Biomedical subjects

P Zanco

Publications and source records attributed to P Zanco.

At least 19 recordsLinked to original sources

PubMed2003

Effect of biventricular pacing on metabolism and perfusion in patients affected by dilated cardiomyopathy and left bundle branch block: evaluation by positron emission tomography.

AIMS: Evaluate the possible changes in myocardial metabolism and perfusion induced by biventricular pacing (BIVP) in patients affected by dilated cardiomyopathy (DC) and left bundle branch block (LBBB). METHODS AND RESULTS: Eight male patients (aged 60-79 years, mean 69) affected by DC (NYHA functional class III and ejection fraction <40%) were submitted to cardiac PET in basal condition and 3 weeks after the implantation of a biventricular device. Metabolism was evaluated using F18-fluorodeoxyglucose (FDG), by the glucose load-insulin technique, and perfusion by N13-ammonia (NH3), injected at rest. Visual and a semi quantitative analyses were performed, calculating by ROIs the septum to lateral uptake ratio (SLR). The myocardial blood flow (MBF) was also calculated in ml/min/g using a dynamic acquisition and a modified Patlak method. In all 8 patients a selective defect in FDG uptake in the septum was present in basal condition (mean SLR 0.59+/-0.17) with a 'reverse mismatch' effect with respect to NH3 (mean SLR 1.07+/-0.18). During BIVP the distribution of FDG in the septal area significatively improved (mean SLR 0.86+/-0.15 P=0.011 with respect to basal); on the contrary, no significant changes were found in NH3 uptake (mean SLR 1.02+/-0.23, P=ns). On quantitative analysis the mean MBF in the septum was 1.05+/-0.37 in basal condition and did not significantly change during BIVP (0.95+/-0.34, P=0.06). CONCLUSIONS: Our results suggest that, in patients affected by DC and LBBB, BIVP improves the septal glucose metabolism without significant changes in myocardial perfusion.

Aged↗

PubMed2001

Adrenergic nervous activity in patients after surgical correction of tetralogy of Fallot.

OBJECTIVES: The study was done to define the role of the autonomic nervous system in postoperative tetralogy of Fallot. BACKGROUND: Subsequent to surgical correction of tetralogy of Fallot, patients are at long-term risk of sudden death owing to ventricular electrical instability. The status of the sympathetic nervous system in these patients, known to play an important role in other patients at risk, remains unknown. METHODS: We used (123)I metaiodobenzylguanidine (MIBG) with tomographic imaging, combined with assessment of heart rate variability (HRV), to evaluate the activity of the sympathetic nervous system. We analyzed 22 patients who had undergone total correction of tetralogy of Fallot: 13 with either no or minor ventricular arrhythmias, and 9 with sustained ventricular tachycardia or ventricular fibrillation. RESULTS: Analysis of HRV revealed a reduction in vagal control and sympathetic dominance in all patients compared with a healthy control group of 20 subjects. A significant difference was found in the standard deviation of all the adjacent intervals between normal beats (SDNN) in patients with or without severe ventricular arrhythmias. A significant reduction in uptake of (123)I MIBG was demonstrated 30 min after IV injection, and a trend toward reduction after 5 h, associated with reduced washout indices. These data reflect a decrease in the number of nerve endings in the right and left ventricular walls, and an inhomogeneous distribution of the adrenergic nervous system. The uptake of MIBG was significantly reduced in the patients at risk of ventricular tachycardia or fibrillation. CONCLUSIONS: Subsequent to surgical correction of tetralogy of Fallot, the positive correlation between myocardial uptake of MIBG, SDNN and the QRS dispersion confirmed the usefulness of analysis of the adrenergic nervous system to stratify patients at risk of life-threatening arrhythmias.

Adolescent↗

PubMed2001

Myocardial perfusion and metabolic changes induced by biventricular pacing in dilated cardiomyopathy and left bundle branch block: description of a case evaluated by positron emission tomography.

The effects of biventricular pacing on myocardial wall function are well known, but, at the moment, its real effects on myocardial metabolism are unclear. In patients affected by left bundle branch block, at positron emission tomography a septal defect of the uptake of 18F-fluorodeoxyglucose (FDG) was referred. There were no alterations in myocardial perfusion, suggesting possible metabolic damage. In this paper we report the case of a patient affected by dilated cardiomyopathy and left bundle branch block treated with a biventricular device. Biventricular pacing resolved both the wall motion alterations as well as the defect in FDG uptake present in the septal area. On the contrary, during biventricular pacing there were no modifications in myocardial perfusion as compared to basal evaluation.

