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Biomedical subjects

H Nonogi

Publications and source records attributed to H Nonogi.

At least 109 records · Page 6Linked to original sources
PubMed1993

[Evaluation of left ventricular early diastolic function by first pass radionuclide angiocardiography after dipyridamole infusion in patients with coronary artery disease--comparison with exercise test].

To evaluate the left ventricular early diastolic function after dipyridamole infusion or during exercise, the first pass radionuclide angiocardiography (FPRA) by a multicrystal gamma camera (SIM-400) was performed in 32 patients with coronary artery disease (CAD) and 14 normal subjects. Dipyridamole was administered intravenously (0.56 mg/kg in 4 min). The first third filling fraction (FF 1/3) and the first third mean filling rate (MFR 1/3) were calculated from the time-activity curve. FF 1/3 decreased and MFR 1/3 increased in both normal subjects and patients with CAD during exercise. After dipyridamole infusion, FF 1/3 and MFR 1/3 unchanged in normal subjects, in contrast, FF 1/3 and MFR 1/3 decreased in patients with CAD. Thus, dipyridamole infusion FPRA is more sensitive method to detect early diastolic dysfunction in patients with CAD than FPRA during exercise.

Aged↗
PubMed1993

Left ventricular filling measured by Doppler echocardiography during dynamic exercise in patients with myocardial infarction.

To assess left ventricular diastolic properties in response to dynamic exercise, mitral inflow velocity integrals were measured by pulsed-wave Doppler echocardiography in ten patients with myocardial infarction and in ten normal subjects, and simultaneous left ventricular pressure was obtained with micromanometry in the patients. Early filling velocity integrals were maintained in the patients during exercise. Late filling velocity integrals were not augmented during exercise in the patients, but were increased in the normal subjects. In the patients, there was an increase in mitral valve opening pressure, left ventricular end-diastolic pressure, and the time constant of left ventricular isovolumic pressure decay. The lowest diastolic pressure and the number of time constants that had elapsed before the lowest diastolic pressure remained unchanged. These results show that in patients with myocardial infarction, early filling is maintained by an increase in driving pressure during exercise, despite incomplete relaxation. Augmentation of late filling, seen in normal subjects, is impaired in patients with myocardial infarction, probably due to an increase in left ventricular stiffness.

Blood Flow Velocity↗
PubMed1992

Pathogenesis, treatment and prognosis of impending myocardial infarction and early post-infarction angina--relation between ST-segment shift during myocardial ischemia and the pathogenesis.

We studied 141 patients to evaluate the pathogenesis and clinical picture of high-risk unstable angina (UA), designated as impending myocardial infarction (IMI) in this study, or severe early post-infarction angina (PIA). IMI and PIA were diagnosed when chest pain appeared at rest and lasted 15 min or more despite extensive pharmacological therapy during hospital stay among consecutive 510 patients with UA. All patients underwent coronary angiography urgently within 72 h after chest pain, and were divided into 2 subgroups according to ST segment shifts during chest pain. In IMI, 42 patients with ST depression had higher incidences of prior myocardial infarction (MI), worsening UA, multivessel disease and complex lesions such as eccentric irregular lesion or ulceration. On the contrary, in 44 with ST elevation, new onset UA, single vessel disease and coronary thrombus (CT) were dominant. In PIA, 32 patients with ST elevation revealed higher incidences in Q wave MI, ST elevation at the MI onset, single vessel disease and CT, compared to 23 with ST depression who showed a high proportion of complex lesions. Thus, it was evident that there was a common link between the pathogenesis of IMI and PIA. The therapeutic options were also different in the groups according to ST segment shift. We conclude that ST segment shifts during chest pain may be useful for determining the pathogenesis and clinical features of high-risk UA.

Angina, Unstable↗
PubMed1992

Assessment of myocardial viability by using newly developed myocardial SPECT imaging.

Thallium myocardial imaging has been widely available for the detection of myocardial ischemia and assessment of myocardial viability in coronary artery diseases. However, myocardial imaging using SPECT and gamma-emitting radiopharmaceuticals has been developed for accurate evaluation of myocardial infarction and ischemia. The present study was undertaken to clinically evaluate myocardial necrosis, metabolism and sympathetic nerve activity. In this study, myocardial fatty acid metabolism was assessed using 123I-BMIPP, myocardial sympathetic neural activity was assessed using 123I-MIBG and myocardial necrosis was assessed using 111-In-antimyosin Fab. Dual energy SPECT using these new agents and thallium gives precise characterization of myocardial viability in coronary artery disease.

