Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 435
Filtrar
1.
Taiwan J Obstet Gynecol ; 58(4): 552-556, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31307750

RESUMO

OBJECTIVE: Patients with Long QT syndrome (LQTS) P may present with torsades de pointes, ventricular tachycardia (VT), or ventricular fibrillation (VF) and are at risk of sudden cardiac death. MATERIALS AND METHODS: A 38 y/o female patient with uterus myoma developed VF during laparoscopic assisted vaginal hysterectomy surgery. Defibrillation was delivered and the electrocardiogram (ECG) returned to sinus rhythm after CPR. RESULTS: Patient survived and implantable cardioverter-defibrillator was implanted and received beta-blocker therapy. ECG obtained in out-patient clinic still showed QT interval prolongation, but revealed no prolongation few months after persistent beta-blocker therapy. LQTS type 8 (CACNA1C E768del mutation) was identified by genetic DNA sequencing study. CONCLUSIONS: Patients with concealed LQTS may have normal QT interval unless exposing to stress or specific stimuli. Unexpected ventricular arrhythmia may happen during any medical management. We should avoid triggers of QT prolongation, and get familiar with management of the episode.


Assuntos
Morte Súbita Cardíaca , Cardioversão Elétrica/métodos , Histerectomia/métodos , Leiomioma/cirurgia , Síndrome do QT Longo/complicações , Neoplasias Uterinas/cirurgia , Adulto , Anestesia Geral/efeitos adversos , Anestesia Geral/métodos , Reanimação Cardiopulmonar/métodos , Desfibriladores Implantáveis , Eletrocardiografia/métodos , Feminino , Humanos , Laparoscopia/métodos , Leiomioma/complicações , Leiomioma/diagnóstico , Síndrome do QT Longo/congênito , Síndrome do QT Longo/diagnóstico , Prognóstico , Medição de Risco , Índice de Gravidade de Doença , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/terapia , Resultado do Tratamento , Neoplasias Uterinas/complicações , Neoplasias Uterinas/diagnóstico
2.
JAMA Cardiol ; 4(3): 246-254, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30758498

RESUMO

Importance: Long QT syndrome (LQTS) is caused by several ion channel genes, yet risk of arrhythmic events is not determined solely by the responsible gene pathogenic variants. Female sex after adolescence is associated with a higher risk of arrhythmic events in individuals with congenital LQTS, but the association between sex and genotype-based risk of LQTS is still unclear. Objective: To examine the association between sex and location of the LQTS-related pathogenic variant as it pertains to the risk of life-threatening arrhythmias. Design, Setting, and Participants: This retrospective observational study enrolled 1124 genotype-positive patients from 11 Japanese institutions from March 1, 2006, to February 28, 2013. Patients had LQTS type 1 (LQT1), type 2 (LQT2), and type 3 (LQT3) (616 probands and 508 family members), with KCNQ1 (n = 521), KCNH2 (n = 487) and SCN5A (n = 116) genes. Clinical characteristics such as age at the time of diagnosis, sex, family history, cardiac events, and several electrocardiographic measures were collected. Statistical analysis was conducted from January 18 to October 10, 2018. Main Outcomes and Measures: Sex difference in the genotype-specific risk of congenital LQTS. Results: Among the 1124 patients (663 females and 461 males; mean [SD] age, 20 [15] years) no sex difference was observed in risk for arrhythmic events among those younger than 15 years; in contrast, female sex was associated with a higher risk for LQT1 and LQT2 among those older than 15 years. In patients with LQT1, the pathogenic variant of the membrane-spanning site was associated with higher risk of arrhythmic events than was the pathogenic variant of the C-terminus of KCNQ1 (HR, 1.60; 95% CI, 1.19-2.17; P = .002), although this site-specific difference in the incidence of arrhythmic events was observed in female patients only. In patients with LQT2, those with S5-pore-S6 pathogenic variants in KCNH2 had a higher risk of arrhythmic events than did those with others (HR, 1.88; 95% CI, 1.44-2.44; P < .001). This site-specific difference in incidence, however, was observed in both sexes. Regardless of the QTc interval, however, female sex itself was associated with a significantly higher risk of arrhythmic events in patients with LQT2 after puberty (106 of 192 [55.2%] vs 19 of 94 [20.2%]; P < .001). In patients with LQT3, pathogenic variants in the S5-pore-S6 segment of the Nav1.5 channel were associated with lethal arrhythmic events compared with others (HR, 4.2; 95% CI, 2.09-8.36; P < .001), but no sex difference was seen. Conclusions and Relevance: In this retrospective analysis, pathogenic variants in the pore areas of the channels were associated with higher risk of arrhythmic events than were other variants in each genotype, while sex-associated differences were observed in patients with LQT1 and LQT2 but not in those with LQT3. The findings of this study suggest that risk for cardiac events in LQTS varies according to genotype, variant site, age, and sex.


