Pulmonary vein isolation procedure was performed for atrial fibrillation associated with mitral valve disease in twelve patients. This simple procedure consisted of only isolation of the four pulmonary veins. Combined mitral valve surgery consisted of mitral valve plasty, mitral valve replacement with or without aortic valve replacement and tricuspid annuloplasty. Ten patients returned to a sinus rhythm. Two patients required DDD pacemaker implant for sick sinus syndrome. Left atrial contraction was detected in eight cases by trans-esophageal echography. Compared with the maze procedure, this operation was less invasive and preserved atrial appendage, helping to maintain normal secretion of atrial natriuretic peptide. This study suggests that the pulmonary vein isolation procedure may be an effective and simple maneuver for atrial fibrillation associated with mitral valvular disease.

Left heart bypass was performed with Bio Medicus Co.-made Bio-pump, a representative centrifugal pump. A vinyl chloride tube for the usual cardio-pulmonary bypass not treated with antithrombogenic material. was used in the bypass circuit. In the experiment, the mongreal adult dogs were divided into the systemic heparinized group and non-heparinized group and the bypass was performed for 6 hours. As a result, coagulation and fibrinolysis were more activated in the non-heparinized group than the other group. So, when this method is used clinically, a small quantity of heparin should be administered. Clinically, this approach was used as an adjunct in operation for 7 cases of thoracic aortic aneurysm. During left heart bypass, a small quantity of heparin (0.5-1.0mg/kg) was administered. A rise in FPA and FDP considered attributable to autotransfusion during the operation was noted. Distal perfusion could be performed fully and the amount of bleeding during and after operation was small, but 1 case each of acute renal failure and paraplegia as postoperative complication was encountered. Neither was considered due to left heart bypass; and, changes in respiratory system and hepato-renal function were considered within the tolerable range. These results have led us to believe that left heart bypass using Bio-pump is safe and useful as an adjunct in operation for thoracic aortic aneurysm and should be used positively in the future.

We have examined the role of readmission of oxygen in the initiation of reperfusion-induced arrhythmias by separating readmission flow from readmission of oxygen on a temporal basis. Isolated rat hearts (n=12/group) were subjected to 10 minutes of global ischemia and reperfusion. In controls reperfused with aerobic perfusion medium, 100% of hearts developed ventricular tachycardia 1.48±0.78 seconds after reperfusion, and ventricular fibrillation occurred 13.47±2.91 seconds after reperfusion. Also in hearts reperfused with anoxic perfusion medium, 100% of hearts developed ventricular tachycardia 1.98±0.96 seconds after reperfusion, and ventricular fibrillation occurred 27.01±18.52 seconds after reperfusion. But the duration of the time from reperfusion to the onset of ventricular fibrillation were statistically differrent in these two groups (p<0.05). In conclusion anoxic reperfusion delayed ventricular fibrillation but prevent neither ventricular fibrillation nor ventricular tachycardia. This implies that oxygen-derived free radicals may play an important role in the initiation of reperfusion-induced arrhythmias, but are unneccessary for arrhythmogenesis.

This study was designed to evaluate the myocardial protection with observation of the monophasic action potential (MAP) which was recorded by suction electrode. Using the isolated working rabbit hearts, amplitude, duration of MAP at 50% repolarization level (MAPD₅₀), aortic flow and heart rate were measured after reperfusion. The comparative study obtained for all five groups under the following various conditions of the aortic cross clamping are stated as follows. Myocardial temperature were maintained at 20°C during aortic cross clamping. Group I was treated with St. Thomas' Hospital cardioplegic solution. The cardioplegic solution was infused every 20min during ischemia and kept at 20°C. The hearts of group I was divided into four sub-groups, all of which were infused with different concentration of diltiazem (D) in cardioplegia: group Ia D=0μg/ml (n=10), group Ib D=1μg/ml (n=5), group Ic D=5μg/ml (n=5). group Id D=10μg/ml (n=5), and in group II cardioplegic solution was not used. The amplitude of MAP following 30min working mode of reperfusion in group I showed a significantly higher recovery compared to those in group II. The MAPD₅₀ of MAP following 30min working mode of reperfusion in group I showed a significantly lower recovery compared to those in group II, and 10min Langendorff mode in group I a showed a significantly higher recovery compared to those in group Ib, group Ic and group Id. 20min working mode in group Ia and group Ib showed a significantly higher recovery compared to those in group Ic and group Id. The heart rate following 30min working mode of reperfusion in group Ia and group Ib showed a significantly higher recovery compared to those in group Ic and group Id. The aortic flow following 30min working mode of reperfusion in group Ia and group Ib showed a significantly higher recovery compared to those in group Ic, group Id and group II. We would like to conclude that the permeability of large amount of calcium across myocardial cell membrane seems to be depressed by diltiazem added to cardioplegia. But when the concentrations of diltiazem in cardioplegia was over 5μg/ml, it showed negative inotropic action and negative chronotropic action.

We have recently experienced a case of impending ruptured aneurysm of the common iliac artery associated with a gelatinous substance in the retroperitoneal space. A 69 year-old male had been diagnosed as a left common iliac aneurysm at another hospital by CTscan during the examination of lower abdominal pain. At the midnight of the day he admitted, the severity of pain gradually intensified. But there was no sign of anemia nor hypotension. Next morning CTscan showed low density left retroperitoneal mass. The patient underwent emergency laparotomy. The further inspection revealed about 600cm³ of gelatinous substance in left retroperitoneal space without the sign of aneurysmal rupture. A bifurcated graft replacement was performed. The low density mass was not recognized by CTscan done 42 days postoperatively. Electrolyte study of the gelatinous substance indicated its serous leakage through the impending ruptured aneurysm. Our present report constitutes a completely distinct variety of common iliac aneurysm, associated with a gelatinous substance in retroperitoneal space without a major rent of the aneurysmal wall.

