Use of intracardiac echocardiography for early detection of phrenic nerve injury during cryoballoon pulmonary vein isolation.

Cryoballoon catheter ablation has recently emerged as an effective tool to achieve pulmonary vein isolation (PVI). Right-sided PVI with cryoballoon ablation has been associated with a significant incidence of phrenic nerve palsy. Multiple modalities are currently utilized to monitor phrenic nerve function during ablation. We describe a novel approach toward monitoring and diagnosing phrenic nerve palsy using intracardiac echocardiography (ICE) during cryoballoon ablation of the right pulmonary veins. This technique of monitoring has the advantage of continuous direct diaphragmatic visualization without the use of fluoroscopy, hence significantly minimizing radiation to both the patient and the operator. In addition, this technique does not require extra personnel to monitor the diaphragm using manual palpation. Further prospective studies of our and other methods for prevention of phrenic nerve palsy are required.