Junji Fukuhara

Clinical effectiveness of pulmonary vein isolation for arrhythmic events in a patient with catecholaminergic polymorphic ventricular tachycardia

An 18-year-old woman with catecholaminergic polymorphic ventricular tachycardia (CPVT) underwent pulmonary vein isolation (PVI) because of frequent and inappropriate shocks from an implantable cardioverter defibrillator (ICD) associated with atrial fibrillation (AF) with a rapid ventricular response. While the PVI did not completely suppress the AF induced by an isoproterenol infusion, the Holter monitor recordings demonstrated a major decrease in the clinical episodes of AF and ventricular tachyarrhythmias in association with a reduced high-frequency (HF) component and ratio of the low-frequency (LF) component power to the HF component (LF/HF) after the PVI. The PVI can decrease the substrates that trigger and maintain the AF when it involves a pulmonary vein origin, and may exert an additional effect on the sympathetic nerve input to the heart. The PVI may be an adjunctive therapy for CPVT cases with drug refractory AF causing inappropriate ICD discharges.

Anderson's disease/chylomicron retention disease in a Japanese patient with uniparental disomy 7 and a normal SAR1B gene protein coding sequence

BackgroundAndersons Disease (AD)/Chylomicron Retention Disease (CMRD) is a rare hereditary hypocholesterolemic disorder characterized by a malabsorption syndrome with steatorrhea, failure to thrive and the absence of chylomicrons and apolipoprotein B48 post-prandially. All patients studied to date exhibit a mutation in the SAR1B gene, which codes for an essential component of the vesicular coat protein complex II (COPII) necessary for endoplasmic reticulum to Golgi transport. We describe here a patient with AD/CMRD, a normal SAR1B gene protein coding sequence and maternal uniparental disomy of chromosome 7 (matUPD7).Methods and ResultsThe patient, one of two siblings of a Japanese family, had diarrhea and steatorrhea beginning at five months of age. There was a white duodenal mucosa upon endoscopy. Light and electron microscopy showed that the intestinal villi were normal but that they had lipid laden enterocytes containing accumulations of lipid droplets in the cytoplasm and lipoprotein-size particles in membrane bound structures. Although there were decreased amounts in plasma of total- and low-density lipoprotein cholesterol, apolipoproteins AI and B and vitamin E levels, the triglycerides were normal, typical of AD/CMRD. The presence of low density lipoproteins and apolipoprotein B in the plasma, although in decreased amounts, ruled out abetalipoproteinemia. The parents were asymptomatic with normal plasma cholesterol levels suggesting a recessive disorder and ruling out familial hypobetalipoproteinemia. Sequencing of genomic DNA showed that the 8 exons of the SAR1B gene were normal. Whole genome SNP analysis and karyotyping revealed matUPD7 with a normal karyotype. In contrast to other cases of AD/CMRD which have shown catch-up growth following vitamin supplementation and a fat restricted diet, our patient exhibits continued growth delay and other aspects of the matUPD7 and Silver-Russell Syndrome phenotypes.ConclusionsThis patient with AD/CMRD has a normal SAR1B gene protein coding sequence which suggests that factors other than the SAR1B protein may be crucial for chylomicron secretion. Further, this patient exhibits matUPD7 with regions of homozygosity which might be useful for elucidating the molecular basis of the defect(s) in this individual. The results provide novel insights into the relation between phenotype and genotype in these diseases and for the mechanisms of secretion in the intestine.

Successful control of life-threatening polymorphic ventricular tachycardia by radiofrequency catheter ablation in an infant

We present a case of a 9-month-old girl in whom malignant polymorphic ventricular tachycardia (VT) was successfully controlled by radiofrequency catheter ablation under guidance with a three-dimensional mapping system. The VTs originated from the left ventricular lateral wall, left ventricular anterior wall, and left ventricular apex. At least six types of VTs were documented during the electrophysiology study. All VTs were successfully controlled after two sessions of radiofrequency catheter ablation, and she was discharged from our hospital on propranolol, mexiletine, flecainide, and aprindine.

Potency of integrating three-dimensional cardiac magnetic resonance imaging into electroanatomic mapping to perform catheter ablation in pediatrics.

Background Radio-frequency catheter ablation (RFCA) in children is difficult because the size of heart chamber change with age and the catheter made for adults is not appropriate for a child. Three-dimensional (3D) images for electroanatomic mapping (EAM) have been used to create from images of multi-detector computed tomography (MDCT) which need to perform entailed by contrast medium injection and radiation exposure. This study sought to evaluate the usability of 3D Cardiac Magnetic Resonance Image (CMR) in pediatrics cases.