Therapeutic Research

Abstract

Background：Many patients with L‒looped transposition of the great arteries（L‒TGA）develop refractory heart failure and sustained ventricular tachycardia. We report a case of successful implantation of cardiac resynchronization therapy defibrillator（CRT‒D）in a patient with L‒TGA, who was later found to be a non‒responder to CRT. Case：The patient was diagnosed with L‒TGA and dextrocardia at birth. At 10 years of age, he had complete atrioventricular block after tricuspid valve replacement and was implanted a permanent pacemaker（VVI）via a transvenous approach. There after he underwent repeated exchange of pacemaker leads and implantation of pacemaker on the other chamber. At age 38, ventricular fibrillation occurred during the perioperative period, but upgrade to implantable cardioverter defibrillator（ICD）was not performed due to foreseen difficulties. Amiodarone was initiated and the course was observed. Two years later, the patient developed sustained ventricular tachycardia. At first, ICD implantation was planned but eventually a CRT‒D（ConcertoTM, Medtronic）was implanted because of reduced cardiac function and dyssynchrony detected by tissue Doppler imaging （TDI）. CRT‒D was successfully implanted in spite of the unusual anatomy of his coronary sinus. However, he developed heart failure after the procedure and was assessed as non‒responder to CRT. Then CRT was discontinued and DDI with prolonged AV delay（A pace＋V sense or fusion）was adopted instead. After that, his condition improved dramatically. He received ICD implantation（ProtectaTM XT DR by Medtronic）with MVP‒mode at 39 years of age, and has been doing well without hospitalization. Conclusion：CRT is efficient in most patients with congenital heart disease with reduced cardiac function, but some patients may be non‒responders. Careful consideration of indication for CRT is needed.