Masayuki Tanizaki

Relation of stroke and cardiac indices to serum catecholamines following open heart surgery.

Serum catecholamines (epinephrine, dopamine and norepinephrine) were measured two, four and six hours after open heart surgery. The ratios of stroke index (SI) and cardiac index (CI) to catecholamines (CA) were determined. Patients studied consisted of 27 with congenital and 14 with acquired heart disease. Extracorporeal circulation (ECC) time was longer than 90 minutes in 17 and shorter in 24 patients. SI and CI diminished in elder patients with congenital disease (Group Cg-ad), patients with acquired desease (Group Ac) and patients with a longer ECC time (Group L). Therefore, elder age and/or longer ECC time seems to be responsible to the lower indices. However, the ratios of the indices to CA showed that the lower indices indicated the poor response of the myocardium to CA in Group Ac and Group L. The response was larger in Group Cg-ad and the lower indices were related to lower serum CA level. It was concluded, therefore, that the indices of stroke volume and cardiac output had inverse correlation to ECC time, but not to age, namely, prolonged ECC compromised more severely the myocardium and resulted in the poor response of the myocardium to CA. Subsequently, to compensate for the poor response, serum CA levels were elevated probably to maintain due SI and CI in patients with prolonged ECC.

Myocardial protection of only the left coronary artery perfusion in patients with isolated aortic valve replacement.

Effectiveness of only left coronary perfusion on myocardial protection was assessed by measuring serially cardiac functions such as cardiac index(CI), stroke index(SI), left ventricular minute work index(LVWI) and left ventricular stroke work index (LVSWI) in 22 consecutive patients with isolated, scheduled aortic valve replacement. The cardiac functions were determined 2,4 and 6 hours after open heart surgery. Correlation coefficients(r) between coronary perfusion time and the cardiac functions were less than 0.23, such being statistically insignificant. SI and LVSWI were in statistically significant inverse correlation to the preoperative NYHA classification and extracorpreal circulation(ECC) time for 4 hours following open heart surgery, and CI and LVWI for 2 hours. The correlation coefficients were highest at the 2nd postoperative hour and then decreased with passage of time. Therefore, the cardiac dysfunctions occurring in the postoperative period correlated either to the preoperative NYHA classification or ECC time, or both. It does, however, seem likely that the dysfunctions were correlated to ECC time as the recovery time of 4 hours from the dysfunctions is too short for preoperatively existing dysfunction. Therefore, it was concluded that the continuous perfusion of only the left coronary artery was not the determinant factor of the postoperative dysfunctions and that the ECC time afforded detrimental effects, although such continued for 4 hours in terms of SI and LVSWI, and 2 hours in term of CI and LVWI.

Prediction of prognosis in open-heart-surgery by regional difference in leg surface temperature.

Change of the surface temperature of the leg during open-heart-surgery was determined in five patients, in whom either side of the femoral artery was ligated for cannulation. While the surface temperature at the patella was least influenced, that at the ankle paralleled closely the changes in the core body temperature and blood supply to the leg. Their difference(P-A difference) was studied to see if they can be used to predict prognosis of patients undergoing open-heart surgery. The P-A difference was followed for several hours after the open-heart surgery. It was marked positive when the surface temperature at the patella was higher than that at the ankle. Total of 54 patients were studied. Only one out of 29 patients with negative P-A difference succumbed. This is in sharp contrast to the 25 remaining patients with positive P-A difference, from whom as many as 12 died. In addition, the postoperative course of the 13 survivors from the latter group was more eventful. Since P-A difference seemed to indicate accurately cardiac output by reflecting the state of the peripheral circulation, it can be used as a useful parameter in prediction of the prognosis in open-heart surgery.