有人认为,既往有链球菌感染的病人有可逆性P-R 间期延长,是急性风湿热的主要诊断标准。但亦有人认为,其房室传导是非特异性的,值得进一步研究。P-R 间期的正常值因年龄和心率而异,因此其价值受一定限制。某些患儿虽有房室传导阻滞,但 P-R间期并未超过正常最高值。有人提出测量 PR 指数[P-R 间期实测值(分子)与年龄和心率相应的已知 Some people think that previous patients with streptococcal infection have reversible P-R interval is the main diagnostic criteria for acute rheumatic fever. However, some people think that the atrioventricular conduction is non-specific, it is worth further study. The normal P-R interval varies with age and heart rate, so its value is limited. Although some children with atrioventricular block, but the P-R interval did not exceed the normal maximum. It has been proposed to measure the PR index [P-R interval measured (numerator) corresponding to age and heart rate known