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Aims A substantial number of patients with dysfunctional but potentially viable myocardium cannot be accurately evaluated by transthoracic echocardiography due to a poor acoustic window. This study compares the diagnostic value of alternative functional imaging techniques, such as dobutamine–transoesophageal echocardiography (dobutamine–TEE) and dobutamine magnetic resonance imaging (dobutamine–MRI) for the detection of viable myocardium and the prediction of left ventricular functional recovery in patients with chronic coronary artery disease following successful revascularization procedures.Methods and Results Rest and low-dose (5, 10μg dobutamine.min−1.kg−1) multiplane dobutamine–TEE and ultrafast cine–MRI studies were performed in 103 patients. Contractile recovery of an infarct region was predicted if a dobutamine contraction reserve could be assessed visually by TEE or MRI in ≥50% of infarct-related a- or dyskinetic segments. Revascularization of the infarct-related vessel was successful in 88 patients, and 4·9±0·7 months later 52 patients still had an angiographically controlled open target vessel. These patients underwent another rest MRI study to assess left ventricular functional recovery. A dobutamine contraction reserve was observed in 27/52 (52%) patients by TEE and in 26/52 (50%) patients by MRI. Functional improvement of the infarct region was diagnosed in 28/52 (54%) patients. The positive and negative predictive accuracy of dobutamine–TEE and dobutamine–MRI for the prediction of left ventricular functional recovery was not significantly different (85% vs 92%, ns and 80% vs 85%, ns). Diagnosis of a predominantly viable infarct region by TEE and MRI predicted a significant increase in left ventricular ejection fraction (TEE: 12±8% vs 2±7%P<0·001, MRI: 13±7% vs 2±7%, P<0·001) compared to infarct regions graded as scar.Conclusion A qualitative visual analysis of TEE and MRI viability studies is highly accurate for the prediction of left ventricular functional recovery in patients with dysfunctional myocardium and proved to be a clinically valuable alternative if transthoracic dobutamine–echocardiography is unsuitable. To date, TEE is cardiologists' preferred choice for the assessment of myocardial viability but MRI may become significantly more attractive with increasing local availability and experience. [ABSTRACT FROM PUBLISHER]

It is not yet clear whether Tc-methoxyisobutyl-isonitrile (MIBI)-uptake is a reliable indicator of myocardial viability, and a threshold value, differentiating viable from scarred myocardium, in comparison to a morphological and functional standard of reference has not been defined. MIBI-uptake was quant in 800 segments from 55 patients with angiographically proven coronary artery disease with and without a history of myocardial infarction. Viable myocardium was defined from gradient-echo magnetic resonance images (MRI) as regions with systolic wall thickening or an end-diastolic wall thickness above the mean value − 2·5 SD of a healthy control group (n=21). Scar was defined as end-diastolic wall thickness >2·5 SD below the normal mean value and absent systolic wall thickening or wall thinning. Mean MIBI-uptake of viable (n=676; 79 ± 14%) and scar segments by MRJ (n = 124, 31 ± 16%) was significantly different (<0·001). Segmental MIBI-uptake vs end-diastolic wall thickness (r=0·7) and systolic wall thickening (r = 0·71) yielded a fair correlation. The highest values as regards sensitivity and specificity of MIBI-uptake in predicting the presence of scar were 89% and 96% respectively for MIBI-uptake ≤50%, However, of the 136 segments with MIBI-uptake ≤50%, 26 (19%) were viable by MRI, resulting in a positive predictive accuracy for scar tissue of 81%. Of the 26 segments diagnosed as scarred by MIBI-SPECT but viable by MRI, 25 (96%) were located in the inferoseptal region. MIBI-SPECT seems useful in the detection of viable myocardium after anterior myocardial infarcts, but over-estimates scar in the inferoseptal regions. Perfusion defects in these regions could be confirmed or denied by additional evaluation of myocardial morphology and function by MRI or tissue metabolism by positron emission tomography (PET). [ABSTRACT FROM PUBLISHER]

