Tomohito Mabuchi

T wave peak-to-end interval and QT dispersion in acquired long QT syndrome: a new index for arrhythmogenicity

QT dispersion (QTD) on 12-lead ECGs has been proposed as a marker of malignant ventricular tachyarrhythmias, and increased QTD has been reported in long QT syndrome (LQTS). On the other hand, it has been demonstrated that transmural dispersion is associated with ventricular tachyarrhythmias in an experimental model. However, the precise type of QTD or transmural dispersion that contributes most to ventricular tachyarrhythmias in patients with LQTS remains unclear. We evaluated 27 patients with acquired LQTS. These patients were divided into two groups: group A (n =12), patients with polymorphic ventricular tachycardia [torsades de pointes (TdP)], and group B (n =15), patients without TdP. The QT intervals were corrected using Bazetts formula. QTD was measured as the difference between the maximum and the minimum QT intervals, and T wave peak-to-end interval divided by the QT interval (Tpe) in the V5 lead was measured as a new index. Both the corrected QTD (QTDc) and Tpe were significantly larger in group A than in group B. Logistic regression analysis revealed that a reliable predictor for TdP in the QT variables in these patients was not QTDc but Tpe. Cumulative frequency distributions revealed that a Tpe of 0.28 is a good cut-off point for TdP. Tpe did not correlate with the corrected maximum QT interval, whereas the QTDc did correlate with this parameter. In conclusion, Tpe may be the best predictor for TdP in patients with acquired LQTS.

Adult Patient With Isolated Noncompaction of Ventricular Myocardium

A 55-year-old woman was admitted to our hospital because of congestive heart failure despite full medical therapy. She had been diagnosed as having and was treated for cardiomyopathy of unknown cause during an extended period. She had no familial history of cardiovascular diseases or sudden cardiac death. Echocardiograms revealed severely reduced left ventricular (LV) contraction, severe mitral regurgitation, thickened myocardium with prominent trabeculations, and …

Mutational and haplotype analysis of AGL in patients with glycogen storage disease type III

AbstractGlycogen storage disease type III (GSD III) is a rare autosomal recessive inherited disorder caused by a deficiency of the glycogen-debranching enzyme (AGL). We investigated two GSD III patients and identified four different mutations. Nucleotide sequence analysis revealed patient 1 of Chinese descent to be a compound heterozygote for a novel nonsense mutation, R34X, and the splicing mutation (IVS32−12A > G) reported in a Japanese patient. Patient 2 of Japanese origin was found to be compound heterozygous for a novel nonsense mutation, Y1148X, and the splicing mutation (IVS14+1G > T) that we had described previously. To determine whether splicing mutations occurred independently, we performed intense AGL haplotype analysis using 21 intragenic polymorphic markers plus a novel polymorphism IVS32−97 A/G in the vicinity of the IVS32 splicing mutation. Patient 1 of Chinese origin and the Japanese patient homozygous for the IVS32−12A > G were found to have different haplotypes, indicating the IVS32−12A > G mutation to be a recurrent mutation. This is the first recurrent mutation established by intense haplotyping in the AGL gene.

Cardiac dysfunction and long-term prognosis in patients with nonobstructive hypertrophic cardiomyopathy and abnormal (123)I-15- (p-Iodophenyl)-3(R,S)-methylpentadecanoic acid myocardial scintigraphy.

To evaluate the relationship between myocardial scintigraphic abnormalities based on 123I-radioiodinated 15-(p-iodophenyl)-3(R,S)-methylpentadecanoic acid (BMIPP) uptake and cardiac function and the relationship between these abnormalities and long-term prognosis in patients with hypertrophic cardiomyopathy (HCM), 27 patients with nonobstructive HCM underwent BMIPP myocardial scintigraphic study, echocardiography, and exercise radionuclide study. Based on the extent of BMIPP scintigraphic defects, the patients were divided into two groups: Group A (n = 19) patients had no or small defects, and group B (n = 8) patients had moderate to large defects. Cardiac events were recorded over an average period of 64 months. The left ventricular end-diastolic and end-systolic dimensions were significantly greater in group B than in group A. The fractional shortening in group B was less than in group A (p = 0.0002). The BMIPP score and fractional shortening at rest correlated significantly (p < 0.05). The BMIPP score and the change in ejection fraction between rest and peak exercise correlated significantly (p < 0.05). While only 1 cardiac event occurred in the 19 patients in group A during a mean follow-up period of 64 months, 6 cardiac events occurred in the 8 patients in group B. The 84-month event-free survival rate was 94.4% in group A and 14.6% in group B (p < 0.01). These results suggest that patients with HCM and moderate to large defects as assessed by BMIPP myocardial scintigraphy have decreased cardiac function and a poor prognosis.

