Humans ; Diagnosis, Differential ; Long QT Syndrome/genetics* ; Syncope/diagnosis* ; Epilepsy/diagnosis* ; Electrocardiography

Long QT syndrome is associated with lethal tachyarrhythmia that can lead to syncope, seizure, and sudden death. Congenital long QT syndrome is a genetic disorder, characterized by delayed cardiac repolarization and prolongation of the QT interval on the electrocardiogram (ECG). Type 2 congenital long QT is linked to mutations in the human ether a go-go-related gene (HERG). There are environmental triggers of adverse cardiac events such as emotional and acoustic stimuli, but fever can also be a potential trigger of life-threatening arrhythmias in long QT syndrome type 2 patients. Herein, we report a healthy young man who experienced fever-induced polymorphic ventricular tachycardia and QT interval prolongation.
Adult ; Electrocardiography ; Fever/*complications ; Humans ; Long QT Syndrome/*diagnosis/*etiology ; Male ; Ventricular Fibrillation/*diagnosis/*etiology

Early recognition and treatment for early warning electrocardiogram (ECG) of sudden death are very important to prevent and treat malignant arrhythmia and sudden death. Previous studies have found that R-on-T and T wave alternation, and QT interval prolongation are closely related to malignant arrhythmia or sudden death, which are included in the critical value of ECG.By analyzing the ECG characteristics of 4 patients with sudden death, we found that although the causes of the patients were different, there were transient prolongation of QT interval after premature contraction in 12 lead ECG, followed by malignant arrhythmia or sudden death. Thus, we thought that the transient prolongation of QT interval after premature contraction had a high value for warning malignant arrhythmia or sudden death. This phenomenon should be paid enough attention to reduce the risk of sudden death.
Arrhythmias, Cardiac/diagnosis* ; Death, Sudden ; Death, Sudden, Cardiac ; Electrocardiography ; Humans ; Long QT Syndrome/diagnosis*

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

OBJECTIVERisk factors, ECG characteristics and treatment options of patients with Torsade de Points associated with acquired QT prolongation are summarized in this study.

METHODUsing "torsade de points" and "QT prolongation" as the keywords to search the inpatients database from 1990 - 2010 of Fuwai hospital, 52 eligible patients were included in this analysis.

RESULTSStructural heart diseases were found in 67.3% and electrolyte disorders in 59.6% patients, 36.5% patients received diuretic therapy and 28.8% received antiarrhythmic drugs which might induce prolonged QT interval. The mean QTc was (571 ± 93) ms and (456 ± 50) ms before and after treatment. All patients received potassium and magnesium supplement. Isoproterenol was used in 32.7% patients. 13.5% patients received temporary pacing therapy.

CONCLUSIONSTorsade de points and acquired QT interval prolongation was often associated with electrolyte disorders and drugs causing QT prolongation. ECG and QTc should be intensively monitored for high risk patients. Early awareness of the warning signs might contribute to early recognition and proper treatment of patients with Torsade de Points associated with acquired QT prolongation.

Adult ; Female ; Humans ; Long QT Syndrome ; complications ; diagnosis ; therapy ; Male ; Middle Aged ; Risk Factors ; Torsades de Pointes ; complications ; diagnosis ; therapy

The idiopathic long-QT syndrome is an infrequent inherited disorder, characterized by prolonged QT interval and by the occurrence of life-threatening tachyarrhythmia, particularly in association with emotional or physical stree. In its characteristic presentation, with obvious QT prolongation and stree induced syncope with torsades de points, the diagnosis is straightforward for physicians aware of the disease. But sometimes in cases of borderline QT prolongation and vague symptom, a correct diagnosis is delayed and frequently misdiagnosed as a seizure disorder. The mortality of untreated symptomatic patients with LQTS exceeds 20% in the year after their first syncopal episode and aapproaches 50% within 10 years. But this high mortality rate has been significantly reduced by the use of pharmacological or surgical antiadrenergic therapy or both. So early detection of the disease and antiadrenergic treatment sympathetic innervation to the heart. Second, there was intrinsic gene abnormality in the mechanisms responsible for cardiac repolarization. We report one case of LQTS in a 24 years old female patient who had been suffering from stree related syncope. Her initial EKG had prologed QT interval(588msec) and increased QT intrval dispersion(200msec). In the Holter monitor, long and short cycle sequence induced (pause-dependent) torsades de pointes was detected. She has been treated by beta-blocker and has maintained her condition without recurrence of the symptoms.
Diagnosis ; Electrocardiography ; Epilepsy ; Female ; Heart ; Humans ; Long QT Syndrome ; Mortality ; Recurrence ; Syncope ; Tachycardia ; Torsades de Pointes ; Young Adult

