Remission and recovery from chronic, established, complete heart block.

The return of A-V conduction is described in a patient after two decades of high-grade or complete congenital heart block. Similar cases have been reported by others, with remission or even recovery commencing up to the fourth decade or later. A similar phenomenon is also described in four patients with acquired heart block of four to ten years' duration; in them, remission was usuallly brief but persisted for seven years in one patient. No full report of this seems to have been published previously. Possible explanations are discussed, but no conclusion is reached. Apart from its interest, the phenomenon is of importance with respect to the selection of demand-type electronic pacemakers in the management of patients with heart block.