[Third degree atrio-ventricular block induced by interferon alpha. Report of a case]

Iatrogenic third degree atrioventricular block due to alpha interferon is rare. The authors present a case which occurred with low dosage, regressed when treatment was withdrawn and reappeared when treatment was reintroduced. The physiopathological mechanism of disease of the conduction pathways and its general cardiotoxicity is not yet understood. The secondary effects of this increasingly widely used anti-tumoral and anti-infectious drug should be recognised in order to prevent them. Initial cardiological investigation and follow-up are indicated to ensure this prevention.