Long QT interval is an important finding that is often missed by electrocardiogram interpreters. Long QT syndrome (inherited and acquired) is a potentially lethal cardiac channelopathy that is frequently mistaken for epilepsy. We present a case of long QT syndrome with multiple cardiac arrests presenting as syncope and seizures. The long QTc interval was aggravated by hypomagnesaemia and drugs, including clarithromycin and levofloxacin. Multiple drugs can cause prolongation of the QT interval, and all physicians should bear this in mind when prescribing these drugs.
Adult ; Defibrillators, Implantable ; Electrocardiography ; Heart Rate ; Humans ; Long QT Syndrome ; complications ; congenital ; diagnosis ; therapy ; Male ; Risk Factors ; Seizures ; complications

Automatic implantable cardioverter defibrillator(AICD) is a device that senses ventricular tarchycardia and ventricular fibrillation and responses with counter-shocks to the heart. We experienced a case of AICD implantation to prevent sudden cardiac death. A-22-year-old male was operated under O2, N2o, fentanyl, low dose enflurane anesthesia. The diagnosis was familial long QT syndrome. Lead was introduced to the right ventricular apex through left subclavian vein and generator was placed between pectoralis muscles. Then defibrillation threshold testing was performed. Ventricular fibrillation was induced with Twave shock of 3 joule and defibrillation with 5 joule terminated ventricular fibrillation successfully. After ventricular fibrillation, his blood pressure decreased to 30mmHg. When ventricular fibrillation was converted to normal rhythm, it retured to normal range. After operation, patient was transferred to the ICU and stayed there for 3 days.
Anesthesia ; Arrhythmias, Cardiac ; Blood Pressure ; Death, Sudden, Cardiac ; Defibrillators* ; Diagnosis ; Enflurane ; Fentanyl ; Heart ; Humans ; Long QT Syndrome ; Male ; Pectoralis Muscles ; Reference Values ; Shock ; Subclavian Vein ; Ventricular Fibrillation

Long QT syndrome (LQTs) is a rare congenital disorder of the heart's electrical activity. Patients with LQTs are at increased risk of developing fatal ventricular arrhythmias. Elevated levels of sympathetic stimulation can exacerbate this risk. Successful behavior management is indispensable in the treatment of patients with LQTs. However, many drugs involved in pharmacologic behavior management are known to adversely affect the QT interval. Therefore, careful selection of a sedative drug is essential in avoiding such incidences. A 10-year-old boy with a known diagnosis of LQTs required restorative treatment due to dental caries at the permanent molar. He required sedation since treatment was painful and dental phobia can trigger sympathetic stimulation, creating a dangerous situation for patients with LQTs. Therefore, the treatment was performed over two sessions under moderate sedation involving propofol combined with nitrous oxide. Restorative treatment was successful without any complications under sedation with a target-controlled infusion (TCI) of propofol. There was no significant QT prolongation during pulpal treatment. Propofol TCI may be a good candidate for sedation in patients with LQTs.
Arrhythmias, Cardiac ; Child ; Congenital, Hereditary, and Neonatal Diseases and Abnormalities ; Conscious Sedation* ; Dental Anxiety ; Dental Caries ; Diagnosis ; Humans ; Incidence ; Long QT Syndrome* ; Male ; Molar ; Nitrous Oxide ; Propofol*

Long QT syndrome (LQTs) is a rare congenital disorder of the heart's electrical activity. Patients with LQTs are at increased risk of developing fatal ventricular arrhythmias. Elevated levels of sympathetic stimulation can exacerbate this risk. Successful behavior management is indispensable in the treatment of patients with LQTs. However, many drugs involved in pharmacologic behavior management are known to adversely affect the QT interval. Therefore, careful selection of a sedative drug is essential in avoiding such incidences. A 10-year-old boy with a known diagnosis of LQTs required restorative treatment due to dental caries at the permanent molar. He required sedation since treatment was painful and dental phobia can trigger sympathetic stimulation, creating a dangerous situation for patients with LQTs. Therefore, the treatment was performed over two sessions under moderate sedation involving propofol combined with nitrous oxide. Restorative treatment was successful without any complications under sedation with a target-controlled infusion (TCI) of propofol. There was no significant QT prolongation during pulpal treatment. Propofol TCI may be a good candidate for sedation in patients with LQTs.
Arrhythmias, Cardiac ; Child ; Congenital, Hereditary, and Neonatal Diseases and Abnormalities ; Conscious Sedation* ; Dental Anxiety ; Dental Caries ; Diagnosis ; Humans ; Incidence ; Long QT Syndrome* ; Male ; Molar ; Nitrous Oxide ; Propofol*