We examined 20 patients undergoing coronary bypass grafting for coronary artery disease with NYHA classifications of II and III who had been treated with beta-blocking agents. Patients were randomised for administration of either adrenaline (0.1 microgram/kg/min) or amrinone (bolus 1 mg/kg, continuous infusion of 5-10 micrograms/kg/min), if following cardiopulmonary bypass their cardiac index was < 2.4 L/min/m2 with normal peripheral resistance and normal or increased right- or left-ventricular filling pressures. Over a period of 1 hour, the hemodynamic parameters mean arterial pressure (MAP), cardiac index (CI), heart rate (HR), coronary perfusion pressure (CPP), total peripheral resistance (TPR), as well as the pressure-work index (PWI) were registered or calculated. By means of a coronary sinus catheter myocardial arterio-venous oxygen content difference (AVDO2cor), myocardial blood flow (MBF), using the thermodilution method, and myocardial oxygen consumption (MVO2) could be measured or calculated. Simultaneously, arterial and myocardial lactate concentrations and, using the arterio-venous lactate ratio, myocardial lactate extraction or production were quantified. Using a transseptal approach, the left-ventricular pressure curve was measured and used to differentiate for myocardial contractility (dp/dtmax). Following induction of anesthesia and after cardiopulmonary bypass, plasma levels of the used beta-blocking agent were determined. Both substances caused a significant increase in myocardial contractility, with adrenaline showing a more potent effect than amrinone. Both substances caused a significant increase in CI with a mild increase in HR. Amrinone caused a significant drop in TPR, while MAP remained practically constant.(ABSTRACT TRUNCATED AT 250 WORDS)

A significant proportion of early graft occlusions after aortocoronary revascularization using autologous saphenous vein grafts (SVG) are due to mechanical and/or metabolic or biochemical endothelial lesions. The morphological examination of the endothelium, usually carried out using light microscopy or by various types of scanning electron microscopy (SEM), does not give any indication of the functioning of the endothelium (E). Functionally intact E is capable of producing endothelium-derived relaxing factor (EDRF); a practicable in vitro test is the relaxation of pre-contracted vein segments (VS) in response to acetylcholine (ACh) application. To study the effect of the solution used to rinse and store the SVG between removal and implantation on the functional characteristics of the E, we performed in vitro tests on macroscopically intact VS removed from the saphenous vein of 30 male patients who underwent elective CABG surgery. Isolated VS rings were incubated for 60 min in heparinized whole blood (HWB), Bretschneider's cardioplegic solution (HTK), human albumin solution (HAS), or Ringer's solution (RS) and compared with the results obtained immediately after the removal of untreated control samples (C) taken from the same patients. After equilibration in carbogen aerated Krebs-Henseleit solution and precontraction by 3 x 10(-7) M noradrenaline (NE), relaxation induced by 10(-6) M ACh was measured. Only the samples stored in HWB (13.4 +/- 0.4 mN) showed similar maximal contractions with NE to those in the control group (14.4 +/- 0.5 mN), i.e. all those segments which showed both contractions with NE and relaxation with ACh.(ABSTRACT TRUNCATED AT 250 WORDS)

The amount of particulate matter present in Bretschneider's cardioplegic solution (HTK) was assessed by laser-mediated particle counting. Permissible levels of contaminant particles with a distribution of diameters between 0.2 and 20 microns were found. A significant further increase in the particle count was observed when the fluid was administered for clinical use, which resulted in the additional release of particles from, for example, the infusion kit, which included an in-line filter with pores of 270 microns. Filtration of the HTK solution by a terminal inline filter (0.2 micron) significantly reduced the number of particles. In order to determine the chemical composition and the potential hazards of the particulate material we used scanning electron microscopy in combination with energy dispersive X-ray analysis and transmission electron microscopy to examine specimens taken from heart tissue obtained from Göttinger minipigs after cardioplegia and from humans undergoing mitral valve replacement after cardioplegia and reperfusion. Particles of various diameters were found either to be plugging coronary capillaries, to be adherent to the endothelial layer, or to be engulfed by polymorphonuclear (PMN) granulocytes, which appeared to be activated. Some of the PMN granulocytes were apparent in the endothelial layer. It is recommended, therefore, that a terminal in-line filter (0.2 micron) should be routinely used.

Attempted venous cannulation with a dual-stage cannula for cardiopulmonary bypass in routine coronary revascularization led to the discovery of an abnormal inferior vena cava in a 65-year-old patient. The operative and postoperative course of the patient were not affected by the inferior caval anomaly. The detailed infradiaphragmatic venous anatomy was elucidated later by MRI and showed bilateral inferior caval veins with azygos continuation. Although this malformation of the inferior cava is rare in adults, the occurrence should be known. Quick recognition and handling should be achieved if detected during cannulation for cardiopulmonary bypass.

Because of the paucity of literature reports about cardiac operations in renal-transplant patients we performed a retrospective study encompassing all such patients operated upon in our institution in 1993 and 1994. During this time 5 renal transplant patients underwent cardiac surgical procedures between 1 and 9 years after transplantation: in 4 patients coronary artery bypass grafting (CABG) was carried out and in one patient aortic valve replacement. We analyzed pre-, peri-, and postoperative data. Late results were obtained by questionnaire from the patients' primary physicians. Short- and long-term results were excellent. Mortality was 0%. At late follow-up (8-23 months) all patients were in NYHA class II or better. Postoperatively all patients experienced a clear improvement of their cardiac symptoms. None of the transplanted kidneys deteriorated. One patient who had to undergo intermittent hemodialysis preoperatively improved so much that she did not require any dialysis postoperatively. Although the total number of patients in this study is limited we believe it can be stated that renal transplant patients can undergo cardiac operations with generally good results.