PubMed Health⌕ Search

Biomedical subjects

C Landoni

Publications and source records attributed to C Landoni.

At least 37 records · Page 2Linked to original sources
PubMed1999

Assessment of CABG-related risk in patients with CAD and LVD. Contribution of PET with [18F]FDG to the assessment of myocardial viability.

BACKGROUND: Previous studies have demonstrated that hibernating myocardium can be assessed by [18F]fluorodeoxyglucose ([18F]FDG) and positron emission tomography (PET). This study evaluated the use of [18F]FDG-PET for CABG related risk assessment in patients with coronary artery disease (CAD) and left ventricle dysfunction (LVD). METHODS: We retrospectively evaluated 241 to patients candidate CABG presenting with signs and symptoms of congestive heart failure (CHF) prevailing over ischemic signs. Of the 241 patients, 153 had undergone [18F]FDG-PET as well as conventional assessment: 110 out of 153 (group A) were operated because of PET evidence of hibernation. Of the 241 patients, 88 had not undergone [18F]FDG-PET: 86 out of 88 (group B) were operated on. The outcome of surgical patients was evaluated by considering all major perioperative complications including the use of mechanical and pharmacological support and in-hospital mortality. After hospital discharge, each patient was examined at 1, 4 and every 6 months thereafter. RESULTS: Perioperative use of mechanical supports and inotropic drugs, was significantly lower for the PET selected group (A) than for the non PET selected group (B). Mortality within 30 days of surgery was 0.9% in group A and 19.8% in group B. The only predictors of perioperative outcome were the presence of hibernating tissue and the ejection fraction. CONCLUSIONS: [18F]FDG-PET prior to CABG can be crucial for the assessment of perioperative risk in patients with CAD.

Coronary Artery Bypass↗
PubMed1999

Primary cardiac lymphoma. A case report and review.

Primary cardiac lymphoma is classically defined as an extranodal non-Hodgkin's lymphoma exclusively located in the heart and/or pericardium. However, over the last few years, this definition has been extended to include other localizations on condition that these are clearly less important then a cardiac site, that must remain the first, during the illness course, and the most important for its entity. PCL is extremely rare in immunocompetent patients, accounting for 1.3% of all cardiac tumours and 0.5% of all extranodal lymphomas, but it has been encountered with increasing frequency in patients with AIDS or other severe immunodepressive syndromes. PCL is difficult to diagnose, especially during the early stage of the disease, because of its non-specific clinical manifestations, the limited possibility of using non-invasive diagnostic techniques, and difficulties or delays in applying invasive methods. The malignancy of its histotypes and its delicate location are responsible for its rapid and frequently unfavourable evolution. Successful treatment, which is mainly based on anthracycline-containing polychemotherapies, is heavily dependent on an early diagnosis. After a general review of the literature, the authors describe the clinical case of a patient with a PCL that had a secondary central nervous system location, treated with polychemotherapy and autologous peripheral blood stem cell transplantation. Emphasis is placed on the fact that it is more difficult to eradicate the disease from the central nervous system than from the heart.

Echocardiography↗
PubMed1999

Comparison of dual-head coincidence PET versus ring PET in tumor patients.

UNLABELLED: This study compared the multiring detector (Ring-PET) and the dual-head coincidence imaging system (DH-PET) for staging/ restaging neoplastic patients before or after surgery or radiochemotherapy. METHODS: Seventy patients with suspected tumor recurrence or metastatic dissemination received an intravenous dose of 18F-fluorodeoxyglucose (FDG) under overnight fasting and were studied in sequence with a dedicated positron emission tomograph with Ring-PET and a DH-PET. Ring-PET studies were performed 45-75 min postinjection and were followed by a DH-PET scan approximately 3 h postinjection. Number and location of the hypermetabolic lesions detected on DH-PET and Ring-PET reconstructed images were blindly assessed by three independent observers. RESULTS: DH-PET identified all 14 head lesions detected by Ring-PET, 53 of 63 thoracic lesions and 36 of 45 abdominal lesions. Of the 19 lesions not identified by DH-PET, 6 were smaller than 10 mm, 8 were between 10 and 15 mm and 1 was 18 mm; dimensions of 4 bone lesions were not available. A concordant restaging, based on location and number of lesions detected, was found in all 14 patients with head tumors, in 28 of 30 patients with thoracic tumors and in 24 of 26 patients with abdominal tumors. CONCLUSION: We found a good agreement between Ring-PET and DH-PET assessment of oncologic patients in detecting hypermetabolic lesions > or = 10-15 mm.

