[Dual SPECT for the assessment of angina pectoris].
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Aged↗
Biomedical subjects
Y Takeishi
Publications and source records attributed to Y Takeishi.
[Myocardial scintigraphy for the detection of unstable angina pectoris].
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Angina, Unstable↗
Left ventricular function and myocardial perfusion during dipyridamole infusion assessed by a single injection of 99Tcm-sestamibi in patients unable to exercise.
First-pass radionuclide ventriculography followed by myocardial single photon emission computed tomography (SPECT) with 99Tcm-methoxyisobutyl isonitrile (sestamibi) was performed at rest and during dipyridamole infusion in 42 patients with suspected coronary artery disease. The presence of coronary stenoses of > or = 50% diameter was compared with the presence of rest or dipyridamole-induced abnormalities in perfusion or left ventricular function. Radionuclide-determined left ventricular ejection fraction (LVEF) was highly reproducible and correlated well with LVEF derived from contrast left ventriculography. Left ventricular ejection fraction decreased significantly after dipyridamole infusion in patients with multivessel disease (58 +/- 10% versus 52 +/- 11%, P < 0.01). The sensitivity and specificity for the detection of patients with coronary artery disease were 85 and 75% by myocardial SPECT, and 47 (P < 0.01 versus SPECT) and 75% by LVEF, respectively. However, in patients with multivessel disease, the sensitivity of LVEF was not different from that of SPECT (72% versus 89%, P = ns). The sensitivity of LVEF was higher in patients with multivessel disease than in those with single-vessel disease (19% versus 72%, P < 0.01). Radionuclide ventriculography followed by myocardial SPECT with 99Tcm-sestamibi allows simultaneous evaluation of ventricular contractile function associated with perfusion abnormality during dipyridamole infusion and may enhance the functional description of myocardial ischaemia.
Adult↗
Comparison of adenosine and treadmill exercise thallium-201 stress tests for the detection of coronary artery disease.
To determine the clinical usefulness of adenosine Tl-201 imaging for the evaluation of coronary artery disease, 22 patients with suspected coronary artery disease who underwent adenosine and exercise Tl-201 single photon emission computed tomography (SPECT) were studied. The peak levels of heart rate (83 vs 123 bpm, p < 0.001), systolic blood pressure (124 vs 164 mmHg, p < 0.001), diastolic blood pressure (70 vs 86 mmHg, p < 0.01) and rate pressure products (10220 vs 20410 bpm x mmHg, p < 0.001) were markedly smaller during adenosine infusion than during exercise. Segmental agreements between adenosine and exercise tests were 90% (218 of 242 segments) regarding the presence of perfusion defects and 89% (215 of 242 segments) regarding the presence of redistribution. Regional Tl-201 uptake (r = 0.85, p < 0.001) and the extent (r = 0.75, p < 0.001) and intensity (r = 0.83, p < 0.001) of Tl-201 defects during adenosine testing were closely correlated with those of exercise testing. Adenosine and exercise tests showed similar sensitivities for the identification of individual coronary stenosis (85% vs 78%). However, in patients who were unable to perform adequate exercise (maximal heart rate < 120 bpm), the sensitivity of adenosine imaging tended to be higher than that of exercise imaging (92% vs 69%, p = 0.07). Adenosine Tl-201 imaging is an alternative to the exercise test for assessing the severity and loci of coronary artery disease, especially in patients who are unable to perform adequate physical exercise.
Adenosine↗
Ratio of lung to heart thallium-201 uptake on exercise and dipyridamole stress imaging in coronary artery disease--implication of SPECT.