Assuntos
Arritmias Cardíacas/genética , Síndrome do QT Longo/congênito , Síndrome do QT Longo/genética , Síndrome do QT Longo/fisiopatologia , Adolescente , Adulto , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/epidemiologia , Arritmias Cardíacas/fisiopatologia , Criança , Pré-Escolar , Canal de Potássio ERG1/genética , Feminino , Genótipo , Humanos , Incidência , Japão/epidemiologia , Canal de Potássio KCNQ1/genética , Síndrome do QT Longo/epidemiologia , Masculino , Estudos Retrospectivos , Fatores de Risco , Caracteres Sexuais , Adulto Jovem
3.
Artigo em Inglês | MEDLINE | ID: mdl-31990159

RESUMO

Left cardiac sympathetic denervation is an effective therapy for patients with congenital long QT syndrome resistant to beta-blocker therapy. In this video tutorial we describe a minimally invasive video-assisted thoracoscopic technique for performing left cardiac sympathetic denervation.


Assuntos
Síndrome do QT Longo , Gânglio Estrelado/cirurgia , Simpatectomia/métodos , Cirurgia Torácica Vídeoassistida/métodos , Criança , Feminino , Humanos , Síndrome do QT Longo/congênito , Síndrome do QT Longo/diagnóstico , Síndrome do QT Longo/cirurgia , Resultado do Tratamento
4.
Hong Kong Med J ; 24(6): 561-570, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30530868

RESUMO

INTRODUCTION: Congenital long QT syndrome (LQTS) is a genetically transmitted cardiac channelopathy that can lead to sudden cardiac death. This study aimed to report the clinical and genetic characteristics of all young patients diagnosed with LQTS in the only tertiary paediatric cardiology centre in Hong Kong. METHODS: This is a retrospective review of all paediatric and young adult patients diagnosed at our centre with LQTS from January 1997 to December 2016. The diagnosis of LQTS was established with a corrected QT interval (QTc) ≥480 ms, Schwartz score of >3 points, or the presence of a pathogenic mutation. RESULTS: Fifty-nine patients (33 males) from 52 families were included, with a mean age of 8.17 years (range, 0.00-16.95 years) at presentation. Five patients had concomitant congenital heart diseases. The mean follow-up duration was 5.33 ± 4.65 years. The mean QTc in the cohort was 504 ± 47 ms. They presented with syncope and convulsion (49%), cardiac arrest (10%), bradycardia and neonatal atrioventricular block (12%). Fifteen (25%) patients were asymptomatic at diagnosis. Thirty-eight (64.4%) patients were confirmed to have a pathogenic mutation for LQTS genes. Forty-five (76.3%) patients received beta blocker therapy. Thirteen (22.0%) patients required implantable cardioverter defibrillator. There was no mortality in the study period. The 1-, 5-, and 10-year breakthrough cardiac event-free rates were 93.0%, 80.7%, and 72.6%, respectively. CONCLUSION: Identification of the disorder, administration of beta blockers, and lifestyle modification can prevent subsequent cardiac events in LQTS. Genotyping in patients with LQTS is essential in guiding medical therapy and improving prognosis.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Desfibriladores Implantáveis , Cardiopatias Congênitas/epidemiologia , Síndrome do QT Longo/congênito , Adolescente , Adulto , Criança , Pré-Escolar , Eletrocardiografia , Feminino , Seguimentos , Hong Kong/epidemiologia , Humanos , Lactente , Recém-Nascido , Síndrome do QT Longo/genética , Síndrome do QT Longo/terapia , Masculino , Prognóstico , Estudos Retrospectivos , Síncope/epidemiologia , Adulto Jovem
5.
J Electrocardiol ; 51(6): 1061-1065, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30497731

