a 53-year - old man presented with drug refractory paroxysmal atrial fibrillation ( afib ) . his history included coronary artery disease , cryptogenic stroke with a large persistent foramen ovale , which was closed with a 30 mm amplatzer multi - fenestrated septal occluder ( aso ; st . jude medical , inc . , st . cryoballoon ablation of the pulmonary veins ( capv ) was recommended to treat his paroxysmal afib . during capv , catheter movements were guided by real - time three - dimensional transesophageal echocardiography ( rt3dtee ) to visualize the aso . an appropriate site for transseptal puncture ( tsp ) was found just anterior and inferior to the aso . an 8.5 f torflex transseptal guiding sheath ( baylis medical , montreal , canada ) and a 71 cm radiofrequency ( rf ) transseptal needle ( nrg transseptal needle ; baylis medical ) were used for tsp . an amplatz super stiff guidewire ( boston scientific , marlborough , ma , usa ) was used to allow for significant support needed to exchange the flexcath steerable sheath ( medtronic , minneapolis , mn , usa ) over the wire ( fig .  1 ) . the transseptal sheath was exchanged for a 15 f cryoablation flexcath sheath ( fig .  2 ) . a 28 mm cryoballoon with a 15 mm achieve mapping catheter ( medtronic , minneapolis , mn , usa ) was advanced into the left atrium . intracardiac echocardiography ( ice ) was used throughout the procedure to verify pulmonary vein ( pv ) balloon occlusion and rule out pericardial effusion . due to the limited space for tsp of the native septum , ice and rt3dtee were used for catheter positioning anterior and inferior to the aso . lesions were applied to all pvs with phrenic monitoring throughout , which showed no evidence of phrenic slowing . entrance and exit block were performed on the veins and following this , all veins were found to be free of signal . the patient was discharged after overnight observation without any complications . at his three - month capv has been shown to be non - inferior to rf ablation for treating paroxysmal afib , . rf ablation of afib has been shown to be safe and effective in patients with atrial septal defect closure devices . however , capv has not been previously reported as a rhythm control strategy for paroxysmal afib in the presence of an aso . due to the large flexcath sheath ( 15 f ) required for tsp , it was unclear whether capv would be feasible in the presence of an aso . prior reports have demonstrated the feasibility of tsp using rf ablation with up to a maximum sheath size of 8.5 f . this case demonstrates that tsp can be performed in portions of the native septum under rt3dtee guidance . capv for paroxysmal afib in the presence of an aso was performed safely and effectively in one patient , and provides electrophysiologists with an additional option to treat atrial arrhythmias in patients with intracardiac devices . the larger sheath combined with the flexibility of the flexcath sheath made it possible to maneuver across a thick septum with an aso without difficulty and allowed for improved torque . the use of capv for afib in patients with closure devices with tsp under rt3dtee guidance is possible in such patients .
cryoballoon ablation of the pulmonary veins ( capv ) has been demonstrated to be non - inferior to radiofrequency ( rf ) ablation for paroxysmal atrial fibrillation ( afib ) . 
 as capv requires a larger transseptal sheath than rf ablation , it can be challenging in the presence of an amplatzer septal occluder ( aso ) device . 
 real - time three - dimensional transesophageal echocardiography ( rt3dtee ) provides enhanced visualization of various complex cardiac defects and has revolutionized interventional procedures by guiding catheter positioning . 
 we describe successful rt3dtee guided transseptal puncture for capv of paroxysmal afib in the presence of an aso in a 53-year - old male .