scholarly journals Territory-Wide Chinese Cohort of Long QT Syndrome: Random Survival Forest and Cox Analyses

2021 ◽  
Vol 8 ◽  
Author(s):  
Gary Tse ◽  
Sharen Lee ◽  
Jiandong Zhou ◽  
Tong Liu ◽  
Ian Chi Kei Wong ◽  
...  
Keyword(s):  
Long Qt Syndrome ◽  
Cox Regression ◽  
Significant Risk ◽  
Initial Presentation ◽  
Long Qt ◽  
Cox Regression Analysis ◽  
Qt Syndrome ◽  
Congenital Lqts ◽  
Random Survival Forest

Introduction: Congenital long QT syndrome (LQTS) is a cardiac ion channelopathy that predisposes affected individuals to spontaneous ventricular tachycardia/fibrillation (VT/VF) and sudden cardiac death (SCD). The main aims of the study were to: (1) provide a description of the local epidemiology of LQTS, (2) identify significant risk factors of ventricular arrhythmias in this cohort, and (3) compare the performance of traditional Cox regression with that of random survival forests.Methods: This was a territory-wide retrospective cohort study of patients diagnosed with congenital LQTS between 1997 and 2019. The primary outcome was spontaneous VT/VF.Results: This study included 121 patients [median age of initial presentation: 20 (interquartile range: 8–44) years, 62% female] with a median follow-up of 88 (51–143) months. Genetic analysis identified novel mutations in KCNQ1, KCNH2, SCN5A, ANK2, CACNA1C, CAV3, and AKAP9. During follow-up, 23 patients developed VT/VF. Univariate Cox regression analysis revealed that age [hazard ratio (HR): 1.02 (1.01–1.04), P = 0.007; optimum cut-off: 19 years], presentation with syncope [HR: 3.86 (1.43–10.42), P = 0.008] or VT/VF [HR: 3.68 (1.62–8.37), P = 0.002] and the presence of PVCs [HR: 2.89 (1.22–6.83), P = 0.015] were significant predictors of spontaneous VT/VF. Only initial presentation with syncope remained significant after multivariate adjustment [HR: 3.58 (1.32–9.71), P = 0.011]. Random survival forest (RSF) model provided significant improvement in prediction performance over Cox regression (precision: 0.80 vs. 0.69; recall: 0.79 vs. 0.68; AUC: 0.77 vs. 0.68; c-statistic: 0.79 vs. 0.67). Decision rules were generated by RSF model to predict VT/VF post-diagnosis.Conclusions: Effective risk stratification in congenital LQTS can be achieved by clinical history, electrocardiographic indices, and different investigation results, irrespective of underlying genetic defects. A machine learning approach using RSF can improve risk prediction over traditional Cox regression models.

A rare indication of permanent pacemaker implantation in children: congenital long QT syndrome

2020 ◽  
Vol 30 (12) ◽  
pp. 1880-1881
Author(s):  
Mehmet Taşar ◽  
Nur Dikmen Yaman ◽  
Huseyin Dursin ◽  
Murat Şimşek ◽  
Senem Özgür
Keyword(s):  
Sudden Death ◽  
Long Qt Syndrome ◽  
Pacemaker Implantation ◽  
Torsades De Pointes ◽  
Permanent Pacemaker ◽  
Long Qt ◽  
Permanent Pacemaker Implantation ◽  
Qt Syndrome ◽  
Congenital Lqts ◽  
Congenital Long Qt Syndrome

AbstractCongenital Long QT Syndrome (LQTS) is a dangerous arrhythmic disorder that can be diagnosed in children with bradycardia. It is characterised by a prolonged QT interval and torsades de pointes that may cause sudden death. Long QT syndrome is an ion channelopathy with complex molecular and physiological infrastructure. Unlike the acquired type, congenital LQTS has a genetic inheritance and it may be diagnosed by syncope, stress in activity, cardiac dysfunction, sudden death or sometimes incidentally. Permanent pacemaker implantation is required for LQTS with resistant bradycardia even in children to resolve symptoms and avoid sudden death.

scholarly journals Long-Term Follow-Up of Patients With Long-QT Syndrome Treated With β-Blockers and Continuous Pacing