Adult↗
PubMed1999

Lack of prognostic value of 99mTc MIBI rest, 18F FDG and 201TL rest/redistribution on PTCA outcome of patients with moderate left ventricle dysfunction.

BACKGROUND: The clinical work-out of patients undergoing coronary revascularization includes the assessment of myocardial viability. This approach has to be defined in the different classes of patients. The aim of this study was to evaluate the predictive prognostic value of different techniques on outcome following PTCA in patients with moderate left ventricle dysfunction (left ventricle EF > or = 40%). METHODS: Seventeen patients with EF > or = 40% and undergoing PTCA were studied by 201Tl rest/redistribution, 18F-FDG and 99mTc-MIBI rest. Regional kinesis was scored by echo, dividing left ventricle in 11 segments. The echo evaluation was repeated at 1 and 6 months after revascularization. RESULTS: Global EF was 52.5 +/- 7% and 69 segments had abnormal kinesis. Patients underwent stress/rest 99mTc-MIBI SPET, rest/redistribution 201Tl SPET and rest 18F-FDG PET. Among the 11 segments defined on echo-matched tomographic images, the one with the highest activity at stress was assumed as reference (activity = 100%). If > 50% of reference segment, 18F-FDG and 201Tl uptakes were considered significant. After PTCA, the echo-follow-up did not demonstrated significant improvement of left ventricle function at 30 days after PTCA (EF 56 +/- 6%) as well as at 6 months (EF 56 +/- 9%). The positive predictive value under these conditions resulted: 46.5% with 99mTc-MIBI rest, 47.4% with 201Tl rest-redistribution and 45.7% with 18F-FDG. CONCLUSIONS: In summary, in the class of patients with moderately compromised function, considering as reference the improved regional kinesis after PTCA, 99mTc-MIBI at rest, 201Tl rest/redistribution and 18F-FDG do not exhibit a clear predictive value; patient population is then a highly relevant point to establish the accuracy of these diagnostic procedures.

Adult↗
PubMed1999

FDG/PET and spiral CT image fusion for medistinal lymph node assessment of non-small cell lung cancer patients.

BACKGROUND: To assess the potential usefulness of 18F-FDG/PET and spiral-CT images concurrent assessment and coregistration in staging mediastinal lymph node involvement in patients with non small cell lung cancer. METHODS: 28 patients waiting to undergo surgical treatment underwent spiral-CT and PET examinations on the same day. The results of the two studies were interpreted separately, together (CT&PET) and following their fusion in a single image (CT+PET). Results of spiral-CT, PET, CT&PET and CT+PET were assessed with respect to the histological diagnosis. RESULTS: A correct assessment of mediastinal lymph nodes was achieved by spiral-CT in 21 of the 28 patients, in 22 of the 28 patients by PET, in 24 patients by CT&PET and in 25 patients by CT+PET. CONCLUSIONS: CT+PET is more accurate than spiral-CT and PET alone in staging mediastinal lymph node involvement in lung cancer patients, with possible implications for their prognosis and therapy.

Aged↗
PubMed1998

Regional glucose utilization in infarcted and remote myocardium: its relation to coronary anatomy and perfusion.

