“…223 poisoning (13), congenital heart disease (14,15,16) or myocardial infarction (17). In a variety of systemic infections (11,18,19,20), complete heart block has been noted ; these infections include tuberculosis, rheumatic fever, viral pneumonia, poliomyelitis, scarlet fever, mumps, whooping cough and German measles. Campbell (21) concluded, after study of 64 cases of complete heart block, that 72 per cent of the cases were between 50 to 70 years of age, and Schnur (22)likewise found 80 to 90 per cent of the cases of complete heart block in the atherosclerotic group.…”