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

Background: The Japanese society of pediatric cardiology and cardiac surgery revised the guidelines for school cardiac screening in 2016. All students with atrioventricular (AV) junctional rhythm must now undergo further examination, and those with a heart rate of ＞80 beats/min must be managed using the same protocol as that used for those with supraventricular tachycardia. However, data are lacking on the frequency of AV junctional rhythm or heart rate in school cardiac screening, and the impact of the guideline change on the findings of school cardiac screening is unclear.

Methods: The frequency of AV junctional rhythm and corresponding heart rate were examined in 7,108 students who underwent cardiac screening at municipal schools in Otsu. AV junctional rhythm was visually determined on the basis of negative P waves in leads II, III, and aVF, rather than using an automated electrocardiogram reading. The PQ interval and whether the P wave was observed before, during, or after the QRS wave were not included in the diagnostic criteria; everything considered to be a negative P wave was extracted.

Results: AV junctional rhythm was detected in 55 first graders (2.4％), 73 fourth graders (3.0％), and 76 seventh graders (3.3％); the heart rate in these groups showed a normal distribution with peaks of 79.2 (SD 7.9), 76.7 (8.6), and 72.5 (9.9) beats/min, respectively.

Conclusions: In school cardiac screening, AV junctional rhythm was found more frequently than previously assumed. The heart rate in these students was also faster than the 30–60 beats/min assumed in the guidelines and was faster at younger ages.