Electrophysiological Correlates of Contractile Change in Mammalian and Amphibian Myocardium

Abstract

Studies of canine and frog myocardium disclose a consistent inverse relation between interval-dependent contractile alterations and the duration of phase 2 of the concomitant action potentials (AP). This is true despite the differing temporal patterns of contractile change in the two species. A relation of both the inotropic state and AP configuration to K+ flux is suggested.