Circulation ◽  
1999 ◽  
Vol 100 (24) ◽  
pp. 2431-2436 ◽  
Author(s):  
Parvin C. Dorostkar ◽  
Michael Eldar ◽  
Bernard Belhassen ◽  
Melvin M. Scheinman
Keyword(s):  
Long Qt Syndrome ◽  
Long Qt ◽  
Long Term Follow Up ◽  
Β Blockers ◽  
Qt Syndrome

scholarly journals Paediatric/young versus adult patients with long QT syndrome

Open Heart ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. e001671
Author(s):  
Sharen Lee ◽  
Jiandong Zhou ◽  
Kamalan Jeevaratnam ◽  
Wing Tak Wong ◽  
Ian Chi Kei Wong ◽  
...  
Keyword(s):  
Long Qt Syndrome ◽  
Primary Outcome ◽  
Population Based ◽  
Public Hospitals ◽  
Qtc Interval ◽  
Onset Age ◽  
Long Qt ◽  
History Of ◽  
Qt Syndrome ◽  
Random Survival Forest

IntroductionLong QT syndrome (LQTS) is a less prevalent cardiac ion channelopathy than Brugada syndrome in Asia. The present study compared the outcomes between paediatric/young and adult LQTS patients.MethodsThis was a population-based retrospective cohort study of consecutive patients diagnosed with LQTS attending public hospitals in Hong Kong. The primary outcome was spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF).ResultsA total of 142 LQTS (mean onset age=27±23 years old) were included. Arrhythmias other than VT/VF (HR 4.67, 95% CI (1.53 to 14.3), p=0.007), initial VT/VF (HR=3.25 (95% CI 1.29 to 8.16), p=0.012) and Schwartz score (HR=1.90 (95% CI 1.11 to 3.26), p=0.020) were predictive of the primary outcome for the overall cohort, while arrhythmias other than VT/VF (HR=5.41 (95% CI 1.36 to 21.4), p=0.016) and Schwartz score (HR=4.67 (95% CI 1.48 to 14.7), p=0.009) were predictive for the adult subgroup (>25 years old; n=58). A random survival forest model identified initial VT/VF, Schwartz score, initial QTc interval, family history of LQTS, initially asymptomatic and arrhythmias other than VT/VF as the most important variables for risk prediction.ConclusionClinical and ECG presentation varies between the paediatric/young and adult LQTS population. Machine learning models achieved more accurate VT/VF prediction.

scholarly journals The Efficacy of Beta-Blockers in Patients With Long QT Syndrome 1–3 According to Individuals’ Gender, Age, and QTc Intervals: A Network Meta-analysis

2020 ◽  
Vol 11 ◽  
Author(s):  
Lu Han ◽  
Fuxiang Liu ◽  
Qing Li ◽  
Tao Qing ◽  
Zhenyu Zhai ◽  
...  
Keyword(s):  
Long Qt Syndrome ◽  
Clinical Evidence ◽  
Beta Blockers ◽  
Meta Analysis ◽  
Cardiac Events ◽  
Long Qt ◽  
Confounding Variables ◽  
Qt Syndrome ◽  
The Relationship

Long QT syndrome (LQTS) is an arrhythmic heart disease caused by congenital genetic mutations, and results in increased occurrence rates of polymorphic ventricular tachyarrhythmias and sudden cardiac death (SCD). Clinical evidence from numerous previous studies suggested that beta blockers (BBs), including atenolol, propranolol, metoprolol, and nadolol, exhibit different efficacies for reducing the risk of cardiac events (CEs), such as syncope, arrest cardiac arrest (ACA), and SCD, in patients with LQTS. In this study, we identified relevant studies in MEDLINE, PubMed, embase, and Cochrane databases and performed a meta-analysis to assess the relationship between the rate of CEs and LQTS individuals with confounding variables, including different gender, age, and QTc intervals. Moreover, a network meta-analysis was not only established to evaluate the effectiveness of different BBs, but also to provide the ranked efficacies of BBs treatment for preventing the recurrence of CEs in LQT1 and LQT2 patients. In conclusion, nadolol was recommended as a relatively effective strategy for LQT2 in order to improve the prognosis of patients during a long follow-up period.