3-Iodobenzylguanidine↗
PubMed1992

[Dipyridamole-thallium myocardial imaging in patients unable to exercise adequately: comparison with arm and bicycle ergometer].

We assessed the usefulness of dipyridamole-thallium myocardial imaging in patients unable to exercise adequately, compared with arm-ergometer and standard (bicycle) ergometer. Fifty-six patients with arteriosclerosis obliterans, aortic aneurysm, aortic dissection and so on, who were revealed normal imaging, were studied. Only one of 13 cases with arm-ergometer and two of 14 with bicycle ergometer reached target heart rate. Lung thallium uptake in the cases with arm-ergometer (37 +/- 9%) is higher than that with dipyridamole (29 +/- 5%). This elevation may be confused with pectoralis muscle uptake. Washout rate is 45 +/- 9% with dipyridamole and 46 +/- 12% with bicycle ergometer, respectively, though there was no significant differences. Myocardial/background counts ratio with dipyridamole (4.6 +/- 0.8%) is significantly higher than that with arm and bicycle ergometer (arm-ergometer; 3.5 +/- 0.7, bicycle ergometer; 4.2 +/- 0.9). Then, myocardial image with dipyridamole have superior quality. We concluded that dipyridamole-thallium myocardial imaging is very useful in the patients who have suboptimal exercise efforts.

Aged↗
PubMed1992

[Influence of hypertensive left ventricular hypertrophy on detection of ischemic area with exercise thallium-201 myocardial scintigraphy].

Sixty-four patients with single left anterior descending artery disease having effort angina (group A: 40 patients without hypertension, group B: 10 patients with hypertrophic hypertension, group C: 14 patients with non-hypertrophic hypertension) were assessed the influence of hypertensive left ventricular (LV) hypertrophy on detection of ischemic area. The criterion of hypertrophy by two-dimensional echocardiography was > 12 mm in the wall thickness of interventricular septal or posterior wall. Population in Group B might show low detectability in ischemic area by 201Tl myocardial scintigraphy (positive thallium rate 60%, defect score 2.7 +/- 3.6), and high lung thallium uptake and high frequence of ECG positive among three groups. In semiquantitative analysis, the washout rate of the posterolateral wall and %RD (delayed %uptake-initial %uptake) of the septal wall in patients with Group B were lowest among three groups. However, the washout rate in the septal wall against the posterior wall, and the initial %uptake and the delayed %uptake of the septal wall were not significantly different among three groups. We could conclude that the decreased washout rate in nonischemic area with hypertensive LV hypertrophy might make the ischemic area masked.

Aged↗
PubMed1992

[Thallium-201 scintigraphy after dipyridamole infusion in patients with ischemic heart disease--comparison with maximal exercise].

Myocardial images after dipyridamole infusion (DIP-Tl) were compared with maximal thallium-201 images (Ex-Tl) to determine the utility for detecting coronary artery disease and the ischemic level in ischemic regions. Ex-Tl was performed in 36 patients of angina pectoris (Group 1), and DIP-Tl was performed in 22 patients of angina pectoris (Group 2), who were divided into two groups (Group 2a: 15 patients with low level exercise, Group 2b: 7 patients without low level exercise). Each group had normal controls (41, 27 and 31 people). The detectability of coronary artery by DIP-Tl was almost same with Ex-Tl (sensitivity 85% vs. 86%, specificity 80% vs. 95%). In the case of normal controls, the mean washout rate of group 2b was 44.4%, which was less than other two groups (50.6% for group 1, 48.8% for group 2a). And the mean myocardial/background (M/B) ratio of group 2b was 4.3 less than other two groups (4.7 for group 1, 4.9 for group 2a). In the case of the patients of angina pectoris, washout rate, M/B ratio, initial % uptake and delayed % uptake in the ischemic region were almost same among the 3 groups. This study demonstrates that DIP-Tl is as effective as Ex-Tl, and the ischemic level in the ischemic region is almost same among the 3 groups. But the thallium accumulation in the background of the group 2b is slightly higher than other two groups in the normal controls, so it is suggested that the image after only dipyridamole infusion becomes slightly unclear.

