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Biomedical subjects

Y Koga

Publications and source records attributed to Y Koga.

At least 469 records · Page 26Linked to original sources
PubMed1987

[Quantitative evaluation of regional myocardial blood flow by digital subtraction angiography: correlations with exercise electrocardiography and Tl-201 myocardial scintigraphy].

We previously reported that the contrast disappearance half-life (T1/2) derived by the computerized washout analysis of digital subtraction coronary arteriograms provides a useful index for quantitatively evaluating regional myocardial blood flow. In the present study, we further evaluated the clinical usefulness of T1/2, comparing it with exercise electrocardiography and exercise thallium-201 myocardial scintigraphy. The study subjects consisted of 25 patients with angina pectoris and 14 patients with normal coronary arteries. Following the manual injection of contrast media into the left anterior descending coronary artery (LAD), a time-density curve was generated in the sectors of the myocardium which were perfused by the LAD and the T1/2 was calculated. T1/2 values correlated closely with double product (r = -0.73). They were significantly greater in patients with exercise-induced ST depression (8.3 +/- 1.0 vs 5.8 +/- 0.7, p less than 0.005). In addition, there was a good correlation between T1/2 values and washout ratio as determined by exercise thallium-201 myocardial scintigraphy, with r = -0.83. Although T1/2 values were within the normal range (mean +/- 2SD of control subjects) in all patients with LAD stenosis of 50 percent or less, these values were abnormally increased, exceeding the normal range, in 11 of the 12 patients with stenosis of 90 percent or more. Compared with exercise electrocardiography, T1/2 values were abnormally prolonged in 11 of the 13 patients with exercise-induced ST depression. Compared with exercise thallium-201 myocardial scintigraphy, T1/2 values were abnormally prolonged in seven of the nine patients with transient perfusion defects.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1987

[Videodensitometric assessment of right and left ventricular functions by digital subtraction angiography].

Right and left ventricular volumes and systolic indices were determined by intravenous digital subtraction ventriculography in 50 patients with various heart diseases. Using a constant injection speed of 35 ml Renografin-76 contrast medium, serial right and left ventriculograms were obtained in the 30 degree right anterior oblique projection. Right ventriculograms were also obtained in the 60 degree left anterior oblique projection. The videotape recordings of subtracted images were continuously digitized into 128 X 128 eight bit (256 gray scales) pixel matrices using an image-processing computer. The endocardial outlines of the right and left ventricles were drawn manually using a joystick, frame by frame, for each cardiac cycle. By integrating overall the pixel densitometric counts within this outline for each frame, the computer generated a time-density curve with maxima and minima represented in the end-diastolic and end-systolic frames, respectively. Systolic indices including ejection fraction (EF), one-third ejection fraction (1/3 EF) and the peak ejection rate (PER) were derived from the time-density curve. Right ventricular volume was determined by the single-plane or biplane mathematical formulae of Ferlinz et al., and left ventricular volume was calculated by the area-length method in the 30 degree right anterior oblique projection. Results by the two geometric methods correlated well for right ventricular volume (r = 0.84) and for EF (r = 0.80). Right ventricular densitometric counts correlated closely with single-plane volume (r = 0.91). Right ventricular ejection fraction (RVEF) determined by videodensitometry also correlated satisfactorily with that by single-plane angiography (r = 0.74).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[Hypertrophic cardiomyopathy manifesting different modes of illness: report of three cases].

Three cases of hypertrophic cardiomyopathy (HCM) which presented with different modes of appearance of left ventricular hypertrophy are reported. Case 1: A 24-year-old man had three relatives with HCM. At 13 years of age, he showed no electrocardiographic or echocardiographic abnormalities characteristic of HCM. During the ensuing 11 years, he developed asymmetric septal hypertrophy (ASH) and systolic anterior motion of the mitral valve (SAM), with right bundle branch block and T-wave inversion. Cardiac catheterization confirmed the diagnosis of hypertrophic obstructive cardiomyopathy by demonstrating an intraventricular pressure gradient of 25 mmHg. These observations indicate that this case developed abnormal hypertrophy during adolescence on the basis of genetic predisposition of an autosomal dominant trait. Case 2: A 51-year-old woman had three proven and three possibly affected relatives. At 35 years of age, she had a normal electrocardiogram, although the echocardiogram was not available. Now, 16 years later, she had developed ASH with abnormal Q-waves and was diagnosed as having non-obstructive HCM. These suggest that ASH can be manifested as late as during middle-age, even in those with genetic predisposition. Case 3: A 47-year-old woman was diagnosed as having hypertension and her blood pressure was 190/100 mmHg at 40 years of age, though she had no abnormal electrocardiographic findings and heart murmurs. Now, at 47 years of age, she had developed T-wave inversion, ASH, SAM, and an intraventricular pressure gradient of 50 mmHg. Thus, her ASH appeared during middle-age, and was probably provoked by hypertension, though a complete family survey could not be conducted. These three patients' findings indicate that there may be various modes of appearance of left ventricular hypertrophy in HCM. In the majority of patients with genetic predisposition, abnormal hypertrophy may develop during adolescence as in Case 1. In others, it may develop in middle-age, as it did in Case 2. The disease spectrum of HCM may additionally include those who develop abnormal hypertrophy during middle-age, following provocation by hypertension, as in Case 3.

Adult↗
PubMed1987

[Effectiveness of multidisciplinary treatment combined with immunotherapy in esophageal cancer--analysis of 287 cases of carcinoma of the thoracic part of the esophagus in Kyushu and Yamaguchi districts].

The effectiveness of surgical adjuvant immunochemotherapy was studied on 287 patients with thoracic esophageal cancer in the Kyushu and Yamaguchi districts. Pre- and postoperative subcutaneous administrations of BCG, 10 mg once a week and an oral administration of PSK, 3 g a day, for as long as possible after surgery were instituted. The control group was designated as the one which neither PSK nor BCG was given. Most patients received chemotherapy and/or radiotherapy. Significant elongation of survival time was observed in immunotherapy patients with stage III and in those with non-curative resection, both having no lymph node metastasis.

Adult↗