Effects of preload reduction on mitral flow velocity pattern in normal subjects.

In the last few years, alterations in transmitral diastolic flow pattern have been used to assess changes in left ventricular diastolic properties. However, since diastolic flow primarily reflects the atrioventricular pressure gradient, loading conditions, as well as intrinsic left ventricular properties, should be able to affect this pattern. This study was selectively designed to decrease preload (a major determinant of the atrioventricular pressure gradient) in normal subjects to observe the effects on the Doppler transmitral flow pattern without pharmacologic interventions that may also affect left ventricular diastolic properties. In 12 normal subjects, preload was reduced by inflation of blood pressure cuffs placed at the level of the root of the 4 limbs. The peak velocity of early mitral flow (E wave) decreased from 62 +/- 8 to 51 +/- 7 cm/s (p less than 0.001), while no changes were found in the maximal velocity after atrial contraction; this caused a significant decrease in the ratio of these 2 velocities (the E to A ratio) from 1.5 +/- 0.3 to 1.1 +/- 0.1 (p less than 0.001). The time-velocity integral of early diastolic inflow decreased from 7.8 +/- 1.3 to 6.1 +/- 1.3 cm (p less than 0.001) with no significant changes of the time-velocity integral of inflow after atrial contraction. Therefore, preload reduction in normal subjects significantly reduces transmitral flow in early diastole with preserved late ventricular filling, producing a pattern that can mimic the changes previously described in left ventricular diastolic dysfunction.

Evaluation of systolic time intervals in a group of healthy children 10-12 years old.

The normal values of the systolic time intervals (STI) in children and their possible relationship with heart rate have not been studied thoroughly. From a group of 9760 healthy school-children 10-12 years old, 488 subjects of both sexes were randomly selected in order to measure the STI and calculate the respective indices. The final population study was composed of 479 children, 249 males and 230 females, aged from 10/1 to 12/2 years/months (mean age 11/1 +/- 0/4 years/months). In each child, the following STI were measured: total electromechanical systole (Q-S2), left ventricular ejection time (LVET), mechanical systole (S1-S2), preejection period (PEP), PEP/LVET ratio and isovolumic contraction time (ICT). For each parameter, the regression equation with heart rate was calculated using a linear model and was verified if a real difference existed between linear regressions of males and females. Moreover, for each parameter, the index from the respective regression equation was calculated as well as its normal value and the standard deviation. Finally, the diastolic time (% diastole) and its correlation with heart rate were calculated. Our results demonstrate that in children, a close correlation exists between the STI and heart rate, although less striking than in adults; only the PEP/LVET ratio appears independent from heart rate, as in adults. The % diastole versus heart rate non-linear relationship shows the same behaviour as in adults. Finally, in agreement with other authors, our results show that in childhood the relationship between the STI and heart rate behaves alike in males and females.

Does aortic regurgitation affect transmitral flow? An echo-Doppler study.

Recent studies suggest that the presence of aortic regurgitation can interfere with Doppler measurement of mitral pressure half-time in patients with mitral stenosis. Amongst the factors affecting the transmitral flow in aortic regurgitation a putative role may be played by the mechanical hit of the aortic regurgitant jet impinging on the anterior mitral leaflet, as is very often seen with Doppler Color Flow examination. This study was designed to evaluate the effects of pure aortic regurgitation on the transmitral flow in patients with normal mitral valves. We studied 35 patients affected by pure chronic aortic regurgitation but with a normal mitral valve and compared them with 30 normal subjects. In all the patients the aortic regurgitant jet was directed toward the anterior mitral leaflet. In all the patients and control subjects a standard echo-Doppler examination was performed, sampling the transmitral flow at the level of the tip of the mitral leaflets. In 7 patients and 11 normal subjects the transmitral flow was also sampled at the level of the mitral annulus. Patients with aortic regurgitation showed significantly higher values of the mitral pressure half-time (61.04 +/- 15.14 vs 50.59 +/- 7.07 ms, P < 0.05) and of the time-velocity integral of the total transmitral flow, while the other parameters of transmitral flow, the mitral annulus diameter and the mitral stroke volume didn't show statistically significant differences. The comparison of the pressure half-time and time-velocity flow values measured at the level of the mitral annulus between patients and normal subjects didn't show significant differences.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma beta-endorphin and beta-lipotropin in congestive heart failure in man.

