Search PubMed⌕ Search

Biomedical subjects

K Kuwako

Publications and source records attributed to K Kuwako.

31 records · Page 2Linked to original sources
PubMed1984

[Two-dimensional pulsed Doppler echocardiographic estimates of cardiac output in man: sampling at the entrance to the main pulmonary artery].

To assess the feasibility and accuracy of measuring cardiac outputs (CO) by two-dimensional (2-D) pulsed Doppler echocardiography, taking samples at the main pulmonary artery just beyond the pulmonary valve, 62 cardiac patients were studied. The results obtained were compared with CO values determined by the thermodilution technique. 2-D Doppler echocardiograms suitable for computing CO were recorded in 37 (60%) of 62 patients. A significant correlation (r = 0.64) was observed between 2-D echocardiographic and angiographic pulmonary ring diameters (PRD), but the echocardiographic PRD was smaller than that of angiography by 0.4 +/- 0.2 cm. Thus, to compute the Doppler CO, the echocardiographic PRD had to be corrected by the difference between the angiographic and echocardiographic PRD. The angle between the ultrasound beam and the pulmonary blood flow was 7.8 +/- 6.1 degrees (0 approximately 18 degrees), and this was negligible for computing the Doppler CO. Even in cases with atrial fibrillation, the Doppler CO could be computed as is done in sinus rhythm. The correlation between the thermodilution and Doppler CO was highly significant (r = 0.92), and the regression equation was as follows: Thermodilution CO = 1.09 X (Doppler CO)-0.19 The difference between thermodilution and Doppler CO was 3.4 +/- 10.0% (-21 approximately +21%). Comparing the differences in CO between the thermodilution and dye-dilution techniques, those between thermodilution and the Fick methods, and those among thermodilution methods reported in the literatures, the difference in this study was not large and was acceptable. Thus, measurement of CO by pulsed Doppler echocardiography, with sampling entrance to the main pulmonary artery, can be used clinically.

Adult↗
PubMed1983

[Contrast echocardiography of the left heart by intravenous injection of perfluorochemical emulsion].

We evaluated a new method of contrast echocardiography of the left heart utilizing the intravenous injection of perfluorochemical emulsion (PFC emulsion: Fluosol-DA 20 W/V%: Green Cross Corp), which was prepared as artificial blood. Observations were made in 18 open-chest dogs. To assess the possibility of detection of mitral valve regurgitation and myocardial perfusion by this method, a small series of experiments were made. Results were as follows: Following the appearance of contrast echoes in the right heart after the injection of PFC emulsion (10 ml) into the inferior vena cava, the left heart contrast echo images were clearly obtained in 16 of the 18 dogs, and they were visible but weak in the remainder 2. The solution of surfactants (Pluronic F-68, yolk phospholipids, and glycerol), which were added to Fluosol-DA, was also used as contrast agent in 6 dogs. The left heart was also opacified by contrast echoes after intravenous injections. However, the density of the left heart contrast echoes appeared lower, as compared with that after the injection of PFC emulsion. When oxygen (95%) was mixed in PFC emulsion or inhaled through the intratracheal tube, the left heart contrast images were slightly enhanced. In 4 of 6 dogs with surgically created mitral valve regurgitation, systolic contrast echoes in the left atrial cavity were detected on the M-mode echograms after the intravenous injection of PFC emulsion (15 ml). These echoes appeared to move across the mitral valve from the left ventricle to the left atrium or away from the mitral valve in the left atrium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

[Effects of beta-blockers and Ca antagonists on diastolic function of the hypertrophied left ventricle: an echocardiographic study].

