PubMed Health⌕ Search

Biomedical subjects

Y Futagami

Publications and source records attributed to Y Futagami.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Exercise radionuclide ventriculography in evaluating successful percutaneous transluminal coronary angioplasty (PTCA)].

To evaluate late success of PTCA in 29 patients with coronary artery disease, exercise radionuclide ventriculography was performed. Twenty-nine patients were classified into two groups according to the presence of restenosis (Group N: 19 patients without restenosis, Group R: 10 patients with restenosis). LVEF improved significantly in Group N, and the sensitivity, specificity and overall accuracy for detecting restenosis were 100%, 68% and 79%, respectively. Regional wall motion abnormality during exercise did not worsened in Group N, and the sensitivity, specificity and overall accuracy for detecting restenosis were 89%, 96%, and 94%, respectively. The left ventricular end-systolic volume during exercise increased in group R but decreased in Group N. The exercise response of the ratio of systolic blood pressure to end-systolic volume in Group N was significantly larger than that of Group R, and was considered to be useful parameter for detecting restenosis.

Adult↗
PubMed1989

Assessments of left ventricular function during exercise in patients with dilated cardiomyopathy: comparison with ischemic cardiomyopathy.

Responses to supine bicycle ergometer exercise were assessed in a study population consisting of 26 patients with dilated cardiomyopathy (DCM) and 23 patients with ischemic cardiomyopathy (ICM). Left ventricular ejection fraction (LVEF) and regional wall motion were analyzed at rest and during supine bicycle ergometer exercise with radionuclide ventriculography. Although the same degree of LVEF between DCM (23 +/- 8%) and ICM (26 +/- 4%) occurred at rest, the left ventricular regional wall motion abnormality was more prominent in DCM. LVEF during the peak exercise stage in DCM was almost unchanged (24 +/- 8%), but in ICM it decreased significantly (22 +/- 5%). Exercise-induced regional wall motion abnormalities were detected in nine patients (35%) in DCM and 13 patients (57%) in ICM. Although patients with DCM are believed to have diffuse hypokinesis of the left ventricle, severe regional wall motion abnormalities (akinesis or dyskinesis) were frequently observed. During the follow-up period of up to six years, eight patients with DCM died of congestive heart failure. In eight patients with DCM who showed decreased LVEF during exercise, five patients died. However, only three of 18 patients without decreased LVEF during exercise died. Exercise-induced left ventricular dysfunction in DCM seems to be a poor prognostic sign.

Adult↗
PubMed1989

[Clinical significance of exercise induced ST segment depression after successful percutaneous transluminal coronary angioplasty--assessment by thallium-201 SPECT].

To evaluate the clinical significance of ST segment depression during repeated Treadmill exercise after successful PTCA, Thallium-201 SPECT was performed. The Thallium-201 SPECT was performed before, one week after and 3-6 months after PTCA. All thirty-five patients had one vessel disease and positive Thallium-201 exercise test. During follow-up period for 3-6 months, 11 of 35 patients had persistent ST segment depression. Restenosis of dilated coronary lesion was demonstrated in 6 of 11 patients. In another 3 of 35 patients, exercise induced ST segment depression was disappeared during follow-up Treadmill exercise. In 14 patients with persistent or transient ST segment depression after PTCA, Thallium-201 SPECT demonstrated transient ischemia in 5 of 6 patients with restenosis. In other 8 patients without restenosis, SPECT images did not demonstrate myocardial ischemia and coronary arteriographic findings could not verify side branch stenosis or intimal dissection which might cause myocardial ischemia. The etiology of ST segment depression after successful PTCA in one vessel disease is not produced by exercise induced myocardial ischemia but still unknown mechanisms may be present.

Adult↗
PubMed1989

[Clinical significance of reverse redistribution in exercise thallium-201 SPECT after percutaneous transluminal coronary angioplasty].