We studied the relationship between coronary anatomy, perfusion and metabolism in myocardial segments exhibiting transient and persistent perfusion defects on stress/rest 99Tcm-MIBI single photon emission tomography in 35 patients (31 males, 4 females, mean age 56 +/- 7 years) with a previous myocardial infarction. Quantitative coronary angiography and assessment of myocardial perfusion reserve and glucose metabolism were performed within 1 week of one another. Perfusion was assessed by SPET after the intravenous injection of 740 MBq of 99Tcm-MIBI at rest and after exercise. Regional myocardial glucose metabolism was assessed by position emission tomography at rest (200 MBq of 18F-2-deoxyglucose, FDG) after an overnight fast with no glucose loading. All 35 patients exhibited persistent perfusion defects consistent with the clinically identified infarct site, and 27 (77%) also showed various degrees of within-infarct FDG uptake; 11 patients developed exercise-induced transient perfusion defects within, or in the vicinity of, 15 infarct segments and resting FDG uptake was present in 10 of these segments (67%). Five patients also showed exercise-induced transient perfusion defects in nine segments remote from the site of infarct: resting FDG uptake was present in six of these regions (67%). Finally, nine patients had increased glucose uptake in non-infarcted regions not showing transient perfusion defects upon exercise testing and perfused by coronary arteries with only minor irregularities. Our results confirm the presence of viable tissue in a large proportion of infarct sites. Moreover, FDG uptake can be seen in regions perfused by coronary arteries showing minor irregularities, not necessarily resulting in detectable transient perfusion defects on a MIBI stress scan. Since the clinical significance of such findings is not clear, further studies should be conducted to assess the long-term evolution of perfusion, function and metabolism in non-revascularized patients of those remote areas which are apparently normally perfused, but show abnormal fasting FDG uptake after myocardial infarction. Such studies may have important implications for the management of post-infarct patients, as the preservation of coronary vasodilator reserve and myocardial metabolism in remote myocardium may be seen as an additional goal in the treatment of such patients.

Blood Glucose↗
PubMed1997

Whole-body scintigraphy with 99Tcm-MIBI, 18F-FDG and 131I in patients with metastatic thyroid carcinoma.

We assessed the relative usefulness of whole-body planar scintigraphy with 99Tcm-methoxyisobutyl isonitrile (99Tcm-MIBI), 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG-RS) rectilinear scanning and with diagnostic and therapeutic doses of 131I, for the detection of local recurrences and metastatic lesions in 12 patients with thyroid carcinoma and elevated thyroglobulin serum levels. All images were evaluated independently by three experienced observers to define the number and location of metastatic lesions. 18F-FDG-RS and 99Tcm-MIBI scintigraphy provided similar results, but the tracer that allowed the detection of the highest number of metastases was 99Tcm-MIBI. Both 99Tcm-MIBI scintigraphy and 18F-FDG-RS appear to be more sensitive than 131I scintigraphy for the detection of metastases of thyroid carcinoma. Tomographic acquisitions were also performed on a limited field of view in each subject and, as expected, 18F-FDG-PET was more sensitive than 18F-FDG-RS. 99Tcm-MIBI scintigraphy, a widely available and relatively non-expensive technique, therefore sems suitable for the assessment and follow-up of patients with metastatic thyroid carcinoma and does not require the withdrawal of hormone therapy for lesion imaging.

Adenocarcinoma, Follicular↗
PubMed1997

Myocardial viability assessed with fluorodeoxyglucose and PET in patients with Q wave myocardial infarction receiving thrombolysis: relationship to coronary anatomy and ventricular function.