Beta-endorphin and beta-lipotropin plasma concentrations were evaluated in 24 patients with congestive heart failure (CHF) (10 patients had chronic CHF and 14 an acute episode superimposing on chronic CHF), and in 35 age matched controls. Beta-endorphin and beta-lipotropin were significantly lower (P less than 0.005 and P less than 0.001 respectively) in patients with CHF than in controls. A significant decrease of both peptides vs controls was observed also in the two subgroups of patients, with chronic and acute CHF, without statistical differences between the subgroups. Beta-endorphin and beta-lipotropin showed a close and significant correlation (r = 0.88, P less than 0.001) amongst the whole series of patients as well as in both subgroups with chronic and acute CHF. In consideration of the long duration of the disease the decreased concentrations of beta-endorphin and beta-lipotropin can be considered to be due to a depletion of the releasable pool of the peptides, as it was previously shown for chronic stress.

Two-dimensional echocardiographic evaluation of right ventricular ejection fraction: comparison between three different methods.

Twelve patients with chronic cor pulmonale due to chronic obstructive pulmonary disease have been examined with 2D echocardiography, performing four-chamber view by apical and subcostal approaches, and the right ventricular outflow tract view by the subcostal approach. These views have permitted evaluation of right ventricular volumes, and hence right ventricular ejection fraction, by the use of three different geometrical formulae: the biplane area-length method, Simpson's rule and the pyramidal method. The ejection fraction values obtained from each method have been compared to those obtained by equilibrium radionuclide angiocardiography. Four-chamber apical and subcostal views were satisfactorily recorded in 10 of the 12 patients (83.3%), and right ventricular outflow tract view in 8 patients (66.6%). No significant statistical differences have been found between measurements obtained from the three different echocardiographic examinations performed on each subject by the same operator, so demonstrating a satisfactory reproducibility of the technique. The highest correlation coefficient for ejection fraction was shown by Simpson's rule (r = 0.96, p less than 0.001), with a very narrow confidence intervals, while the r values for the biplane area-length method was 0.63 (p less than 0.05) and for the pyramidal method 0.50 (not statistically significant), with increasingly wider confidence intervals. The statistically significant difference between the three correlation coefficients demonstrates the higher accuracy of Simpson's rule for the determination of right ventricular ejection fraction.

Effects of infusion of glucose-insulin-potassium on myocardial function after a recent myocardial infarction.

UNLABELLED: We studied the effects of glucose, insulin, and KCl infusion (GIK), on regional myocardial perfusion and function by 99m-Tc-tetrofosmin-gated SPECT. METHODS: We studied 21 male patients with their first uncomplicated acute myocardial infarction (AMI). All patients underwent a rest and submaximal stress before and after 24-hour infusion of GIK-solution (group A) or saline solution (group B). RESULTS: Group A showed better stress tolerance and ischaemic threshold improvement after GIK infusion whilst no statistical differences were found between basal and post-infusion test in group B. At first the stress test in group A, of the 192 segments analysed, 52 (27%) showed reversible perfusion defect. In group B, of 144 segments analysed, 31 (21%) showed reversible perfusion defect. A post-infusion analysis in group A showed a post-GIK end-diastolic significant count improvement in 21 segments, and a post-GIK end-systolic count improvement in 22 segments. In group B, perfusion increase was observed only in 4 segments, whilst systolic thickening increase was observed only in 1 segment. CONCLUSION: These data demonstrate the efficacy of GIK infusion to improve regional myocardial perfusion and function mainly in segments adjacent to the recently infarcted area.

[Hypertrophic cardiomyopathy mimicking clinical picture of Budd-Chiari syndrome]. / Cardiomiopatia ipertrofica condizionante quadro clinico tipo sindrome di Budd-Chiari.

A case of a patient with clinical picture of hepatosplenomegaly, portal hypertension, dilatation of hepatic veins and inferior vena cava, without venous thrombosis or other causes of obstruction of right-sided heart, is described. This picture is compatible with the Budd-Chiari syndrome. Echocardiography has shown a hypertrophic cardiomyopathy causing relevant dilatation of both atria and it has allowed us to exclude the presence of a constrictive pericarditis. The hypertrophic cardiomyopathy is first considered as a cardiac cause of cirrhosis mimicking the Budd-Chiari syndrome.

Demonstration of the relationship between heart dimensions and QRS voltage amplitude.

