Abstract
Isolated atrial tissue preparations provide convenient models for studying drug effects on the myocardium. However, there are several points we must be aware of. Interventions which change the beating rate also affect contractile force (Starling’s Law). The membrane currents involved in the action potential as well as the excitation-contraction mechanisms differ between the atria and ventricle. Some membrane currents present only in the sino-atrial node and atrial myocardium may provide targets for novel bradycardiac agents and anti-atrial fibrillatory agents, respectively. The atrial tissue contains non-myocardial cells such as autonomic neurons and endocardial endothelial cells, which may be involved in the responses to various pharmacological stimuli.