To examine whether measurements of lung thallium-201 (Tl-201) uptake with single photon emission computed tomography (SPECT) following exercise or dipyridamole infusion provide complementary information as reported in planar imaging, we examined 140 patients undergoing exercise or dipyridamole Tl-201 SPECT and coronary arteriography for the diagnosis of coronary artery disease (CAD). On the reconstructed coronal tomographic image, regions of interest were placed over the left upper lung field and the left ventricular myocardium. Lung to heart ratio (L/H ratio) was calculated as a fraction of average Tl-201 counts per pixel in the lung divided by those in the myocardium. An L/H ratio of larger than a value of mean +2 standard deviation, derived from patients without significant coronary stenosis, was considered as abnormal. The patients with abnormal L/H ratio on exercise Tl-201 SPECT had larger extent and severity scores of Tl-201 defects on the initial image, lower left ventricular ejection fraction, higher end-diastolic pressure and higher incidence of multi-vessel CAD than those with the normal ratio. However, in dipyridamole studies, abnormal L/H ratio did not relate to scintigraphic or hemodynamic severity. These data confirmed that increased lung Tl-201 uptake after exercise suggested the presence of extensive CAD or left ventricular dysfunction. However, L/H ratio might be less useful in dipyridamole studies. Thus, quantitative measurements of L/H ratio with exercise but not dipyridamole SPECT could provide additional information related to the involved cardiac pump performance in CAD.
Adult↗
Heterogeneous myocardial distribution of iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in patients with hypertrophic cardiomyopathy.
IT has been proposed that iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (123I-BMIPP) is an agent for myocardial fatty acid metabolism in animal models. The aim of the present study was to determine whether alterations in fatty acid uptake and/or utilization in patients with hypertrophic cardiomyopathy (HCM) could be detected by 123I-BMIPP. Myocardial imaging with 123I-BMIPP and thallium-201 (201Tl) was performed in 14 fasted patients. A dose of 111 MBq of 123I-BMIPP was administered intravenously at rest, and myocardial emission computed tomography was obtained 20 min and 3 h after injection. The 201Tl imaging was also performed within 1 week after the 123I-BMIPP study. The regional myocardial uptake and clearance of 123I-BMIPP and 201Tl were assessed quantitatively. The myocardial distribution of 123I-BMIPP was more heterogeneous than that of 201Tl in patients with HCM. The myocardial uptake of 123I-BMIPP was lower in the anteroseptal region of the left ventricle than in the posterolateral region (74% vs. 85%, P less than 0.001). The anteroseptal wall showed a faster clearance of 123I-BMIPP than the posterolateral wall (33% vs. 27%, P less than 0.01). Both a decreased uptake and rapid clearance of 123I-BMIPP were observed in the hypertrophied myocardium of the anteroseptal wall, where 201Tl uptake was normal or even increased. Myocardial segments with a markedly increased thickness showed a lower uptake and faster clearance of 123I-BMIPP than those with mild hypertrophy (uptake 73% vs. 82%, P less than 0.05; clearance 30% vs. 25%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Cardiomyopathy, Hypertrophic↗
[Thallium-201 myocardial perfusion imaging during adenosine-induced coronary vasodilation in patients with ischemic heart disease].
201Tl myocardial perfusion imaging during adenosine infusion was performed in consecutive 55 patients with suspected coronary artery disease. Adenosine was infused intravenously at a rate of 0.14 mg/kg/min for 6 minutes and a dose of 111 MBq of 201Tl was administered in a separate vein at the end of third minute of infusion. Myocardial SPECT imaging was begun 5 minutes and 3 hours after the end of adenosine infusion. For evaluating the presence of perfusion defects, 2 short axis images at the basal and apical levels and a vertical long axis image at the mid left ventricle were used. The regions with decreased 201Tl uptake were assessed semi-quantitatively. Adenosine infusion caused a slight reduction in systolic blood pressure and an increase in heart rate. The rate pressure products increased slightly (9314 +/- 2377 vs. 10360 +/- 2148, p < 0.001). Chest pain (24%) and headache (13%) were the frequent side effects. The second-degree atrioventricular block was developed in 11 of 55 (20%) patients. All symptoms and hemodynamic changes were well tolerated and disappeared within 1 or 2 minutes after discontinuing adenosine infusion. The sensitivity and specificity for the detection of patients with coronary artery disease were 100% (31/31) and 88% (7/8), respectively. 201Tl myocardial imaging during adenosine infusion was considered to be safe and useful for evaluating the patients with ischemic heart disease.