RESUMO

Congenital long QT syndrome (LQTS) is a hereditary cardiac disorder characterized by QT-interval prolongation and T-wave abnormalities on electrocardiogram (ECG), and is associated with an increased risk of torsade de pointes and sudden cardiac death. Beta-blocker medication is effective in most patients except those with a very slow heart rate. Increased late sodium currents (INa-L) can result in bradycardia-dependent QT prolongation. Mexiletine, an inhibitor of INa-L, is not only effective in treating type-3 LQTS, but also shows the promise in managing LQTS patients of other genotypes with markedly prolonged QT interval at slow heart rates.


Assuntos
Antiarrítmicos/uso terapêutico , Doença do Sistema de Condução Cardíaco/tratamento farmacológico , Síndrome do QT Longo/tratamento farmacológico , Mexiletina/uso terapêutico , Bloqueadores do Canal de Sódio Disparado por Voltagem/uso terapêutico , Antagonistas Adrenérgicos beta/efeitos adversos , Antagonistas Adrenérgicos beta/uso terapêutico , Eletrocardiografia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Síndrome do QT Longo/congênito , Síndrome do QT Longo/genética , Masculino , Mutação
6.
J Appl Genet ; 59(4): 463-469, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30244407

RESUMO

Congenital long QT syndrome (LQTS) is a primary cardiac channelopathy. Genetic testing has not only diagnostic but also prognostic and therapeutic implications. At present, 15 genes have been associated with the disease, with most mutations located in 3 major LQTS-susceptibility genes. During a routine genetic screening for KCNQ1, KCNH2 and SCN5A genes in index cases with LQTS, seven novel variants in KCNH2 and SCN5A genes were found. Genotype-phenotype correlations were analysed in these patients and their families. An open reading frame and splice site analysis of the exons was conducted using next-generation sequencing. In novel variants, phenotypes of carriers and their affected relatives were analysed. In 39 unrelated patients, 40 pathogenic/putative pathogenic mutations were found. Thirty-three of them, predominantly missense, were reported previously: 11 were in the KCNQ, 17 in the KCNH2 and 5 in the SCN5A gene. Seven novel missense variants were found in eight families. Among them, four variants were in typical for LQTS location. Two variants in the KCNH2 gene (p.D803Y and p.D46F) and one in the SCN5A gene (G1391R) were in amino acid (AA) position which up to present has not been reported in LQTS. Phenotype analysis showed the life-threatening course of the disease in index cases with a history of sudden cardiac death in six families. Mutation carriers presented with ECG abnormalities and some of them received beta-blocker therapy. We report three novel variants (KCNQ1 p.46, KCNH2 p.D803Y, SCN5A p.G1391R) which have never been reported for this AA location in LQTS; the phenotype-genotype correlation suggests their pathogenicity.