Left ventricular (LV) relaxation was studied in patients with hypertensive heart disease with LV hypertrophy (HHD, n = 25) and hypertrophic cardiomyopathy (HCM, n = 9), and these data were compared with that of normal controls (n = 20). The effects of oral administration of propranolol (n = 11), pindolol (n = 3), nifedipine (n = 6) and diltiazem (n = 5) in patients with HHD and that of propranolol (n = 9) in patients with HCM were also studied. Isovolumic relaxation time (IRT) was measured using dual M-mode echocardiography and peak normalized rate of change of the LV cavity in early diastole (peak dD/dt/D) was calculated by M-mode echocardiography using a digitizer and microcomputer system. IRT was significantly longer in HHD (112 +/- 24 msec, p less than 0.001) and in HCM (85 +/- 40 msec, p less than 0.05) compared with that of normal subjects (64 +/- 24 msec). The normal value of peak dD/dt/D was 3.8 +/- 0.7 sec-1, and it was significantly lower in HHD (2.7 +/- 0.8 sec-1, p less than 0.001). It was also lower in HCM (3.2 +/- 0.8 sec-1), but without a statistical significance. In HHD there was a significant relationship (r = -0.611, p less than 0.01) between peak dD/dt/D and wall thickness of the LV (interventricular septum + LV posterior wall). There was no significant change in IRT before and after the administration of beta-blockers and calcium antagonists except nifedipine in HHD (before: 116 +/- 28 msec, after: 80 +/- 14 msec, p less than 0.005). It was probably due to the effect of an accompanied decrease in heart rate. However, peak dD/dt/D was significantly increased in both HHD and HCM groups after the administration of propranolol, pindolol, nifedipine and diltiazem. These data show that LV relaxation is abnormal in the hypertrophied LV. Although the genesis of this abnormality is not clear, there seems to be a close relationship between the relaxation abnormality and increased LV mass in HHD. Oral administration of propranolol, pindolol and diltiazem for patients with HHD and propranolol for patients with HCM seems to improve the abnormal LV relaxation of each disease.

Adrenergic beta-Antagonists↗
PubMed1981

[Scinti-angiographic investigation of aortic dissection (author's transl)].

We perform scinti-angiography regularly in suspected cases of dissecting aneurysms. In our experience, the dissection is well demonstrated by this method. In correctly selected cases, scinti-angiography is a method which is well tolerated by the patient and which carries very little risk, since the complications due to contrast media are absent.

Aortic Dissection↗
PubMed1981

[Cross-sectional echocardiographic findings of a case with ruptured aneurysm of the sinus of Valsalva into the right atrium (author's transl)].

A case with ruptured aneurysm of the sinus of Valsalva into the right atrium directly visualized by cross-sectional echocardiography was reported. A 31-year-old male was referred to our hospital for evaluation of recently developed cardiac murmur. A systolic ejection murmur and diastolic blowing murmur were audible maximally at 3-4L and the latter one was also well audible at the right lower sternal border. Cardiac catheterization data revealed a large left-to-right shunt at the atrial level. The cross-sectional echocardiogram, obtained with a transducer at 5R towards the upwards and the medial direction, revealed a mass echo showing a pendulous motion through cardiac cycle in the right atrial cavity. Ruptured aneurysm of the sinus of Valsalva originated from the non-coronary sinus was demonstrated by aortography, and it showed the same motion as in echocardiography. From this angiographic finding and its disappearance after operation, the mass visualized by echocardiography was considered to be ruptured aneurysm itself. Thus, direct visualization of ruptured aneurysm of the sinus of Valsalva into the right atrium, as well as other types, was possible by cross-sectional echocardiography. In addition, multiple coronary A-V fistulae with a small shunt were demonstrated by coronary angiography in this case. Clinical significance of the complication has not been clarified.

Adult↗
PubMed1977

A clinicopathological study on mitral ring calcification.

The incidence, the size of mitral ring calcification (MRC) and its relation to the mitral valve disease were examined in a total of 600 consecutive autopsy cases of over 60 years of age. (1) The incidence of MRC was 10% (60 cases among 600), and the sex difference was statistically significant with 6.7% in male and 13.3% in female (p less than 0.01). The age was 82 years in average, and an increase of its incidence with aging was significant only in female (p less than 0.005). (2) MRC was found in the annulus of the posterior mitral leaflet. The length of MRC was 12.5 +/- 10.3 mm in male, and 31.8 +/- 23.5 mm in female (p less than 0.01). Large MRC more than 30 mm were found in 1 man and 19 women. (3) The relationship between the length and cross sectional diameter of the MRC showed a positive correlation (r=0.75). Three cases of mitral stenosis or combined stenosis and regurgitation belonged to the extremely large MRC group. (4) There were 27 cases with systolic murmur; 3 holosystolic and 24 ejection type. In large and small MRC groups, systolic murmurs were found in 70% and 33% (p less than 0.05), MRC extending to the anterior leaflet in 65% and 2.5% (p less than 0.005), moderate to severe calcification of the aortic valve in 40% and 20% (n.s.), respectively. (5) X-ray films were examined retrospectively, and large MRC was diagnosed in 85%, and incidence of calcification in the other soft tissues (trachea, bronchi, costal cartilage, aortic arch, thoracic and abdominal aorta) was higher in large MRC group than in the control group (87 cases) without MRC (p less than 0.005).

Adult↗