Adenosine↗
Functional recovery of hibernating myocardium after coronary bypass surgery: does it coincide with improvement in perfusion?
To determine the relationship between functional recovery and improvement in perfusion after coronary artery bypass graft surgery (CABG), 49 patients were studied. Radionuclide angiography was performed before, 1 month after, and 6 to 12 months after CABG to evaluate regional wall motion. Exercise thallium-201 myocardial perfusion imaging was done before and 1 month after CABG to assess regional perfusion. Preoperative asynergy was observed in 108 segments, and 74 of them showed an improvement in wall motion 1 month after CABG (segment A). Sixty-six of these segments (89%) were associated with an improvement in perfusion. Eight segments that had not improved 1 month after CABG demonstrated a delayed recovery of wall motion 6 to 12 months after CABG (segment B). However, seven of eight segments (88%) already showed an improvement in perfusion 1 month after CABG. A total of 82 segments exhibited functional recovery after CABG and were considered hibernating segments. In the preoperative study segment B more frequently had areas of akinesis or dyskinesis than segment A (75% vs 34%, p less than 0.05). The mean percent thallium-201 uptake in segment B was lower than that in segment A (74% +/- 9% vs 83% +/- 8%, p less than 0.05). Functional recovery of hibernating myocardium usually coincided with an improvement in perfusion. However, delayed functional recovery after reperfusion was observed in some instances. Severe asynergy and severe thallium-201 defects were more frequently observed in these segments with delayed recovery. Hibernating myocardium might remain stunned during those recovery periods.
Coronary Artery Bypass↗
Dilatation of the left ventricular cavity on dipyridamole thallium-201 imaging: a new marker of triple-vessel disease.
To investigate the significance and mechanism of dilatation of the left ventricular cavity on dipyridamole thallium-201 imaging, we performed both dipyridamole thallium-201 imaging and dipyridamole radionuclide angiography on 83 patients with known angiograms. The dipyridamole/delayed ratio of the left ventricular dimension from the thallium-201 image was defined as the left ventricular dilatation ratio (LVDR). An LVDR greater than the mean + two standard deviations in patients without coronary artery disease was defined as abnormal. Twenty-two of 83 patients showed an abnormal LVDR, and 18 of the 22 patients (82%) had triple-vessel disease. By defect and washout analysis, the sensitivity and specificity for correctly identifying the patients as having triple-vessel disease was 72% and 76%, respectively, whereas LVDR had a sensitivity of 72% and a specificity of 93%. When LVDR was used in combination with the defect and washout criteria, sensitivity increased to 84% without a loss of specificity. In those 22 patients with abnormal LVDRs, end-diastolic volume measured by radionuclide angiography did not change after dipyridamole infusion. Dilatation of the left ventricular cavity on dipyridamole thallium-201 imaging reflected relative subendocardial hypoperfusion induced by dipyridamole rather than actual chamber enlargement. The LVDR was moderately sensitive and highly specific for triple-vessel disease and provided complementary information to dipyridamole thallium-201 imaging.
Adult↗
Simultaneous assessment of left ventricular wall motion and myocardial perfusion at rest and during exercise by technetium-99m methoxy isobutyl isonitrile.
First-pass radionuclide ventriculography followed by myocardial SPECT with technetium-99m methoxy isobutyl isonitrile (Tc-99m MIBI) was performed on 12 patients with suspected coronary artery disease at rest and during exercise. Left ventricular wall motion and myocardial perfusion were assessed simultaneously and compared on a segment-by-segment basis. Segmental agreement between Tc-99m MIBI and Tl-201 with regard to the presence of perfusion defects was 95% (57/60) at rest and 93% (37/40) during exercise. With respect to the assessment of myocardial ischemia and/or infarction, abnormalities in regional wall motion agreed with the presence of myocardial perfusion defects in 18 out of 21 segments (86%). Simultaneous evaluation of regional wall motion and myocardial perfusion by Tc-99m MIBI may provide useful information for the assessment of myocardial ischemia.
Adult↗
The relationship between chest pain during thallium-201 scintigraphy with dipyridamole and myocardial ischemia.