Assuntos
Estudos de Associação Genética , Síndrome do QT Longo/genética , Adulto , Análise Mutacional de DNA , Canal de Potássio ERG1/genética , Feminino , Testes Genéticos , Heterozigoto , Humanos , Canal de Potássio KCNQ1/genética , Síndrome do QT Longo/congênito , Masculino , Mutação de Sentido Incorreto , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Linhagem , Fenótipo , Polônia , Adulto Jovem
7.
Cochlear Implants Int ; 19(6): 350-354, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30227792

RESUMO

Congenital long QT syndrome (cLQTS) is an inherited cardiac ion channelopathy characterized by a long corrected-QT interval on the ECG, associated with a risk of syncope and sudden death as a result of arrhythmias. The archetypal arrhythmia associated with cLQTS is torsade de pointes which may degenerate into ventricular fibrillation. Children with Jervell and Lange-Neilsen syndrome have the combination of cLQTS and congenital sensorineural deafness and may present for cochlear implantation (CI). Sympathetic stimulation and administration of QT-prolonging medications may trigger arrhythmias in children with cLQTS and thus the perioperative period is a time of increased risk of adverse events, with deaths reported in the CI literature. Our Paediatric Cochlear Implant Programme had previously elected to discontinue offering CI to children with cLQTS following a perioperative death. However, subsequent demand for this service by parents led us to develop and introduce a multidisciplinary, evidence-based pathway of care. This pathway modifies the perioperative management of these children to reduce the associated risk. We present the cases of four children with cLQTS who underwent CI in our specialist children's hospital.


Assuntos
Implante Coclear/efeitos adversos , Surdez/cirurgia , Síndrome de Jervell-Lange Nielsen/complicações , Síndrome do QT Longo/complicações , Criança , Surdez/congênito , Feminino , Humanos , Síndrome do QT Longo/congênito , Masculino
8.
Heart Rhythm ; 15(9): 1413-1419, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29723683

RESUMO

BACKGROUND: Little is known about the spectrum and prevalence of ECG features beyond the length and morphology of repolarization in patients with congenital long QT syndrome (LQTS). OBJECTIVE: The purpose of this study was to characterize the full ECG phenotype of LQTS patients and evaluate differences by age and LQTS genotype. METHODS: Retrospective review of 943 patients with LQTS (57% female; median age 25 years; interquartile range 9-34 years) was performed. Comprehensive analysis of their initial evaluation ECG was performed using definitions outlined in professional guidelines. RESULTS: Bradycardia was common (n = 320 [34%]), regardless of beta-blocker use. Left-axis deviation (n = 33 [3.5%]) and bundle branch block (n = 5 [0.5%]) were uncommon. T-wave inversion (TWI) involving leads V1 and V3 was more common in LQTS type 2 compared to LQTS type 1 or type 3 (odds ratio [OR] for V1: 2.67, 95% confidence interval [CI] 1.8-3.9; OR for V3: 1.76, 95% CI 1.2-2.6), whereas TWI in leads III and aVF was most common in LQTS type 3 (OR for III: 2.38, 95% CI 1.4-4.2; OR for aVF: 3.14, 95% CI 1.6-6.4). Notched T waves were most apparent at younger ages (48% in patients age 4-10 compared to 12% in patients age >40: P <.0001). CONCLUSION: Beyond the QT interval and bradycardia, ECG abnormalities are uncommon in LQTS patients, and patients almost never have concomitant bundle branch block. Notably, 19% of LQTS patients overall and 27% of LQTS type 2 patients exhibit anterior TWI that would satisfy a diagnostic criterion for arrhythmogenic right ventricular cardiomyopathy, thus creating the potential for diagnostic miscues.


Assuntos
Eletrocardiografia , Frequência Cardíaca/fisiologia , Síndrome do QT Longo/fisiopatologia , Adolescente , Adulto , Criança , Feminino , Seguimentos , Genótipo , Humanos , Síndrome do QT Longo/congênito , Masculino , Fenótipo , Estudos Retrospectivos , Adulto Jovem
9.
J Electrocardiol ; 51(3): 396-401, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29550106

