Biomedical subjects

T Sumimoto

Publications and source records attributed to T Sumimoto.

At least 73 records · Page 4Linked to original sources

PubMed1993

Overshoot in mixed venous oxygen saturation during recovery from supine bicycle exercise in patients with recent myocardial infarction.

During recovery from dynamic exercise, systemic oxygen extraction rapidly decreases below the resting level in patients with heart failure, which leads to a subsequent increase in mixed venous oxygen saturation (SvO2) above its resting value (postexercise SvO2 overshoot). To evaluate the pathophysiologic basis of this phenomenon, postexercise SvO2 overshoot was evaluated in relation to hemodynamic, metabolic, and neurohumoral responses during recovery from maximal supine bicycle exercise in 22 patients with recent myocardial infarction. Postexercise SvO2 overshoot closely correlated with increased systemic vascular resistance (r = 0.79, p < 0.001) and reduced cardiac output (r = -0.74, p < 0.001), suggesting that SvO2 overshoot is primarily due to increased peripheral arteriovenous shunting caused by an enhanced peripheral vasoconstriction in the setting of reduced cardiac output. Postexercise SvO2 overshoot and systemic vascular resistance were significantly higher and cardiac output was significantly lower in New York Heart Association functional class 3 and 4 (8 patients) compared with class 1 and 2 (14 patients), whereas systemic arterial blood pressure was maintained at normal levels in both groups. Thus, postexercise SvO2 overshoot and, hence, decreased systemic oxygen extraction during recovery represent a compensatory response of an enhanced peripheral vascular tone that maintains systemic arterial blood pressure in the setting of reduced cardiac output by linking central and peripheral blood flow.

Adult↗

PubMed1993

Effect of infarct site on diastolic time during exercise.

To assess the difference in left ventricular performance during exercise between anterior (11 patients) and inferior (10 patients) myocardial infarction (MI) of equivalent size, patients performed a supine bicycle exercise 6 to 8 weeks after the first acute MI. All patients had negative exercise test results and despite no significant differences in HR, blood pressure and stroke volume index at peak exercise, pulmonary artery wedge pressure was significantly higher in anterior (35 +/- 7 mm Hg) than in inferior MI (27 +/- 9 mm Hg). Although there were no significant differences in electromechanical systole (QS2) and diastolic time (DT) at rest, a significant prolongation of QS2 with consequent shortening of DT (p < 0.01) was observed at peak exercise in anterior MI. In addition to decreased subendocardial coronary blood flow from increased left ventricular end-diastolic pressure, a disproportionate shortening of DT in anterior MI may initiate subendocardial ischemia in the noninfarcted segments, which may further impede subendocardial blood flow.

Blood Pressure↗

PubMed1993

An adult case with multiple cardiac valve prolapse and regurgitation.

A 56-year-old female had pure regurgitation in all cardiac valves. Color Doppler echocardiography showed a regurgitant jet in all cardiac valves. The severity of regurgitation due to the prolapse in all valves was moderate. The patient had no history of rheumatic fever, ischemic heart disease, endocarditis or hypertension. Physical characteristics of the patient were neither of Marfan's nor Ehlers-Danlos' syndrome. The etiology of regurgitation in all cardiac valves of this patient may be due to multiple valve prolapse.

Aortic Valve Insufficiency↗

PubMed1993

Dietary fiber intake of Japanese younger generations and the recommended daily allowance.

A method was introduced for the estimation of total dietary fiber (TDF) intake of a population using a menu-oriented questionnaire and a menu-based calculation table. TDF intake correlated well with age in a population investigated, and in younger generations TDF consumption was very low (less than 11.5 g/day in teenagers). The similar results were obtained from the calculation using data of National Nutrition Survey (10.7 g/day). The foodstuffs they consumed were more processed and refined. This fact suggested that in younger generations a future resumption of their present eating habits might produce a serious lack of TDF intake in later years. To clarify the optimal level of TDF intake for the upper limit of recommended daily allowance (RDA) of an average Japanese, the following were measured and calculated. (I) Estimation of recent TDF intake (1990) and of 30 and 50 years ago (1955, 1935), based on TDF data of foodstuffs by the enzymatic-gravimetric method. (II) Measurement of the TDF of model duplicate meals and model composite diets for the average Japanese in 1985 using the same assay method. (III) Conversion of a recommendation of 20-35 g/day for American into RDA for Japanese considering energy consumption and lower fat intake. (IV) Re-estimation of the literature data on the adverse effects of DF on the human mineral balance considering the insufficient calcium intake of Japanese. The results indicated an RDA of 10-12 g TDF/1,000 kcal fit better for an average Japanese.