Clinical significance of reverse redistribution on thallium image was evaluated in 54 patients who had undergone PTCA. Thallium SPECT imaging was performed one week and three to six months after PTCA. Reverse redistribution was detected eight of 54 patients one week after PTCA and five of 38 patients three to six months after PTCA. In the segments with reverse redistribution, reduced regional wall motion and lesser degree of coronary stenosis was common features (p less than 0.05) angiography. In conclusion, reverse redistribution had a tendency to appear in the region with mild myocardial injury and relatively high coronary blood flow after PTCA. But in cases with new occurrence and disappearance of reverse redistribution during follow up period, we can not assess the factors to explain these phenomena. In these segments, "coronary flow reserve", "stunned myocardium", "hibernating myocardium" or other factors may be related.

Angioplasty, Balloon, Coronary↗
PubMed1988

[Graft patency and myocardial viability after aorto-coronary bypass surgery evaluated by exercise 201T1 myocardial SPECT].

To evaluate graft patency and myocardial viability after aorto-coronary (AC) bypass surgery, 58 patients (29 with old myocardial infarction and 29 with effort angina) underwent symptom-limited exercise 201T1 myocardial SPECT using a bicycle ergometer before and after surgery. The results were as follows: 1. The overall angiographic graft patency was 87% (97 of 112 grafts). 2. According to the stress SPECT images, graft patencies were 98% for areas with postoperative improvement by 201T1 uptakes, 79% for areas with unchanged patterns, and 53% for areas with worsened patterns. In spite of patent grafts, among cases with worsened 201T1 uptakes the etiologies included perioperative infarction, anastomotic strictures, and poor run-off distal to the anastomoses. 3. Following patency of grafts, postoperative normalized perfusion patterns were observed in 69% (27 of 39 segments) of segments with persistent preoperative low uptakes and 25% (4 of 16 segments) of segments with persistent preoperative defects. Thus, exercise 201T1 myocardial SPECT proved a useful diagnostic means of assessing graft patency and effectiveness. However, after AC bypass surgery, 25% of the regions which had persistent defects before surgery exhibited normal perfusion patterns. These findings suggest that persistent defects may represent hypoperfusion of viable myocardium, and that we should carefully diagnose myocardial scars.

Adult↗
PubMed1987

Incidence and clinical course of right ventricular infarction: assessment with radionuclide ventriculography.

The incidence and prognosis of right ventricular infarction were studied by radionuclide ventriculography (RNV) in 50 consecutive cases of acute myocardial infarction. RNV was performed within thirty-six hours of symptoms and one month after onset. Right ventricular infarction was absent in all 25 patients with anterior infarction. It was found in 15 of the 25 patients with inferior infarction, accompanied by a marked reduction in right ventricular ejection fraction (28 +/- 8%), but was notably alleviated one month later with normalization of right ventricular ejection fraction (39 +/- 7%) and wall motion. These phenomena seem to be specific in right ventricular infarction.

Adult↗
PubMed1987

Myocardial infarction in Graves' disease without coronary artery disease.

A 45-year-old female without coronary risk factors showed a 20 kg decrease in body weight, hyperhydrosis, palpitations and dyspnea on exertion for 2 months, and nocturnal dyspnea for 1 month before admission. She did not notice chest pain indicative myocardial infarction or fever suggestive myocarditis. Graves' disease was confirmed by exophthalmos and elevated titers of T3 and T4 thyroid hormones. Cardiac catheterization studies demonstrated no significant coronary artery disease but showed akinesis of the anteroseptal and apical walls which suggested myocardial infarction. Thyroid hormone may directly influence myocardial oxygen supply and demand and, by some unknown mechanism, cause a critical imbalance in coronary circulation resulting in myocardial infarction.

Coronary Disease↗
PubMed1987

[Acute right ventricular infarction: assessment with radionuclide ventriculography].

