolis, USA) is advanced through the inner lumen of the catheter shaft, allowing safe over-the-wire placement of the balloon into the target PV. Electrodes on the Achieve mapping catheter facilitate real-time recording of PV potentials while their sudden disappearance during cryoenergy delivery signifies acute PVI. The time to PVI has evolved as a strong predictor of long-term success with higher AF recurrence rates seen at durations > 43 s [4, 5]. The shorter muscle bundles penetrating the inferior PVs often require the Achieve mapping catheter to be retracted to the most proximal aspect of the PV ostium. Despite all operator efforts, in a subset of patients, PV potentials may not be recorded and acute PVI can only be confirmed after completion of the freeze cycle. Would these patients experience worse long-term outcome? …