Adenosine A1 antagonism attenuates beta-adrenergic-resistant sudden hypoxic cardiac insufficiency.

Objectives: In states such as hypoxia, shock, and cardiac arrest, compromised systemic oxygenation or perfusion appears to induce cardiac insufficiency that can be resistant to beta-adrenergic drugs. Elevated levels of adenosine may mediate such beta-adrenergic-resistant cardiac insufficiency via the adenosine A(1) receptor (A(1)AdoR). The objective of this study was to test the hypothesis that selective A(1)AdoR antagonism attenuates hypoxic cardiac insufficiency more efficaciously than beta(1)-adrenergic agonism or nonselective adenosine antagonism.