Protective effect of chronic versus acute cardiac denervation on contractile force during coronary occlusion

The effects of acute coronary artery (CA) occlusion on myocardial contractile force were studied in mongrel dogs with (1) chronically denervated hearts (n = 10), (2) acutely denervated hearts (n = 5), and (3) normally innervated hearts (n = 6). Contractile force was measured in ischemic and nonischemic areas using Walton-Brodie strain gauge arches sutured to the epicardium. Coronary occlusion was accomplished by ligating several small branches of the left anterior descending and the circumflex arteries supplying the apical region on the left ventricle. Following occlusion, contractile force in the ischemic area decreased by 66.8% in the control group, by 73.6% in the acutely denervated group, but only by 21.6% (P less than 0.001) in the chronically denervated group. These results demonstrate that chronic cardiac denervation protects from the severe loss of contractile force in the ischemic area. This salutary effect is not seen with acute cardiac denervation.