RESUMO

BACKGROUND AND OBJECTIVES: Congenital long QT syndrome (LQTS) predisposes affected individuals to ventricular tachycardia/fibrillation (VF/VF), potentially resulting in sudden cardiac death. The Tpeak-Tend interval and the Tpeak-Tend/QT ratio, electrocardiographic markers of dispersion of ventricular repolarization, were proposed for risk stratification but their predictive values in LQTS have been controversial. A systematic review and meta-analysis was conducted to examine the value of Tpeak-Tend intervals and Tpeak-Tend/QT ratios in predicting arrhythmic and mortality outcomes in congenital LQTS. METHOD: PubMed and Embase databases were searched until 9th May 2017, identifying 199 studies. RESULTS: Five studies on long QT syndrome were included in the final meta-analysis. Tpeak-Tend intervals were longer (mean difference [MD]: 13ms, standard error [SE]: 4ms, P=0.002; I2=34%) in congenital LQTS patients with adverse events [syncope, ventricular arrhythmias or sudden cardiac death] compared to LQTS patients without such events. By contrast, Tpeak-Tend/QT ratios were not significantly different between the two groups (MD: 0.02, SE: 0.02, P=0.26; I2=0%). CONCLUSION: This meta-analysis showed that Tpeak-Tend interval is significant higher in individuals who are at elevated risk of adverse events in congenital LQTS, offering incremental value for risk stratification.


Assuntos
Eletrocardiografia , Síndrome do QT Longo/congênito , Síndrome do QT Longo/fisiopatologia , Medição de Risco , Humanos , Fatores de Risco
10.
Br J Anaesth ; 120(4): 629-644, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29576105

RESUMO

QT prolongation can be attributable to various causes that can be categorised as acquired or congenital. Arrhythmias related to QT prolongation can result in clinical presentations, such as syncope and sudden cardiac death. The perioperative period presents a number of issues that may affect a patient's risk of developing polymorphic ventricular tachycardia or torsades de pointes. Although most patients may have an unremarkable perioperative course, some may have complications; this review article aims to help clinicians avoid potential complications, and to help them address treatment for perioperative issues that may occur.


Assuntos
Síndrome do QT Longo/cirurgia , Assistência Perioperatória/métodos , Humanos , Síndrome do QT Longo/congênito
11.
Am J Med ; 131(5): 565-572.e2, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29309742

RESUMO

BACKGROUND: Rare, high-arousal negative emotions are known triggers of sudden death in individuals with preexisting heart disease. Whether everyday fluctuations in emotional arousal influence arrhythmia risk is unknown. METHODS: We studied 160 patients with the congenital long QT syndrome, 199 patients with coronary artery disease, and 2 groups of matched healthy volunteers (n = 52 and 50, respectively). Three-day home visits including a 12-hour Holter recording each day were completed. Subjects engaged in typical daily activities and were paged 10 times per day. On each occasion, subjects rated the intensity of 16 different emotions during the 5 minutes preceding the page. Holter data over those 5-minute epochs were analyzed for heart rate and QT interval corrected for heart rate (QTc). Analyses focused on within-subject covariation of momentary emotion and QTc. RESULTS: In patients with long QT syndrome, activated positive affect and activated negative affect were associated with QTc shortening, whereas low arousal positive affect (calm and relaxed) was associated with QTc lengthening, which at times exceeded 500 msec. Findings were not affected by beta-blocker status or observed in younger healthy subjects. Findings were 3 to 8 times stronger in the LQT2 genotype, known to be prone to emotion-induced events, relative to the LQT1 genotype. Findings in patients with long QT syndrome for activated positive affect and low arousal positive affect were replicated in patients with coronary artery disease relative to older healthy subjects. CONCLUSION: These findings suggest that even subtle changes in emotional arousal may alter repolarization reserve and contribute to sudden death risk in vulnerable individuals.


