Cardiac angiosarcoma is a rare disease which occurs most often in young males and has a remarkably unfavorable prognosis. We experienced one male case aged 46 who had an initial symptom of cardiac tamponade due to rupture of the right ventricle. Hemostasis was made under extracorporeal circulation, and the patient was discharged temporarily. However, a large volume of hemoptysis occurred from right B₆ about 1 month after discharge, because of which resection of the right lower lobe was performed. Tumorous cells identical to those in the perforated cardiac region were detected in the resected tissue, and it was diagnosed histopathologically that the cardiac rupture was caused by angiosarcoma, resulting in pulmonary metastasis. Multiple pulmonary metastases were observed in bilateral lung following fields by CT, but administration of CDDP in iv×2 and in 150mg/day cyclophosphamide, the pulmonary metastases disappeared completely on CT on the 45th day. However, the metastases recurred soon thereafter without responding to chemotherapy, and the patient died 5 months after diagnosis of this disease because of exacerbated dyspnea.

Because supraventricular tachyarrhythmias after open heart surgery are often resistant to DC cardioversion and treatment with antiarrhythmic agents, we sometimes have difficulty in the postoperative management of these arrhythmias. We attempted to use intravenous infusion of diltiazem hydrochloride (3-5mcg/kg/min) for 6 patients with supraventricular tachyarrhythmias, 5 of whom had atrial fibrillation and 1 with sinus tachycardia after open heart surgery. The ventricular rate was remarkably reduced from the pretreatment value by this infusion therapy. Diltiazem infusion during atrial fibrillation in 5 patients regularized the ventricular rate (normalization of R-R intervals). These results indicate that diltiazem was effective in obtaining almost constant preload with each cardiac cycle for the postoperative deteriorated cardiac muscle. The hemodynamic parameters obtained with the Swan-Ganz catheter showed that both right and left ventricular functions improved after the infusion of diltiazem. There was no adverse effect due to the administration of diltiazem. We concluded that the intravenous infusion of diltiazem is an effective method to manage supraventricular tachyarrhythmias after open heart sugery without deterioration of the cardiac function or side effects.

Re-do open cardiac surgery may sometimes require complete ablation around the pericardium for the 2 major reasons of attaining better myocardial protection and obtaining effective DC cardioversion. However, this ablation may increase postoperative hemorrhage which may require blood transfusion. Hypothermia is based on the concept of myocardial protection during open heart surgery by suppressing myocardial metabolism, but recently the approach has been changed to maintaining myocardial metabolism with aerobic or anaerobic energy production. We have already reported that histidine-buffered cardioplegia which promote anaerobic glycolysis, provided an excellent functional recovery of myocardium post-ischemia with lower inotropic requirements in a range from 10°C to 37°C of myocardial temperature. Based on our theoretical background and clinical data, we tested the efficacy of this type of cardioplegia in patients receiving multiple surgical procedures with minimum ablation after sternotomy. First case, who had undergone a Bentall procedure for annulo-aortic ectasia 14 years previously had a thrombotic valve and mitral regurgitation. Aortic valve plasty and mitral valve replacement (MVR) was performed. The second case who had undergone MVR 15 years previously had malfunction of the prosthetic valve and underwent re-MVR. The third and fourth cases had ventricular septal defect (VSD) which were closed using Teflon patches. The third case had patch closure during second operation for residual shunt. The fourth case received tricuspid valve replacement (TVR) for tricuspid regurgitation due to a pacemaker lead implanted into the right ventricle through the left subclavian vein. The fifth case received coronary artery bypass surgery in a second operation for restenosis of the graft and progressing atherosclerosis. All hearts started beating spontaneously without DC cardioversion after the aortic unclamp. Ventricular fibrillation occurred in the first case while the patient was weaned from cardiopulmonary bypass and treatment was performed by aortic cross clamp, infusion of the cardioplegia followed by aortic unclamp to start own beat again. Two of 3 patients who were able to donate their own blood preoperatively did not require homologous blood transfusion. Due to advantages such as excellent myocardial protection under hypothermic or normothermic condition, ease of use and relatively lower potassium concentration, histidine-buffered cardioplegia can be an excellent candidate for myocardial protection in re-do cases with less ablation technique.

