| Abstrakt: |
The modalities of 25 mEq. per liter potassium-induced arrest in a simulated extracellular fluid, and 15° C. perfusion hypothermia were combined and used exclusively for myocardial protection during cardiac surgery in 108 consecutive patients. Over half of the patients had impaired preoperative myocardial function, as assessed by a subnormal ejection fraction and by New York Heart Association Class IV status. Ten patients were semiemergencies and eight were emergencies, including three in cardiogenic shock. The 30-day operative mortality rate was 4.6 percent, and during a mean follow-up of 9 months there were two late deaths-both cerebrovascular. The excellence of the myocardial protection is attested to by spontaneous defibrillation in over 50 percent of the patients, the very infrequent use of pressors, the immediate postoperative improvement in cardiac output, the early improvement in postoperative functional status of almost all of patients, and the very low level of specific myocardial isoenzyme released following the open heart procedures. The significant advantages of 15° C. potassium-induced arrest are (1) simplified high-volume temperature and pressure-monitored aortic root perfusion, effective even with aortic insufficiency, (2) the preclusion of the “calcium paradox,” (3) minimization of defibrillator induced myocardial injury, (4) operating conditions superior to normothermic ischemic arrest or topical hypothermia, (5) avoidance of coronary artery trauma, high and low perfusion pressure injuries, low-flow/high-energy demand situations and low-temperature injury, and (6) extensive clinical and experimental evidence of superior myocardial protection. |