This study was undertaken to elucidate the still debated question of the relationship between cardiac volume and QRS voltage amplitude. The authors studied 14 healthy men, aged 24-61 years (mean age, 41.2 +/- 12.1 years). They underwent a reduction in venous return, produced by simultaneously inflating sphygmomanometric cuffs placed around the most proximal portion of each of the four limbs. In basal conditions and 5 minutes after cuff inflation, two-dimensional and M-mode echocardiograms were recorded with vectorcardiographic loops and scalar Frank leads. The reduction of the venous return to the heart induced a significant decrease of the end-diastolic left ventricular diameter (from 52.4 +/- 4.2 to 48.5 +/- 4.6 mm, P < .001), of the R wave amplitude in leads X and Y, of the sum of the R wave amplitudes in the three leads,and of the maximal vector in the frontal and horizontal planes. No significant changes in the heart rate or arterial blood pressure were observed. These results support Brody's theory concerning the relationship between cardiac blood volume and QRS voltage.

[Coronary vasospasm secondary to subcutaneous administration of sumatriptan]. / Vasospasmo coronarico secondario a somministrazione sottocutanea di sumatriptan.

We present the case of a 38-year-old woman with no previous history of coronary heart diseases, who suffered from cluster headaches and had undergone a subcutaneous sumatriptan treatment for two years. With no previous history of underlying ischaemic heart diseases or Prinzmetal's angina or any other significant coronary diseases supported by an angiographic exam, the patient suffered from an episode of coronary vasospasm following a subcutaneous administration of sumatriptan. Therefore particular care should be placed when subcutaneous sumatriptan is administered to patients who experienced chest pain or other related symptoms after the use of the drug.

[Echocardiographic study of left ventricular function in the mitral valve prolapse syndrome]. / Studio echocardiografico della funzione ventricolare sinistra nella sindrome da prolasso valvolare mitralico.

In the aim to clarify the magnitude and features of alterations in left ventricular function observed in patients with mitral valve prolapse syndrome (MVPS), we studied 41 patients with MVPS with M-mode echocardiography and computerized reading of recordings (with particular regard to the diastolic phase), and compared them with a control group of 15 healthy subjects matched for age and sex. Routine morphological and functional echocardiographic parameters were evaluated and, in addition, peak rates of movement of left ventricular endocardia, of wall thicknesses change and of cavity dimensions variations were obtained. Finally, a detailed analysis of various diastolic phases have been performed, according to the method proposed by Hanrath et al. There were no significant statistical differences in the morphological echocardiographic parameters (ventricular diameters, wall thicknesses) between the two groups. Patients with MVPS showed (compared to the control group) a significant increase in the peak rate of posterior wall endocardium movement during systole (1.64 +/- 0.42 vs 1.29 +/- 0.30, p less than 0.01) and a reduction of peak rate of interventricular septum thickening (1.21 +/- 0.36 vs 1.45 +/- 0.46, p less than 0.05). The comparison of all other systolic function parameters did not show statistical differences. As far as diastolic phase is concerned, no significant differences were found in the analysis of the peak velocities. However, evaluation of the diastolic phases demonstrated, in MVPS group, a significantly shorter slow filling period, both in absolute value (185.88 +/- 78.91 vs 303.15 +/- 117.58, p less than 0.001) and in percent of the whole diastole (37.42 +/- 11.88 vs 52.50 +/- 10.61, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Vectorcardiographic evaluation of diabetic cardiomyopathy and of its contributing factors.

In order to investigate the prevalence of vectorcardiographic bites, expression of small areas of fibrosis, atrophy or degeneration of the myocardium, we studied, using the vectorcardiograms (VCG) of 101 diabetic patients (35 with insulin-dependent and 66 with non-insulin-dependent diabetes mellitus, aged from 25 to 60 years, without hypertension, coronary artery disease, or intraventricular conduction defects) and 228 normal control subjects, matched for age and sex. The prevalence of bites was 38.6% in diabetic patients and 10.0% in the control group (p less than 0.001). Diabetic patients were also subdivided into groups according to age, sex, metabolic control, risk factors for coronary heart disease, type of diabetes, duration of diabetes and diabetic microangiopathy. No correlation was found between any of the variables investigated nor of a combination of these, and the presence of bites. We conclude that VCG is a sensitive test for cardiac involvement in diabetic patients but that it cannot be used to identify any specific factor able to influence the onset and evolution of this involvement.

