The effect of digoxin on the contractility of transplanted heart.

The effects of digoxin on the contractility of orthotopically transplanted heart was studied in dogs. Intravenously administered digoxin produced a fall in the rate and output of the transplanted heart without any change in stroke volume, whereas the output of the intact heart was slightly improved due to a small increase of stroke volume. This difference was thought to be due to the action of digitalis which is mediated via the nervous pathways, which are interrupted in the transplanted heart.