The non-invasive quantification of mitral and aortic regurgitation using the left-to-right stroke count ratio (SCR) calculated with gated equilibrium radionuclide ventriculography (RNV), is affected by the overlap of atria and ventricles and the consequent difficult definition of the ventricular regions of interest (ROI). Various solutions of the problem have been proposed. In this study we evaluated the results obtained with a technique based on visual inspection of the RNV images (variable ROI method—VRI) and those of two approaches which utilize functional images (stroke volume image method—SVI—and Fourier amplitude ratio—FAR), by comparing them with the invasive quantification of valvular regurgitation according to Sandier et al.[1] (stroke volume ratio — SVR). Forty patients (15 controls and 25 valvular patients) were studied. In the control group the range of the SVR wasO.81±1.11 (mean±lSD=1.01±0.08). The SCR was O.83–1.28 (1.03±0.15) with VRI, 1.10–1.15 (1.30±0.14) with SVI and 1.11–1.58 (1.35±0.17) with FAR. The correlations between SVR and SCR were r=0.47 (P<0.05), r=0.62 (P<0.001) and r=0.55 (P<0.01) respectively with VRI, SVI and FAR. The SCR of valvular patients fell in the range of controls in 11/25 using VRI, 6/25 using SVI and in 4/25 using FAR. This overlap was present in 2/25 with the invasive quantification. Irrespective of the method used, a reliable assessment of the valvular regurgitation was not possible in two patients with severely depressed left ventricular function. We conclude that the use of techniques based on functional images clearly improves the effectiveness of the non-invasive quantification of valvular regurgitation with the SCR even if this cannot be regarded as a substitute for invasive quantification and has a limited reliability in particular groups of patients. [ABSTRACT FROM PUBLISHER]

I.S.A.M. was a prospective, placebo-controlled, double-blind multicentre trial of high-dose short-term intravenous streptokinase in acute myocardial infarction (AMI) within 6 h of the onset of symptoms. Determination of left ventricular ejection fraction (LVEF) by radionuclide ventriculography was performed 1 and 7 months after AMI in a subset of 192 patients at rest and, in 140 of them, also during exercise. Regional myocardial function was analysed in all 145 patients with neither a history of a previous myocardial infarction nor revascularization procedures or reinfarction within the 7-month follow-up period. One month after AMI, mean LVEF was higher in the streptokinase group in patients with anterior AMI (50 +/- 15% vs 42 +/- 16%, P = 0.013). This difference was more marked in the subgroup treated within 3 h (53 +/- 14% vs 42 +/- 15%, P = 0.004), whereas patients treated 3-6 h after the onset of symptoms did not differ from respective controls (41 +/- 16% vs 41 +/- 18%). In patients with inferior AMI, the difference in mean LVEF was small (57 +/- 11% vs 55 +/- 12%, P = 0.47). After anterior AMI benefit due to streptokinase therapy was preserved up to 7 months (52 +/- 14% vs 44 +/- 17%, P = 0.013). During exercise, the increase of mean LVEF was greater in the streptokinase group at both dates, especially 7 months after AMI (4.1 +/- 6.1% vs 1.2 +/- 6.3%, P = 0.015). In streptokinase-treated patients with anterior AMI, regional LVEF at rest was higher at both dates compared with controls, within the infarct zone as well as in remote myocardium. No treatment-control differences were demonstrable in patients with inferior AMI. During exercise, regional contractile reserve was better in the streptokinase group within the infarct zone as well as in remote myocardium, irrespective of the site of infarction. Thus, intravenous streptokinase within 3 h after the onset of AMI preserves global left ventricular function in anterior AMI over a period of at least 7 months. Intravenous streptokinase improves regional myocardial function within the infarct zone as well as in remote areas. In inferior AMI investigation solely at rest may underestimate the benefit of streptokinase therapy.