Assuntos
Afeto/fisiologia , Doença da Artéria Coronariana/fisiopatologia , Eletrocardiografia Ambulatorial , Frequência Cardíaca/fisiologia , Síndrome do QT Longo/fisiopatologia , Adulto , Estudos de Casos e Controles , Emoções/fisiologia , Feminino , Genótipo , Humanos , Síndrome do QT Longo/congênito , Síndrome do QT Longo/genética , Masculino , Pessoa de Meia-Idade
13.
J Electrocardiol ; 51(2): 303-308, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29183619

RESUMO

BACKGROUND: Patients with long QT syndrome (LQTS) are predisposed to polymorphic ventricular tachycardia (VT) during adrenergic stimulation. Microvolt T-wave alternans (MTWA) is linked to vulnerability to VT in structural heart disease. The prevalence of non-sustained MTWA (NS-MTWA) in LQTS is unknown. METHODS: 31 LQT1, 42 LQT2, and 80 controls underwent MTWA testing during exercise. MTWA tests were classified per standardized criteria, and re-analyzed according to the modified criteria to account for NS-MTWA. RESULTS: LQT1 and LQT2 patients had a significantly higher frequency of late NS-MTWA (26% and 12%) compared to controls (0%). There was no significant difference between the groups with respect to sustained and early NS-MTWA. Late NS-MTWA was significantly associated with QTc. CONCLUSION: LQT1 and LQT2 patients had a higher prevalence of late NS-MTWA during exercise than matched controls. NS-MTWA likely reflects transient adrenergically mediated dispersion of repolarization, and could be a marker of arrhythmic risk in LQTS.


Assuntos
Síndrome do QT Longo/congênito , Síndrome do QT Longo/fisiopatologia , Taquicardia Ventricular/congênito , Taquicardia Ventricular/fisiopatologia , Adulto , Estudos de Casos e Controles , Eletrocardiografia , Teste de Esforço , Feminino , Genótipo , Humanos , Síndrome do QT Longo/genética , Masculino , Taquicardia Ventricular/genética
14.
PLoS One ; 12(10): e0185680, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29059199

RESUMO

BACKGROUND: Beta-blockers are first-line therapy in patients with congenital long-QT syndrome (LQTS). OBJECTIVE: This study sought to determine the differences in effectiveness of beta-blockers on risk reduction according to LQTS genotype. METHODS: We searched MEDLINE, EMBASE, and CENTRAL databases to investigate the use of beta-blockers (atenolol, nadolol, propranolol, and metoprolol) in patients with LQTS. Hazard ratio (HR) and relative risk (RR) were extracted or calculated from studies reporting cardiac events (syncope, aborted cardiac arrest (ACA), or sudden cardiac death (SCD)). RESULTS: Among 2,113 articles searched, 10 studies (7 registry-based cohort studies (Cohort) and 3 interrupted time series studies (ITS)) involving 9,727 patients were included. In a meta-analysis using a random-effect model, the use of beta-blocker was associated with significant risk reduction of all cardiac events (HR 0.49, p<0.001 in Cohort; RR 0.39, p<0.001 in ITS) and serious cardiac events (ACA or SCD) (HR 0.47, p<0.001 in Cohort). In both LQT1 and LQT2, the risk was reduced with beta-blocker therapy in Cohort (HR 0.59 in LQT1; HR 0.39 in LQT2) as well as ITS (RR 0.29 in LQT1; RR 0.48 in LQT2). Among the beta-blockers, nadolol showed a significant risk reduction in both LQT1 and LQT2 (HR 0.47 and 0.27, respectively), whereas atenolol and propranolol decreased the risk only in LQT1 (HR 0.36 and 0.46, respectively). Metoprolol showed no significant reduction in either genotype. In LQT3, beta-blocker therapy was not as effective as LQT1 or LQT2; however, it was inconclusive due to data insufficiency. CONCLUSION: This meta-analysis showed that beta-blockers were effective in reducing risk of cardiac events in patients with LQTS. Among them, nadolol was effective in LQT1 and LQT2, whereas other drugs showed different effectiveness depending on LQT genotype.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Genótipo , Síndrome do QT Longo/tratamento farmacológico , Feminino , Humanos , Síndrome do QT Longo/congênito , Masculino
16.
Am J Cardiol ; 120(2): 256-261, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28532774