The clinical significance of right ventricular (RV) infarction has been neglected compared with left ventricular infarction. In recent years, however, the clinical importance of RV function in the treatment of myocardial infarction has been well recognized. We performed prospective radionuclide studies to assess the incidence and prognosis of RV infarction in 50 cases of initial acute myocardial infarction (25 cases of anterior and 25 of inferior infarction). Radionuclide ventriculography was performed within the first two days after onset of symptoms, and repeated one-two weeks and one month after the attack, respectively. RV infarction was diagnosed by the presence of severe RV regional wall motion abnormalities and positive signs of at least one of the following diagnostic signs: ST elevation at V4R in the ECG, positive 99m-technetium pyrophosphate myocardial scintigram at the RV free wall, and positive right heart catheterization findings. Results were as follows: 1. RV infarction was documented in 15 of 25 cases with inferior infarction, but there were no cases in anterior infarction. 2. There were no remarkable changes of RV ejection fraction (EF) in anterior myocardial infarction during one month (41% +/- 8% in acute phase and 43 +/- 8% in four weeks later). However, RVEF was markedly improved from 34 +/- 11% during first two days, to 38 +/- 7% during one-two weeks, and 39 +/- 8% four weeks after the attack, in cases of inferior infarction with RV infarction. Without RV infarction, RVEF in cases of inferior infarction did not show improvement. 3. In 11 of 15 cases with RV infarction, RV regional wall motion abnormalities improved to the normal range, which seemed to contribute to the improvement of RVEF. 4. Hemodynamic findings with Swan-Ganz catheters showed typical findings compatible with RV infarction only in seven of 13 cases with RV infarction. Thus this finding implies that RV failure did not always accompany RV infarction. 5. Coronary arteriography revealed that right coronary arterial lesions proximal to the RV branch were documented in all 10 cases with RV infarction who had coronary arteriography. RV infarction, caused by deranged coronary blood flow at the RV branch of the right coronary artery, showed marked improvement of RVEF during four weeks after the attack in prospective radionuclide studies. This finding was not seen in left ventricular infarction. The pathophysiological mechanism of improvement of RVEF in RV infarction would be the difference of its coronary circulation compared with that of the left ventricle.(ABSTRACT TRUNCATED AT 400 WORDS)

Cardiac Catheterization↗
PubMed1987

[Stress Tl-201 myocardial single photon emission computed tomography in diagnosing ischemic heart disease: its value and limitations].

The value and limitations of stress 201T1 myocardial single photon emission computed tomography (SPECT) for diagnosing ischemic heart disease (IHD) was studied. Using a dual-head rotating gamma camera system, stress SPECT and conventional planar imaging were performed for 138 patients while they were examined by symptom-limited graded bicycle ergometer exercise. All patients underwent selective coronary arteriography and left ventriculography, and 93 had myocardial infarction (MI), 30 had effort angina (EA) and 15 were normal (control). Sensitivities for detecting IHD (SPECT: planar = 96%: 89%, p less than 0.01), individual coronary arterial lesions (left anterior descending artery = LAD, 84%: 68%, p less than 0.005; left circumflex artery = LCX, 60%: 47%, NS; right coronary artery = RCA, 88%: 69%, p less than 0.01), multivessel disease (= LAD + LCX and/or RCA, 53%: 31%, p less than 0.025), and three vessel disease (60%: 13%, p less than 0.005) were significantly higher by SPECT than by planar imaging. In addition, detection of ventricular aneurysms by SPECT was possible with a reasonably high sensitivity (94%) and specificity (84%). Signs of aneurysm included 1) an extensive anterior permanent defect, 2) a large left ventricular cavity, and 3) widening of the angle composed by the septal and lateral walls toward the apex in transaxial images. Sensitivity for detecting IHD was significantly lower in patients without MI (i.e., EA) than in patients with MI (MI: EA = 100%: 83%, p less than 0.005). Sensitivity for detecting individual coronary arterial lesions was lower in the absence than in the presence of MI (LAD; 77%: 87%, LCX; 38%: 68%, RCA; 71%: 90%, respectively), with multivessel disease than with single vessel disease, and with mild than with severe grade of stenosis. Sensitivity for detecting multivessel disease was lower in patients without MI than in those with MI (31%: 61%, respectively), and in anterior MI than in posteroinferior MI, or both MIs (36%: 69%: 100%, respectively). Stress-induced ischemia of infarcted area (anterior MI, 36%; posteroinferior MI, 24%) and ventricular aneurysm (anterior MI, 21%; posteroinferior MI, 0) masked other coronary arterial stenoses in patients with previous MI. We concluded that stress 201T1 myocardial SPECT was a useful non-invasive technique for detecting IHD and individual coronary arterial lesions, multivessel disease (especially posteroinferior MI and anterior + posteroinferior MI), three vessel disease and ventricular aneurysms. However, there were limitations in detecting multivessel disease in patients with anterior MI and EA.