Effects of venous return reduction in hypertensive patients: is there a Doppler diastolic dysfunction index independent of preload reduction?

The aim of this study was to evaluate the effects of preload reduction on the Doppler transmitral flow pattern in the presence of diastolic dysfunction (hypertensive patients) and normal diastolic function (normal subjects) to identify, if present, one or more indexes of abnormal diastolic ventricular filling independent of variations in preload. For this purpose Doppler echocardiography was performed in 17 patients with hypertension and in 18 normal subjects under basal conditions and after 5 minutes of blood pressure cuff inflation at the root of the four limbs. The two groups showed a similar response to preload reduction: a significant reduction in peak velocity and the time-velocity integral of the E wave and in the ratio of peak velocities of E and A waves. Therefore the differences in left ventricular filling patterns between hypertensive and normal subjects observed under basal conditions were still present after preload reduction. The comparison between normal subjects after preload reduction and hypertensive patients in the basal state showed a higher peak velocity and time-velocity integral of the A wave in the latter (61.2 +/- 16.2 vs 46.2 +/- 9 cm/sec [p less than 0.002] and 5.4 +/- 1.8 vs 3.7 +/- 1 cm [p less than 0.002], respectively) with no differences in the ratios of peak velocities and time-velocity integrals of the E and A waves.(ABSTRACT TRUNCATED AT 250 WORDS)

Time-course of dobutamine-induced wall motion abnormalities in the infarct area following thrombolytic therapy.

Stress-induced asynergies in the infarct area following thrombolytic therapy are considered to reflect incomplete recanalization of the culprit vessel. However, reperfusion is a dynamic process with successive pathophysiological phases, so that the timing of assessment of residual ischemia may have relevant clinical implications. We studied the time-course of dobutamine-induced homozonal asynergies in 61 (group B) survivors of uncomplicated infarction as compared to 54 (group A) control subjects showing normal response to dobutamine stress echocardiography within 10 days of acute myocardial infarction. The 79 (43 of group A and 36 of group B) patients not presenting new cardiac events underwent further dobutamine stress echo within 90 +/- 17 days, which was positive in 20 and negative in 59. Persistence of test positivity was observed in just 17/36 (47%) patients, who showed significantly more extensive dobutamine-induced asynergies as compared to pre-discharge evaluation and less frequent (p < 0.01) evidence of viable myocardium. These results arise question about the decisional impact of stress-induced wall motion abnormalities in the culprit vessel area early after thrombolysis in low-risk patients and emphasize the need to further clarify the time factor role in this setting.

[A comparison between mitral and aortic outputs evaluated by Doppler echocardiography in a group of healthy subjects: false regurgitation]. / Confronto tra portata mitralica ed aortica valutate con eco-Doppler in un gruppo di soggetti sani: il falso rigurgito.

Doppler echocardiography is a potentially useful tool for the non invasive evaluation of cardiac output and, therefore, for the quantitative assessment of valvular regurgitation. The aim of our study was to establish the presence of possible pitfalls in the evaluation of mitral and aortic regurgitant fraction obtained by Doppler echocardiography comparing the cardiac output measured at the level of the mitral and aortic valve. For this purpose 19 healthy volunteers, aged between 14-68 years, were studied. Stroke volume and cardiac output were calculated at the level of the mitral and aortic valve. The methods we used for the measurement of both the mitral and aortic cardiac output had already been validated and presumes that the shape of the valve annulus, is circular. No statistically significant differences were found between the parameters obtained at the two different valvular levels. Furthermore, cardiac output values correlated fairly well (r = 0.83, ESS = 0.78 l/min). In 9 subjects the aortic cardiac output was greater than the mitral one, while in the others mitral cardiac output was greater. The average of the differences between the two cardiac outputs was 0.58 +/- 0.48 l/min with a regurgitation fraction of 9.5 +/- 7.9%. Our results show that the mitral and aortic stroke volume and cardiac output, as measured by Doppler echocardiography (considering a circular shaped valve annulus, are not statistically different and correlate fairly well in our normal subjects. Nevertheless, we observed a certain degree of variability between the mitral and the aortic cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of ibopamine in combination with furosemide on renal function in patients with chronic congestive heart failure.

