Intraventricular conduction disturbances in flying personnel: right bundle branch block.

The evolutive characteristics, as well as the qualification criteria, applied to 41 cases of complete right bundle branch block (CRBBB), detected in a presumably healthy population composed of 6,915 male individuals performing civil flying activities (prevalence = to 5.9 per 1,000) were studied. In 17 cases, the CRBBB was detected in the first electrocardiogram (ECG). In 24 cases, the CRBBB appeared after normal ECGs; the CRBBB development did not change the electrical axis in 75%, and in 50% of them an incomplete right bundle branch block (IRBBB) appeared first, suggesting a progressive compromise of the right bundle branch. One case developed arterial hypertension and coronary heart disease, another one mitral valve prolapse, and there were two cases of non-cardiovascular diseases. The CRBBB etiology in asymptomatic individuals is uncertain. The prognosis depends on the underlying disease. Once those etiologies which by themselves imply a future risk are ruled out, they may be waivered for flying activities with periodical ECG controls.