The authors encountered 22 cases of congenital bicuspid aortic valve, some of which occurred in siblings. In this paper, a 58-year-old brother and a 56-year-old sister cardiac valve disease was diagnosed first at the age of 51 in the brother and at the age of 15 in the sister. Aortic valve replacement using a 21mm Medtronic-Hall prosthesis was done in both cases. Additionally, pacemaker implantation was carried out in the sister. Both cases showed favorable progress after operation. Hereditary factors are involved in congenital bicuspid aortic valve. Therefore if congenital bicuspid aortic valve are found in any patients, thorough investigations including cardiac auscultation, ECG and ultrasound cardiogram should be carried out routinely among immediate family members and relatives to reveal whether any of them is suffering from this congenital anomaly.

A 63-year-old woman underwent coronary artery bypass grafting and mitral annuloplasty 4 years previously. She was readmitted owing to heart failure. Cardiac catheterization revealed worsened mitral regurgitation, although the internal thoracic artery (ITA) graft had good patency. Reoperation was performed by median resternotomy and continuous retrograde cardioplegia without clamping the ITA graft. The mitral valve had a perforation in the anterior leaflet, and was replaced by a 29mm Carbo-Medicus valve. The patient was discharged with transient myocardial ischemia. Although median resternotomy and continuous retrograde cardioplegia at reoperation provided on excellent view and myocardial protection, myocardial ischemia in the region perfused by the ITA graft may occur when the ITA graft cannot be clamped during continuous retrograde cardioplegia.

A 24-year-old woman had been injured in an automobile accident. The chest X-ray showed widening of the mediastinum and computed tomography showed mediastinal hematoma around the aortic arch. Aortic rupture was suspected, so we performed aortography, which revealed pseudoaneurysm of the descending aorta. Moreover, she also had splenic rupture and pelvic fracture. She underwent an emergency operation 4 hours after the accident. Medial tear of the descending aorta was replaced with a graft under temporary bypass without heparin. Simultaneously, splenectomy was performed. Her postoperative course was uneventful. We consider that temporary bypass without heparin is a useful method during repair of the descending aortic rupture due to trauma.

In dialysis cases complicated with ischemic heart disease, there are many problems, such as poor preoperative general condition, calcified aorta, water-electrolyte control, and the necessity for other simultaneous operations. Off-pump coronary artery bypass grafting (OPCAB) was considered very useful in coping with these problems. OPCAB, employed in five cases, was compared with conventional coronary artery bypass grafting with extracorporeal circulation (ECC group, 9 cases). Regarding preoperative coexisting diseases, collagen diseases, porcelain aorta, cerebral infarction, and others were recognized in the OPCAB group in 3 of 5 cases. Emergency operations were performed in 5 of 9 cases in the ECC group, and in 2 of 5 cases in the OPCAB group. The bypass number (3.2 vs. 2.0) and complete revascularization rate (7 of 9 vs. 2 of 5), tended to be higher in the ECC group. The OPCAP group was significantly superior in blood transfusion (6.7 vs. 3.0u), postoperative CK-MB (63 vs. 33u), and the postoperative usual hemodialysis commencing time (4.2 vs. 1.0 day). Concerning use of postoperative IABP (3 of 9 vs. 0 of 5), and postoperative ventilator weaning time (2.7 vs. 1.0 day), a good tendency was shown in the OPCAB group. Although a high mortality rate (2 of 5) was recognized in OPCAB group compared with ECC group (1 of 9), those were urgent cases who had a very poor preoperative condition, and both cases suffered non-cardiac deaths. Excluding special cases, such as an unstable hemodynamic state requiring assisted circulation, and poor coronary run off, OPCAB seems useful for the treatment of coronary artery disease in dialysis patients.

Combined monitoring of rSO₂ and SSEP is routinely performed during cardiopulmonary bypass (CPB), but it is not sensitive enough to detect focal lesions of the brain. Thus, we assessed whether simultaneous measurement of S-100β is able to enhance diagnostic sensitivity or not. Between September 1999 and February 2000, serial measurement of plasma levels of S-100β and SSEP and rSO₂ monitoring during CPB were simultaneously performed in 26 consecutive patients (19 men and 7 women). Ages ranged from 46 to 85 (mean 67±10 years). Neurological complications developed in 5 (19.2%). Among those patients, hemiplegia developed in 2, and dementia, temporary convulsion, and deep coma in 1 each. Three of them showed abnormally low rSO₂ levels during surgery, but no patient showed abnormal change in SSEP waves after surgery. There was no significant difference in S-100β level 1h after CPB between patients associated with or without neurological complications (1.98±0.48 vs. 1.89±1.65), however, its level 24h after CPB remained significantly higher in patients with neurological complications (1.01±1.14 vs. 0.22±0.24). S-100β level 24h after CPB appears to improve diagnostic sensitivity for detecting such focal brain damage lesions as those in which SSEP or rSO₂ are not efficient enough to make a diagnosis. However, further study is required to evaluate how fast it can differentiate patients with and without brain damage.