RESUMO

Congenital long QT syndrome (LQTS) is characterized by QT prolongation with predisposition to life-threatening arrhythmia. There have been sporadic reports of LQTS coexisting with more common forms of congenital heart disease (CHD). However, the diagnosis of LQTS when CHD is present may be confounded by several common variables including postoperative electromechanical factors predisposing to ventricular arrhythmia, intrinsic, and postoperative QRS abnormalities. This report documents a single-center experience with patients who have both genetically confirmed LQTS and CHD to examine their modes of presentation and factors associated with making the diagnosis of LQTS in this patient population, as well as potential confounding variables that may mask or delay both LQTS diagnosis and initiation of therapy. A retrospective review was performed of subjects with confirmed LQTS and associated CHD from 1999 to January 2017. Genetic analysis was performed predominantly using commercially available panel testing. A chart review included detailed analysis of electrocardiograms, 24-hour 3-lead rhythm monitors and exercise stress test tracings as well as the genetic test reports. QT intervals were measured using Bazett's formula. Eleven patients were identified. Four patients had LQTS type 1, 6 had LQTS type 2, and 1 had a disease-associated mutation in KCNQ1 and a variant of unknown significance in KCNH2 gene. Two patients had positive cascade screening. Arrhythmia presentations of the LQTS were at both extremes of the cohort age range (in-utero and midchildhood age). There was a seeming overrepresentation of conotruncal anomalies and/or arch anomalies, with 7 of the 11 patients. In conclusion, the diagnosis of LQTS may be challenging in the setting of CHD (a prolonged ST segment may be helpful), and high index of suspicion is required. The overall incidence of LQTS in CHD appears extremely rare, but the diagnosis and true incidence may be masked by confounding electrocardiogrpahic findings and other variables common in CHD.


Assuntos
Anormalidades Múltiplas , Eletrocardiografia , Cardiopatias Congênitas/genética , Síndrome do QT Longo/genética , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Testes Genéticos , Genótipo , Cardiopatias Congênitas/diagnóstico , Humanos , Lactente , Recém-Nascido , Síndrome do QT Longo/congênito , Síndrome do QT Longo/diagnóstico , Masculino , Estudos Retrospectivos
17.
Artigo em Inglês | MEDLINE | ID: mdl-28429460

RESUMO

BACKGROUND: Prolongation of the QT on the surface electrocardiogram can be due to either genetic or acquired causes. Distinguishing congenital long QT syndrome (LQTS) from acquired QT prolongation has important prognostic and management implications. We aimed to investigate if quantitative T-wave analysis could provide a tool for the physician to differentiate between congenital and acquired QT prolongation. METHODS: Patients were identified through an institution-wide computer-based QT screening system which alerts the physician if the QTc ≥ 500 ms. ECGs were retrospectively analyzed with an automated T-wave analysis program. Congenital LQTS was compared in a 1:3 ratio to those with an identified acquired etiology for QT prolongation (electrolyte abnormality and/or prescription of known QT prolongation medications). Linear discriminant analysis was performed using 10-fold cross-validation to statistically test the selected features. RESULTS: The 12-lead ECG of 38 patients with congenital LQTS and 114 patients with drug-induced and/or electrolyte-mediated QT prolongation were analyzed. In lead V5 , patients with acquired QT prolongation had a shallower T wave right slope (-2,322 vs. -3,593 mV/s), greater T-peak-Tend interval (109 vs. 92 ms), and smaller T wave center of gravity on the x axis (290 ms vs. 310 ms; p < .001). These features could distinguish congenital from acquired causes in 77% of cases (sensitivity 90%, specificity 58%). CONCLUSION: T-wave morphological analysis on lead V5 of the surface ECG could successfully differentiate congenital from acquired causes of QT prolongation.