Coronary Disease↗
PubMed1992

[Diagnostic utility of myocardial imaging using 123I-labeled beta-methyl-iodophenyl pentadecanoic acid in ischemic heart disease].

We evaluated the myocardial metabolism in the acute and subacute phases of myocardial infarction or unstable angina using 123I-labeled beta-methyl-iodophenyl pentadecanoic acid (BMIPP). We then compared those findings with (1) myocardial perfusion images obtained with 201TlCl and (2) the regional and global left ventricular function determined by left ventriculography. Thirty-one patients were examined, consisting of 16 with acute myocardial infarction (6.8 +/- 2.6 days after onset), 8 with subacute myocardial infarction (35 +/- 3.0 days after onset) and 7 with unstable angina. The BMIPP images showed a larger uptake-defect than 201TlCl images in the patients in the acute or subacute phase of myocardial infarction. This finding was especially remarkable in the acute phase after successful coronary revascularization therapy. Moreover, in such cases, the myocardial BMIPP uptake improved to the same degree as 201TlCl one month later. The decrease in myocardial uptake of BMIPP agreed well with the decrease in regional wall motion in the acute and subacute phases of myocardial infarction. In contrast, the myocardial perfusion of 201TlCl did not always agree with the regional wall motion in stunned or hibernating myocardium, where BMIPP showed an uptake-defect in the acute phase but improved in the subacute phase. Thus, BMIPP is surmised to be able to depict fatty acid metabolism in in vivo myocardial imaging.

Adult↗
PubMed1992

[Usefulness of 201Tl myocardial scintigraphy after dipyridamole infusion in patients with atherosclerotic vascular disease].

To determine the utility for detecting ischemic heart disease (IHD), Dipyridamole thallium myocardial images (DIP-Tl) have been performed in the 103 patients with atherosclerotic vascular disease who can't exercise fully. Of 103 patients, there were 36 patients with arteriosclerosis obliterans (ASO), 31 patients with aneurysm of the abdominal aorta (AAA), 24 patients with aneurysm of the thoracic aorta (TAA) and 12 patients with dissecting aortic aneurysm (DAA). Clinical evidence of IHD was found in 20 patients with ASO, 10 with AAA, 7 with TAA and 4 with DAA respectively. Positive evidence of DIP-Tl was identified in 66% of 41 patients who had clinical evidence of IHD, and particularly in the patients with AAA (80%) and ASO (65%). On the other hand, in the patients without clinical evidence of IHD, positive evidence of DIP-Tl was identified in 19% of 62 patients and particularly in the patients with AAA (39%). In all patients, the percentage of the positive DIP-Tl ratio was 38%. And, when the 38% patients of the positive DIP-Tl were added to the patients of the negative DIP-Tl who had clinical evidence of IHD, almost half patients (51%) were considered to be complicated with IHD. This study suggests that the atherosclerotic vascular disease is highly complicated with IHD and DIP-Tl is useful to detect IHD.

Aged↗
PubMed1992

[A case of unstable angina pectoris associated with an active phase of polymyositis].

We report a case of unstable angina in an active phase of polymyositis. A 51 year-old man was admitted with a diagnosis of polymyositis and unstable angina with ST elevation on prolonged rest chest pain. Rest anginal attack which had been refractory to conventional antianginal medications was controlled by high dose of glucocorticosteroid. Electrocardiography revealed multifocal premature ventricular contraction. Since silent ischemia on exercise persisted, percutaneous transluminal coronary angioplasty (PTCA) was performed on a stenotic lesion in the left anterior descending artery. Since there was recurrent anginal attack, re-PTCA was carried out at the same site. He was discharged in a good condition. This case is considered to be associated with cardiac involvement of polymyositis because of ventricular arrhythmia, persistent increased serum levels of CPK-MB, and the marked benefits of corticosteroid against unstable angina. In addition, clinical manifestations, coronary arteriographic findings, and increased plasma levels of thrombin-antithrombin III complex suggest that cardiac involvement in polymyositis accelerates intracoronary thrombus formation and/or coronary spasm.