Universal Electrocardiographic Screening for Long QT Syndrome in Hospitalized Neonates

2019 ◽  
Vol 37 (03) ◽  
pp. 322-325
Author(s):  
Bethany D. Kaemingk ◽  
Timothy J. Ulrich ◽  
Man Li ◽  
William A. Carey ◽  
Marc A. Ellsworth
Keyword(s):  
Long Qt Syndrome ◽  
Neonatal Intensive Care ◽  
Electronic Monitoring ◽  
Screening Method ◽  
Unexpected Death ◽  
Long Qt ◽  
Level Ii ◽  
Qt Syndrome ◽  
Unnecessary Testing

Objective Long QT syndrome (LQTS) is a known cause of unexpected death, leading some to recommend routine neonatal electrocardiographic (ECG) screening. We used continuous electronic heart rate corrected QT interval (QTc) monitoring to screen for interval prolongation in a cohort of hospitalized neonates to identify those at a risk of having LQTS. We hypothesized that this screening method would yield an acceptable positive predictive value (PPV). Study Design A cohort of 589 infants hospitalized in a level II neonatal intensive care unit were screened through continuous electronic QTc monitoring linked to an investigator-designed, computerized data sniffer. Screening was conducted from days-of-life 3 through 7 or until hospital discharge. The data sniffer alerted investigators for a 24-hour average QTc of ≥475 ms. Positively screened patients were further evaluated with 12-lead ECG. Results Positive screens were obtained in 5.6% of patients, all of whom had negative follow-up ECG testing (PPV = 0%). Furthermore, one-quarter of positively screened neonates underwent echocardiography based on ECG findings, none of which identified clinically relevant pathology. Conclusion Electronic monitoring of QTc in hospitalized neonates during the first week of life was not an efficient way to identify those at a risk of having LQTS. Conversely, screening triggered unnecessary testing.

scholarly journals Exercise Training-Induced Repolarization Abnormalities Masquerading as Congenital Long QT Syndrome

Circulation ◽  
2020 ◽  
Vol 142 (25) ◽  
pp. 2405-2415 ◽  
Author(s):  
Federica Dagradi ◽  
Carla Spazzolini ◽  
Silvia Castelletti ◽  
Matteo Pedrazzini ◽  
Maria-Christina Kotta ◽  
...  
Keyword(s):  
Long Qt Syndrome ◽  
Stress Test ◽  
Diagnostic Errors ◽  
Exercise Stress ◽  
Medical Visit ◽  
Long Qt ◽  
Qt Syndrome ◽  
Congenital Lqts ◽  
Ecg Abnormalities ◽  
Repolarization Abnormalities

Background: The diagnosis of long QT syndrome (LQTS) is rather straightforward. We were surprised by realizing that, despite long-standing experience, we were making occasional diagnostic errors by considering as affected subjects who, over time, resulted as not affected. These individuals were all actively practicing sports—an observation that helped in the design of our study. Methods: We focused on subjects referred to our center by sports medicine doctors on suspicion of LQTS because of marked repolarization abnormalities on the ECG performed during the mandatory medical visit necessary in Italy to obtain the certificate of eligibility to practice sports. They all underwent our standard procedures involving both a resting and 12-lead ambulatory ECG, an exercise stress test, and genetic screening. Results: There were 310 such consecutive subjects, all actively practicing sports with many hours of intensive weekly training. Of them, 111 had a normal ECG, different cardiac diseases, or were lost to follow-up and exited the study. Of the remaining 199, all with either clear QTc prolongation and/or typical repolarization abnormalities, 121 were diagnosed as affected based on combination of ECG abnormalities with positive genotyping (QTc, 482±35 ms). Genetic testing was negative in 78 subjects, but 45 were nonetheless diagnosed as affected by LQTS based on unequivocal ECG abnormalities (QTc, 472±33 ms). The remaining 33, entirely asymptomatic and with a negative family history, showed an unexpected and practically complete normalization of the ECG abnormalities (their QTc shortened from 492±37 to 423±25 ms [ P <0.001]; their Schwartz score went from 3.0 to 0.06) after detraining. They were considered not affected by congenital LQTS and are henceforth referred to as “cases.” Furthermore, among them, those who resumed similarly heavy physical training showed reappearance of the repolarization abnormalities. Conclusion: It is not uncommon to suspect LQTS among individuals actively practicing sports based on marked repolarization abnormalities. Among those who are genotype-negative, >40% normalize their ECG after detraining, but the abnormalities tend to recur with resumption of training. These individuals are not affected by congenital LQTS but could have a form of acquired LQTS. Care should be exercised to avoid diagnostic errors.

