Abstract 16394: Effect of Brief Repetitive Ischemia/Reperfusion on Myocardial Electrical Activity Visualized and Quantified by 3D Endocardial Electroanatomical Mapping
Introduction: Brief repetitive ischemia/reperfusion (R-IR) confers cardioprotection against subsequent prolonged ischemia, referred to ischemic preconditioning (IP).
Hypothesis: In this study we intended to visualize and quantify for the first time the effect of R-IR on the on-line changes of myocardial electrical activity via on-line 3D electroanatomical mapping of the left ventricle (LV) using the NOGA system.
Methods: Under general anaesthesia, domestic pigs underwent coronary catheterization. After completion of a baseline NOGA endocardial map, R-IR or sham procedure was performed by 3x10 min consecutive repetitive occlusion/reperfusion of the mid left anterior descending (LAD) coronary artery. During the R-IR cycles, endocardial mapping were repeatedly started and continued. For quantification of the myocardial electrical activity of the ischemic affected area, the mean unipolar voltage values of the apical and mid anterior segments were calculated. At 6h, 12h and 24h, NOGA procedures were repeated. Control coronary angiography confirmed the patency of the LAD.
Results: Ten-min coronary occlusion resulted in immediate decrease in myocardial electrical activity in the mid and apical anterior wall, with partial restoration during the reperfusion. However, during the 2nd and 3rd 10-min occlusion, the extension and severity of the reduced electrical activity improved gradually but without complete recovery (Fig). Decreased electrical activity lasted up to 24h.
Conclusions: R-IR conditions the myocardium against next ischemic insult with sequential improvement in electrical activity. Short-term reperfusion after profound ischemia seems to be insufficient to restore tissue viability. R-IR of coronary arteries result in delayed recovery of the myocardial electrical activity up to 24h. Decreased electrical activity of the myocardium may contribute to cardioprotection by both classic and delayed IP.
- © 2013 by American Heart Association, Inc.