Aged↗

PubMed2000

Positron emission tomography is a useful tool in differentiating idiopathic from ischemic dilated cardiomyopathy.

We evaluated the utility of positron emission tomography in differentiating patients with idiopathic dilated cardiomyopathy from those with ischemic cardiomyopathy. Twenty consecutive non-diabetic patients with dilatation (end-diastolic volume > or = 120 cc/m2) and reduced systolic function (ejection fraction < or = 40%) of the left ventricle on cineangiography, underwent coronary angiography, F18 fluorodeoxyglucose (F18-FDG) (glucose load technique) and N13-ammonia (N13-NH3) positron emission tomography. A semiquantitative score based on the extension and the severity of the uptake defects was calculated. Endomyocardial biopsy was performed in patients with normal coronary arteries. Ten patients (group A) had normal coronary arteries and histologic features of the endomyocardium fitting with the diagnosis of idiopathic dilated cardiomyopathy. Cineangiography showed critical stenosis of at least one major coronary artery in the other 10 patients (group B). The two groups were similar in age. left ventricular end-diastolic volume and ejection fraction. Both N13-NH3, positron emission tomography and F18-FDG positron emission tomography scores were lower in group A than in group B: 0.1 +/- 0.3 vs. 10.6 +/- 5.1 (P<0.0001) and 2.4 +/- 4.4 vs. 9.9 +/- 4.1 (P<0.0001) respectively. but only N13-NH3 positron emission tomography allowed a complete separation of the two groups (score range 0-1 group A vs. 4-12 group B). The F18-FDG score value showed some overlapping between the two groups (score range 0-12 in the group A vs. 2-17 in the group B). All three idiopathic dilated cardiomyopathy patients with a F18-FDG score value >2 had left bundle branch block on standard ECG. Positron emission tomography imaging with N13-NH3 and F18-FDG provided a complete differentiation between idiopathic dilated cardiomyopathy and ischemic cardiomyopathy patients. However patients with left bundle branch block on ECG could present defects in FDG uptake even if affected by idiopathic dilated cardiomyopathy.

Adult↗

PubMed2000

Effects of left bundle branch block on myocardial FDG PET in patients without significant coronary artery stenoses.

UNLABELLED: Cardiac PET studies in patients with left bundle branch block (LBBB) are few, and the results are conflicting. In particular, even if a reduced uptake of FDG is reported, confirmation in a large group of patients and exact understanding of the underlying cause are lacking. METHODS: We selected 29 consecutive patients who had complete LBBB and no significant stenosis on coronary angiography scheduled for FDG and 13N-NH3 PET for myocardial viability evaluation at our center. Wall motion was evaluated using 2-dimensional echocardiography. Ten volunteers without coronary stenosis or LBBB served as a control group. RESULTS: All LBBB patients had a reverse mismatch in the septum, defined as reduced uptake of FDG in comparison with 13N-NH3. The mismatch extended to the anterior and inferior walls in 17 patients. The mean (+/-SD) septal-to-lateral ratio was 0.57 +/- 0.11 for FDG (range, 0.28-0.76) and 0.99 +/- 0.12 for 13N-NH3 (range, 0.75-1.18), with P < 0.0001. In contrast, no significant differences in uptake were seen in the control group, which had a septal-to-lateral ratio of 0.95 +/- 0.13 for FDG (range, 0.78-1.15; P < 0.01 with respect to LBBB patients) and 0.94 +/- 0.11 (range, 0.85-1.20) for 13N-NH3. CONCLUSION: Our study suggests that in LBBB patients without significant coronary stenosis, FDG uptake in the septum changes without a correlating change in perfusion. To avoid possible overestimation of necrosis, especially in the LAD territory, this phenomenon must be considered in evaluations of myocardial viability using FDG images.

Adult↗

PubMed1998

Brain positron emission tomography (PET) in chronic fatigue syndrome: preliminary data.

