Re-entry Circuit in Ventricular Tachycardia Due to Focal Fatty-fibrosis in a Patient with Myotonic Dystrophy

抄録

A 69-year-old man with a recurrent ventricular tachycardia (VT) was admitted. The patient was diagnosed as myotonic dystrophy type 1 (DM1) and DNA analysis revealed 1,800 CTG-repeat expansion in the myotonic dystrophy protein kinase (DMPK) gene. Ultrasonic cardiogram (UCG), left ventriculogram (LVG) and magnetic resonance imaging (MRI) did not show any abnormal sign including fatty infiltration. But, endomyocardial biopsy obtained from ventricular outflow tract revealed severe fatty infiltration and interstitial fibrosis. Radiofrequency catheter ablation at the biopsy site could eliminate VT, so it was strongly suggested that the re-entry circuit was formed by focal fatty-fibrosis. Careful observation should be continued for a long period.