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L Meloni

Publications and source records attributed to L Meloni.

At least 19 recordsLinked to original sources
PubMed2006

Non-invasive coronary flow reserve is correlated with microvascular integrity and myocardial viability after primary angioplasty in acute myocardial infarction.

OBJECTIVE: To test whether preserved coronary flow reserve (CFR) two days after reperfused acute myocardial infarction (AMI) is associated with less microvascular dysfunction (" no-reflow" phenomenon) and is predictive of myocardial viability. DESIGN: 24 patients with anterior AMI underwent CFR assessment in the left anterior descending coronary artery (LAD) with transthoracic echocardiography and myocardial contrast echocardiography (MCE) 48 h after primary angioplasty in the LAD (mean 4 (SD 2) and 3 (1) days, respectively). Low-dose dobutamine echocardiography was performed 6 (3) days after AMI and follow-up echocardiography at three months. RESULTS: No-reflow extent was greater in patients with impaired CFR (< 2.5) than in those with preserved CFR (> 2.5) (55 (35)% v 11 (25)%, p < 0.001). MCE reflow was more common in patients with preserved CFR (8/12) than in those with reduced CFR (1/12, p < 0.05). Wall motion score index in the LAD territory (A-WMSI) was similar at the first echocardiography (2.14 (0.39) v 2.32 (0.47), NS), although it was better in patients with preserved CFR at dobutamine (1.38 (0.45) v 1.97 (0.67), p < 0.05) and follow-up echocardiography (1.36 (0.40) v 1.97 (0.64), p < 0.05). An inverse correlation was found between CFR and A-WMSI at dobutamine and follow-up echocardiography (r = -0.49, p = 0.016 and r = -0.55, p = 0.005) and between MCE and A-WMSI at dobutamine and follow-up echocardiography (r = -0.75, p < 0.001 and r = -0.75, p < 0.001). By multivariate analysis MCE reflow remained the only predictor of recovery at both dobutamine and follow-up echocardiography (odds ratio 1.06, 95% CI 1 to 1.1, p = 0.009). CONCLUSION: CFR is inversely correlated with the extent of microvascular dysfunction at MCE two days after reperfused AMI. CFR and MCE reflow early after AMI are correlated with myocardial viability at follow up.

Angioplasty, Balloon, Coronary↗
PubMed2001

Contrast-enhanced harmonic color Doppler for left ventricular opacification: improved endocardial border definition compared to tissue harmonic imaging and optimization of methodologyin patients with suboptimal echocardiograms.

OBJECTIVES: This study compared the efficacy of contrast-enhanced harmonic color Doppler (C-HCD) and tissue harmonic imaging (THI) for left ventricular endocardial border delineation and explored the optimal methodology of C-HCD in patients with suboptimal echocardiograms. BACKGROUND: The value of C-HCD in improving endocardium remains unknown. Effects of harmonic velocity-encoded color Doppler (HVD) and harmonic power Doppler (HPD) as well as contrast administration and image acquisition modalities on left ventricular opacification (LVO) have not been established. METHODS: One hundred (50 HVD, 50 HPD) patients with suboptimal echocardiograms during conventional fundamental echocardiography were studied with THI and C-HCD using Levovist. Each patient underwent different random contrast administration and image acquisition modalities. Endocardial border definition score index (EBDI), blooming artifacts, contrast destruction, and salvage of suboptimal echocardiograms were calculated in each patient after contrast enhancement. RESULTS: EBDI improved from 2.05 +/- 0.61 in THI to 2.73 +/- 0.48 in HVD, and 1.98 +/- 0.73 in THI to 2.69 +/- 0.51 in HPD (both P < 0.001). The conversion of a nondiagnostic image from fundamental echocardiography to an optimal diagnostic image was 33 (33%) patients in THI compared to 77 (77%) patients in C-HCD (P < 0.001). Blooming artifacts were seen more commonly in HVD than HPD, intermittent than continuous image acquisition, and bolus than infusion administration (all P < 0.001). There was less contrast destruction in intermittent compared with continuous image acquisition (P < 0.001). Contrast destruction was similar in HVD and HPD, bolus and infusion injection of contrast. The highest salvage rate of a nondiagnostic image from THI to an optimal diagnostic image was 45.5% and 42.4% in HPD mode, with intermittent image acquisition during bolus and infusion contrast administrations. CONCLUSIONS: C-HCD seems more effective in demonstrating improved endocardial border definition compared to THI. HPD has less blooming artifacts compared with HCD. The optimal method for LVO was to use HPD with intermittent image acquisition during bolus or infusion administration of Levovist.