Chronic fatigue syndrome (CFS) has been widely studied by neuroimaging techniques in recent years with conflicting results. In particular, using single-photon emission computed tomography (SPECT) and perfusion tracers, hypoperfusion has been found in several brain regions, although the findings vary across research centers. The objective of this study was to investigate brain metabolism of patients affected by CFS, using [18F]fluorine-deoxyglucose (18FDG) positron emission tomography (PET). We performed 18FDG PET in 18 patients who fulfilled the criteria of the working case definition of CFS. Twelve of the 18 patients were females; the mean age was 34 +/- 15 years (range, 15-68) and the median time from CFS diagnosis was 16 months (range, 9-138). Psychiatric diseases and anxiety/neurosis were excluded in all CFS patients. CFS patients were compared with a group of 6 patients affected by depression (according to DSM IV-R) and 6 age-matched healthy controls. The CFS patients were not taking any medication at the time of PET, and depressed patients were drug-free for at least 1 week before the PET examination. The PET images examined 22 cortical and subcortical areas. CFS patients showed a significant hypometabolism in right mediofrontal cortex (P = 0.010) and brainstem (P = 0.013) in comparison with the healthy controls. Moreover, comparing patients affected by CFS and depression, the latter group showed a significant and severe hypometabolism of the medial and upper frontal regions bilaterally (P = 0.037-0.001), whereas the metabolism of brain stem was normal. Brain 18FDG PET showed specific metabolism abnormalities in patients with CFS in comparison with both healthy controls and depressed patients. The most relevant result of our study is the brain stem hypometabolism which, as reported in a perfusion SPECT study, seems to be a marker for the in vivo diagnosis of CFS.

Adult↗

PubMed1998

T wave normalization in infarct-related electrocardiographic leads during exercise testing for detection of residual viability: comparison with positron emission tomography.

OBJECTIVES: We investigated the sensitivity and specificity of exercise-induced T wave normalization (TWN) in infarct-related electrocardiographic leads (IRLs) for detection of residual viability in the infarct area. BACKGROUND: The meaning of exercise-induced TWN on IRLs is not yet well understood. Recent reports suggest that TWN during dobutamine echocardiography could indicate the presence of viable myocardium. METHODS: We evaluated 40 consecutive patients with a recent acute myocardial infarction and negative T waves in at least two IRLs. All patients underwent exercise testing; positron emission tomography (PET) with nitrogen-13 ammonia and fluorine-18 fluorodeoxyglucose; and coronary angiography. RESULTS: Twenty-four patients showed exercise-induced TWN: 18 at a work load < or =50 W (group la) and 6 at a work load > or =75 W (group 1b); 16 patients did not show TWN (group 2). On the PET study, viability in the infarct area was present in 17 patients (94%) from group la, in only 1 (16%) from group 1b and in 4 (25%) from group 2 (p < 0.0001). The sensitivity, specificity and diagnostic accuracy of exercise-induced TWN, in comparison with residual viability, were, respectively, 82%, 67%, 75% for TWN at every work load and 77%, 94%, 85% for TWN at a work load < or =50 W. Moreover, the sensitivity and diagnostic accuracy of TWN at the low work load were higher for anterior infarctions (87% and 88%, respectively). CONCLUSIONS: Exercise-induced TWN on IRLs at low work loads is a sensitive and specific index for the presence of residual viability in the infarct area. Sensitivity and diagnostic accuracy of this sign are higher for anterior infarctions.

Adult↗

PubMed1998

Myocardial perfusion, glucose utilization and oxidative metabolism in a patient with left bundle branch block, prior myocardial infarction and diabetes.

A diabetic patient affected by insulin-dependent diabetes, significant stenosis of left anterior descending (LAD) coronary, thrombolyzed myocardial infarction and complete left bundle branch block (LBBB) was examined by PET. Myocardial perfusion, glucose utilization and oxidative metabolism were evaluated by 13N-ammonia, 18F-fluorodeoxyglucose (FDG) and 11C-acetate, respectively. Despite severe damage in 18F-FDG uptake in the septum, with a septum-to-lateral ratio (S/L R) equal to 0.38, the oxidative metabolism in this area, evaluated quantitatively by dynamic acquisition, was relatively preserved (S/L R = 0.82), with a distribution similar to perfusion (S/L R = 0.87). These data reveal selective damage in glucose utilization in the septum in LBBB, unrelated to perfusion reduction and with preserved oxidative metabolism. Moreover, our experience could suggest an overestimation of the necrotic area by 18F-FDG in LBBB patients.