The effects of ibopamine and furosemide on renal function given alone and in combination at single doses were studied in 6 men and 6 women aged 45 to 73 years with chronic congestive heart failure of NYHA class II. After 3 days of dietary stabilization, the patients received either ibopamine 200 mg, furosemide 40 mg, or furosemide 40 mg plus ibopamine 200 mg with 2-day washout between treatments, according to a double-blind, balanced three-way crossover design using all possible treatment sequences. On each treatment day urine collections were performed at 2-hourly intervals from 2 h before to 6 h after dosing, and urine volume and Na+, K+, Cl-, and creatinine concentrations were measured for every period. The patients received a standardized breakfast 3 h before treatment and then were allowed 250 ml tap water to drink before starting each urine collection period. Venous blood samples were taken before breakfast and midway between each urine collection period for analysis of serum Na+, K+, Cl-, creatinine, and glucose. Heart rate, blood pressure, and physical signs were recorded 2, 1 h, immediately before, and then 0.5, 1, 2, 3, 4, 5, and 6 h after treatment. At the same times the patients were asked for any symptoms. The time course of the diuretic effect of furosemide 40 mg was consistent with the data reported by other authors.(ABSTRACT TRUNCATED AT 250 WORDS)

["Incomplete closure" of the mitral valve: the relationships to valvular regurgitation and to the morphofunctional characteristics of the left ventricle]. / "Chiusura incompleta" della mitrale: rapporti con il rigurgito valvolare e con le caratteristiche morfofunzionali del ventricolo sinistro.

OBJECTIVES: The present study was designed in order to evaluate the prevalence of mitral regurgitation in patients with the "incomplete mitral leaflet closure" echocardiographic pattern, to verify whether the amount of "incomplete mitral leaflet closure" is related to the severity of mitral regurgitation and, last, to verify the relation between the "incomplete mitral leaflet closure" and left ventricular morphology and function. METHODS: We studied 80 patients (14 patients with dilatative cardiomyopathy, 26 patients with coronary artery disease, and 40 patients with hypertensive heart disease or aortic valve disease) showing the "incomplete mitral leaflet closure" pattern, retrospectively selected from a population composed of 1700 consecutive patients routinely examined in our echocardiographic laboratory. In all patients we evaluated the presence and the severity of mitral regurgitation, the morphological and functional parameters of the left ventricle, the systolic diameter of the mitral annulus, the distance between the point of mitral leaflet coaptation and the annular plane, and the incomplete mitral closure area, assuming the last two parameters as indexes of the severity of incomplete closure of the mitral valve. RESULTS: We observed the presence of mitral regurgitation in 51 out of 80 patients (64%). The valvular insufficiency was considered mild in 78% of the patients. We observed no significant difference between patients with mitral regurgitation and without, as regards the diameter of the mitral annulus, the distance between the point of mitral leaflet coaptation and the annular plane, and the incomplete mitral closure area in different types of heart diseases. The incomplete mitral closure area and the diameter of the mitral annulus showed a significant, although not elevated, correlation with the severity of the mitral regurgitation (r = 0.36 and r = 0.32, respectively). The severity of mitral regurgitation showed significant correlations with all of the left ventricular morphological and functional parameters evaluated. Finally, we observed significant correlations between the incomplete mitral closure area and all of the morphological and functional parameters of the left ventricle. CONCLUSIONS: On the basis of the results obtained we can conclude that: 1) the "incomplete mitral leaflet closure" pattern does not appear to be a highly specific marker of mitral regurgitation, 2) this pattern appears to be related to the morphology and function of the left ventricle, and 3) the severity of the incomplete mitral valve closure is more easily evaluated by a parameter that takes into account the numerous factors acting on the mitral apparatus, that is the incomplete mitral closure area.

Early assessment of viable myocardium after acute myocardial infarction by low-dose echo-dobutamine.