In previously thrombolysed patients, we analysed residual myocardial viability using the PET-FDG technique and correlated its presence and extent to the angiographic appearance of the infarct-related vessel and left ventricular function. Thirty-six patients who had undergone intravenous thromboloysis for acute myocardial infarction 4.8 +/- 7.2 months previously were studied. Coronary angiography, left ventriculography, and assessment of myocardial perfusion and metabolism were all performed within 1 week. All patients exhibited perfusion defects consistent with the clinically identified myocardial infarction site. Residual viability, as assessed by the PET-FDG technique, was present in 53% of cases. The infarct-related coronary artery was patent in 19 (53%) patients (TIMI grade 3, 79%); of the remaining 17 with occluded infarct-related arteries, 11 had collaterals to the infarct area. Significant FDG uptake was observed in 63% of patients with a patent infarct-related artery and in 41% of those with an occluded infarct-related artery. The same study protocol was adopted in a control group of 30 patients with myocardial infarction who did not receive thrombolysis. The number of infarct-related patent vessels was significantly lower in these patients (30 vs 53%) (TIMI grade 3, 56%), but the overall percentage of PET viability was again 53%. Qualitative analysis of the regional perfusion pattern showed that the magnitude and severity of the perfusion defect was similar in the two groups, regardless of the presence or absence of FDG uptake. Global left ventricular function was also similar in the two groups. However, regional wall motion was significantly better in the thrombolysed patients with a patent infarct-related artery than in those who had not received thrombolysis and whose culprit vessel was also patent. In conclusion, the results of our study support the notion that early recanalization of the infarct-related artery is critical for preserving left ventricular function. Although the number of patent infarct-related coronary arteries is greater and left ventricular function is better in successfully thrombolysed patients, the regional metabolic pattern does not apparently correlate with the patency of the infarct-related artery. This suggests that, in "chronic' myocardial infarction, residual tissue viability as assessed by fluorodeoxyglucose uptake does not necessarily correlate with coronary recanalization.

Blood Glucose↗
PubMed1997

Abnormal myocardial glucose handling in patients with syndrome X: effect of beta-adrenergic blockade.

The present study was designed to test the hypothesis that patients with angina, positive exercise test and angiographically smooth coronary arteries (syndrome X), may exhibit abnormal myocardial glucose handling, as assessed by fluorodeoxyglucose (FDG) and positron emission tomography (PET) and to investigate the possibility that this abnormality could be reversed by treatment with betablockers, the drugs of choice in most patients with syndrome X. Eight consecutive patients (4 females, age 53 +/- 4 yrs) with syndrome X were studied. Off therapy, they underwent stress/rest 99m-TcMIBI SPET (360 degrees) and assessment of resting glucose metabolism by PET. PET studies were again performed after a 10 day treatment period on oral atenolol (100 mg/o.d.). All patients exhibited significant fasting FDG uptake in 2 or more myocardial regions. Overall, there were 28 of 48 segments (58%) with abnormal tracer uptake. On atenolol, there were only 5 segments with persistent FDG uptake (10%) in 2 patients. At rest, 7 patients exhibited perfusion defects in 14 myocardial segments. With stress performed in pharmacological wash-out, 5 patients developed perfusion defects in 10 myocardial segments. Eight of these segments were already underperfused at rest, and showed further reduction in perfusion after stress. All hypoperfused segments showed abnormal FDG uptake when the PET study was performed off therapy. The results suggest that, in patients with syndrome X, imbalance of the demand/supply ratio, either caused by limited coronary flow reserve or by primary vasoconstriction with reduction in myocardial perfusion, may determine a sustained metabolic shift towards anaerobic glycolysis. The mechanism by which atenolol improves metabolism in these patients could be simply related to reduction in O2 consumption.

Adrenergic beta-Antagonists↗
PubMed1996

Exercise-induced ischemic arrhythmias in patients with previous myocardial infarction: role of perfusion and tissue viability.

