A hermetically sealed mercury cell pacemaker: advantages and early clinical results.

Despite the known advantages of hermetic encapsulation of implanted pacemakers, only a few conventionally powered models are totally hermetically sealed, and most of them are not yet clinically available. This report describes the results with a mercury cell unit which has been in clinical use since 1970 and has been totally hermetically sealed since 1974. The lowered premature failure rate with the newer model substantiates the theoretical advantages of hermetic encapsulation. The rate behavior of the pulse generator, upon which our telephone follow-up system is based, is essentially the same for both models.