BACKGROUND: The aim of the study was to evaluate the usefulness of low-dose dobutamine echocardiographic testing performed within 48 hours from anterior AMI in order to identify the extent of viable myocardium and predict its functional outcome. The early echo-dobutamine test was also compared with a predischarge test in order to evaluate the effects of different timing on the accuracy of the test. METHODS: Nineteen consecutive patients, aged 54 +/- 11 years, with a first anterior AMI entered the study. All patients underwent a low-dose dobutamine echocardiographic test within 48 hours from hospital admission and at predischarge. In all the patients, a rest follow-up echocardiogram was performed three months after hospital discharge. Eleven patients underwent a revascularization procedure (7 underwent PTCA and 4 CABG). RESULTS: Of the 159 dyssynergic segments, 26% improved spontaneously at predischarge and 51% improved at the three-month follow-up. Of the 145 predischarge dyssynergic segments, 38% improved at three months. Considering the results on a segmental basis, early low-dose dobutamine echocardiography showed a sensitivity of 52%, a specificity of 87%, a positive predictive value of 81%, a negative predictive value of 64% and a diagnostic accuracy of 69% for wall-motion improvement at three months. The predischarge test showed very similar values. A slight enhancement of the sensitivity of both tests was observed considering the akinetic segments only. Finally, considering the amount of segmental reversible dysfunction inside the infarct area in the single patients, early low-dose dobutamine echocardiography showed a sensitivity of 86% and a specificity of 80%. CONCLUSIONS: Our results indicate that: 1) recovery of regional wall motion after AMI is slow and progressive, with substantial improvement ensuing within the first days after infarction; 2) considering results on a segmental basis, low-dose dobutamine echocardiography performed within 48 hours of AMI shows a high specificity but a low sensitivity for late recovery of regional function, although it gave information similar to what was obtained performing the test at predischarge; 3) the efficiency of test can be improved by considering the amount of reversible segmental dysfunction inside the infarct area in the single patients.

Dobutamine echocardiography: usefulness of digital image processing.

The present study was undertaken in order specifically to evaluate the usefulness of digital image processing so as to enhance the diagnostic power of dobutamine stress echocardiography. For this purpose 44 dobutamine echocardiographic tests, routinely performed in our echo laboratory, were analysed blindly by two observers using traditional videotape recording and digitized image acquisition. The results obtained from both observers show a trend which suggests that the traditional videotape approach provides more true-positive tests than the digitized approach (27/38 vs 23/38 and 24/38 vs 22/38 for the first and second observer, respectively). True-negative test detection was 6/6 with the videotape and 5/6 with the digitized method for both observers. As a consequence of the discrepancies observed between the two modalities, the videotape indicates that it can provide higher diagnostic accuracy than the digitized approach (72 +/- 9% vs 63 +/- 10%). The tests results concordance (positive or negative) between the two modalities of analysis was 66% for both the observers. The inter-observer agreement on the test results was 84% and 80% for the videotape analysis and the digitized analysis, respectively. On the basis of the results, we consider that digitized analysis applied to dobutamine stress echocardiography does not afford significant diagnostic advantages and should not be considered as an alternative option to traditional videotape analysis. However, it may be considered an extremely useful integrative tool since it produces the on-line image evaluation more easily and faster and allows a more practical form of stress test storage.

Myocardial viability assessment after acute myocardial infarction: low-dose dobutamine echocardiography versus rest-redistribution thallium-201 SPECT.

BACKGROUND: The presence of tissue viability is of great importance in the prognostic work-up of patients recovering from acute myocardial infarction. However, uncertainty still exists concerning the optimal tool for its assessment. The present study was undertaken in order to compare low-dose dobutamine echocardiography and rest-redistribution thallium SPECT for predicting late improvement of regional left ventricular function after acute myocardial infarction. METHODS: Fifteen patients undergoing coronary angiography, low-dose dobutamine echocardiography and rest-redistribution thallium SPECT after thrombolyzed anterior acute myocardial infarction were studied. A 3 month follow-up echocardiogram was performed in all patients and 9 underwent coronary revascularization. RESULTS: A significant (> or = 70%) residual stenosis of the infarct-related artery was present in 14 patients, whilst a total occlusion was observed in 1. At 3 month follow-up, 41% of the dyssynergic segments improved. The sensitivity, specificity and accuracy for late wall motion improvement was 61, 89 and 77% for low-dose dobutamine echocardiography and, respectively, 76, 45 and 58% for rest-redistribution thallium SPECT. Tissue viability was detected in 65 and 31% of dyssynergic segments by rest-redistribution thallium SPECT and low-dose dobutamine echocardiography, respectively (p < 0.001). The agreement between the two techniques was 48%. CONCLUSIONS: Low-dose dobutamine echocardiography is more accurate than rest-redistribution thallium SPECT for predicting 3 month wall motion improvement in patients with acute anterior myocardial infarction, mainly due to its significantly better specificity.