A threshold ambiguity problem involving a cardiac pacemaker.
A case report of an apparently paradoxical electricl threshold required for cardiac "capture" based upon differences in construction in external as opposed to internal pulse generators is presented. The electrical characteristics of each type are discussed and recommendations made for more reliable determinations of cardiac "capture" thresholds.
D000368:Aged; D004560:Electricity; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial