FORCE-FREQUENCY RELATIONS IN NONFAILING AND FAILING ANIMAL MYOCARDIUM

This paper reviews the recent data concerning the force-frequency rela tions in experimental animals with heart failure. After a brief overvi ew of the nature of these relations, which are induced by 2 opposite p henomena, the potentiation of force of contraction by heart rate and t he restitution process, the paper reviews first the force-frequency re lations in isolated failing myocardium. This is followed by a review o f recent data obtained in the in situ failing heart. The cellular mech anisms of the force-frequency relations are then discussed.