Acetic Acid↗

PubMed1998

[Effects of spinal cord stimulation on regional myocardial blood flow in patients with refractory angina. A positron emission tomography study].

BACKGROUND: Spinal cord stimulation (SCS) is an alternative therapy in patients with refractory angina pectoris when coronary revascularization cannot be performed. Several hypotheses have been given to explain the effects of SCS in reducing the number and the intensity of anginal crises. These hypotheses include possible variations in myocardial blood flow (MBF). The aim of our study was to assess regional MBF in a group of patients with spinal cord stimulator, using positron emission tomography (PET). METHODS: We studied 15 patients (9 male and 6 female), mean age 74 +/- 7 years, who were carriers of a spinal cord stimulator implanted 17 +/- 14 (range 1-48) months before. All patients had been affected with angina pectoris that was refractory to maximal tolerated pharmacological therapy. Eight patients had had a previous myocardial infarction and four patients had undergone a revascularization procedure. Every patient underwent two PETs with nitrogen-13-ammonia as the perfusion tracer. The first one was performed with the stimulator switched off for at least 20 hours, and the second one with the stimulator switched on for at least 4 hours. The quantitative evaluation of regional MBF (anterior, inferior, lateral, septal walls and apex) was performed with Patlak graphic analysis. The normal value of basal MBF in our laboratory is 0.6-1 ml/min/g. RESULTS: The mean value of MBF increased from 0.72 +/- 0.33 ml/min/g with the stimulator off, to 0.80 +/- 0.33 ml/min/g with it on (p = 0.004). An increase in regional myocardial perfusion, with the stimulator on as opposed to off, was observed in 47 (62%) of the 75 regions studied. With the stimulator on, in comparison with off, the value of MBF increased from 0.45 +/- 0.11 ml/min/g to 0.56 +/- 0.19 (p = 0.0001) in the 35 regions with low basal MBF (< 0.6 ml/min/g), and from 0.77 +/- 0.14 ml/min/g to 0.92 +/- 0.29 ml/min/g (p = 0.013) in the 23 regions with basal MBF between 0.6 and 1 ml/min/g. Instead, in the 17 regions with high basal MBF (> 1 ml/min/g) it decreased with the stimulator on instead of off, going from 1.22 +/- 0.20 to 1.13 +/- 0.22 ml/min/g (p = 0.112). CONCLUSIONS: Our study suggests that the beneficial effects of SCS in refractory angina may also be related to an increase in mean MBF and to a redistribution of MBF between the regions with low or normal basal flow and the regions with high basal flow.

Aged↗

PubMed1997

Exercise technetium 99m sestamibi single-photon emission computed tomography late after coronary artery bypass surgery: long-term follow-up.

BACKGROUND AND HYPOTHESIS: The prognostic value of exercise technetium 99m sestamibi single-photon emission computed tomography (SPECT) imaging in patients with previous bypass surgery is unknown. The aim of our study was to assess the prognostic information obtained with exercise scintigraphy performed for routine follow-up or reappearance of symptoms. METHODS: We studied 75 patients referred to our Center at a mean of 38 +/- 53 months from the revascularization procedure and prospectively followed them for 38 +/- 24 months. RESULTS: Fifteen patients (20%) had events at follow-up: there were 4 cardiac deaths, 3 nonfatal acute myocardial infarctions, 8 late revascularization procedures (4 percutaneous transluminal angioplasty and 4 repeat bypass surgery). Univariate analysis identified a history of typical angina (p = 0.001), a clinically positive ergometric test (p = 0.009), peak exercise heart rate (p = 0.0003), percentage of maximal predicted heart rate (p = 0.0001), peak exercise double product (p = 0.048), therapy during exercise (p = 0.003), scintigraphic summed reversibility score (i.e., the summation of the segmental differences between stress and rest) (p = 0.014), as significant predictors of events. Three multivariate models were built, with clinical variables (Model 1, chi square 15.97), ergometric variables (Model 2, chi square 19.66), and with scintigraphic variables added to clinical/ergometric variables (Model 3, chi square 31.13). The scintigraphic variable selected in the model as significant predictor of events was the summed reversibility score (p = 0.008). CONCLUSIONS: Exercise sestamibi SPECT scintigraphy provides optimal prognostic information after clinical and ergometric parameters in patients with previous bypass surgery.