Dipyridamole thallium-201 scintigraphy (DP-Tl) and coronary angiography were studied on 74 patients with suspected coronary artery disease. We compared the clinical features, hemodynamic responses, angiographic results and scintigraphic findings of patients who had chest pain during DP-Tl testing ('chest pain' group) with those of patients who did not have chest pain ('no pain' group). Thirty eight (51%) of the 74 patients developed chest pain. Heart rate and rate pressure product during DP infusion of 'chest pain' group were greater than those of the 'no pain' group (p less than 0.05). Ischemic ST depression was more frequently observed among 'chest pain' patients (p less than 0.01). There were no differences in angiographic severity of coronary artery disease between 'chest pain' and 'no pain' group. Also, we could find no differences in extent and severity scores of perfusion defects and washout abnormalities between the two groups. However, when patients with myocardial infarction were excluded, the 'chest pain' group had significantly greater extent and severity scores of washout abnormalities than the 'no pain' group (extent score: 38 +/- 8 vs 18 +/- 5, p less than 0.05, severity score: 55 +/- 15 vs 18 +/- 7, p less than 0.01). Our study indicated that in patients without myocardial infarction, patients with 'chest pain' had more severe ischemia than 'no pain' patients. But in patients with myocardial infarction, myocardial ischemia not accompanied by chest pain might be as severe as that with chest pain. The presence or absence of myocardial infarction might have great influence on results regarding the relation of chest pain to myocardial ischemia.
Adult↗
[Evaluation of non-circular orbit in thallium-201 myocardial SPECT].
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Heart↗
[Evaluation of silent myocardial ischemia by exercise radionuclide ventriculography: comparison between patients with and without old myocardial infarction].
We evaluated left ventricular systolic function during exercise in patients with silent or symptomatic myocardial ischemia by radionuclide ventriculography (RNV). The subjects consisted of 61 patients who had evidence of myocardial ischemia during exercise RNV defined as positive exercise electrocardiographic changes and angiographically documented coronary artery disease. The patients without angina during exercise (SMI) had less exercise-induced left ventricular systolic dysfunction than patients with angina (CP) (change in ejection fraction during exercise: delta EF; -1 +/- 13 vs -6 +/- 10%, p less than 0.05, systolic blood pressure/end-systolic volume in exercise divided by systolic blood pressure/end-systolic volume in rest: SP/ESV (ex/rest); 1.1 +/- 0.6 vs 0.8 +/- 0.3, p less than 0.05). The 61 patients were divided into two groups, that is, those with and without old myocardial infarction (OMI), and we compared the degree of left ventricular systolic dysfunction during exercise between SMI and CP by RNV in each group. In patients without OMI, SMI had less exercise-induced left ventricular dysfunction than CP (delta EF; 1 +/- 12 vs -10 +/- 8%, p less than 0.01, SP/ESV (ex/rest); 1.1 +/- 0.6 vs 0.7 +/- 0.2, p less than 0.01). However, there were no differences between SMI and CP with OMI. In conclusion, it was thought that SMI without OMI was less degree of myocardial ischemia, and that SMI with OMI was potentially caused by some factors except for the degree of myocardial ischemia.
Aged↗
[Simultaneous assessment of wall motion and myocardial perfusion by technetium-99m methoxy isobutyl isonitrile].
The aim of this study was to assess whether or not myocardial uptake of Technetium-99m methoxy isobutyl isonitrile (Tc-MIBI) indicated myocardial viability. We performed simultaneous Tc-MIBI angiography and myocardial SPECT at rest on 12 patients with suspected coronary artery disease. Left ventricle was divided into 3 segments, and regional wall motion was graded as normal, hypokinesis and akinesis/dyskinesis. Myocardial uptake of Tc-MIBI was assessed as normal, reduced and absent in each segment. In segments with normal and reduced Tc-MIBI uptake, 7% (2 of 28) and 33% (2 of 6) showed wall motion abnormalities of akinesis/dyskinesis, respectively. However, all segments with absent Tc-MIBI uptake had asynergy of akinesis/dyskinesis (2 of 2, 100%). Myocardial Tc-MIBI uptake at rest indicated wall motion abnormalities and was considered to be useful for the evaluation of myocardial viability. First-pass radionuclide angiography followed by myocardial SPECT with Tc-MIBI demonstrated to be useful for the simultaneous assessment of the left ventricular wall motion and myocardial perfusion.
