Diphtheria as a cause of late heart-block

Pathological basis of primary heart block.

“…Hudson (1965) has suggested that bundle-branch fibrosis may represent healed myocarditis, and it is known that myocarditis in the acute stage heavily involves the bundle-branches (Lev and Unger, 1955). Previous diphtheria has been implicated (Butler and Levine, 1930), but in the present series of bundle-branch fibrosis no support for this view is found (Table). The conduction system in bundle-branch fibrosis shows no acute inflammatory changes, and if previous myocarditis is implicated, the long latent phase preceding symptoms is difficult to explain.…”

Aetiology of chronic heart block. A clinico-pathological correlation in 65 cases.

“…This seems unlikely, since these changes are not seen in the middle and lower parts of the septum adjoining the conducting tissue, and in any case, were found to be just as commnon in 40 patients of similar age without heart block on an electrocardiagram recorded shortly before death (Davies, Redwood, and Harris, 1967). It has been suggested that diphtheria plays a part in the development of chronic heart block (Butler and Levine, 1930;Leys, 1945;Penton et al, 1956), but this also seems unlikely since in the 65 patients only 3 had diphtheria (Table III), 2 of the 3 patients having bilateral bundle-branch fibrosis and the other coronary arterial disease. In our first 100 patients with heart block (Harris et al, 1965a) the incidence of diphtheria was 18 per cent, and was probably a reflection of the relatively high incidence of diphtheria during the childhood of these patients.…”

Complete heart block due to diphtheritic myocarditis in the present era

“…[16] Left bundle branch block (LBBB) is also recognized as an independent predictor of long-term survival in diphtheritic myocarditis. [17] However, long-term CHB seems rare as literature search revealed only two case reports[1819] of diphtheria myocarditis in preimmunization era, which resulted in long-term CHB.…”