Micra Transcatheter Pacing System implantation in a Patient with a History of Mustard Repair and Transposition of Great Arteries

Abstract

Patients with congenital heart disease commonly have abnormalities of conduction system, directly related to congenital abnormality or a result of surgical correction. Leadless pacemaker is a relatively new option for patients who need only ventricular pacing. The Micra Transcatheter Pacing System (Medtronic Inc., Dublin, Ireland) is a leadless pacemaker currently used in our centre. The device is fixed into the endocardium using four self-expanding tines located on the distal end of the device. Although the absence of a screwing system reduces the risk of perforation, its implantation can be problematic in implant sites without significant trabeculation. We describe a 56-year-old man with a history of Mustard repair at age of 7 years, transposition of great arteries and superior vena cava obstruction. In 2005, the patient had undergone epicardial permanent pacemaker owing to complete heart block and atrial flutter. Because of the high pacing threshold and the need for generator replacement, we need to implant a new pacing system. Hence, we decided to implant a Micra. Despite the fact that the patient's right ventricle had the morphology of the left ventricle and did not have significant trabeculation, we could implant the device on lower part of interventricular septum. X-ray and device interrogation at 6-month follow-up showed good pacing and sensing thresholds, and no change in the position of the device. In conclusion, a leadless pacemaker can be an option in patients with congenital heart disease whose right ventricles do not have significant trabeculation.