A novel mutation in the cardiac myosin-binding protein C gene is responsible for hypertrophic cardiomyopathy with severe ventricular hypertrophy and sudden death

It has been demonstrated previously that clinical phenotypes of HCM (hypertrophic cardiomyopathy) caused by mutations in the cardiac MyBP-C (myosin-binding protein C) gene show late onset, low penetrance and favourable clinical course. However, we have encountered severe phenotypes in several carriers of the MyBP-C gene mutations. The aim of the present study was to screen novel MyBP-C gene mutations in patients with HCM and to investigate the genetic differences in affected subjects with severe phenotypes. The MyBP-C gene was screened in 292 Japanese probands with HCM, and a novel c.2067+1G-->A mutation was present in 15 subjects in five families. Clinical phenotypes of carriers of the c.2067+1G-->A mutation were compared with those of a previously identified Arg820Gln (Arg820-->Gln) mutation in the MyBP-C gene. The disease penetrance in subjects aged > or =30 years was 90% in carriers of the c.2067+1G-->A mutation and 61% in carriers of the Arg820Gln mutation. Sudden death occurred in four subjects from three families with the c.2067+1G-->A mutation and in two subjects from one family with the Arg820Gln mutation. Two carriers of the c.2067+1G-->A mutation had substantial hypertrophy (maximal wall thickness > or =30 mm). In contrast, two carriers of the Arg820Gln mutation had end-stage HCM. In conclusion, the c.2067+1G-->A mutation is associated with HCM with substantial hypertrophy and moderate incidence of sudden death, whereas the Arg820Gln mutation is associated with end-stage HCM. These observations may provide important prognostic information regarding the clinical practice of HCM.

Acute increases in plasma oxidized low-density lipoprotein immediately after percutaneous transluminal coronary angioplasty

To investigate the acute changes in plasma oxidized low-density lipoprotein before and immediately after coronary angioplasty, we studied 132 consecutive patients who successfully underwent this procedure. Plasma oxidized low-density lipoprotein levels were significantly increased immediately after coronary angioplasty in patients with stable angina pectoris as well as in those with acute coronary syndromes.

Primary Percutaneous Coronary Intervention by a Stentless Technique for Acute Myocardial Infarction with Idiopathic Thrombocytopenic Purpura: A Case Report and Review of the Literature.

A 78-year-old man who had been diagnosed with idiopathic thrombocytopenic purpura (ITP) was admitted to our hospital with chest pain, cold sweating and nausea. An electrocardiogram and echocardiogram revealed an ST elevated acute lateral myocardial infarction. He underwent an immediate cardiac catheterization. An occluded left circumflex artery was detected by coronary angiography. Reperfusion was performed successfully by non-slip element balloon angioplasty alone, without stenting, to avoid prolonged dual anti-platelet therapy. In this report we discussed the management strategies of acute myocardial infarction in a patient with concomitant ITP.

Very late bare metal stent thrombosis in the setting of discontinuation of optimal medical therapy for 2 years

A 52-year-old man was admitted to our hospital because of acute anteroseptal myocardial infarction. After a bare metal stent (BMS) was implanted in the left anterior descending artery (LAD), aspirin, clopidogrel, statin, angiotensin II receptor blocker, and β blocker were prescribed. 6 years later, however, the patient stopped taking all medication by himself. Further 2 years later, the patient was admitted to our hospital again with chest pain, and emergent coronary angiography showed the total occlusion of the LAD at the site where the previous stent was deployed. Optical coherent tomography (OCT) showed lipid rich neointima with thin cap, suggesting neoatherosclerosis at the proximal to the occlusive site. OCT also showed white thrombus formation around at the occlusive site. Intravascular ultrasound (IVUS) showed the ruptured cavity within the stent at the occlusive site. These findings suggest that the neoatherosclerosis had progressed and ruptured within BMS for 2 years. We would suggest continuation of not only an antiplatelet agent but other optimal medical therapy to prevent the substantial neoatherosclerotic burden and occurrence of late phase stent thrombosis even in BMS.

Emergent thoracic aortic angioplasty and stenting for middle aortic syndrome in non-specific aortitis

A 61-year-old Japanese male was admitted to hospital due to severe congestive heart failure and pre-renal failure with middle aortic syndrome. The patient was successfully treated with emergent aortic angioplasty and kissing stents implantation whilst in a hemodynamically unstable state. Our experience confirms that stenosis of the descending aorta when treated with catheter intervention may be palliative, however, it was a very effective method for life threatening clinical conditions in the short and mid-term and may be an alternative to surgery.

Scintigraphic evaluation of regression of abnormal Q waves in myocardial infarction

We report regression of the abnormal Q waves of an inferior old myocardial infarction after an additional anterior acute myocardial infarction, and demonstrate the scintigraphic correlation and chronological course of this phenomenon. Scintigraphic findings in the present case here may contribute to an interpretation of regression of abnormal Q waves in myocardial infarction.