Adult↗

PubMed1997

[Echocardiography or stress scintigraphy with dipyridamole for the stratification of risk after acute myocardial infarction?].

UNLABELLED: Increased risk of subsequent cardiac events after an acute infarction can be identified through dipyridamole infusion. It remains to be determined whether echocardiographic or scintigraphic imaging modes are equivalent. The aim of our study was to compare the prognostic information obtained early after an acute uncomplicated myocardial infarction through high-dose dipyridamole coupled with echocardiography or scintigraphy via Tc 99m sestamibi SPECT imaging. METHODS AND RESULTS: Fifty-one patients underwent simultaneous dipyridamole stress echocardiography and scintigraphy at a mean +/- SD of 12 +/- 3 days after admission for acute uncomplicated myocardial infarction. A subgroup of 44 patients performed exercise testing according to maximal symptom limited protocol. All patients were followed prospectively for 346 +/- 273 days (range 11-959). Cardiac events occurred in 20 patients (39%), and 1 death, 2 myocardial reinfarctions and 17 cases of unstable angina were recorded. Univariate predictors of cardiac events were: positive dipyridamole echo (p < 0.001), ischemia in the infarct zone or in remote zones by echo (p < 0.001), ejection fraction < 40% (p = 0.042) and positive exercise testing (p = 0.003). Risk was best predicted by multivariate Cox analysis on the basis of 1) ischemia in remote zones by dipyridamole echo (p < 0.001) and 2) ischemia in the infarct zone by dipyridamole echo (p = 0.003), blood pressure at peak exercise < 150 mmHg (p = 0.010) and non-Q wave infarction (p = 0.003). CONCLUSIONS: Echocardiographic imaging during dipyridamole infusion is superior to sestamibi scintigraphy for predicting events after uncomplicated myocardial infarction.

Aged↗

PubMed1996

Three-phase bone scan pattern in asymptomatic uncemented total knee arthroplasty.

In this study we investigated the bone scan pattern in a homogeneous group of asymptomatic patients implanted with the same type of total knee arthroplasty (TKA) and with a minimum follow-up of 2 years. Twenty-nine patients (21 females, 8 males, mean age 62 years), with a total of 30 uncemented Hofmann TKAs, were entered in the study. The time interval from surgery to scintigraphic evaluation ranged from 2 to 4 years. Bone scan was performed using the three-phase technique and images were interpreted by visual analysis using a three-point scale for the dynamic and blood pool phases and a five-point scale for the bone phase. Areas of increased periprosthetic technetium-99m methylene diphosphonate (MDP) uptake were observed until 4 years after surgery. However, comparing the TKAs implanted 2, 3 and 4 years previously, a decreasing pattern in tracer uptake intensity was noted this being more evident in the femoral and lateral tibial components. In some cases, a persistently elevated tracer uptake, not exceeding a moderate grade, was found in the medial tibial component. In conclusion, increased periprosthetic 99mTc-MDP uptake is a common finding in asymptomatic uncemented Hofmann TKAs for a prolonged period after surgery, but the uptake intensity is generally mild or moderate and shows a characteristic decreasing pattern over time. Furthermore, in contrast with other types of asymptomatic knee implants previously investigated, no case of high or very high bone uptake was recorded with this type of implant. We may speculate that scintigraphic parameters of normality, and pathology, should be determined for each type of TKA. It is likely that, with the uncemented Hofmann TKA, a high or very high tracer uptake or a progressive increase in the uptake intensity is suggestive of the presence of complications.

Female↗

PubMed1996

The characteristics of the thrombi of the lower limbs, as detected by ultrasonic scanning, do not predict pulmonary embolism.