Adolescent↗

PubMed1993

Left ventricular cardiac structure and diastolic function in isolated systolic hypertension in the elderly.

We examined the left ventricular cardiac structure and the diastolic function in patients with isolated systolic hypertension (ISH; SBP > or = 160 mmHg and DBP < 90 mmHg) in the elderly. We studied 17 patients with ISH, 24 age-matched patients with essential hypertension (EHT; DBP > or = 90 mmHg) and 17 normotensive controls (NT; SBP < 140 mmHg and DBP < 90 mmHg). EHT were divided into two groups based on the mean wall thickness (MWT) of the left ventricle. Group 1 patients (EHT-I, n = 12) had a MWT < 10 mm and group 2 patients (EHT-II, n = 12) had a MWT > or = 10 mm. We measured left ventricular end-diastolic dimension (LVDd), end-systolic dimensions (LVDs), left ventricular mass index (LVMi) and left ventricular isovolumic relaxation time (IRT) to assess the left ventricular cardiac structure and the diastolic function by M-mode echocardiography. LVDd was significantly smaller in ISH than in NT, EHT-I and EHT-II (P < 0.01). Relative wall thickness was greatest in ISH because of both the decreased chamber size and the increased left ventricular wall thickness. LVMi in ISH was similar to that in EHT-I, but IRT in ISH was significantly longer than that in EHT-I (P < 0.05). These results suggest that ISH in the elderly shows a left ventricular concentric hypertrophy and a severely impaired diastolic function.

Aged↗

PubMed1992

Effects of a long-term treatment with alacepril on left ventricular hypertrophy and function in patients with essential hypertension.

The authors examined the effects of a long-term treatment with the angiotensin-converting enzyme inhibitor, alacepril, with respect to the reversal of left ventricular hypertrophy and the improvement of left ventricular function. Ten uncomplicated essential hypertensive patients with left ventricular hypertrophy, aged 53 +/- 8 years, were treated with alacepril alone for 12 months. All patients underwent echocardiography to to assess left ventricular dimensions and function before and after the treatment. After the treatment, blood pressure was decreased significantly from 163 +/- 14.1/98 +/- 4.2 to 142 +/- 20.3/86 +/- 11.0 mm Hg (each, P less than .01), whereas heart rate did not change (66 +/- 6 versus 69 +/- 8 beats/min). The left ventricular mass index was decreased significantly from 146 +/- 27 to 119 +/- 29 g/m2 (P less than .01). Ejection fraction, fractional shortening, peak shortening rate, and peak lengthening rate all improved significantly after the treatment. There was a significant inverse relationship between fractional shortening and end-systolic wall stress before the treatment (r = .63, P less than .05), and this relationship did not change after the treatment. It is concluded that alacepril improved both left ventricular systolic and diastolic function without causing any consistent augmentation of left ventricular contractility.

Adult↗

PubMed1992

Effect of disopyramide on left ventricular diastolic function in patients with hypertrophic cardiomyopathy: comparison with diltiazem.

Left ventricular diastolic function before and after the administration of disopyramide (100 mg) or diltiazem (30 mg) was assessed in 10 patients with nonobstructive type hypertrophic cardiomyopathy. Left ventricular diastolic function was assessed by Doppler echocardiography. The peak early (E) and late (A) diastolic flow velocities and E/A ratio (E/A) were measured. Three hours after the administration of disopyramide, blood pressure did not significantly change, but heart rate was decreased significantly (p less than 0.01). Disopyramide increased the E velocity and E/A ratio from 43.8 +/- 15.0 cm/sec to 51.3 +/- 16.1 cm/sec and from 0.71 +/- 0.20 to 1.00 +/- 0.24 (each p less than 0.01), respectively, and decreased the A velocity from 63.9 +/- 18.5 cm/sec to 52.1 +/- 14.9 cm/sec (p less than 0.01). Diltiazem increased the E velocity and E/A ratio from 42.8 +/- 12.5 cm/sec to 46.4 +/- 13.4 cm/sec (p less than 0.05) and from 0.74 +/- 0.21 to 0.96 +/- 0.28 (p less than 0.01), respectively, and decreased the A velocity from 60.6 +/- 16.4 cm/sec to 50.2 +/- 15.6 cm/sec (p less than 0.01). These results indicate that disopyramide improved left ventricular diastolic filling in hypertrophic cardiomyopathy, and its effect was similar to that of diltiazem.

Adult↗

PubMed1992

A large conus artery in patients with hypertrophic cardiomyopathy.

We retrospectively analyzed coronary arteriograms in 66 patients with hypertrophic cardiomyopathy (HCM) who underwent coronary arteriography. Four of these patients showed a large conus artery supplying the interventricular septum, and the characteristics of their echocardiograms revealed a marked interventricular septal hypertrophy. It is suggested that in some patients with HCM, the conus artery may develop in compensation for the relatively reduced coronary blood flow which is due to the hypertrophied myocardium.

Adult↗

PubMed1992

Analysis of blood flow patterns in aortic aneurysm by cine magnetic resonance imaging--a review of case material.

Cine magnetic resonance imaging (MRI) (0.5-T) using rephased gradient echo technique was performed in 5 normal volunteers and 14 patients with aortic aneurysm to study the patterns of blood flow in aortic aneurysm. In the transaxial section, blood flow in normal aorta appeared as homogeneous and high intensity during systole. Blood flow in aneurysm appeared as inhomogeneous flow enhancement with flow void. In the sagittal scan, the homogeneous flow enhancement in normal aorta was also observed during systole, and its apex of flow enhancement was "taper." The blood flow patterns in aneurysm were classified as "irregular," "zonal," "eddy," and "obscure," depending on the contrast of flow enhancement and flow void. Their apexes were "taper" or "round." When the size of aneurysm became larger, the flow pattern in aneurysm tended to become "eddy" or "obscure" and the flow enhancement became "round." Though the exact mechanism of abnormal flow patterns in aneurysm remains to be determined, cine MRI gives helpful information in assessing blood flow dynamics in aneurysm.

Adult↗

PubMed1992

Clinical significance of the calcification of coronary arteries in patients with angiographically normal coronary arteries.

In order to clarify the clinical significance of coronary calcification in patients with angiographically normal coronary arteries, exercise electrocardiography was used and left ventricular function was examined noninvasively and invasively. The patient groups were as follows: (1) patients with coronary artery calcification on only the left anterior descending artery but no narrowing lesion on any other arteries (calcified group), (2) patients with a significant stenosis on only the left anterior descending artery (stenotic group), and (3) the control group. The left ventricular function in the calcified group, as indicated by systolic time intervals and invasive parameters such as ejection fraction and mean systolic ejection rate, showed a depression similar to that in the stenotic group, compared with the control group. The incidence of electrocardiographically ischemic responses to exercise testing was significantly higher in the calcified group (75%, p less than 0.01) and the stenotic group (68%, p less than 0.01) than in the control group (25%). Exercise tolerance time and the maximum double product were markedly smaller in the calcified and the stenotic groups as compared with the control group. These results indicate that the left ventricular function and coronary reserve in the calcified group were reduced and almost identical with those in the stenotic group. The authors conclude that a calcified coronary artery, even if patent, cannot supply an adequate blood flow for the myocardium, resulting in impaired left ventricular function.

Angina Pectoris↗

PubMed1992

Hemodynamic characteristics of patients with coronary artery disease presenting false-negative exercise stress test.

The present study was designed to clarify the characteristics of left ventricular hemodynamics and coronary arteries in patients with coronary artery disease presenting false-negative response to the Master's two-step stress test. Eighty-eight consecutive patients performed the Master's two-step stress test and had coronary angiography for evaluation of suspected or known coronary artery disease. The frequency of false-negative and true-positive responses in the Master's two-step stress test was 20% and 45%, respectively. Elevated left ventricular end-diastolic pressure, reduced ejection fraction, and low cardiac output characterized the left ventricular hemodynamics in patients with false-negative responses, as compared with those with true-positive response. The severity and extent of coronary artery disease, as well as prior myocardial infarction, did not affect the frequency of false-negative response. This study indicates that the false-negative response to the Master's two-step test is unexpectedly frequent in coronary artery disease with severe left ventricular dysfunction. Thus, one should be careful in judging the results of the Master's two-step test in symptomatic patients with severe left ventricular dysfunction.

