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Biomedical subjects

T Inou

Publications and source records attributed to T Inou.

At least 19 recordsLinked to original sources
PubMed1999

[Usefulness of exercise echocardiography in ischemic heart disease: comparison with exercise cardiac scintigraphy].

Exercise echocardiography and exercise thallium-201 (201Tl) single photon emission computed tomography (SPECT) were performed in 152 patients with suspected coronary artery disease, including 61 patients with old myocardial infarction. All patients underwent coronary arteriography, and coronary artery disease was defined as > or = 75% diameter stenosis. Digital two-dimensional echocardiography was performed before and after the treadmill exercise test, and wall motion abnormality was evaluated using quad-screen. Sensitivity and specificity for the diagnosis of coronary artery disease were similar for the 2 exercise tests (77% and 80% for echocardiography and 75%, and 83% for SPECT, respectively). Diagnoses for one-vessel disease, 2-vessel disease and 3-vessel disease were similar for echocardiography (79%, 72% and 77%, respectively) and SPECT (74%, 75% and 77%, respectively). Sensitivity for the diagnosis of ischemia at the area remote from infarct area was low for both exercise echocardiography and exercise SPECT (45% and 48%, respectively). Exercise echocardiography has comparable diagnostic value to SPECT for the detection of coronary artery disease. However, both exercise tests have limitations for the diagnosis of ischemia at the area remote from infarct area.

Echocardiography↗
PubMed1998

Successful surgical treatment for hepatic encephalopathy caused by a pancreatic siphon: report of a case.

We report herein the case of a 39-year-old man with cirrhosis of the liver who developed hepatic encephalopathy and progressive diabetes caused by a pancreatic siphon after undergoing a distal splenorenal shunt (DSRS) for a variceal hemorrhage. Radiologic occlusion was judged to be inappropriate because of the extensive DSRS. The DSRS was surgically closed 6 years after the operation to restore portal perfusion. To alleviate the portal hypertension, splenectomy and gastric devascularization were performed, which proved successful, as the encephalopathy disappeared completely, the ammonia levels decreased, liver function improved, and the diabetes subsided. Our experience indicates that a small percentage of cirrhotic patients who undergo DSRS with longterm followup may develop various undesirable complications, although some of these patients benefit from a combination of surgical shunt occlusion, splenectomy, and gastric devascularization.

Adult↗
PubMed1996

Ischemic heart disease 31 years after possible Kawasaki disease.

We present a 38-year-old woman who had experienced an acute febrile illness lasting more than 1 week at the age of 6, with erythema on the palms and soles following skin desquamation in the subacute phase and skin eruption. Thirty one years later, she experienced acute myocardial infarction and episodes of angina pectoris. She had no coronary risk factors or autoimmune diseases. Coronary angiography revealed an aneurysm of the proximal left coronary artery with occluded lesions at the distal site. The right coronary artery was also occluded at the proximal site. These findings strongly suggest Kawasaki disease should be considered in the differential diagnosis of early-onset ischemic heart disease in young adults.

Adult↗
PubMed1995

Immediate relief of spontaneous coronary artery spasm by intracoronary infusion of an endothelium-dependent vasodilator, substance P.

This report describes a 45-year-old Japanese man who had episodes of anginal chest pain on effort. Coronary arteriography in the baseline state revealed subtotal occlusion in the mid-portion of the left anterior descending coronary artery. After intracoronary infusion of an endothelium-dependent vasodilator, substance P, the subtotal occlusion was immediately abolished. We concluded that endothelium-dependent vasodilation evoked with substance P was present at the site where coronary vasospasm occurred spontaneously in our case.

Coronary Angiography↗
PubMed1994

Evaluation of laser Doppler flowmetry in renal transplantation.

Renal grafts are presently evaluated based on the surgeon's observation of the organ microcirculation. Effectiveness of organ microcirculation has traditionally been accomplished through evaluation of the appearance of the graft. Laser doppler flowmetry (LDF) has been suggested as a possible means to determine graft effectiveness. Renal grafts in 46 transplants were studied using LDF and the technique was evaluated. It was found to be a useful technique for monitoring effectiveness of grafts.

Evaluation Studies as Topic↗
PubMed1994

Effects of intracoronary infusion of atrial natriuretic peptide on pacing-induced myocardial ischemia in patients with effort angina pectoris.

