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 54-year-old man with unstable angina and Wolff-Parkinson-White (WPW) syndrome was admitted. Coronary angiography showed 90% stenosis of the left main trunk and 75% stenosis of the obtuse marginal branch. Coronary artery bypass grafting under cardioplegic arrest was done emergently. The left internal mammary artery graft was anastmosed to the left anterior descending artery, and a saphenous vein graft was used as a sequential bypass graft to the high lateral branch and obtuse marginal branch. Immediately after weaning from cardiopulmonary bypass, paroxysmal supraventricular tachycardia (PSVT) requiring electrical cardioversion was occurred, and catheter ablation was performed on the first postoperative day. There are controversus concerning the strategies of surgical treatment for unstable angina concomitant with WPW syndrome. Coronary bypass operation may trigger PSVT in patients with WPW syndrome. The optimal timing of perioperative catheter ablation needs further discussion.