Assuntos
Eletrocardiografia/métodos , Síndrome do QT Longo/diagnóstico , Síndrome do QT Longo/fisiopatologia , Adolescente , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Síndrome do QT Longo/congênito , Masculino , Estudos Retrospectivos , Sensibilidade e Especificidade
19.
Cardiol Rev ; 25(4): 197-201, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27054604

RESUMO

Congenital long QT syndrome (LQTS) is a disorder of myocardial repolarization and is characterized by a prolonged QT interval on an electrocardiogram. A prolonged QT predisposes patients to an increased risk of syncope and sudden cardiac death secondary to polymorphic ventricular tachycardia. Several mutations linked to the LQTS have been identified, the most common of which have been found in the potassium channel KCNQ1 (LQT1) and hERG (LQT2) genes and in the sodium channel SCN5A (LQT3) gene. Female sex is an independent risk factor for the development of torsades de pointes in LQTS. Furthermore, although pregnancy may be associated with protection against cardiac events in LQTS, the 9-month postpartum period represents a time of increased arrhythmogenicity. Interestingly, these cardiac events during the postpartum period are more common in patients with LQT2. The precise mechanisms that influence the cardiac repolarization during the postpartum period are unclear. Beta-blockers are considered reasonably safe during pregnancy and should be continued or initiated in patients with LQTS to reduce the risk of cardiac events. Implantable cardioverter defibrillators are safe in pregnancy, and there is no evidence that pregnant women with these devices are at any greater risk for adverse complications solely on the grounds of having the device.


Assuntos
Síndrome do QT Longo/congênito , Complicações Cardiovasculares na Gravidez/terapia , Feminino , Humanos , Síndrome do QT Longo/terapia , Gravidez
20.
Pacing Clin Electrophysiol ; 40(3): 232-241, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28012188

RESUMO

BACKGROUND: Left cardiac sympathetic denervation (LCSD) has been underutilized in patients with hereditary ventricular arrhythmia syndromes such as congenital long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT). The purpose of this study was to investigate the safety and efficacy of video-assisted thoracoscopic (VATS) LCSD in such patients. METHODS: Fifteen patients (four men, 24.6 ± 10.5 years old) who underwent VATS-LCSD between November 2010 and January 2015 for hereditary ventricular arrhythmia syndromes at Kyungpook National University Hospital were enrolled in this study. The safety and efficacy of VATS-LCSD were evaluated by periprocedural epinephrine tests and assessing the development of complications and cardiac events during follow-up. RESULTS: Fourteen patients with LQTS and one patient with CPVT underwent VATS-LCSD. Six and one patients developed ventricular tachyarrhythmia during preprocedural and postprocedural epinephrine test, respectively (P = 0.063). No serious complications such as Horner syndrome, pneumothorax, or bleeding developed after LCSD. Mean hospital stay after VATS-LCSD was 3.7 ± 1.5 days. During a mean follow-up of 927 ± 350 days, one LQTS patient and one CPVT patient, neither of whom manifested tachyarrhythmia during post-LCSD epinephrine test, developed torsades de pointes and syncope, respectively. The annual event rates of six patients who were symptomatic during the period preceding LCSD decreased from 0.97 to 0.19 events/year (P = 0.045). CONCLUSIONS: VATS-LCSD was a safe, and effective procedure for patients with hereditary ventricular tachycardia syndrome, with no serious adverse events and with short hospital stay.


Assuntos
Ventrículos do Coração/cirurgia , Síndrome do QT Longo/congênito , Síndrome do QT Longo/cirurgia , Simpatectomia/métodos , Taquicardia Ventricular/congênito , Taquicardia Ventricular/cirurgia , Cirurgia Torácica Vídeoassistida/métodos , Adulto , Feminino , Ventrículos do Coração/inervação , Ventrículos do Coração/patologia , Humanos , Síndrome do QT Longo/patologia , Masculino , Taquicardia Ventricular/patologia , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA