1/21. ST segment and T wave alternans in a patient with brugada syndrome.We describe a patient with brugada syndrome in whom J point and ST-segment elevation in leads V1 and V2 were augmented by atrial pacing and intravenous administration of propranolol or cibenzoline. Significant T wave alternans with a 2:1 appearance of terminal negative T wave was observed in the absence and presence of atrial pacing after the administration of cibenzoline. The cellular mechanism responsible for T wave alternans, beat-to-beat appearance of terminal negative T wave and augmented J point and ST-segment elevation is discussed.- - - - - - - - - - ranking = 1keywords = cell (Clic here for more details about this article) |
2/21. Prevention of ventricular fibrillation by cilostazol, an oral phosphodiesterase inhibitor, in a patient with brugada syndrome.We report the case of 67-year-old man with brugada syndrome, in whom daily episodes of ventricular fibrillation (VF) occurred every early morning for 4 days. The episodes of VF were completely prevented by an oral administration of cilostazol, a phosphodiesterase inhibitor. This effect was confirmed by the on-and-off challenge test, in which discontinuation of the drug resulted in recurrence of VF and resumption of the drug again prevented VF. This effect may be related to the suppression of I(to) secondary to the increase in heart rate and/or to an increase in Ca2 current (I(Ca)) due to an elevation of intracellular cyclic amp concentration via inhibition of phosphodiesterase activity. This drug might have an anti-VF potential in patients with brugada syndrome.- - - - - - - - - - ranking = 1keywords = cell (Clic here for more details about this article) |
3/21. A case of secondary myocardial lymphoma presenting with ventricular tachycardia.Malignant lymphoma can involve the cardiac cavity or myocardium as a mass. Clinical symptoms of its cardiac involvement are usually absent or nonspecific, making the diagnosis of the cardiac involvement very difficult before death. We experienced a patient with secondary myocardial non-Hodgkin's lymphoma presenting with sustained ventricular tachycardia (VT) as a primary clinical problem. A 39-yr-old woman visited our hospital because of dyspnea and palpitation for 7 days. physical examination revealed rapid heart beat with variable intensity of the first heart sound and soft mass in the lower abdomen. VT with a cycle length of 480 msec was recorded in resting 12-lead electrocardiogram. Two well-circumscribed hypo-echogenic round masses were demonstrated in the interventricular septum and left ventricular posterior wall. Cytological examination of aspirated pericardial fluid and percutaneous needle biopsy of the abdominal mass revealed a diffuse large cell type non-Hodgkin's lymphoma. Myocardial masses and ventricular tachycardia resolved with chemotherapy using cyclophosphamide, adriamycin, vincristine and prednisone regimen. To our best knowledge, the same case as ours has not been reported previously.- - - - - - - - - - ranking = 1keywords = cell (Clic here for more details about this article) |
4/21. Hypertrophic non-obstructive cardiomyopathy caused by disorder of the myofiber texture.A case of hypertrophic non-obstructive cardiomyopathy caused by a disorder of the myofiber texture was observed in a 10 year old boy. The heart weighed 390 g and showed concentric hypertrophy of the left and right ventricles as well as of the ventricular septum. Additional findings consisted in an abnormal septum membranaceum and a accessory tricuspid valve leaflet. Severe cardiac hypertrophy was associated with prominent interstitial and subendocardial fibrosis, and pronounced intimal fibrosis of the intramural arteries. Electron microscopy revealed various degrees and stages of hypertrophy of the myocardial cells combined with severe degenerative changes. Additional changes of the sinus node and conduction system were responsible for a tachycardia-bradycardia syndrome, complete left bundle branch block and final total AV-block.- - - - - - - - - - ranking = 1keywords = cell (Clic here for more details about this article) |
5/21. The brugada syndrome.brugada syndrome describes the syndrome of sudden cardiac death in the setting of the following electrocardiographic findings: right bundle branch block pattern with ST-segment elevation in the right precordial leads. The right bundle branch block may be incomplete while the ST segment elevation is minimal. The electrocardiographic findings are not constant. patients suspected of having brugada syndrome should be promptly referred for electrophysiological testing and treatment. Rapid referral and placement of an implantable cardioverter defibrillator (ICD) is associated with an excellent prognosis, whereas failure to diagnose this condition is associated with a high risk for sudden death. Therefore, it is imperative that all emergency physicians be familiar with the typical ECG manifestations of brugada syndrome. Three illustrative cases are presented with a review of the syndrome.- - - - - - - - - - ranking = 1keywords = cell (Clic here for more details about this article) |
