Epicardial Cryotherapy of Ventricular Tachycardia as Hybrid Procedure in Congenital Heart Disease

Objectives: Because of prior surgical procedures, ventricular tachycardia (VT) in congenital heart disease is of different mechanism, occurs in even younger age groups, and often needs different approaches, especially since epicardial ablation is handicapped by postsurgery adhesions.

Methods: We report a case of a 21-year-old male patient with recurrent VT requiring electric cardioversion. He had previous surgical repair of congenital heart disease, truncus arteriosus communis A1, lately he got bioprosthetic aortic valve replacement in 2016. Shortly after this surgical procedure, he developed VTs. Imaging examinations (CT angiography and MRI) showed an intramural diverticle from the aortic sinus toward the right ventricle (RV). A first attempt of 3D activation mapping showed a macroreentrant RV-VT in which the diverticle was involved. Radiofrequency ablation of the VT in the RV in 2016 was not successful, an interventional closure of the diverticle with plug devices did not show any effect either. Under antiarrhythmic medication with metoprolol and amiodarone, his course was stable for 3 years but unfortunately frequency of VTs now increased. Therefore, another electrophysiological study (EPS) was done. First a noninvasive body surface mapping was performed showing the course of the VT, arising from the aortic root, leading right through the diverticle structure to proceed in the lateral wall of the RV. In the following endocardial EPS, the activation map during VT (CL, 440 ms) missed almost half of cycle length in the area of the diverticle, so there was no isthmus target to terminate the macro reentry mechanism by an endocardial approach. To reach the diverticle, a hybrid procedure was planned. Due to pulmonary homograft stenosis, surgical valve replacement was necessary anyway. After sternotomy, the VT was induced by epicardial pacing. The cryoablation probe was placed along the epicardial site of the diverticle structure. The tool was cooled by argon gas down to −80°C, the VT terminated after application time of 30 seconds, cryoenergy was administered for a total time of 4 minutes. Afterward, the VT was non inducible. Surgery then was completed with pulmonary valve replacement. Follow-up was uneventful with freedom from VT for more than 3 months.

Conclusion: Epicardial ablation for VT therapy also in patients with congenital heart disease can be essential. In specific cases, the effort of open surgery in combination with epicardial cryotherapy or radiofrequency ablation should be considered.

Publication History

Article published online:
21 February 2021