The changes in left ventricular segmental contractile force induced by brief periods of ischemia (15 – 90 s) and subsequent reperfusions were analyzed in anesthetized dogs. Segmental coronary artery occlusion (left anterior descending or left circumflex) produced a decrease in segmental ventricular function in the occluded area and an increase in contractile force in the myocardial segment away from the occluded area. With reperfusion, a transient overshoot in contractile force above preischemic control levels was observed in the occluded segment. This overshoot was shown not to be dependent on adrenergic mechanisms but appears to indicate changes in calcium permeability.
Role of a paracrine action of mesenchymal stem cells in the improvement of left ventricular function after coronary artery occlusion in rats