Adult↗

PubMed1992

Torsade de pointes induced by hypocalcemia in a postoperative patient with thyrotoxicosis.

A 29-year-old woman with a long-term history of Graves' disease was admitted for thyroidectomy. Torsade de pointes occurred after the subtotal thyroidectomy. The level of her serum calcium was lower than normal. After administration of calcium gluconate intravenously, torsade de pointes disappeared and was no longer recorded. It is assumed that her torsade de pointes was caused by hypocalcemia as a complication of subtotal thyroidectomy.

Adult↗

PubMed1992

[Tl-201 myocardial scintigraphic findings in patients with aortic regurgitation].

To evaluate the myocardial damage associated with aortic regurgitation, thallium-201 myocardial scintigraphy was performed in 13 patients with aortic regurgitation. The data obtained by thallium-201 single photon emission computed tomography were expressed as the extent score, and were compared with data by echocardiography. The results were as follows: 1. In 11 of 13 patients, there were moderate Tl defects in the distribution of bull's eye map, 80% in the apex, 50% in the inferior and lateral regions, 30% in the anterior region and 10% in the septal region. The mean extent score was 22.3 +/- 11.0%. 2. The extent score correlated with the increase in aortic regurgitant flow volume. The extent score according to the Sellers' classifications II, III, and IV was 13.8 +/- 3.7%, 20.1 +/- 9.8% and 31.9 +/- 10.2%, respectively. 3. There was a good negative correlation between the extent score and fractional shortening (r = -0.66, p < 0.01), however, no significant correlation was observed between the extent score and the left ventricular end-diastolic volume. These results suggest that Tl defects in patients with aortic regurgitation are mainly due to myocardial ischemia associated with a decrease in coronary perfusion pressure and that the extent score may sensitively reflect the severity of myocardial damage in cases with aortic regurgitation.

Adult↗

PubMed1992

[A case of middle aged women with isolated left coronary ostial stenosis].

A-50-year-old woman was admitted to our hospital for the examination of exertional chest pain. She had no coronary risk factors. No hormonal disorders were observed. Physical and laboratory examinations revealed that she had not suffered from syphilis or aortitis syndrome or any other inflammatory diseases. An exercise electrocardiogram (Master's test) demonstrated ST segment depression in V3-6, II, III and a VF. On coronary angiography, a 75% stenosis of the left coronary ostial stenosis was found, but no abnormality was found in other arterial trees. The patient was diagnosed as having isolated coronary ostial stenosis. She underwent coronary bypass surgery from the aorta to the circumflex artery and the anterior descending coronary artery. She is now completely asymptomatic. A review of the literature together with this patient reveals the following characteristics of patients with isolated coronary ostial stenosis. Firstly, the patients are almost always middle aged woman with no coronary risk factors. Secondly, the involved coronary artery is the left main coronary artery, so its obstruction results in a serious condition. Therefore, though its pathogenesis remains to be determined, isolated left coronary ostial stenosis seems to be a distinct clinical entity.

Age Factors↗

PubMed1992

Ectopic ACTH-producing adenocarcinoma of the stomach.

A 73-year-old female was admitted to our hospital because of weight loss and pretibial edema. Plasma levels of adenocorticotropic hormone (ACTH) and cortisol were elevated, and neither hormone showed circadian rhythm. Dexamethasone (2 mg for 2 days) failed to reduce the urinary excretion of 17-hydroxycorticosteroids and the plasma cortisol level. The stomach biopsy specimens showed a moderately-differentiated papillo-tubular adenocarcinoma. Computed tomography of the abdomen showed multiple metastases to the liver. Immunohistochemical staining of the autopsy specimens showed immunoreactive ACTH in the primary tumor cells of the stomach as well as the metastatic tumor cells of the liver. On the basis of the clinical, histological and immunohistochemical findings, we diagnosed this patient as having ectopic ACTH syndrome caused by adenocarcinoma of the stomach.

