Effect of age and overweight on the QT interval and the prevalence of long QT syndrome in children

Fukushige, Tomoko; Yoshinaga, Masao; Shimago, Atsushi; Nishi, Junichiro; Kono, Yukiharu; Nomura, Yoshio; Miyata, Koichiro; Imamura, Masato; Shibata, Toshimitsu; Nagashima, Masami; Niimura, Ichiro

doi:10.1016/s0002-9149(01)02259-7

Cited by 43 publications

(35 citation statements)

References 20 publications

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“…The same 1st and 7th graders were the subjects of a previous report. 10 ECGs from 10th graders were obtained 3 years later, in 2003; only 2,735 subjects (1,312 boys and 1,423 girls) from this cohort re-entered the present study, either because they moved out of Kagoshima or because they entered private high schools. Children and adolescents in public schools participated only in the Kagoshima City Medical Association programs during the study period.…”

Section: Subjectsmentioning

confidence: 99%

Cut-Offs for Screening Prolonged QT Intervals From Fridericia's Formula in Children and Adolescents

Hazeki

Yoshinaga

Takahashi

et al. 2010

Circ J

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Background:The corrected QT interval (QTc) according to Bazett's formula (QTc = QT/RR 1/2 ) has been used in clinical practice. Bazett's formula, however, overcorrects the QT interval at fast heart rates and undercorrects it at low heart rates. Guidelines and some investigators have recommended using Fridericia's formula (QTc = QT/RR 1/3 ) in these cases, especially in tachycardic subjects. The aim of the present study was to determine cutoffs for QTc suitable for screening pediatric subjects with prolonged QT intervals, based on manually measured values corrected by Fridericia's formula in a large number of subjects. Methods and Results:Three consecutive QT and RR intervals were measured in 4,655, 4,655, and 5,273 1st, 7th, and 10th graders, aged 6, 12, and 15 years, respectively. Each QT interval was corrected by Fridericia's formula, and mean values were calculated. Determination of the cut-offs for screening was based on the prevalence of abnormal electrocardiographic phenotypes of 1:1,164 and on the upper 0.025 percentile in the QTc distribution derived from previous studies. The tentative cut-offs suitable for screening subjects with prolonged QT intervals were 430 ms for 1st graders, 445 ms for 7th graders, and 440 and 455 ms for 10th grade boys and girls, respectively. Conclusions:These tentative cut-offs can be used to screen subjects with prolonged QT intervals in the clinical setting. Further studies are needed to confirm their validity. (Circ J 2010; 74: 1663 - 1669

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Section: Subjectsmentioning

confidence: 99%

Cut-Offs for Screening Prolonged QT Intervals From Fridericia's Formula in Children and Adolescents

Hazeki

Yoshinaga

Takahashi

et al. 2010

Circ J

Self Cite

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“…[12][13][14] The initiation of drug therapy for these young patients is controversial because many pediatric cardiologists consider that few young LQTS patients without a past history have experienced new cardiac events after diagnosis. The objective of the present study, then, was to examine the characteristics of Japanese pediatric patients with LQTS and to determine the predictive factors for cardiac events after diagnosis in these young patients with and without a past history of cardiac events.…”

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confidence: 99%

Who Is at Risk for Cardiac Events in Young Patients With Long QT Syndrome?

Yoshinaga

Nagashima

Shibata

et al. 2003

Circ J

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ong QT syndrome (LQTS) is a rare disease characterized by prolonged ventricular repolarization and a high risk for cardiac events including sudden cardiac death. 1 Mutations causing LQTS have been identified in 5 genes, each encoding a cardiac ion channel and its regulatory subunit. [2][3][4][5] Most cases of LQTS that come to the attention of physicians are either symptomatic or familial. [6][7][8] Recent studies have reported that life-threatening arrhythmias in LQTS patients tend to occur under specific circumstances (eg, exercise, emotion, and sleep/rest without arousal) in a gene-specific manner. 9 Beta-blocker therapy is reported to be effective in preventing LQTS-related cardiac events in these patients, but they continue to occur while patients are on the prescribed medication. 10 A recent report has reported a gender reference in the electrocardiographic (ECG) response to -blockers in patients with LQTS. 11 A screening program conducted for Japanese children (1st, 7th and 10th grades) has uncovered large numbers of children with LQTS both without a family history and without a history of LQTS-related cardiac events at the Circulation Journal Vol.67, December 2003 time of diagnosis. 12-14 The initiation of drug therapy for these young patients is controversial because many pediatric cardiologists consider that few young LQTS patients without a past history have experienced new cardiac events after diagnosis. The objective of the present study, then, was to examine the characteristics of Japanese pediatric patients with LQTS and to determine the predictive factors for cardiac events after diagnosis in these young patients with and without a past history of cardiac events. Methods Subjects and DataA questionnaire was sent to 111 hospitals where the trustee(s) of the Japanese Society of Pediatric Cardiology and Cardiac Surgery were working. Subjects were those who visited one of those hospitals from January 1997 to August 2000 and who were less than 20 years old at the time of diagnosis. Characteristics of the subjects obtained from the survey included the following: past history of LQTS-related cardiac events, ECG findings, clinical and family history for diagnosis of LQTS according to the criteria of Schwartz et al, 15 cardiac events during the period after diagnosis and medication. When medication was prescribed, those patients were re-surveyed for compliance. Subjects were classified into 2 groups on the basis of the presence or absence of a past history of LQTS-related cardiac events at the time of diagnosis. The index events for diagnosis were classified as follows: (1) Who Is at Risk for Cardiac Events in Young PatientsWith Long QT Syndrome?Masao Yoshinaga, MD*; Masami Nagashima, MD; Toshimitsu Shibata, MD; Ichiro Niimura, MD; Mitsuo Kitada, MD; Toshiaki Yasuda, MD; Mari Iwamoto, MD; Junko Kamimura, MD; Mayu Iino, MD; Hitoshi Horigome, MD; Masashi Seguchi, MD; Sumi Aiba, MD; Naomi Izumida, MD; Takashi Kimura, MD; Hiroya Ushinohama, MD; Junichiro Nishi, MD*; Yukiharu Kono, MD*; Yuichi Nomura, MD*; Ko...

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“…According to another study, the prevalence of long QT was 1 in 1,164 among 7th graders aged 12 years. 14 In general, approximately 90% of patients with genotyped LQTS carry a mutation in KCNQ1, KCNH2 (HERG), or SCN5A, which is responsible for the LQTS subtype. 5, 8 The most prevalent form of LQTS appears to be caused by mutations in KCNQ1, which encodes the potassium channel (LQT1).…”

Section: Prevalence Of Lqt3mentioning

confidence: 99%

High Prevalence of the <i>SCN5A</i> E1784K Mutation in School Children With Long QT Syndrome Living on the Okinawa Islands

Takahashi

Shimizu

Miyake

et al. 2014

Circ J

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Effect of age and overweight on the QT interval and the prevalence of long QT syndrome in children

Cited by 43 publications

References 20 publications

Cut-Offs for Screening Prolonged QT Intervals From Fridericia's Formula in Children and Adolescents

Cut-Offs for Screening Prolonged QT Intervals From Fridericia's Formula in Children and Adolescents

Who Is at Risk for Cardiac Events in Young Patients With Long QT Syndrome?

High Prevalence of the <i>SCN5A</i> E1784K Mutation in School Children With Long QT Syndrome Living on the Okinawa Islands

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