BACKGROUND: Atrial natriuretic peptide (ANP) has been shown to dilate the coronary artery. The aim of this study was to determine whether, in patients with effort angina pectoris, intracoronary infusion of ANP attenuates pacing-induced myocardial ischemia either by dilating the stenotic lesion in a large coronary artery or by dilating collateral vessels. METHODS: We studied six patients who had total or subtotal occlusion in one coronary artery and well-developed, angiographically visible collateral vessels (group A) and five patients who had a significant stenosis in a large coronary artery with no visible collateral vessels (group B). Their heart rate was increased by atrial pacing both before and after intracoronary infusion of ANP (0.03 microgram/kg/min for 15 min) into the donor artery of collateral vessels in group A or into the stenotic artery in group B. RESULTS: Before ANP infusion, all patients of both groups developed an ischemic ST-segment depression (> or = 0.1 mV) and angina-like chest pain from pacing tachycardia. After ANP infusion, significant ST-segment depression was induced by rapid pacing in only one out of six patients of group A, whereas it was noted in all patients of group B (P < 0.01). After ANP infusion, chest pain developed in one out of six patients in group A, whereas it appeared in four out of five patients in group B (P < 0.05). ANP significantly dilated the angiographically normal segment of the epicardial coronary artery, but it did not significantly change the severity of the stenotic lesion in either group. ANP did not change the basal arterial pressure or heart rate, nor did it change their response to pacing tachycardia. CONCLUSION: Infusing ANP into the donor artery of collateral vessels, but not into the artery with culprit stenotic lesion, attenuated pacing-induced myocardial ischemia. Therefore, the beneficial effects of ANP in reducing pacing-induced myocardial ischemia may result from the increase in myocardial perfusion to the ischemic area caused by dilating the collateral vessels.

Aged↗
PubMed1994

Reduction in serum cholesterol with pravastatin improves endothelium-dependent coronary vasomotion in patients with hypercholesterolemia.

BACKGROUND: This study aimed to determine if cholesterol-lowering therapy improves endothelium-dependent coronary vasomotion in patients with hypercholesterolemia. METHODS AND RESULTS: Nine patients with hypercholesterolemia were studied before and after cholesterol-lowering therapy with pravastatin (an inhibitor of HMG-CoA reductase) for 6 +/- 3 months, which lowered serum cholesterol from 272 +/- 8 to 187 +/- 16 mg/dL (P < .01). Control patients with serum cholesterol of 218 +/- 23 mg/dL also were studied twice in a similar interval (8 +/- 2 months) with no cholesterol-lowering drugs. Acetylcholine (the endothelium-dependent vasodilator) and papaverine and nitrate (endothelium-independent vasodilators) were infused into the study coronary artery. Changes in the diameter of the epicardial coronary artery and coronary blood flow were assessed by quantitative coronary arteriography and an intracoronary Doppler catheter. In patients with hypercholesterolemia, acetylcholine-induced vasoconstriction of the epicardial artery was less (P < .05) and the acetylcholine-induced increases in coronary blood flow were greater (P < .001) after than before pravastatin. In control patients, responses of the epicardial coronary artery and coronary blood flow to acetylcholine did not change over the follow-up period. The vasomotor responses to papaverine or nitrate were similar between the two groups, and no interval changes in their responses were noted in either group. CONCLUSIONS: These results suggest that cholesterol-lowering therapy with pravastatin may improve endothelium-dependent coronary vasomotion, which may possibly contribute to the improvement of myocardial perfusion as well as the regression of coronary atherosclerosis.

Adult↗
PubMed1994

Prevalence and pathogenesis of silent myocardial ischemia following myocardial infarction.

The objective of this study was to examine the prevalence and pathogenesis of silent myocardial ischemia during exercise following myocardial infarction. Exercise-induced myocardial ischemia was assessed by 201Tl-SPECT (single photon emission computed tomography) 4.5 weeks after acute myocardial infarction in 229 patients. Exercise-induced myocardial ischemia occurred in 109 patients (48%), and 72 (32%) had silent ischemia. Although the prevalence of multivessel coronary artery disease was similar between patients with silent and symptomatic ischemia, the size of reversible myocardial ischemia was larger in patients with symptomatic ischemia than in those with silent ischemia (21.3 +/- 3.0% vs 13.2 +/- 1.9% of LV, p < 0.05). The incidence of reversible ischemia remote from the infarct area was higher in patients with symptomatic ischemia than in those with silent ischemia (30% vs 17%, p < 0.10). The cause of silent ischemia after myocardial infarction may be closely related to the smaller size of reversible myocardial ischemia. Ischemia remote from, or adjacent to, the infarct area could be a factor in determining the presence or absence of pain.

Coronary Angiography↗
PubMed1993

Evidence of impaired endothelium-dependent coronary vasodilatation in patients with angina pectoris and normal coronary angiograms.

