日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

Online ISSN: 2187-2988 Print ISSN: 0911-1794
特定非営利活動法人日本小児循環器学会 Japanese Society of Pediatric Cardiology and Cardiac Surgery
〒162-0801東京都新宿区山吹町358-5アカデミーセンター Japanese Society of Pediatric Cardiology and Cardiac Surgery Academy Center, 358-5 Yamabuki-cho, Shinju-ku, Tokyo 162-0801, Japan
Pediatric Cardiology and Cardiac Surgery 38(1): 21-28 (2022)
doi:10.9794/jspccs.38.21

原著Original

学校心臓病検診において胸部誘導位置の誤りを認めた心電図の検討Analysis of Electrocardiograms with Misplaced Precordial Leads in School Cardiac Screening

しばた医院Shibata Clinic ◇ Kanagawa, Japan

受付日:2021年6月13日Received: June 13, 2021
受理日:2021年12月27日Accepted: December 27, 2021
発行日:2022年2月1日Published: February 1, 2022
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背景:近年,学校心臓病検診で初発見される先天性心疾患の多くは心房中隔欠損症である.そのためV1誘導でのrsR′型の不完全右脚ブロック型には注意しているが,二次検診でその所見が消失することがある.また,V6誘導の深いQ波も二次精検で消失することがある.この原因を検索した.

方法:V1誘導でrsR′型の生徒14名とV6誘導で深いQ波の生徒3名の心電図と合成ベクトル心電図(VCG)をとり,さらに高位肋間でも記録した.

結果:rsR′型症例で,二次検診ではrsR′型が消失したが,1~2肋間上の記録では一次検診と同じ波形が再現された.深いQV6症例において,二次でその所見が消失したが,1肋間上の誘導で深いQV6が再現した.上位肋間では合成VCGのQRSループ後半が前方偏位した.深いQV6波例では,ループ初期部分が増幅し,最大QRSベクトルの増大も認められた.

結論:高位肋間で出現したrsR′型は,合成VCG解析の結果,単極誘導から遠い部分の電位が減衰しループが前方偏位したと考えられた.深いQV6例は,誘導が1肋間上がるとQRSループに電極が接近し高電位が記録されたと考えた.

Background: In recent years, atrial septal defect has been the most common congenital heart disease discovered during school heart disease screening. Therefore, we carefully examine the electrocardiogram (ECG) of incomplete right bundle branch block (IRBBB) pattern in lead V1, particularly the rsR′ type. The rsR′ pattern, however, frequently disappeared at the secondary screening. The presence of a deep Q wave in lead V6 (QV6), which is a screening criterion for heart disease, occasionally disappeared at the secondary screening. The findings were investigated because they were thought to be the lead misplacement.

Methods: The subjects included 14 students who showed rsR′ pattern in lead V1 and 3 students who had an ECG finding of deep QV6 (≧0.5 mV). Their ECGs were recorded in both the standard and upward displaced positions on the chest. Furthermore, synthesized vectorcardiography was simultaneously recorded.

Results: At the secondary screening, the finding of IRBBB pattern of rsR′ type had vanished in 14 students and an atypical IRBBB pattern or normal wave form was discovered. When the chest leads were displaced to the upper position, the rsR′ pattern appeared. At the secondary screening, deep QV6 amplitude decreased to <0.5 mV in 3 students. When the chest electrodes were positioned upward by one intercostal space, deep QV6 appeared.

Conclusions: These findings were thought to be the result of precordial lead displacement. They could be because the amplitude of waves in unipolar leads changed in inverse proportion to the square of the distance between an electrode and the heart.

Key words: misplacement; precordial lead; incomplete right bundle branch block; deep Q wave; school cardiac screening

This page was created on 2022-04-04T11:15:02.422+09:00
This page was last modified on 2022-05-25T19:46:49.000+09:00


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