DYNAMICS OF ELECTROCARDIOGRAPHIC RIGHT BUNDLE BRANCH BLOCK CHANGES IN ATHLETES OF VARIOUS AGE GROUPS

Abstract

It is well-known from the medical literature that incomplete right bundle branch block (IRBBB) is a common finding among athletes and is associated with training process. Although, in the process of review of athletes’ pre-participation screening data, along with stable occurrence of IRBBB we observed significant number of cases with marked alterations of electrocardiography (ECG) patterns, such as development of new IRBBB in case of its previous absence, transformation of IRBBB into complete right bundle branch block (CRBBB), or other unclear dynamic patterns. With purpose to determine prevalence of above-mentioned changes in ECG patterns and their diagnostic significance, we reviewed medical records of pre-participation screening of 790 athletes and observed their ECG dynamics during last 4 years. We selected a sample of those athletes, who demonstrated a change in RBBB pattern during this 4year period – 128 athletes in total - and divided it into 4 age groups. We obtained the following findings: (1) Right bundle branch block (RBBB) was absent at the initial ECG but developed later in the process of training: 1st group – 23 athletes (79%); 2nd group – 28 athletes (70%); 3rd group – 23 athletes (88%); 4th group – 4 athletes (12%). (2) IRBBB was present at the initial ECG and transformed into CRBBB in the process of training: 1st group -1 athlete (3%); 2 group – 12 athletes (30%); 3 group 11 athletes (33%). (3) Unclear dynamical pattern with periodical appearance and disappearance of RBBB was observed: 1st group – 7 athletes (27%); 4 group – 7 athletes (24%); 2nd group – 8 athletes (20%); 3rd group – 7 athletes (27%); 4th group – 6 athletes (18%). Several conclusions can be drawn from above-mentioned findings: (1) development of RBBB in cases, where it was absent previously, is common under 20 years of age, but is uncommon after 20 years of age. (2) Transformation of IRBBB into CRBBB is uncommon in very young athletes, but relatively more common in athletes aged 14 years and above. (3) Intensive physical training results in right ventricular remodeling, which can be interpreted as adaptation of athlete’s heart towards the training process. This can be confirmed by significantly higher values of physical work- ing capacity in athletes with RBBB, as compared to control group.