BACKGROUND: A group of patients has been described who have chest pain resembling angina and positive exercise tests, but normal coronary angiograms and no coronary-artery spasm. This constellation of features has sometimes been called syndrome X or microvascular angina. We attempted to determine whether endothelium-dependent vasodilatation of the coronary vasculature was impaired in patients with this syndrome. METHODS: We infused the endothelium-dependent vasodilator acetylcholine and the endothelium-independent vasodilators papaverine and isosorbide dinitrate into the left coronary artery of 9 patients and 10 control subjects. The diameter of the left anterior descending coronary artery was assessed by quantitative angiography, and changes in coronary blood flow were estimated with the use of an intracoronary Doppler catheter. RESULTS: Acetylcholine, given in doses of 1, 3, 10, and 30 micrograms per minute, increased coronary blood flow in a dose-dependent manner in both groups. However, the mean (+/- SD) acetylcholine-induced increases in coronary blood flow were significantly less (P < 0.001) in the patient (8 +/- 14, 37 +/- 37, 59 +/- 67, and 103 +/- 77 percent, respectively) than in the controls (62 +/- 52, 186 +/- 93, 341 +/- 128, and 345 +/- 78 percent, respectively). The changes in coronary blood flow in response to 2 mg of isosorbide dinitrate (236 +/- 66 percent vs. 280 +/- 56 percent) and 10 mg of papaverine (366 +/- 168 percent vs. 411 +/- 92 percent) did not differ significantly between the patients and controls. The administration of papaverine resulted in myocardial lactate production in the patients but not in the controls. The three lower doses of acetylcholine caused a similar degree of dilatation of the left anterior descending coronary artery in the two groups, and the highest dose caused a similar degree of constriction in the two groups. Isosorbide dinitrate and papaverine caused a similar degree of dilatation in both groups. CONCLUSIONS: These findings suggest that endothelium-dependent dilatation of the resistance coronary arteries is defective in patients with anginal chest pain and normal coronary arteries, which may contribute to the altered regulation of myocardial perfusion in these patients.

Acetylcholine↗
PubMed1993

Correlation of basal coronary artery tone with constrictive response to ergonovine in patients with variant angina.

OBJECTIVES: This study was conducted to examine whether basal coronary artery tone is elevated at the spastic site in patients with variant angina and to determine the significance of basal artery tone in predicting provocation of coronary artery spasm. BACKGROUND: Previous data have been conflicting on whether basal coronary artery tone is elevated in patients with variant angina. METHODS: We assessed basal coronary artery tone by obtaining the percent increase in coronary artery diameter induced by nitroglycerin in 20 patients with variant angina and 24 control subjects. We also examined the correlation between basal coronary artery tone and the constrictive response to ergonovine. RESULTS: In the patients with variant angina in whom spasm was provoked by the lower doses (1 or 5 micrograms) of ergonovine, basal coronary artery tone was greater (p < 0.05) at the spastic site (54 +/- 15% or 36 +/- 16%, respectively) than at the nonspastic site (40 +/- 25% or 25 +/- 15%, respectively). Basal coronary tone at the nonspastic site in these patients was greater (p < 0.01) than that in control subjects (15 +/- 6%). In the patients with variant angina in whom spasm was provoked only by the higher doses (15 or 50 micrograms) of ergonovine, basal coronary artery tone was comparable at the spastic and nonspastic sites and was not different from that in control subjects. The diagnostic sensitivity and specificity of elevated basal coronary artery tone (> or = 40%) in predicting provocation of spasm were 26% and 98%, respectively. CONCLUSIONS: These results indicate that elevated basal coronary artery tone may be useful in predicting provocation of coronary spasm, but the normal level of basal coronary artery tone does not exclude such provocation.

Adult↗
PubMed1993

Effects of age on endothelium-dependent vasodilation of resistance coronary artery by acetylcholine in humans.

BACKGROUND: It has been suggested that endothelium-related vasomotion is important in the control of coronary circulation. Our goal was to determine if endothelium-dependent dilation of the coronary vasculature was altered with aging in 18 patients with atypical chest pain (age, 23-70 years) who had angiographically normal coronary arteries and no coronary risk factors. METHODS AND RESULTS: We infused an endothelium-dependent vasodilator acetylcholine (1, 3, 10, and 30 micrograms/min) and an endothelium-independent vasodilator papaverine (10 mg) into the left coronary artery. The large coronary diameter was assessed by arteriography, and the increase in coronary blood flow was measured using the intracoronary Doppler catheter technique. Acetylcholine increased coronary blood flow in a dose-dependent manner with no changes in arterial pressure and heart rate. The maximum increase in coronary blood flow evoked by acetylcholine varied widely among patients (increase in coronary blood flow ranged from 200% to 560%) and was correlated significantly with aging (r = -.86, P < .001), whereas the peak coronary blood flow response to papaverine was affected slightly by aging (r = -.44, P = .07). The percent increase in blood flow response to acetylcholine to the response to papaverine correlated with aging (r = -.87, P < .001). The slope of the coronary blood flow response to acetylcholine also correlated significantly with aging. The large epicardial coronary artery response to the low doses of acetylcholine (< or = 10 micrograms/min) correlated inversely with aging. CONCLUSIONS: The results of this study suggest that endothelium-dependent dilation of coronary arteries evoked by acetylcholine may be decreased with aging in humans.

Acetylcholine↗