The efficacy of cold blood potassium cardioplegia during aortic cross-clamp ing time longer than 150 minutes was evaluated in 27 patients with cardiac valvular surgery at Kagoshima University Hospital from August, 1978, to June, 1983. Ischemic intervals ranged from 150 to 241 minutes with a mean of 173 minutes.
Cardiac-related hospital death occurred in two patients (7.4%); one died of massive intrathoracic bleeding in a case with aortic and mitral regurgitation due to infectious endocarditis, and the other was due to an immobilized valve of the implanted aortic prosthesis. Although the patients with aortic cross-clamping time of more than 150 minutes were obviously in more serious condition by preoperative assessments than the patients with aortic cross-clamping time less than 150 minutes, there was no significant relationship between the length of cross-clamping time and cardiac-related hospital death or the occurrence of postoperative low-output syndrome.
These findings suggest that cold blood potassium cardioplegia provides ex cellent myocardial protection during aortic cross-clamp times longer than 150 minutes.