ACTH Syndrome, Ectopic↗

PubMed1991

Oxygen utilization, carbon dioxide elimination and ventilation during recovery from supine bicycle exercise 6 to 8 weeks after acute myocardial infarction.

The pattern of oxygen (O2) consumption (VO2), carbon dioxide (CO2) production (VCO2), ventilatory and metabolic responses during and in recovery from supine bicycle exercise was examined in 18 patients with recent myocardial infarction. An increase in VO2 with increasing work load was accomplished by proportional increases in both cardiac output and the arteriovenous O2 difference. During recovery, however, the arteriovenous O2 difference rapidly decreased below levels at rest, whereas VO2 and cardiac output remained elevated, indicating that VO2 during recovery further depended on relatively high cardiac output. The ratio of VCO2 to VO2 further increased after exercise, suggesting that such cardiac output contributed to the remaining high CO2 flow to the lung and therefore enhanced ventilation. Increased arterial catecholamines during exercise remained elevated for the first 5 minutes of recovery. Arterial lactate during this period continued to increase and resulted in profound metabolic acidosis, causing alveolar hyperventilation after exercise. These results suggest that during recovery from exercise, cardiopulmonary responses remain enhanced because of continuing high cardiac output, resulting in subsequent high CO2 flow to the lung and metabolic acidosis, and that this may be associated with profound fatigue or dyspnea after exercise.

Acidosis, Lactic↗

PubMed1991

Effect of disopyramide on systolic and early diastolic time intervals in patients with hypertrophic cardiomyopathy.

The present study clarified the effect of disopyramide on left-ventricular function in patients with hypertrophic cardiomyopathy (5 obstructive type: HOCM, 21 non-obstructive type: HNCM). The systolic and early diastolic time intervals were assessed 3 hours after a single oral administration of 100-mg disopyramide. The following parameters were evaluated at rest and after administration of disopyramide: 1) left-ventricular ejection time index (LVETI), 2) pre-ejection period index (PEPI), 3) the interval from aortic component of the second heart sound to mitral valve opening (IIA-MVO), and 4) the interval from MVO to O point of apexcardiogram (MVO-O). LVETI in HNCM did not change after disopyramide but that in HOCM was significantly shortened (P less than .05). PEPI in both HOCM and HNCM was significantly prolonged after administration of disopyramide. IIA-MVO time in both HOCM and HNCM was not influenced by disopyramide. MVO-O time in both HOCM and HNCM was significantly shortened after disopyramide. These results suggest that 1) shortening of LVETI in HOCM after disopyramide seemed to be due to the decrease in pressure gradient, 2) PEPI prolongation after disopyramide reflected the decrease in myocardial contractility, and 3) shortening of MVO-O time after disopyramide indicated the improvement of left-ventricular filling. The authors conclude that disopyramide may be an important new therapeutic agent in the treatment of patients with hypertrophic cardiomyopathy.

Adult↗

PubMed1991

Mixed venous oxygen saturation as a guide to tissue oxygenation and prognosis in patients with acute myocardial infarction.

The relation of mixed venous oxygen saturation and the cardiac index to tissue oxygenation and prognosis was investigated in 119 patients with acute myocardial infarction. There was a positive correlation between mixed venous oxygen saturation and the cardiac index in 97 survivors and 22 nonsurvivors, but a significantly lower mixed venous oxygen saturation level at the same level of cardiac index was observed in nonsurvivors compared with survivors. Results of multivariate analysis with mixed venous oxygen saturation and the cardiac index indicated that only mixed venous oxygen saturation was significantly related to survival and to hyperlactacidemia. Oxygen delivery to tissues declined significantly in nonsurvivors because of a lower cardiac index and a lower hemoglobin concentration in these patients than in survivors. However, at the same level of oxygen delivery to tissues, nonsurvivors had a significantly higher rate of oxygen consumption leading to a correspondingly greater decrease in mixed venous oxygen saturation, suggesting that a greater increase in oxygen demand was also observed in nonsurvivors than in survivors. Thus mixed venous oxygen saturation after acute myocardial infarction is a better predictor of hyperlactacidemia and survival than the cardiac index, and this may be associated with an increased oxygen demand and an impaired oxygen transport system in seriously ill patients.

Aged↗