QT短縮とQT短縮症候群Short QT Interval and Short QT Syndrome
新潟大学医歯学総合病院魚沼地域医療教育センターUonuma Institute of Community Medicine, Niigata University Medical and Dental Hospital ◇ Niigata, Japan
新潟大学医歯学総合病院魚沼地域医療教育センターUonuma Institute of Community Medicine, Niigata University Medical and Dental Hospital ◇ Niigata, Japan
QT短縮症候群(short QT syndrome: SQTS)は遺伝性の致死的不整脈である.2000年に初めて報告され,心電図上のQT短縮を特徴とし,心室細動や心房細動などの不整脈を来す.臨床像は未だ不明な点も多いが,10~20歳台の突然死が多く報告されている.よって小児期での診断が重要であり,学校心臓検診でも問題になる.2013年の三大陸合同のExpert consensus statement以降は,QTcが一定基準以下のものは,遺伝子異常も家族歴もない無症状例もSQTSと診断される.一般成人集団よりQT短縮例を抽出する検討では,SQTSの診断基準を満たす例はあったが無症状で予後も良いと報告されている.我々の学校心臓検診の検討でもSQTSは存在したが,有症状例はなかった.SQTSの中でも高リスクの既報例と検診・健診などで抽出される低リスク例には臨床像に大きな隔たりがあり,SQTSのリスク層別化が重要となる.そこで我々は,有症状のSQTS既報例と学校心臓検診で抽出された無症状で家族歴もないQT短縮例の心電図を比較し,高リスクのSQTS例の鑑別が可能か検討した.さらにSQTSのリスク層別化を進めるには無症状のSQTS小児例の中長期予後を知ることが求められる.
Short QT syndrome (SQTS) is a hereditary lethal arrhythmia; it was first described in 2000. SQTS is characterized by an abnormal short QT interval on electrocardiogram (ECG), and causes arrhythmia, such as ventricular fibrillation and atrial fibrillation. Although clinical characteristics of SQTS have not been appropriately elucidated, several victims, individuals in the teenage and those in their 20s, have been reported. Therefore, SQTS diagnosis at an early age is important and is recognized as a concern in a school screening program for heart disease. According to an expert consensus statement published in 2013, even an asymptomatic individual with a short QT interval, who has neither a family history nor a pathogenic gene mutation, can be diagnosed with SQTS. Studies with various adult populations have identified individuals who met the SQTS diagnostic criteria; however, these patients were asymptomatic and did not have a poor prognosis. Some asymptomatic children and adolescents with SQTS were also identified in our study, in which we mainly focused on a school screening program for heart disease. Risk stratification of SQTS is necessary because clinical characteristics of SQTS are variable, including no symptoms and sudden cardiac death. Hence, we compared the ECGs of asymptomatic individuals with a short QT interval in a school screening program for heart disease with those of previously reported symptomatic patients with SQTS, to screen for SQTS patients with a high risk. A prospective study thus needs to be conducted to elucidate the prognosis of asymptomatic patients with SQTS who are diagnosed in their childhood.
Key words: short QT syndrome; QT interval; sudden cardiac death; lethal arrhythmia
© 2019 特定非営利活動法人日本小児循環器学会© 2019 Japanese Society of Pediatric Cardiology and Cardiac Surgery
This page was created on 2019-02-22T11:10:50.406+09:00
This page was last modified on 2019-03-15T14:35:01.000+09:00
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