Angina, Unstable↗
PubMed1991

[Clinical and anatomical features of acute myocardial infarction associated with double rupture of the interventricular septum and ventricular free wall].

Four patients with acute myocardial infarction (MI) complicating double rupture; interventricular septum and ventricular free wall ruptures, were studied. All patients had histories of hypertension, and pre-infarction angina pectoris of short duration less than 8 days without previous MI. The sites of infarction were anteroseptal in 2 patients and inferoposterior in the other 2. Only one case was complicated with mild pump failure (Killip class II). Blood pressure was adequately controlled after the onset of MI in all patients. Interventricular septal rupture occurred between 2 and 10 days after the onset of MI. Free wall rupture occurred between 2 and 22 days after MI. Types of free wall ruptures were oozing in 2 patients and blow-out in the other 2. Surgical repair was performed in 2 patients with the oozing type rupture, who however died soon after surgery. The autopsy findings were as follows: 3 patients had left ventricular free wall ruptures and one had right ventricular free wall rupture. One of the patients with left ventricular free wall rupture showed a secondary rupture of a pseudo-ventricular aneurysm. Postmortem coronary angiograms revealed 3 patients with single-vessel disease and one patient with double-vessel disease, indicating that coronary arterial lesions and complicated heart failure were not severe in these 4 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Medical therapy in patients with left main coronary artery stenosis].

To elucidate the long-term prognosis of medically-treated patients with left main coronary artery (LMCA) lesions, 119 consecutive patients with LMCA lesions undergoing coronary angiography were analyzed retrospectively. Among these, 3 patients died soon after angiography and were excluded from this study. Among the remaining 116 patients, 22 were treated medically (Group M) for the following reasons: profound left ventricular (LV) dysfunction (3 patients), effective pharmacological treatment (10), and patients' refusal of surgical therapy (9). Among 94 patients who underwent coronary artery bypass graft (CABG), 83 patients survived (Group S). During the follow-up period, cardiac events occurred in 5 patients in Group M; cardiac deaths in 3, non-fatal myocardial infarction (MI) in one and late application of CABG in one. Two-year cardiac event-free rate after diagnosis was 77%, which remained unchanged thereafter. The cumulative survival rate was 83%. The incidence of cardiac events in Group M was higher than that in Group S (p < 0.01). However, cardiac event rates were similar between these 2 groups for patients with good collateral circulations to the left coronary arteries, no preceding MI and LV end-diastolic pressure less than 15 mmHg. We concluded that the Japanese patients with severe LMCA lesions who respond favorably to pharmacological intervention have unexpectedly good prognoses, however, obstructed collateral circulation to the left coronary system, the presence of preceding MI and high LV end-diastolic pressure were all high-risk factors for medically-treated patients.

Adult↗
PubMed1991

[Prognostic significance of scintigraphic silent myocardial ischemia detected by stress thallium scan in patients with recent myocardial infarction].

To evaluate the prognostic significance of scintigraphic silent myocardial ischemia (SMI) detected by stress thallium scan in patients with myocardial infarction (MI), we performed a retrospective investigation on cardiac events (CE) during a two-year follow-up period in 149 patients with MI within three months of onset (34 +/- 19 days). SMI was defined as asymptomatic redistribution (RD) in the infarcted area. The patients were divided into three groups based on results of stress thallium scan as follows: 50 patients with neither chest pain nor RD (Group A), 46 patients with SMI (Group B) and 53 symptomatic patients (Group C). In comparison of the incidence of CE, which included cardiac death, recurrent MI, chronic heart failure, angina pectoris, PTCA, CABG and severe ventricular arrhythmia (lown grade greater than or equal to 3) during two-year follow-up, Group C had significantly higher incidence of PTCA and CABG than Group B (p less than 0.01), but there was no significant difference of other CE between groups B and C except PTCA and CABG. In addition, Groups B and C had a significantly higher incidence of CE than Group A in cardiac event-free curves, but there was no significant difference for Groups B and C. We conclude that patients with SMI are associated with unfavorable prognosis as symptomatic patients and that these patients should undergo careful follow-up.

Aged↗
PubMed1991

[Invasive treatment in patients with prior coronary artery bypass grafting].