OBJECTIVE: To evaluate whether pulmonary embolism (PE), as detected by perfusion lung scan, could be predicted by the ultrasonic (US) characteristics of the thrombi in patients with deep venous thrombosis (DVT) of the lower limbs. PATIENTS: Ninety-three consecutive patients with DVT and no symptoms of lung involvement (52 men, 41 women; mean age, 67 +/- 17 years). MEASUREMENTS AND RESULTS: The degree of thrombotic involvement of the lower limbs was assessed using a US score system ranging from 1 (indicating a subsegmental, nonocclusive thrombus) to 16 (massive, occlusive). According to the echographic and color-Doppler features, the thrombi were classified in terms of echoreflectivity, adhesiveness to the vein wall, and organization. The diagnosis of PE (PIOPED criteria) was highly probable in 46% of the patients, intermediate in 15%, low in 8%, and very low/normal in 31%. No correlations were found between the lung scan findings on one side and the venous scoring system or the US features of the thrombi on the other side. CONCLUSIONS: While confirming that the prevalence of PE in patients with DVT is elevated, we failed to define a subgroup of patients at higher risk. Our data imply that lung scan should be used extensively for the detection of silent PE and that anticoagulation should not be graded on US findings.

Adult↗

PubMed1996

[Effects on myocardial perfusion of epidural spinal cord stimulation in refractory angina. Description of a case studied with positron emission tomography].

We describe a case of patient with severe angina pectoris unresponsive to medical therapy who was treated with spinal cord stimulation. The patient was studied by dynamic positron emission tomography (PET) (13-N ammonia) and with heart rate variability. Spinal cord stimulation was effective in reducing anginal attacks and PET documented an enhancement of myocardial perfusion when spinal stimulator was activated. Heart rate variability did not change during spinal cord stimulation.

Aged↗

PubMed1996

[Dobutamine echocardiography and positron emission tomography in the assessment of viable myocardium after a thrombolized acute myocardial infarction. Comparison with spontaneous recovery].

BACKGROUND: Aim of the present study was to compare the ability of low-dose (5-10 gamma/Kg/min) dobutamine echocardiography (DE) and of positron emission tomography (PET), performed after a thrombolized acute myocardial infarction (AMI), to predict the spontaneous functional recovery (SFR) of viable but akinetic myocardial segments. PATIENTS AND METHODS: Twenty-one pts were studied by DE, 10 +/- 2 days (DE1) and 31 +/- 2 days (DE2), after a thrombolized AMI, and by PET (18F-FDS, glucose load) within 7 days after DE2; a basal echo was also performed 3 months after AMI. The left ventricle was divided in 16 segments, both in echo and PET examination. DE viability was defined as improvement in wall motion of akinetic seg; PET viability was defined as an FDG uptake > or = 40% of the maximum. RESULTS: In the 89 akinetic segments, DE1, DE2 and PET, respectively, identified, 16, 27 and 60 viable segments; the concordance with PET, in viable and not viable segments, resulted of 50% for DE1 and of 62% for DE2. After 3 months 29/89 segments had a SFR. In comparison with SFR the sensitivity of DE1 and DE2 was lower (51% and 68%) than PET (89%); the specificity was higher for DE1 and DE2 (98% and 96%) respect to PET (43%). CONCLUSIONS: In comparison with DE performed 10 days after a thrombolized AMI, DE performed 30 days after AMI revealed a greater extension of viable myocardium and a greater diagnostic accuracy in predicting SFR of akinetic segments. The concordance between DE and PET is high, if all myocardial segments are considered, and lower, if only akinetic segments are considered; in fact, PET identifies, as viable, a greater number of segments. In comparison with SRF, DE revealed the greatest specificity and PET the greatest sensitivity.

Adrenergic beta-Agonists↗

PubMed1996

Functional meaning of scintigraphic and echographic patterns, and of circulating anti-peroxidase antibodies in asymptomatic chronic thyroiditis.

