Yasushi Ashida

Transvenous Dual Chamber Pacing via a Unilateral Left Superior Vena Cava

A 74‐year‐old woman with a unilateral left superior vena cava required dual chamber permanent pacing after a radical cardiac operation for an incomplete form of endocardial cushion defect. An active fixation ventricular lead was used to prevent the instability induced by the strange course of the electrode. For atrial pacing, a ventricular passive fixation lead was used. A transvenous dual chamber pacemaker was successfully inserted via a unilateral left superior vena cava.

Surgical removal of left atrial myxoma through mini sternotomy and the superior transseptal approach

A 32-year-old man admitted for treatment of a left atrial myxoma showed a 76 x 25 mm tumor in the left atrium originating in the interatrial septum upon echocardiography. The myxoma was surgically removed using a mini sternotomy and the superior transseptal approach. The hospital course was unremarkable. In the 2 years since operation, the patient has remained asymptomatic and tumor-free. The superior transseptal approach is thus useful in surgical removal of left atrial myxoma because it can be excised with minimum manipulation despite the mini sternotomy and small skin incision.

Effects of Calcium in Continuous Cardioplegia on Myocardial Protection

The effects of calcium (Ca) on a hyperkalemic cardioplegic solution for continuous cardioplegia were examined in an isolated perfused working rat heart model. The coronary arteries were perfused with a modified Krebs-Henseleit bicarbonate buffer (K-H) solution, containing various concentrations of Ca(0.1, 0.6, 1.2, and 2.5 mmol/l) and a high concentration of potassium (20 mmol/l), for 180 min, after which cardiac arrest was induced at 37°C for 180 min. Cardiac function and creatine kinase (CK) were measured. In the control group, K-H solution was infused in place of the cardioplegic solution, and cardiac arrest was not induced. No significant differences were observed between the groups infused with the K-H solution containing Ca concentrations of 0.6, 1.2, and 2.5 mmol/l in the percent recovery of aortic flow (82.1±2.9%, 80.6±2.0%, and 71.5±3.7% (mean±SEM) respectively) or in the recovery of other indices of cardiac function, or in CK leakage. There were also no significant differences in the recovery of cardiac function and CK leakage between these groups and the control group. In the Ca 0.1 mmol/l group, however, the characteristic Ca paradox was observed. These findings suggest that if the Ca concentration in a cardioplegic solution is higher than 0.6 mmol/l during continuous cardioplegia, excellent cardioprotective effects will be achieved.

A Case of Emergency Surgery for Ruptured Descending Thoracic Aortic Aneurysm into the Left Lung in an Elderly Patient.

超高齢者の胸部下行大動脈瘤肺内穿破症例を経験した. 症例は85歳, 女性. 突然の喀血, 胸背部痛にて当院入院. 胸部CTで左下葉に穿破する胸部下行大動脈嚢状瘤を認めた. 血液型がAB・Rh (-) であったが, 部分体外循環下に人工血管置換術と左肺下葉切除術を施行した. 術後は人工呼吸器からの離脱が遷延し一時気管切開を要したが, 重篤な感染症を起こすことなく独歩退院できた. 救命のポイントは術後呼吸機能低下は予想されたものの, 肺炎および graft 感染の温床となる血腫を残さぬよう, 十分な肺切除を施行したことと考えられた. われわれが行った肺下葉切除は区域切除と比較し, 出血量が少なく, また手術時間も短く, 本症例のような超高齢者の大血管手術においては適切な処置と考えられた.