Introduction: We present a case of left-sided atrial flutter complicated by PentaRay Catheter (PRC) entrapment in the mechanical mitral valve (MVR) and the manoeuvre used to free the catheter.
Background: Atrial fibrillation (AF) and flutter are common post MVR and confer a worse prognosis. AF is often refractory to pharmacological agents and radiofrequency ablation (RFA) is usually needed to maintain sinus rhythm.
Left atrial catheter ablation is safe, albeit associated with a small risk of complications. The advent of multipolar mapping catheters had greatly enhanced the speed of obtaining 3D maps. A rare complication unique to the post mechanical MVR population is entrapment of mapping catheters in the prosthetic valve apparatus. Failure to retrieve the catheter percutaneously often necessitates open heart surgery to extract the catheter and restore valve function. Entrapment of PRC is less frequently reported in the literature compared to circular mapping catheters.
Explanation of basic methods: A 52-year-old female with a distant history of mechanical mitral and aortic valve replacement underwent pulmonary vein isolation and extensive ablation in the body of the left atrium and coronary sinus for refractory AF. Eighteen months later, she developed atypical flutter and returned for another ablation procedure.
Decapolar catheter was placed in the coronary sinus and two trans-septal punctures were performed. A PRC was used to build an electro-anatomical map using CARTO (Biosense Webster, Inc). This showed reconnection of the right inferior pulmonary vein. Despite careful attention to avoid the anterior aspect of the LA, two of the PRC splines became entrapped in the annular edge of the mechanical MVR apparatus which fixed one leaflet in the closed position. The usual manoeuvres to free the catheter such as gentle traction, clockwise–counter clockwise rotation, and advancing the sheath over the catheter failed to free the catheter. Forceful traction was not used to avoid the splines shearing off. Instead, a 4 mm irrigated tip ablation catheter (Biosense Webster, Inc) was introduced through the second transseptal sheath and directed anteriorly. Gentle pressure with the ablation catheter on the leaflet allowed it to open and freed the catheter which was withdrawn easily and without any complications. The right lower vein was re-isolated again. Normal MV function was confirmed at the end of the procedure with fluoroscopy and echocardiography. Her recovery after the procedure was unremarkable and she remains arrhythmia free 18 months after the procedure.
Conclusion: This case describes the potential danger of mapping with a PRC in patients with MVR. Catheter entrapment in the mitral valve during left atrial ablation has been mainly reported with circular mapping catheters. Entrapment of the PRC catheter is less frequently described. Since the splines are not isodiametric, traction on the PRC exacerbates the entrapment of electrodes on the ventricular side of the leaflet. Various manoeuvres have been described to attempt the retrieval of the catheter, but surgical intervention is sometimes required if percutaneous retrieval fails or valve function is affected. We describe an alternative approach to help retrieve and entrapped PRC using an ablation catheter. The deflectable ablation catheter allows accurate positioning on the affected valve leaflet and is rigid enough to exert sufficient force to open the valve leaflet and allow the PRC to be freed without complications.