6/21. An autopsy case of brugada syndrome with significant lesions in the sinus node.A 30-year-old man with brugada syndrome died suddenly. The heart weighed 380 g. The left ventricular wall showed mild thickening, and marked fatty tissue deposition was noted in the right ventricular outflow tract. Neither ventricle was enlarged. Contraction band necrosis was diffuse in both ventricles. In the ventricles no cardiac muscle cell hypertrophy or atrophy, or significant interstitial fibrosis was observed. In the sinus node the number of nodal cells was reduced by half, with fatty tissue and fibrosis prominent. But no lesions were evident in the right bundle branch.- - - - - - - - - - ranking = 2keywords = cell (Clic here for more details about this article) |
7/21. Detection of proximal tubular motile cilia in a patient with renal sarcoidosis associated with hypercalcemia.In a normal human kidney, almost every cell type gives rise to a solitary primary cilium, an apical hair like nonmotile organelle that recently was linked to the pathogenesis of polycystic kidney disease. Motile cilia normally are not expressed by renal tubular cells in the mammalian kidney. Here, we report the unexpected detection of motile cilia arising from proximal tubular cells in a patient with sarcoidosis associated with hypercalcemia and renal impairment. The possible significance of this unusual finding is discussed.- - - - - - - - - - ranking = 3keywords = cell (Clic here for more details about this article) |
8/21. Unmasking of brugada syndrome by lithium.BACKGROUND: The characteristic ECG pattern of ST-segment elevation in V1 and V2 in the brugada syndrome is dynamic; it is often intermittently present in affected individuals and can be unmasked by sodium channel blockers, including antiarrhythmic drugs and tricyclic antidepressants. We report here 2 patients who developed the Brugada ECG pattern after administration of lithium, a commonly used drug not previously reported to block cardiac sodium channels. methods AND RESULTS: Lithium induced transient ST-segment elevation (type 1 Brugada pattern) in right precordial leads at therapeutic concentrations in 2 patients with bipolar disorder. Lithium withdrawal in the patients resulted in reversion to type 2 or 3 Brugada patterns or resolution of ST-T abnormalities. In Chinese hamster ovary cells transfected with SCN5A, which encodes the cardiac sodium channel, lithium chloride caused concentration-dependent block of peak INa at levels well below the therapeutic range (IC50 of 6.8 /-0.4 micromol/L). CONCLUSIONS: The widely used drug lithium is a potent blocker of cardiac sodium channels and may unmask patients with the brugada syndrome.- - - - - - - - - - ranking = 1keywords = cell (Clic here for more details about this article) |
9/21. High risk for bradyarrhythmic complications in patients with brugada syndrome caused by SCN5A gene mutations.OBJECTIVES: We carried out a complete screening of the SCN5A gene in 38 Japanese patients with brugada syndrome to investigate the genotype-phenotype relationship. BACKGROUND: The gene SCN5A encodes the pore-forming alpha-subunit of voltage-gated cardiac sodium (Na) channel, which plays an important role in heart excitation/contraction. Mutations of SCN5A have been identified in 15% of patients with brugada syndrome. methods: In 38 unrelated patients with clinically diagnosed brugada syndrome, we screened for SCN5A gene mutations using denaturing high-performance liquid chromatography and direct sequencing, and conducted a functional assay for identified mutations using whole-cell patch-clamp in heterologous expression system. RESULTS: Four heterozygous mutations were identified (T187I, D356N, K1578fs/52, and R1623X) in 4 of the 38 patients. All of them had bradyarrhythmic complications: three with sick sinus syndrome (SSS) and the other (D356N) with paroxysmal complete atrioventricular block. SCN5A-linked Brugada patients were associated with a higher incidence of bradyarrhythmia (4 of 4) than non-SCN5A-linked Brugada patients (2 of 34). Families with T187I and K1578fs/52 had widespread penetrance of SSS. Notably, the patient with K1578fs/52, who had been diagnosed as having familial SSS without any clinical signs of brugada syndrome, showed a Brugada-type ST-segment elevation after intravenous administration of pilsicainide and programmed electrical stimulation-induced ventricular tachycardia. All of the mutations encoded non-functional Na channels, and thus were suggested to cause impulse propagation defect underlying bradyarrhythmias. CONCLUSIONS: Our findings suggest that loss-of-function SCN5A mutations resulting in brugada syndrome are distinguished by profound bradyarrhythmias.- - - - - - - - - - ranking = 1keywords = cell (Clic here for more details about this article) |
10/21. Failure of cilostazol in the prevention of ventricular fibrillation in a patient with brugada syndrome.The ECG appearance in brugada syndrome is caused by failure of the dome of the action potential to develop. Increased activity of the I(to) current in epicardial cells generates a transmural gradient with repolarization dispersion between the epicardium and the endocardium in the right ventricular wall, thus favoring the development of VF by a phase 2 reentry mechanism. The efficacy of cilostazol for the management of these arrhythmias has been reported. This drug is a phosphodiesterase inhibitor with positive chronotropic properties, thus blocking outward potassium currents I(to) in the myocardial tissue. We present a patient with brugada syndrome with an implantable cardioverter defibrillator (ICD), who suffered multiple ICD discharges due to VF during therapy with this drug.- - - - - - - - - - ranking = 1keywords = cell (Clic here for more details about this article) |
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