No abstract available.
Atrioventricular Block* ; Long QT Syndrome*

Electrocardiography ; Humans ; Long QT Syndrome

No abstract available.
Electrocardiography ; Humans ; Long QT Syndrome ; Pulmonary Embolism

Taxifolin glycoside is a new drug candidate for the treatment of atopic dermatitis (AD). Many drugs cause side effects such as long QT syndrome by blocking the human ether-a-go-go related gene (hERG) K+ channels. To determine whether taxifolin glycoside would block hERG K+ channels, we recorded hERG K+ currents using a whole-cell patch clamp technique. We found that taxifolin glycoside directly blocked hERG K+ current in a concentration-dependent manner (EC50=9.6+/-0.7 microM). The activation curve of hERG K+ channels was negatively shifted by taxifolin glycoside. In addition, taxifolin glycoside accelerated the activation time constant and reduced the onset of the inactivation time constant. These results suggest that taxifolin glycoside blocks hERG K+ channels that function by facilitating activation and inactivation process.
Dermatitis, Atopic ; Humans ; Long QT Syndrome ; Quercetin

In order to assess the clinical manifestations and electrocardiogram (ECG) characteristics of Chinese long QT syndrome (LQTS) patients and describe the phenotype-genotype correlation, the subjects from 5 congenital LQTS families underwent clinical detailed examination including resting body surface ECG. QT interval and transmural dispersion of repolarization (TDR) were manually measured. Five families were genotyped by linkage analysis (polymerase chain reacting-short tandem repeat, PCR-STR). The phenotype-genotype correlation was analyzed. Four families were LQT2, 1 family was LQT3. Twenty-eight gene carriers were (14 males and 14 females) identified from 5 families. The mean QTc and TDRc were 0.56 +/- 0.04 s (range 0.42 to 0.63) and 0.16 +/- 0.04 s (range 0.09 to 0.24) respectively. 35.7% (10/28) had normal to borderline QTc (< or = 0.460 s). There was significant difference in QTc and TDRc between the patients with symptomatic LQTS and those with asymptomatic LQTS, and there was significant difference in TDRc between the asymptomatic patients and normal people also. A history of cardiac events was present in 50% (14/28), including 9 with syncope, 2 with sudden death (SD) and occurred in the absence of beta-blocker. Three SDs occurred prior to the diagnosis of LQTS and had no ECG record. Two out of 5 SDs (40%) occurred as the first symptom. Typical LQT2 T wave pattern were found in 40% (6/15) of all affected members. The appearing-normal T wave was found in one LQT3 family. Low penetrance of QTc and symptoms resulted in diagnostic challenge. ECG patterns and repolarization parameters may be used to predict the genotype in most families. Genetic test is very important for identification of gene carriers.
Arrhythmia/etiology ; Arrhythmia/genetics ; Asian Continental Ancestry Group ; Electrocardiography ; Genotype ; Long QT Syndrome/complications ; Long QT Syndrome/congenital ; Long QT Syndrome/*genetics ; Pedigree ; *Phenotype

No abstract available.
Humans ; Long QT Syndrome ; Postoperative Period ; Torsades de Pointes

Anemia ; complications ; Hematologic Diseases ; complications ; Humans ; Long QT Syndrome ; etiology

Adolescent ; Defibrillators, Implantable ; Female ; Humans ; Long QT Syndrome ; therapy

Implantable cardioverter defibrillator (ICD) can be a crucial therapeutic modality for pediatric patients with congenital heart disease, Brugada syndrome, long QT syndrome and cardiomyopathy. Because transvenous implantation of ICD is mostly unfeasible for pediatric patients due to anatomical and technical limitations, epicardial patch type or subcutaneous type ICD have been used. Implantation of these alternative ICDs, however, was reported to be frequently associated with significant complications. We report a case of successful intrapericardial implantation of a single coil-type ICD through the transverse sinus in a 27 month-old child weighing lesser than 10 kg, and it was inferred from this experience that this alternative technique may decrease complications and morbidities after ICD implantation in children.
Arrhythmias, Cardiac ; Brugada Syndrome ; Cardiomyopathies ; Child ; Defibrillators ; Defibrillators, Implantable ; Heart Diseases ; Humans ; Long QT Syndrome

BACKGROUND AND OBJECTIVES: Congenital long QT syndrome (LQTS) is a genetic disease that brings prolongation of the QT interval on an electrocardiogram and leads to syncope and sudden death by a fatal ventricular arrhythmia. In Korea, there have been studies about the clinical characteristics and treatment of LQTS, but there are no studies for the molecular and biological evaluation of its genetic mutation. SUBJECTS AND METHODS: Six nationwide university hospitals and laboratories segregated DNA from the blood of 10 patients diagnosed with LQTS to analyze the genetic mutation. RESULTS: Nine out of ten individuals were female. Eight showed genetic mutations. Three had an abnormality in the KvLQT1, 6 in the HERG and 2 had abnormalities in both KvLQT1 and HERG. None had abnormalities in KCNE1 and 2 showed no abnormalities in KvLQT1, HERG or KCNE1. CONCLUSION: Congenital LQTS shows various genetic mutations, and this indicates the necessity for further organized study in more individuals for confirmation of the relationship between the results of clinical diagnosis and genetic analysis.
Arrhythmias, Cardiac ; Death, Sudden ; Diagnosis ; DNA ; Electrocardiography ; Female ; Hospitals, University ; Humans ; Korea ; Long QT Syndrome* ; Syncope