OBJECTIVES: This study sought to investigate whether residual viability of infarcted myocardium may play a role in the pathogenesis of exercise-induced ventricular arrhythmias. BACKGROUND: We previously showed that transient ischemia within partially infarcted areas often precipitates ventricular arrhythmias during exercise that are consistently obliterated by intravenous nitrates. METHODS: We studied 60 patients with chronic stable angina and a previous myocardial infarction. All underwent at least two consecutive exercise stress tests, coronary angiography and stress/rest myocardial perfusion tomography by Tc-99m 2-methoxy isobutyl isonitrile (MIBI). In the last 26 consecutive patients, residual viability was assessed by single-photon emission computed tomography (SPECT) using fluorine (F)-18 fluorodeoxyglucose. Perfusion and metabolic data were evaluated qualitatively by three independent observers in blinded manner. RESULTS: With exercise, 30 patients (group A) consistently developed ventricular arrhythmias (> 10 ventricular ectopic beats/min, couplets, nonsustained ventricular tachycardia); the remaining 30 patients (group B) did not. The severity of coronary artery disease (Gensini score) was similar in the two groups. Postexercise SPECT showed partial reperfusion of an infarcted area in 28 of 30 patients of group A but in only 9 of 30 of group B (p < 0.0001). Uptake of F-18 fluorodeoxyglucose was observed within the infarcted zone in 10 of 13 and 1 of 13 patients in groups A and B, respectively (p = 0.0003). CONCLUSIONS: In patients with myocardial infarction, exercise-induced ventricular arrhythmias appear to be triggered by transient ischemia occurring within a partially necrotic area containing large amounts of viable myocardium. Therefore, occurrence of arrhythmias during exercise may represent a clue to the presence of residual viability within a previously infarcted area.

Case-Control Studies↗
PubMed1996

A procedure for wall detection in [18F]FDG positron emission tomography heart studies.

Quantitative positron emission tomography (PET) heart studies require the accurate localization of regions of interest (ROIs) on the myocardial wall (MW) and left ventricle (LV). The procedure is often inaccurate, especially when there is low tracer uptake. We implemented a data processing technique to improve the accuracy of the localization of ROIs on the MW and LV in fluorine-18 labelled deoxyglucose ([18F]FDG) PET heart studies. This technique combines transmission data, acquired before tracer administration and used for attenuation correction, and dynamic emission data (DY), acquired to obtain myocardial time-activity curves and used to calculate regional myocardial glucose utilization, to generate a new set of "transmission" images (TRDY) with enhanced contrast between MW and LV. These new transmission images identify the extravascular myocardial tissue and can be used for ROI placement. Validation of the method was performed in 25 patients, studied after an oral glucose load, by drawing irregular ROIs on three transaxial slices outlining the septum and anterior-apical and lateral wall on the last frame of the DY images (steady state) and then on the TRDY images. Two kinds of analysis were performed on a total of 225 myocardial segments: (1) mean counts per pixel in the DY images from ROIs independently drawn on DY and TRDY images were compared; (2) TRDY ROIs were copied onto DY images and repositioned in the event of mismatch between ROIs and myocardial tissue edge. Mean counts per pixel in the DY images from the original and the repositioned TRDY ROIs were compared. An excellent correlation was found in both cases (using TRDY and DY ROIs: y=0.908 x+0.068, r=0.97; using TRDY ROIs alone: y=0.975 x+0.006, r=0.99). This technique can be used for clinical applications in physiological and pathological conditions in which the myocardial [18F]FDG uptake is reduced or minimal, including diabetes and myocardial infarction.

Calibration↗
PubMed1996

Glucose metabolism and pathological findings in uveal melanoma: preliminary results.

The aims of this study were to assess the sensitivity of positron emission tomography (PET) using [18F]fluorodeoxyglucose (18F-FDG) in the detection of uveal melanoma, and to establish the relationship between pre-operative 18F-FDG uptake and a number of pathological features of uveal melanoma. Twenty consecutive patients with a clinical diagnosis of uveal melanoma were enrolled in the study. 18F-FDG uptake was assessed in all subjects and the following parameters were assessed in 11 enucleated subjects: the mitotic index, the MIB-1 proliferating cell index, number of epithelioid cells, largest tumour diameter, tumoral necrosis and inflammatory infiltration. Tumours with a diameter less than 7.5 mm were not detected by PET, possibly because of limited spatial resolution, and only 7 of 12 tumours with a diameter greater than 7.5 mm were detected. With tumours greater than 7.5 mm in diameter, PET and 18F-FDG allow two subgroups to be distinguished: those with high and those with low glucose consumption. Apart from tumour size, 18F-FDG uptake was not related to the pathological features examined. We hypothesize that 18F-FDG uptake may be related to the ratio of viable to non-viable cells, or to the hypoxic cell fraction within the tumour.

