Effect of ethanol on frequency-force relationship in isolated right atrial muscle of the dog.

Publisher Website
Google Scholar
Abstract
The effects of ethanol and verapamil [a Ca antagonist] on the frequency-force relationship in isolated right atrial muscle of the dog were investigated. The atrial muscles of 6 mongrel dogs, kept at a constant perfusion pressure of 100 mm Hg, were electrically driven by a stimulus 1 .mu.s in duration, 1-2 V in strength and 1.5-4.0 Hz in frequency. At all examined frequencies, 1 mmol of ethanol produced a moderate, rather uniform depression of tension, whereas 1 .mu.g of verapamil produced a greater depression at higher frequency rates. Ethanol and verapamil probably interfere with cardiac excitation-contraction coupling at different sites.