Asymptomatic chronic thyroiditis (ACT) is a variant of the autoimmune thyroiditis characterized by the presence of circulating anti-thyroid antibodies and the absence of palpable goiter. Thyroid function can be normal but a considerable percentage of ACT patients tend to develop subclinical hypothyroidism over time and thus periodical controls of thyroid hormones and TSH levels are needed. At present, useful parameters for predicting the functional outcome of ACT patients are lacking. To investigate this aspect, we evaluated 57 consecutive ACT patients (51 females, 6 males, aged 22-56 years) by means of thyroid 99mTc-pertechnetate scintigraphy and echography, and by measuring the serum level of anti-peroxidase antibodies (TPOAbs), FT4, T3 and TSH. At first observation, 30 patients were euthyroid whereas 27 had subclinical hypothyroidism. No patient had been previously treated with thyroid hormones. Thyroid scan showed a normal pattern or a diffuse and mild irregular uptake, without differences between euthyroid and subclinical hypothyroid patients. TPOAb levels tend to be higher in patients with subclinical hypothyroidism in comparison to the euthyroid patients (5893 +/- 1423 and 3943 +/- 912 UI/mL, respectively) but the difference was not statistically significant by using Student's "t"-test. Echography showed a normal pattern in 14 patients, while a diffuse hypoechoic pattern in the other cases, mild in 12, moderate in 19 and marked in 12, was found. A significantly higher prevalence of subclinical hypothyroidism was observed in the group of patients with a moderate or marked hypoechoic pattern in comparison to the group with a normo-echoic or mild hypoechoic pattern (70.4% versus 23.0%, Fisher's exact test p = 0.00003). Furthermore, the 3 patients who developed thyroid failure during a one-year follow-up also presented a moderate or marked hypoechoic pattern. Our data suggest that the echo-pattern can be a useful predictor of thyroid failure in ACT patients and thus the echographic evaluation should be included in the diagnostic protocol of these patients.

Adult↗

PubMed1995

Myocardial technetium-99m sestamibi single-photon emission tomography as a prognostic tool in coronary artery disease: multivariate analysis in a long-term prospective study.

To date several studies have evaluated the accuracy of thallium-201 myocardial scan in risk stratification of coronary artery disease (CAD), while reports using technetium-99m methoxyisobutylisonitrile (MIBI), a tracer particularly suited to single-photon emission tomographic (SPET) imaging, are lacking. To rectify this omission, a prospective study was started in 1988 and at present 176 consecutive, and thus unselected, patients have been enrolled. All of them have been submitted to stress-rest MIBI SPET for the diagnosis or evaluation of CAD; 147 patients (121 males and 26 females, aged 53 +/- 9 years) have completed a surveillance period of at least 36 months following the scintigraphic study (range 36-60 months, mean 43). Sixty-one patients had a documented previous myocardial infarction. The mean pre-test likelihood of CAD was 44% in the patients without prior infarction. The main anamnestic, clinical, EKG and scintigraphic findings were evaluated and statistically correlated with the incidence of ensuing cardiac events using both univariate (chi-square test) and multivariate analysis (logistic regression model). Twenty-nine patients suffered from a cardiac event during the follow-up period (i.e. three cardiac deaths, six myocardial infarctions and 20 cases of unstable angina). Statistical multivariate analysis identified MIBI scan as the only highly significant and independent prognostic predictor [P = 0.006, relative risk (RR) = 17.62]. In detail, the most important scintigraphic parameters were the presence of a reversible defect (P = 0.0089, RR = 5.11) and the extension of the stress perfusion defect (P = 0.0255, RR = 3.27). The presence of typical angina proved to be a slightly significant predictor (P = 0.051, RR = 2.45), while no other examined parameter showed a significant correlation with a bad prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina, Unstable↗

PubMed1995

Three-phase bone scintigraphy pattern of loosening in uncemented hip prostheses.

The three-phase bone scintigraphy pattern of loosening in uncemented hip prostheses (UHPs) has not previously been elucidated. We evaluated 28 patients with complicated UHPs who had undergone total hip arthroplasty a very long time previously (range 3-20 years, mean 8.4). All the patients were surgically reviewed: 26 UHPs were found to be loosened and two infected. Nine asymptomatic UHPs were taken as controls. The dynamic phase was invariably negative in both loosened and asymptomatic UHPs while markedly positive in the infected ones. The blood pool phase was positive to various degrees in 16 of the 26 loosened UHPs as well as in the infected UHPs, but was invariably negative in painless replacements. In the bone phase, areas of significantly (discrete to marked) increased uptake were observed in all the loosened prostheses as well as in two-thirds of the asymptomatic ones. However, the regions of the lesser trochanter and/or tip and/or shaft were involved exclusively in the case of the loosened UHPs, and diffuse periprosthetic uptake was found only with loosened or infected implants. Areas of slight methylene diphosphonate (MDP) uptake were found at every periprosthetic site and areas of discrete to marked MDP uptake were commonly found in the acetabulum and/or the greater trochanter with both loosened and painless prostheses and are thus considered to be nonspecific findings.

Bone Cements↗