Final answer:
A significant cardiac complication of diphtheria is myocarditis, heart damage caused by the diphtheria toxin produced by Corynebacterium diphtheriae. The toxin results in a pseudomembrane formation and systemic administration can lead to myocarditis.
Step-by-step explanation:
A possible cardiac complication of diphtheria, caused by Corynebacterium diphtheriae, is myocarditis, which is damage to the heart muscle. Diphtheria toxin, produced by the bacteria, can spread throughout the body if not contained, leading to this serious complication. Myocarditis can affect the heart's ability to pump blood and can lead to heart failure and other severe outcomes.
The diphtheria toxin is an A-B toxin that inactivates elongation factor (EF)-2, causing the death of host cells and a significant inflammatory response. This toxin can lead to the formation of a pseudomembrane in the throat, which is a hallmark sign of the infection. This blockage can be severe enough to require medical intervention such as intubation. Moreover, if diphtheria is not treated properly and the toxin is allowed to disseminate, it can reach the heart and cause myocarditis.
Broad-spectrum antibiotics, such as penicillin and erythromycin, are effective against C. diphtheriae, and vaccinations are crucial in preventing the disease. However, antibiotics do not neutralize the preformed toxin, and thus an antitoxin may be needed in cases where the toxin has already been produced. Vaccination efforts worldwide have greatly decreased the incidence of diphtheria.