Total numbers of 154 patients were examined with signal-averaged electrocardiograms(SAE)in this research. Usually the patients were examined twice at preoperatively, several times immediately after cardiopulmonary bypass and twice at following days by ART-101PC. Times of measurement were added in cases of assisted circulation. Some of the patients were measured micro-electrical potentials during cardiac arrest using MULTICARDINA(VCH-3000, FUKUDA DENSHI).
Following characters of filtered QRS were clarified. (1)Degree of reduction of RMST at reperfusion was correlated to high value of CPK-MB, which meant cardiac muscle damage was able to be evaluated by SAE. Those findings were confirmed by both patients and experimental animal model using dogs. (2)RMST reflects the volume of activated left ventricular myocardial volume. (3)Aged patients were tended to decrease RMS_<40> which might be cause the perioperative arrhythmias in aged patients. (4)In animal experimental model using Wistar rat, r
eaction of cathecolamine onRMST was specific in drugs which modulates adrenoceptors. That is, alpha- stimulation increased RMST, and alpha- or beta-blockade decreased RMST temporarily. beta-stimulation showed no significant changes.
Data from patients with open heart surgery indicated that reduction of RMST at reperfusion was in correspondence with postoperative heart failure. In patients-who were not infused noradrenalin(N=19), RMST at reperfusion was 90+__-27%, whereas in patients who were infused noradrenalin more than 10mug/kg(N=27), RNST was 57+__-32%(P<0.001, statistically significant). In cases of patients who were applied IABP(intra-aortic balloon pumping), RMST was lowered to 49+__-13% as compared with preoperative value. In cases of lower RMS_<40>(less than 20muV)there was a possibility of attack of ventricular tachyarrhythmias(sensitivity 61%). Whereas, in cases of higher RMS_<40>(more than 40muV)there seemed to be free from attack of VT(specificity 80%).
From the cases with assisted circulation, trend of RMST was important to evaluated the cardiac state of assisted circulation. Among 15 cases with application of IABP, 10 cases were weaned from assisted circulation, and the rest of 5 cases were not weaned from assisted circulation. RMST of weaned patients were increased from 47+__-15%(before IABP)to 83+__-15%(at weaning of IABP). RMST of unweaned patients were declined from 34+__-15% to 24+__-12%(final measurement). It was supposed that trend of RMST during assisted circulation would reflect the degree of recovery from myocardial damage.
Micro-electrical potentials were measured during cardiac arrest using VCM-3000. The configuration of micro-electrical potentials were changed as time has passed from initial cardioplegia infusion. Prolongation of the configulation was seemed to reflect the transmission of electrical potential to adjacent cardiac muscle, which would not occured in ideal cardioplegic arrest. Thus, prolonged delta-shaped configuration of micro-electrical potentials might indicate the insufficient situation of cardiac preservation during cold anoxic cardioplegic arrest.
As mentioned above, application SAE on open heart surgery is quite useful on management and recognition of post operative heart patients. Less