PURPOSE : The purpose of the present study was to clarify the effect of static stretching on muscular performance with concentric isotonic muscle actions under various loads.METHODS : Concentric isotonic leg extension power outputs were assessed in 12 healthy male subjects after two types of pre-treatment. The pre-treatments included 1) static stretching (SS) treatment performing static stretching of leg extensors, and 2) non-stretching (NS) treatment by resting in a sitting position. Loads during the assessment of the power output were set to 5%, 30% and 60% of the maximum voluntary contractile (MVC) torque with isometric leg extension in each subject.RESULTS : The peak power output following the SS treatment was significantly (P<0.05) lower than that following the NS treatment under each load.CONCLUSION : The present study demonstrated that static stretching significantly reduces power output with concentric isotonic muscle actions under various loads. This result suggests that static stretching decreases power performance.

We performed exercise intervention for 12 weeks in young females (22.3±2.5 yrs ; mean±SD) with a %fat value of 30% or more (dual energy X-ray absorptiometry : DXA) despite a body mass index (BMI) of less than 25 kg/m², which indicates hidden obesity, and the following results were obtained.The intensity of exercise was established as the double product break point calculated from heart rate and systolic blood pressure, and the subjects were instructed to exercise for 30 minutes or more for 3 or more times a week. Six weeks after exercise intervention, the BMI, body fat level, and plasma glucose level were lower than those before exercise intervention, and the %fat value was lower 12 weeks after intervention. Furthermore, cardiac autonomic function (CAF) was negatively correlated with changes in Total power and changes in fat (kg), suggesting that exercise-related improvement in CAF is involved in a decrease in %fat.

Myxoma of the left ventricle is exceedingly rare and to the best of our knowledge not a single case of its recurrence has been reported in Japan. We have recently experienced a case in which a myxomatous tumor of the left ventricle recurred at the same site as the primary lesion 2.5 years after operation and was treated by surgical excision. The patient was a 28-year-old female who, under the diagnosis of myxoma of the left ventricle, underwent surgical removal of the tumor and mitral valve replacement at her age of 25 years. Although her postoperative course was uneventful, she was noticed, at her age of 28 years, of her inaudible prosthetic valve clicks on auscultation at the outpatient service. Echocardiography revealed a tumor mass in the left ventricle, which tended to grow with the elapse of time. Echocardiography on rehospitalization disclosed a mobile cystic tumor on the posterior wall of the left ventricle, while pulmonary arteriography also revealed a movable tumor in the left ventricle. Intraoperatively, there was noted a solid tumor, composed partly of cystic structure, on the posterior wall of the left ventricle and quick pathology led to a suspected diagnosis of myxoma. Since the tumor was found to have involved the ventricular septum and myocardial tissue of the posterior wall of the left ventricle, its complete surgical excision was impossible. The tumor, with its growth pattern and morphology, was diagnosed as a malignant clinical behavior one, although histopathological evidence indicates its benignancy.

The current technique of retrograde coronary sinus perfusion (RCSP) has been provided double cannulation of the vanae cavae and isolation of these vessels, and right atriotomy. Most aortic valve and coronary artery bypass surgery are performed with single venous cannulation. We used a new RCSP catheter, Retroplegia (Research Medical Co.), and performed Cabrol procedure safely with single venous cannulation. This catheter can be cannulated to the coronary sinus through a right atrial purse-string suture without opening the right atrium. The occlusion balloon is inflated spontaneously by infusing the cardioplegic solution and occlude the coronary sinus adequately and nicely. This catheter has double lumen, one is for infusion of the cardioplegic solution, the other is for measurement of the coronary sinus pressure. We believe that this catheter is useful for RCSP of the cardiac surgery using single venous cannulation.

The 37-year-old woman underwent mitral valve replacement (MVR) with a Carpentier-Edwards bioprosthesis for hypertrophic obstructive cardiomyopathy (HOCM) 14 years previously. Since the 10th postoperative year, progressive right heart failure due to tricuspid valve regurgitation was recognized. Therefore, reoperation was recommended. At the time of reoperation in the 14th postoperative year, the cavity of the left ventricle was markedly diminished. In particular, deformitiy of the right ventricle was found. This was considered to be the effect of progressive septal hypertrophy. The mitral valve was replaced with a 25mm Carpentier-Edwards and the tricuspid valve with a 31mm Carpentier-Edwards bioprosthesis. Although the weaning from the cardiopulmonary bypass was uneventful, postoperative right heart failure occured with hyperbilirubinemia followed by multiple organ failure. She died on the 47th postoperative day. At autopsy, the intraventricular septal thickness was 24mm and the cavities of left and right ventricle were almost occluded by septal hypertrophy. This is considered to be a rare case of long-term survival after MVR in a patient with HOCM.

The purpose of this study was to compare effects of different amounts of carbohydrate (CHO) in beverage on plasma glucose (GLU) concentration during exercise after feeding breakfast. Seven healthy Japanese male subjects performed 30-min cycling at an intensity on the 75% of maximal load at 3-h after feeding breakfast under 3 types of CHO (0 g, 30 g and 150 g) beverage conditions. The subjects ingested 500 mL of beverage dissolved each amount of glucose at 30-min before the exercise. The GLU concentrations were measured at 35- and 10-min before the exercise and every 5-min during the exercise. The minimum GLU concentrations under the 30 g condition for all subjects were lower than a criterion for hypoglycemic (72 mg / dL). The mean value also fell below the criterion at from 10- to 20-min during exercise. The minimum GLU concentration under the 150 g condition of only one subject was lower than the criterion, but the mean value did not fall below the criterion. Significant negative correlations were found between the subjects’ maximum oxygen uptake (VO2max) and the decreases in GLU concentration from maximum to minimum under both the 30 g (r = -0.947, p < 0.01) and 150 g conditions (r = -0.884, p < 0.01). This study clarified that feeding breakfast at 3-h before the exercise followed by the 30 g CHO beverage ingestion at 30 min before the exercise induced exercise-induced hypoglycemia, and that the subjects with higher VO2max had the greater decreases in GLU concentration.