Coronary Disease↗
PubMed1987

[Myocardial ischemia with negative stress electrocardiography: evaluation by stress RI studies].

Patients with negative stress electrocardiography (ECG) (no ST segment depression) were re-evaluated by means of stress RI studies including 201T1 single photon emission computed tomography (SPECT) and 99mTc-RBCs radionuclide ventriculography (RNV). Four hundred seven patients, including 303 with old myocardial infarction (OMI; SPECT: 188, RNV: 115) and 104 with effort angina (EA; SPECT: 58, RNV: 46), all of whom underwent left ventriculography and coronary arteriography, were re-evaluated by symptom-limited graded bicycle ergometer exercise RI testing. The results were as follows: 1. Among those with negative stress ECG (53% of OMI and 31% of EA), 54% and 73% of OMI and EA, respectively, had positive SPECT. 2. Among those with negative stress ECG (56% of OMI and 39% of EA), 70% and 39% of OMI and EA, respectively, had positive delta EF (poor increase in ejection fraction: delta EF less than 5%) and, 41% and 28% of OMI and EA had deteriorated regional wall motion. 3. Those with OMI and negative ECG showed no correlations with the numbers of diseased vessels, infarcted sites, or ischemic areas. In conclusion, RI testing appears to be a significantly more sensitive means of detecting stress-induced ischemia, compared to stress ECG.

Adult↗
PubMed1986

[Right ventricular ischemia evaluated by radionuclide ventriculography].

The clinical usefulness of radionuclide ventriculography (RNV) was evaluated in patients with right ventricular ischemia. The subjects consisted of 25 patients with acute inferior myocardial infarction, 19 patients with old myocardial infarction and six patients with angina pectoris who had severe stenosis of the right coronary artery. In patients with acute inferior myocardial infarction, follow-up radionuclide studies were performed during the recovery periods on the first, 7th-14th, and 30th hospital day. Fifteen of the 25 patients initially had decreased right ventricular ejection fractions (evidence of right ventricular infarction). The mean value was 28 +/- 8% on the initial day, but 7-14 days and 30 days after the acute attack, it improved markedly to 36 +/- 9% and 39 +/- 9%, respectively. Regional wall motion abnormality resolved in 10 of the 15 patients on the 30th hospital day. In 25 patients with old myocardial infarction or with angina pectoris, RNV was performed at rest and during supine exercise to determine the influence or right coronary artery disease. Right ventricular ejection fraction was changed by exercise from 42 +/- 7% to 44 +/- 10% in patients with proximal artery lesions, and from 45 +/- 7% to 50 +/- 10% in patients with distal artery lesions. Right ventricular ejection fraction increased in patients with isolated right coronary artery disease (rest: 44 +/- 8%, exercise: 49 +/- 9%), decreased in patients with combined left anterior descending artery disease (rest: 40 +/- 6%, exercise: 38 +/- 11%) and increased in patients with combined circumflex artery disease (rest: 43 +/- 5%, exercise: 47 +/- 6%). We concluded that right ventricular infarction is a frequent complication in patients with inferior myocardial infarction. However, right ventricular ejection fraction and right ventricular regional wall motion abnormality improve dramatically within one month. Stress-induced ischemia would be rare in patients with isolated right coronary artery disease. The above findings support the notion that the right ventricular myocardium has peculiar coronary perfusions.

Angina Pectoris↗