Studies of retrograde cardioplegia. II. Advantages of antegrade/retrograde cardioplegia to optimize distribution in jeopardized myocardium.

摘要: This study tests the hypothesis that retrograde/antegrade cardioplegic delivery can overcome limitations of poor distribution resulting from either technique alone and, potentially, may expand safety using internal mammary artery grafts in cardiac muscle jeopardy inadequate protection. Jeopardized myocardium was produced 20 dogs by ligating left anterior descending coronary for 15 minutes before starting cardiopulmonary bypass and 1 hour aortic clamping with multidose 6 degrees C cold blood cardioplegia. Five received antegrade cardioplegia via root. Ten retrograde sinus. additional both routes. The ligature on removed after unclamping, regional myocardial temperature (thermistor probe), segmental shortening (ultrasonic crystals), global ventricular right function were evaluated. Antegrade excellent cooling (14 C) allowed complete functional recovery. However, it failed to cool supplied (only 31 versus 12 C, p less than 0.05), postischemic recovered only 38% (p region 22% 0.05). Retrograde homogeneous (17 near normal recovery (99% 86%), but variable (19 30 inconstantly (range 64% 100%, average 82%). best protection occurred cardioplegia; homogeneous, completely (95% 90%), contractility returned 84% control. We conclude provides better alone, ensures good ventricles, allows flow segments occluded arteries.(ABSTRACT TRUNCATED AT 400 WORDS)