title: Estimation of adequate subendocardial blood flow by online computation of systolic pressure time index and diastolic pressure time index after cardiopulmonary bypass.
abstract: Subendocardial perfusion was monitored in 48 patients subjected to valve replacement by calculation of diastolic pressure time index (DPTI), systolic pressure time index (TTI) and DPTI/TTI. An on-line computer which derives these values from the systemic pressure and wave-form was applied. For myocardial protection general body hypothermia (esophageal temperature 25 degrees C) and hypothermic injection cardioplegia were employed. No low cardiac output state occurred and no inotropic drugs were required. In all patients DPTI/TTI rose above 1 within 60 minutes from termination of cardiopulmonary bypass so that the necessity to intraaortic balloon counterpulsation could be denied in all cases. We believe that the calculation of DPTI/TTI after extracorporeal circulation is a useful modality to predict the adequacy of subendocardial perfusion and monitor myocardial performance.
mesh_terms: D006328:Cardiac Catheterization; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D003326:Coronary Circulation; D003327:Coronary Disease / Q000517:prevention & control; D003971:Diastole; D006324:Heart Arrest, Induced; D006350:Heart Valve Prosthesis; D006801:Humans; D007036:Hypothermia, Induced; D008991:Monitoring, Physiologic / Q000379:methods*; D009206:Myocardium / Q000378:metabolism*; D009862:Online Systems; D010101:Oxygen Consumption; D013599:Systole