Search results for "Long QT Syndrome"

Incomplete Timothy syndrome secondary to a mosaic mutation of the CACNA1C gene diagnosed using next-generation sequencing.

2016

Autosomal dominant genetic diseases can occur de novo and in the form of somatic mosaicism, which can give rise to a less severe phenotype, and make diagnosis more difficult given the sensitivity limits of the methods used. We report the case of female child with a history of surgery for syndactyly of the hands and feet, who was admitted at 6 years of age to a pediatric intensive care unit following cardiac arrest. The electrocardiogram (ECG) showed a long QT interval that on occasions reached 500 ms. Despite the absence of facial dysmorphism and the presence of normal psychomotor development, a diagnosis of Timothy syndrome was made given the association of syndactyly and the ECG features.…

Systematic ajmaline challenge in patients with long QT 3 syndrome caused by the most common mutation: a multicentre study

2016

Aims Overlap syndromes of long QT 3 syndrome (LQT3) and the Brugada syndrome (BrS) have been reported. Identification of patients with an overlapping phenotype is crucial before initiation of Class I antiarrhythmic drugs for LQT3. Aim of the present study was to elucidate the yield of ajmaline challenge in unmasking the Brugada phenotype in patients with LQT3 caused by the most common mutation, SCN5A-E1784K. Methods and results Consecutive families in tertiary referral centres diagnosed with LQT3 caused by SCN5A-E1784K were included in the study. Besides routine clinical work-up, ajmaline challenge was performed after informed consent. A total of 23 subjects (11 female, mean age 27 ± 14 yea…

Syncope in pediatric patients: role of arrhythmias

2009

The Disease-Specific Phenotype in Cardiomyocytes Derived from Induced Pluripotent Stem Cells of Two Long QT Syndrome Type 3 Patients

2013

Long QT syndromes (LQTS) are heritable diseases characterized by prolongation of the QT interval on an electrocardiogram, which often leads to syncope and sudden cardiac death. Here we report the generation of induced pluripotent stems (iPS) cells from two patients with LQTS type 3 carrying a different point mutation in a sodium channel Nav1.5 (p.V240M and p.R535Q) and functional characterization of cardiomyocytes (CM) derived from them. The iPS cells exhibited all characteristic properties of pluripotent stem cells, maintained the disease-specific mutation and readily differentiated to CM. The duration of action potentials at 50% and 90% repolarization was longer in LQTS-3 CM as compared t…

Prevalence and correlates of QTc prolongation in Italian psychiatric care: cross-sectional multicentre study.

2016

Aims.In recent years several warnings have been issued by regulatory authorities on the risk of electrocardiogram abnormalities in individuals exposed to psychotropic drugs. As a consequence of these warnings, monitoring of the QT interval corrected for heart rate (QTc) has become increasingly common. This study was conducted to measure the frequency of QTc prolongation in unselected psychiatric patients, and to document the associated factors using a cross-sectional approach.Method.The study was carried out in 35 Italian psychiatric services that are part of the STAR (Servizi Territoriali Associati per la Ricerca) Network, a research group established to produce scientific knowledge by col…

Positive selection at codon 38 of the human KCNE1 (= minK) gene and sporadic absence of 38Ser-coding mRNAs in Gly38Ser heterozygotes

2009

Abstract Background KCNE1 represents the regulatory beta-subunit of the slowly activating delayed rectifier potassium channel (IKs). Variants of KCNE1 have repeatedly been linked to the long-QT syndrome (LQTS), a disorder which predisposes to deafness, ventricular tachyarrhythmia, syncope, and sudden cardiac death. Results We here analyze the evolution of the common Gly38Ser variant (rs1805127), using genomic DNAs, complementary DNAs, and HEK293-expressed variants of altogether 19 mammalian species. The between species comparison reveals that the human-specific Gly38Ser polymorphism evolved under strong positive Darwinian selection, probably in adaptation to specific challenges in the fine-…

Role of Bisoprolol in Patients with Long QT Syndrome

2013

Background Long QT syndrome (LQTS) is a disorder of ventricular repolarization usually treated with β-blockers, mostly with propanolol and nadolol. The aim of our study was to evaluate the role of bisoprolol in LQTS patients. Methods A total of 34 patients were evaluated in an average follow-up time of 93 months: 31 months without treatment, 31 months in treatment with nadolol or propanolol and 31 months in treatment with bisoprolol. The average age of patients at diagnosis was 17.3 years. The enrolled patients were followed through a semiannual electrocardiogram and an annual 24-hour Holter monitoring. All patients underwent genotyping, routine hematologic tests, and an echocardiogram. Res…

The long QT syndrome in pediatric age: Prognosis and risk factor

2008

AIM: Long QT syndrome is a rare arrhythmic disease with a low incidence in the general population. There are no sure clinical or electrocardiographic parameters that could lead to a correct prognostic stratification in patients affected by this syndrome. The correlation between the incidence of a sudden death or dangerous ventricular arrhythmias and the duration of QTc interval is still a controversial topic. METHODS: Twenty nine children affected by QT long syndrome were admitted to the Division of Pediatric Cardiology of the Casa del Sole Hospital of Palermo (Italy). Their diagnosis was made by electrocardiogram (ECG). The average age of the patients was 7.6 years. The average follow-up w…

QTc Time Correlates with Amitriptyline and Venlafaxine Serum Levels in Elderly Psychiatric Inpatients

2018

Abstract Introduction Many antidepressants cause QT prolongation but the classification of cardiac risk of these drugs varies markedly in different published lists. This retrospective study analyzed the correlation of QTc time with amitriptyline and venlafaxine serum level in elderly psychiatric inpatients. Methods Elderly inpatients aged≥65 years for whom venlafaxine or amitriptyline serum level had been measured were selected retrospectively from a therapeutic drug monitoring database and screened for an electrocardiogram measurement at the time of blood withdrawal. The correlation of amitriptyline or venlafaxine serum levels with QTc time was examined by using Pearson’s correlation analy…

Changes of QTc interval after opioid switching to oral methadone.

2013

Abstract A consecutive sample of patients who were switched from strong opioids to methadone in a period of 1 year was surveyed. QTc was assessed before switching (T0) and after achieving adequate analgesia and an acceptable level of adverse effects (Ts). Twenty-eight of 33 patients were switched to methadone successfully. The mean initial methadone doses at T0 were 67.1 mg/day (SD ±80.2, range 12-390). The mean QTc interval at T0 was 400 ms (SD ±30, range 330-450). The mean QTc interval at Ts (median 5 days) was 430 ms (SD ±26, range 390-500). The difference (7.7 %) was significant (p < 0.0005). Only two patients had a QTc of 500 ms. No serious arrhythmia was observed. At the linear regres…