Adult↗
PubMed1995

Assessment of myocardial perfusion and viability with technetium-99m methoxyisobutylisonitrile and thallium-201 rest redistribution in chronic coronary artery disease.

We compare thallium-201 rest redistribution and fluorine-18 fluorodeoxyglucose ([18F]FDG) for the assessment of myocardial viability within technetium-99m methoxyisobutylisonitrile (MIBI) perfusion defects in 27 patients with chronic stable coronary artery disease. The following studies were performed: (1) stress 99mTc-MIBI, (2) rest 99mTc-MIBI, (3) 201Tl rest-redistribution single-photon emission tomography, (4) [18F]FDG positron emission tomography. The left ventricle was devided into 11 segments on matched tomographic images. The segment with the highest activity at stress was taken as the reference (activity=100%). Perfusion defects at 99mTc-MIBI rest were classified as severe (activity<50%), moderate (activity 50%-60%) or mild (activity 60%-85%). Uptakes of [18F]FDG and rest-redistributed 201Tl were recognized as significant if they exceeded 50% of that in the reference segment. Among the 33 segments with severe 99mTc-MIBI rest perfusion defects, 21 had significant [18F]FDG and 10 significant rest-redistributed 201Tl uptake. As regards the 37 segments with moderate defects, [18F]FDG was present in 29 and 201Tl in 31, while of the 134 segments with mild defects, 128 showed [18F]FDG uptake, and 131, 201Tl uptake. In conclusion, there is an inverse relationship between the severity of 99mTc-MIBI perfusion defects and the uptake of rest-redistributed 201Tl and [18F]FDG. Both tracers are adequate markers of viability in mild and moderate defects; in severe defects 201Tl might underestimate the presence of viability as assessed by [18F]FDG.

Adult↗
PubMed1995

Spatial registration of echocardiographic and positron emission tomographic heart studies.

A method has been developed to match corresponding heart regions from functional echocardiographic (Echo) and metabolic fluorine-18-fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography (PET) studies in individual patients. Echo and PET images are spatially correlated by determining homologous anatomical landmarks (the two papillary muscles and the inferior junction of the right ventricle), identifiable in images obtained by both acquisition modalities. Echo-PET image registration is first performed in the plane identified by the three landmarks, using a rigid rotate-translate scale model. The registration parameters are then used to transform the whole PET volume. This allows a consistent Echo-PET regional analysis, according to a segmental subdivision of the heart. The technique was tested on patients. The overlay of Echo and PET registered images proved the reliability of realignment of the three markers and a good spatial correlation of myocardial walls. This approach to image registration could be applied to other acquisition modalities (such as magnetic resonance imaging and single-photon emission tomography), provided that the three anatomical landmarks are visualized.

Deoxyglucose↗
PubMed1995

Specificity and sensitivity of exercise-induced ST segment elevation for detection of residual viability: comparison with fluorodeoxyglucose and positron emission tomography.