scholarly journals QT-prolongation and noncompaction

2019 ◽  
pp. 01-03
Author(s):  
Josef Finsterer ◽  
Claudia Stöllberger
Keyword(s):  
Ventricular Fibrillation ◽  
Long Qt Syndrome ◽  
Qt Interval ◽  
Genetic Defect ◽  
Neuromuscular Disorder ◽  
Left Ventricular ◽  
Qt Prolongation ◽  
Long Qt ◽  
Qt Syndrome

In a recent article, Szulik et al. reported about a 22 years old female with ventricular fibrillation, QT-prolongation, and left ventricular hypertrabeculation/noncompaction (LVHT) who died from hypoxic cerebral damage 5 days after admission [1]. We have the following comments and concerns. Patients with LVHT have a disposition for any type of cardiac arrhythmia [2,3]. This is why ventricular fibrillation not only could be due to hereditary long-QT syndrome but also due to LVHT. Ventricular fibrillation was either due to LVHT or a consequence of QT-prolongation. QT-prolongation is not unusual in LVHT and has been reported in several cases (table 1) [3-7]. LVHT has been also reported in association with long-QT-syndrome due to mutations in the KCNQ1 gene [8], in the KCNH2 gene [9], or due to an unidentified genetic defect (table 1) [10]. In a study of 105 patients with LVHT, the QT-interval increased during a mean follow up of 3.6y in 15 patients and normalized in 21 patients [11]. The increase was associated with the extension of LVHT and the presence of a neuromuscular disorder (NMD) [11].

scholarly journals Early Identification of Prolonged QT Interval for Prevention of Sudden Infant Death

2021 ◽  
Vol 9 ◽  
Author(s):  
Georgia Sarquella-Brugada ◽  
Oscar García-Algar ◽  
María Dolores Zambrano ◽  
Anna Fernández-Falgueres ◽  
Sebastian Sailer ◽  
...  
Keyword(s):  
Sudden Death ◽  
Genetic Analysis ◽  
Long Qt Syndrome ◽  
Early Identification ◽  
Sudden Infant ◽  
Clinical Value ◽  
Long Qt ◽  
Invasive Approach ◽  
Qt Syndrome

Introduction: Long QT syndrome is the main arrhythmogenic disease responsible for sudden death in infants, especially in the first days of life. Performing an electrocardiogram in newborns could enable early diagnosis and adoption of therapeutic measures focused on preventing lethal arrhythmogenic events. However, the inclusion of an electrocardiogram in neonatal screening protocols still remains a matter of discussion. To comprehensively analyse the potential clinical value of performing an electrocardiogram and subsequent follow-up in a cohort of newborns.Methods: Electrocardiograms were performed in 685 neonates within the first week of life. One year follow-up was performed if QTc &gt; 450 ms identified. Comprehensive genetic analysis using massive sequencing was performed in all cases with QTc &gt; 470 ms.Results: We identified 54 neonates with QTc &gt; 450 ms/ &lt;470 ms; all normalized QTc values within 6 months. Eight cases had QTc &gt; 480 ms at birth and, if persistent, pharmacological treatment was administrated during follow-up. A rare variant was identified as the potential cause of long QT syndrome in five cases. Three cases showed a family history of sudden arrhythmogenic death.Conclusions: Our prospective study identifies 0.14% of cases with a definite long QT, supporting implementation of electrocardiograms in routine pediatric protocols. It is an effective, simple and non-invasive approach that can help prevent sudden death in neonates and their relatives. Genetic analyses help to unravel the cause of arrhythmogenic disease in diagnosing neonates. Further, clinical assessment and genetic analysis of relatives allowed early identification of family members at risk of arrhythmias helping to adopt preventive personalized measures.

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