In eight hundred eighty three patients with prior coronary bypass grafting (CABG), cardiac symptoms were recurred in 179 patients in late follow-up period (mean 5 +/- 2.8 years). Of 179 patients, 43 patients had PTCA eventually. In these, 57 times of angioplasties were attempted. Twenty-one lesions in venous bypass grafts and 50 in native coronary arteries were performed, respectively. The initial success rate per bypass graft and per stenosis of native coronary artery were 68% and 74%, respectively. Five patients had elective CABG following failed PTCA. There were no emergency CABG procedures required after unsuccessful PTCA. Intracoronary thrombolysis (ICT) were performed in 13 patients. In these, 15 ICT attempts were made. Nine lesions in venous bypass grafts, 9 for native coronary arteries, and 3 for both were attempted. The primary success rate per occlusion was 67%. Twenty reoperation were done. There was one hospital death and one late death due to congestive heart failure 4 years after the reoperation. In conclusion, invasive treatments in patients with prior CABG can be performed with satisfactory safety and good results. Therefore, invasive treatment should be considered in the patients with CABG if cardiac symptoms are disabling and angiographically suitable lesions are present in the native coronary arteries or vein grafts.

Aged↗
PubMed1991

[Clinical significance of ST segment shifts during chest pain in predicting the pathogenesis of impending myocardial infarction].

To know whether the pathogenesis of impending myocardial infarction(IMI) could be predicted by the direction of ST segment shifts during an ischemic chest pain, we studied 62 patients with IMI and undergoing emergent coronary angiography(CAG). They were selected from a consecutive number of 474 patients with unstable angina. IMI was defined when patients had more than 2 episodes of chest pain at rest under intensive pharmacological interventions after their CCU admission, and at least one of those was not relieved by nitroglycerin given intravenously. They were divided into 2 groups according to ST segment shifts during chest pain; 35 patients with ST elevation (G-1) and 27 patients with ST depression (G-2). The time of CAG was individually determined in each patient according to the severity of illness. Those with acute MI within 3 months before the study and 24 hours following the chest pain just before CAG were excluded from the study. New onset angina accounted for 49% in G-1 and 4% in G-2(p less than 0.01). Average history length of IMI, frequency of symptoms after CCU admission, and interval from the last symptom to CAG were similar in each groups. Single vessel disease was more predominant in G-1 than in G-2 (54% vs 11% p less than 0.01). Intracoronary thrombus(IT) in an ischemia related artery(IRA) was found in 97% of G-1 and 22% of G-2(p less than 0.001), while complex lesions(CL) proposed by Ambrose as another genesis of IMI were in 26% of G-1 and 74% of G-2(p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina, Unstable↗
PubMed1990

Estimation of left-ventricular systolic performance and its determinants in man from pressures and dimensions of one beat: effects of aortic valve stenosis and replacement.

Within a thick heart-chamber wall, there is a midwall element or layer whose displacements best express systolic performance. The volume enclosed by that midwall element (Vm) and the average stress in that element (sigma m) can be calculated accurately by simple formulae. From simultaneous left-side pressure tracings and contrast cine-ventriculograms, Vm and sigma m were calculated at 20-ms intervals for an entire cardiac cycle in five normal subjects and in eight patients before and one year after replacement of stenotic aortic valves. Prior to surgery, the overloaded left ventricles were not hypertrophied enough to restore normal mid- and end-ejection stresses. Four had subnormal cavity ejection fractions, but all had subnormal midwall ejection fractions. All had subnormal fractional midwall ejection rates and prolonged active intervals (from the beginning of activation to the end of deactivation). Judging from pre-ejection pressure-development rates, the pressure-developing ability was not consistently elevated by concentric hypertrophy, because the stress-developing ability (contractility) was usually subnormal. The ability to shorten in the absence of afterload appeared to be subnormal in about half of the cases. The subnormal midwall ejection fractions appeared to be due to various combinations of increased mid- and late-ejection stresses, reduced contractility, and reduced shortening ability. On average and in several cases, reduced shortening ability appeared to be the main cause of the reduced performance. The effect of the slowed fractional midwall ejection rate to reduce the midwall ejection fraction was partially compensated by a prolonged active interval, by prolonged ejection time relative to the active interval, and by a more sustained ejection rate. Valve replacement partially restored all values except contractility towards normal, but the restorations of wall/cavity ratio and active interval were slight.

Adult↗