Coronary Circulation↗
[Assessment of right ventricular function by first-pass radionuclide ventriculography: fixed area vs separate area method for calculation of right ventricular ejection fraction].
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Female↗
[Effect of aminophylline on thallium-201 washout rate during myocardial perfusion imaging with dipyridamole].
Thallium-201 myocardial perfusion imaging with dipyridamole was performed on 78 patients (pts) with suspected coronary artery disease (CAD). Twenty eight pts had normal coronary arteries (control group), and 50 pts had 50% or greater stenosis in one or more major coronary arteries (CAD group). In control group, aminophylline (Am) was infused intravenously on 12 pts during dipyridamole testing. Mean washout rate (WR) of these 12 pts was greater than that of 16 pts without Am (42% vs 35%, p less than 0.01). Then normal limit of WR was defined separately from the pts of control group with and without Am. The sensitivity for detecting the pts with CAD by WR analysis which normal limit was calculated separately with and without Am was 92% (46/50). When normal limit of WR was determined from all pts in control group, the sensitivity decreased to 84% (42/50). Am significantly affected thallium-201 washout during dipyridamole testing. WR of CAD pts should be estimated by specific set of normal limit with and without Am.
Aminophylline↗
Relationship of thallium-201 defect and left ventricular function after dipyridamole infusion.
Tl-201 imaging and first-pass radionuclide ventriculography (RNV) by 4 min infusion of 0.56 mg/kg dipyridamole were performed on 22 patients with coronary artery disease in order to know the relationship of myocardial perfusion and left ventricular function after dipyridamole-infusion, and thereby to define whether Tl-201 defect with dipyridamole could imply myocardial ischemia. Initial and delayed Tl-201 images were divided into anterior, apical, and infero-posterior segments, and segmental perfusion defects were categorized as reversible, fixed and no defect. RNV on the 30-degree right anterior oblique view was also divided into anterior, apical, and infero-posterior wall to be evaluated for regional wall motion by a 5 point score before and after dipyridamole. Changes in left ventricular ejection fraction (LVEF) with dipyridamole were also calculated. Normal responses of regional wall motion and LVEF to dipyridamole were established from the data of 14 normal subjects. Reversible defects were closely associated (69%) with an abnormal response of regional wall motion (score decrease of 1 or more after dipyridamole). Both fixed defects and no defects showed little association with abnormal response of regional wall motion. Moreover, 77% of the patients having reversible-defect segment showed an abnormal response of LVEF (reduction of 3% or more following dipyridamole). However, patients without reversible defect did not show an abnormal response to dipyridamole. These results suggest that dipyridamole-induced Tl-201 defects represent a myocardial ischemia which causes a reduction of ventricular function.
Adult↗
[Detection of coronary artery disease by exercise radionuclide ventriculography: using sector analysis].
Exercise first-pass radionuclide ventriculography was performed on 65 patients with coronary artery disease (CAD) and 18 control subjects with normal coronary artery, Left ventricle (LV) was divided into 5 sectors in radial, and volume curves were generated for whole LV and each sector for estimating LVEF and time to end systole (TES). The differences of TES between whole LV and each sector were calculated and these 5 differences were averaged (Variation of TES). We defined this Variation of TES as an index of LV asynchrony, and used for detection of CAD. The overall sensitivity and specificity for identifying CAD were 63% and 83% (LVEF during exercise), 51% and 83% (delta LVEF). Variation of TES during exercise had a sensitivity and a specificity of 88% and 83%, and was more sensitive than both LVEF during exercise and delta LVEF (p less than 0.01). In conclusion, Variation of TES was a good marker of LV asynchrony and useful for the detection of CAD.
Coronary Disease↗