Shephard R J, Rode A
School of Physical & Health Education, Department of Preventive Medicine & Biostatistics, Faculty of Medicine, University of Toronto, Ontario, Canada.
Arctic Med Res. 1991 Jul;50(3):120-6.
The prevalence of right-branch bundle block (RBBB) has been examined in the Inuit residents of Igloolik (69 degrees 40'N, Canadian N.W.T.) over a twenty-year period. Original reports of a very high prevalence of RBBB probably reflected a selective testing of patients with chronic respiratory disease by visiting physicians. Cases of RBBB are certainly seen somewhat more frequently than in a southern community, but the majority of subjects show no more than a slight notching of the R wave of the electrocardiogram, with no appreciable broadening of the QRS complex. While a few of the more marked cases of RBBB may be attributable to chronic respiratory disease, the majority are associated with high normal values for both lung function and predicted maximal oxygen intake. The probable cause is thus a ventricular hypertrophy due to the vigorous physical activity demanded by life in a northern community rather than chronic respiratory disease. The physical demands of life in Igloolik have diminished over the past two decades, and an apparent increase in the prevalence of RBBB over this period is probably due mainly to a great awareness+ of the condition by those reading the electrocardiograms.
在20年的时间里，对伊格卢利克（北纬69度40分，加拿大西北地区）的因纽特居民进行了右束支传导阻滞（RBBB）患病率的调查。最初关于RBBB患病率极高的报告可能反映了来访医生对慢性呼吸道疾病患者进行的选择性检查。RBBB病例的出现确实比南方社区稍频繁一些，但大多数受试者心电图R波仅有轻微切迹，QRS波群无明显增宽。虽然少数较为明显的RBBB病例可能归因于慢性呼吸道疾病，但大多数与肺功能和预测最大摄氧量的高正常数值有关。因此，可能的原因是北方社区生活所需的剧烈体力活动导致的心室肥厚，而非慢性呼吸道疾病。在过去二十年里，伊格卢利克的生活对体力的需求有所减少，在此期间RBBB患病率明显上升可能主要是由于解读心电图者对该病的认识大幅提高。