We tried to evaluate the right ventricular function using a modified Swan-Ganz catheter with a rapid responsive thermistor. Twenty-four dogs comprised this series. Twelve were the model of left heart failure (Group A), and the other twelve were the model of right heart failure (Group B) produced by multiple ligation of coronary arteries. Dogs were studied for some of the circulatory indices before and after ligation with left atrial pressure at 10, 15 and 20mmHg in group A, and right atrial pressure at 10, 15 and 20mmHg in group B by volume loading. In group A, when the left atrial pressure was kept constant, right ventricular ejection fraction (RVEF) and right ventricular stroke work index (RVSWI) were decreased significantly after the ligation of coronary arteries. But there was no significant change in the peak right ventricular pressure-right ventricular endsystolic volume index ratio (peak RVP/RVESVI) associated with ligation. In group B, significant changes were observed in RVEF, RVSWI and peak RVP/RVESVI. Thus, it was found that right ventricular contractility in selective left heart failure was not reduced. E_max was considered to be a valuable index of ventricular contractility not affected by preload and afterload of ventricle, but this index is not easily measured clinically. The index peak RVP/RVESVI which is nearly equivalent to E_max, has an advantage in that it can be determined by the thermodilution method widely used in general. We conclude that this index is very useful to us for post-operative care in cardiac surgery.

Recently, arterial keton body ratio (AKBR) has attracted attention as a new indicator of liver function which is in equibilium with the ratio between oxidized and reduced forms of free nicotinamide-adenine dinucleotides (free NAD⁺/NADH ration) in the mitochondria. There are few reports on whether AKBR contributes to the hepatic energy charge in the open heart surgery with extra corporeal circulation (ECC) or not. This study was undertaken to clarify the contribution of AKBR to the hepatic energy charge during ECC and the relationship between AKBR and hepatic blood flow. AKBR was determined before, during and after ECC in the open heart surgery for 14 patients. Furthermore, the blood flow in hepatic artery, portal vein and liver microcirculation was measured before, during and after ECC in canine models. Finally, the pulsatile perfusion was performed in canine models and compared with the conventional non-pulsatile perfusion for the blood flow and AKBR. In clinical cases, AKBR was decreased in all cases during the ECC. AKBR which was measured at 2 or 3hr after weaning from the ECC was negatively correlated to the total perfusion time with -0.57 as the correlation coefficient. Six patients who were on the ECC over 180min did not show a good recovery of the AKBR after weaning from the ECC. Especially, three patients presented a clinical picture of acute hepatic failure with jaundice, elevation of the serum levels of transaminase and direct hyperbililubinemia, but only one showed hypoglycemia. These patients showed no improvement in clinical data and AKBR. The patient with improved AKBR recovered clinically. In our experiment, the blood flow in the hepatic artery, portal vein was measured by electromagnetic blood flow meter and the liver microcirculation was measured by laserdoppler flowmeter. The blood flow was decreased remakably in the non-pulsatile group at all sites of measurement: it recovered after ECC in hepatic artery and portal vein, but liver microcirculation did not improve well. AKBR was decreased during ECC and did not recover after ECC in the non-pulsatile perfusion. When the pulsatile perfusion was performed, liver circulation was maintained well, and AKBR recovered well after ECC. The above results suggest that AKBR reflects the liver microcirculation and pulsatile perfusion is beneficial to the liver microcirculation. Pulsatile circulation, however, involves several problems, hemolysis, the decrease of platelets, and so on, but these problems have been improved gradually. We think that the pulsatile perfusion will be used in clinical operations to maintain the good hepatic circulation.

A medical-ethics course was anonymously evaluated by first-year students over 2 years. The course emphasizes problem-based learning through group discussion of clinical cases and lectures on ethical issues. A tutorial system was added to the course in the second year. Students' evaluations indicated that most students had positive attitudes about the course and that both group discussion and lectures were helpful for achieving the general instructional objectives and specific behavioral objectives of the course. A comparison of the 2 years showed that a majority of evaluated items received higher evaluations from second-year students than from first-year students. We attribute the difference to the livelier discussion with the introduction of the tutorial system and the smaller discussion groups. These results indicate that students consider medical-ethics education to be useful.

Our medical ethics course emphasizes problem-based-learning (PBL) via group discussion of clinical cases. The significanceof instructors' assessments of PBL in ethics education was studied with different assessment tools during thelast 2 years. In the first year, students' behavior and level of functioning in group discussion were assessed on a group basiswith an 8-item instrument. In the second year, students' level of functioning and flexibility in response to differentopinions in group discussion were assessed on an individual basis with a 2-item instrument. Instsments ofstudent's performance in group discussion were positively but weakly correlated with scores of their reports derivedfrom group discussions. Instructors could consistently assess student performance in PBL in terms of behavior and levelof functioning in group discussions. Furthermore, instructors rated flexibility in response to other opinions as an importantfactor in group dynamics, including interaction between students and instructors. These results suggest that instructors'assessments can be used to help evaluate students in a medical ethics course. Instructors' assessments of studentflexibility during PBL can be particularly useful in this regard.