Raccourcissement myocardique régional et débit sanguin des greffons apres chirurgie de pontage aorto-coronarien

In 56 patients operated on for coronary artery bypass grafting the relation between regional epicardial shortening, bypass flow, reactive hyperemia, and time postoperative was determined. Regional shortening in the newly perfused region was measured by a new technique employing four to six radiopaque markers sutured in pairs to the epicardium juxtaposed by 2 cm, and from 0 to 3 cm distal to the coronary anastomosis. Marker pairs were filmed sequentially at each follow up. Excluding dyskinesia, shortening fraction (ratio of shortening to maximum marker separation) for all graft regions at 1 week was 9.8 p. 100, 1 month 12.8 p. 100, 3 months 13.3 p. 100, and 6 months 13.9 p. 100. Average graft flow was 56 ml/mn and average reactive hyperemia was 25 p. 100 with 37 p. 100 of grafts having no response. There was a positive correlation between shortening fraction and flow, becoming significant (null hypothesis: r = 0) when reactive hyperemia exceeded 20 p. 100. Correlation was greatest at 1 week and 1 month, but became non-significant at 6 months implicating other factors such as new collateral development, bypass closure, new infarction, or altered medical therapy. It appears that bypass flow and reactive hyperemia do have a certain predictive value as to regional shortening up to 1 to 3 months postoperative.