OBJECTIVES: We evaluated the sensitivity and specificity of exercise-induced ST segment elevation for the detection of residual myocardial viability. BACKGROUND: Assessment of residual viability after myocardial infarction is relevant for establishing indication for revascularization. We have previously shown that exercise-induced ST segment elevation is a marker of residual viability. METHODS: We studied 34 patients with a previous Q wave myocardial infarction (anterior in 21, inferior in 13) of whom 18 (group A) had exercise-induced ST segment elevation in more than one lead (mean [+/- SD] 1.8 +/- 0.9 mm, range 1 to 4) and 16 (group B) did not. All patients underwent rest technetium-99m methoxyisobutyl isonitrile single-photon emission computed tomography (SPECT), fluorine-18 (F-18) fluorodeoxyglucose positron emission tomography and coronary angiography. The time elapsed between the infarction and the viability study was 72 +/- 108 days (range 15 to 400) in group A and 516 +/- 545 days (range 14 to 1,800) in group B. RESULTS: The presence and site of previous infarction were confirmed by SPECT studies in all 34 patients. Uptake of F-18 fluorodeoxyglucose within the infarcted area was present in 18 of 18 patients in group A but in only 9 (56%) of 16 in group B (p < 0.01). In patients with an anterior infarction, the sensitivity, specificity and predictive accuracy of exercise-induced ST segment elevation for detection of residual viability were 82%, 100% and 86%, respectively (95% confidence intervals 46% to 83.5%, 59% to 100% and 55.6% to 87.1%, respectively). CONCLUSIONS: Exercise-induced ST segment elevation in infarct-related leads has a high specificity and acceptable sensitivity for detection of residual viability within the infarcted area.

Coronary Angiography↗
PubMed1995

Application of a surface matching image registration technique to the correlation of cardiac studies in positron emission tomography (PET) by transmission images.

The aim of this work is to assess the accuracy of a surface matching registration (SMR) technique for the correlation of cardiac studies in positron emission tomography (PET). Registration parameters were estimated by matching corresponding body surfaces, extracted from transmission studies, aligned to the PET emission images to be correlated. The accuracy of the SMR technique in this specific application was assessed by computer simulations, phantom experiments and on clinical PET data. Registration accuracy was evaluated in relation to the body surfaces (external, internal and the combination of the two) used by the SMR method. Better results were found when matching shaped and irregular surfaces such as internal lung contours. The robustness of the method was verified for different counting statistics recorded in transmission images. A clinical validation of the SMR method was performed on fluorine-18-deoxyglucose PET cardiac studies.

Computer Simulation↗
PubMed1995

Relation between dobutamine trans-thoracic echocardiography, 99Tcm-MIBI and 18FDG uptake in chronic coronary artery disease.

The relationships between rest conditions of myocardial asynergy, response to dobutamine administration, perfusion and glucose metabolism were examined in 12 patients with chronic coronary artery disease and left ventricular dysfunction. We evaluated (1) rest and stress myocardial perfusion by 99Tcm-methoxyisobutylisonitrile (MIBI) and single photon emission tomography (SPET), (2) rest myocardial segmental wall motion by trans-thoracic echocardiography and low-dose dobutamine, and (3) myocardial metabolism by [18F]-2-fluoro-2-deoxy-D-glucose (18-FDG) and positron emission tomography (PET), in the fasting state. The analysis was carried out on 16 left ventricular myocardial segments. The SPET studies were analysed semi-quantitatively by normalization to the peak activity. Wall motion was assessed by a visual score. An 18FDG index was determined as the tissue/blood pool radioactivity ratio in each segment. The results showed: (1) remarkably good agreement between the number of dobutamine responsive segments and 18FDG positive segments among those that were only moderately hypoperfused and hypokinetic; (2) a smaller number of dobutamine responsive segments than 18FDG positive segments among those that were hypoperfused and akinetic; and (3) the presence of 18FDG in 50% of the segments that were severely hypoperfused and akinetic or dyskinetic and without improvement with dobutamine. These results indicate that in severely hypoperfused and akinetic or dyskinetic segments, trans-thoracic echocardiography under inotropic stimulation provides little additional information compared with that obtained with rest echocardiography and perfusion studies; the assessment of 18FDG uptake provides information that is complementary to that obtained by perfusion assessment, rest and dobutamine trans-thoracic echocardiography.

Adult↗