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Biomedical subjects

K Toyomasu

Publications and source records attributed to K Toyomasu.

9 recordsLinked to original sources
PubMed1990

Physical training in patients with valvular heart disease after surgery.

The necessity, the methodology and clinical benefit of physical training were evaluated in 85 patients with valvular heart surgery. In 21 patients who had undergone the exercise stress test before surgery, corrective valvular surgery increased maximal oxygen uptake (max.VO2) from 15.4 before to 18.9 ml/min/kg, while 11 (52%) of them failed to increase exercise capacity over 5 METs. Of the total 85 patients, 41 (58%) again showed reduced exercise capacity in the initial postoperative stress test, suggesting that a return to work might be difficult without rehabilitation in these patients. We then compared two training programs: program A of short duration and frequent exercise and program B of longer duration and less frequent exercise, both using a bicycle exercise set at an intensity of 70% of the max.VO2. Both programs similarly increased max.VO2, while patients preferred program A, suggesting that exercise of longer duration could not be tolerated because of deconditioning. Program A was then prescribed to 62 patients, and it increased max.VO2 from 18.2 to 20.7 ml/min/kg after 4 weeks training without any complication. In 9 patients who served as controls undergoing no physical training, no spontaneous improvement in exercise capacity was observed. Of the 76 patients who received either program A or B, 28 patients failed to increase the max.VO2 by 10% or more. These patients presented atrial fibrillation, a cardiothoracic ratio greater than or equal to 60% or exercise-induced ST depression more frequently, suggesting that residual cardiac dysfunction might inhibit the training effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Comparable effects of oral diltiazem and verapamil in the treatment of hypertrophic cardiomyopathy. Double-blind crossover study.

The effects of oral diltiazem, 180 mg/day, were compared with those of oral verapamil, 240 mg/day, in 32 patients with hypertrophic cardiomyopathy (HCM), using a double-blind crossover study design. In the first treatment period, diltiazem and verapamil improved subjective complaints in 83% and 71% of those who were symptomatic in the baseline period. Maximal oxygen consumption on exercise stress test increased with verapamil by 2.9 +/- 4.2 ml/Kg/min (p less than 0.05), and tended to increase with diltiazem. Verapamil also reduced the amplitude of negative T wave. In the statistical analysis based on the crossover design, diltiazem and verapamil did not differ in global improvement, overall safety and global utility ratings. In addition, both drugs showed comparable effects on electrocardiographic and echocardiographic variables and exercise tolerance except for minor differences in diastolic blood pressure, T wave amplitude and peak exercise heart rate. On the other hand, verapamil tended to induce more serious side effects, forcing the discontinuation of medication in 3 patients. Therefore, the present study indicates that diltiazem is essentially equally as effective as verapamil and is preferable in the treatment of patients with HCM since it may exhibit fewer serious side effects.

Administration, Oral↗
PubMed1984

[Mechanism of exercise-induced ST segment deviation in myocardial infarction: a 201T1-myocardial scintigraphic study].

Exercise-induced ST segment deviation was investigated using thallium-201 myocardial scintigraphy and correlated with coronary artery lesions in 25 patients with old myocardial infarction. Seven of eight patients without ST deviation showed no reversible perfusion defect by near maximal exercise, and six had no significant stenosis in the coronary arteries perfusing the non-infarcted area. During exercise, ST segment depression was induced in 12 patients and six of them developed a reversible perfusion defect in the non-infarcted area, associated with significant stenosis of the corresponding coronary arteries. Remaining six patients, however, did not show a reversible perfusion defect and four of them had no significant stenosis of the coronary arteries perfusing the non-infarcted area. In nine patients with exercise-induced ST segment elevation in leads with Q waves, a reversible perfusion defect was not detected in seven (78%) and five (71%) of them had no significant coronary artery stenosis as well. Four patients developed both ST segment elevation in leads with Q waves and ST segment depression in other leads. One patient who had significant coronary artery stenosis in the non-infarcted area and showed a reversible perfusion defect developed 1.5 mm ST elevation in II, III, a VF leads and 4 mm ST depression in precordial leads. In the remaining three patients who did not show a reversible perfusion defect and significant coronary artery stenosis in the non-infarcted area, ST depressions were less than 2 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Increased left ventricular function as an adaptive response in vibration disease.

Vibration disease results from the long-term use of vibrating tools. Vibration, noise, and cold are stressors that impair the human body, inducing vibration disease. From echocardiographic methods, the left ventricular ejection fraction in vibration disease was 79 +/- 4%, a significantly higher value than that in control subjects (75 +/- 6%) (p less than 0.01). The increase in ejection fraction appeared to be due mainly to an increase in left ventricular end-diastolic dimension. The value of the ejection fraction was proportional to the activity of the autonomic nerves. The stroke volume index in patients with vibration disease was also significantly larger than that in the control subjects (p less than 0.001). Electrocardiograms revealed a significantly lower heart rate at rest and an increase in the ratio of T waves to R waves in precordial lead V6. These data suggest that the cardiovascular system in patients with vibration disease provides an adaptive response to the stressors.

Adaptation, Physiological↗