Adolescent↗
PubMed2001

Quantification of left ventricular function with contrast-enhanced harmonic colour Doppler and a semiautomated boundary detection algorithm in technically difficult patients: feasibility, accuracy, and inter-observer variability.

AIMS: Patients with poor quality echocardiograms impede the application of available automatic boundary detection technologies. Tissue harmonic imaging and contrast media can allow optimal differentiation of left ventricular blood pool and tissue, making it possible to utilize automatic boundary detection software for automatic non-operator-dependent computation of left ventricular volumes. We integrated contrast-enhanced harmonic colour Doppler with a semiautomated boundary detection algorithm to explore the feasibility, accuracy and inter-observer variability for left ventricular volume assessment in technically difficult patients. METHODS AND RESULTS: Twenty-six patients with more than two segments not clearly visualized in tissue harmonic imaging were studied with contrast-enhanced harmonic colour Doppler using Levovist. Twenty patients (77%) achieved full left ventricular contrast filling without apparent blooming artefacts. Contrast-enhanced harmonic colour Doppler-automatic boundary detection was successfully implemented in these 20 patients, despite three (15%) in which it was not possible to acquire more than three cardiac cycles' values. Contrast-enhanced harmonic colour Doppler-automatic boundary detection measurements agreed closely with the manually drawn data. Among the three independent readers in the three techniques, the best correlation, lowest SEE, smallest limits of agreement and inter-observer variability were obtained in contrast-enhanced harmonic colour Doppler-automatic boundary detection. CONCLUSION: Contrast-enhanced harmonic colour Doppler-automatic boundary detection was feasible and accurate in estimation of left ventricular volume and function in patients with poor acoustic windows. This technique significantly reduced inter-observer variability, thus improving reliability and confidence of investigators in left ventricular function assessment. Contrast-enhanced harmonic colour Doppler-automatic boundary detection may have great potential in clinical evaluation of left ventricular volume and function, especially when on-line software is available.

Algorithms↗
PubMed2000

Transmural heterogeneity of myocardial contraction and ischemia. Diagnosis and clinical implications.

Myocardial contraction behaves heterogeneously, being greater in subendocardial than in subepicardial layers. Similarly, during acute myocardial ischemia or infarction, the subendocardium is the first myocardial layer to suffer. Conventional two-dimensional echocardiography cannot distinguish the transmural extension of myocardial ischemia or infarction, showing akinesia also when only the subendocardium is affected. Novel ultrasonographic techniques (like tissue characterization with integrated backscatter or Doppler tissue imaging) and nuclear magnetic resonance tagging can investigate myocardial contraction in different transmural layers and distinguish subendocardial from transmural ischemia or infarction. With the advent of thrombolysis and primary angioplasty in the acute phase of myocardial infarction a correct diagnosis of the extension of myocardial necrosis cannot ignore its transmural wavefront development. The salvage of the subepicardial layer does not give direct information on overall myocardial thickening but is one of the major determinants of overall left ventricular dysfunction and size. Although it is still necessary to investigate this phenomenon, new ultrasonographic techniques give us important information and more opportunities to appropriate diagnosis and future treatment of cardiac patients.

Animals↗
PubMed1999

Effects of acute myocardial ischemia on intramyocardial contraction heterogeneity: A study performed with ultrasound integrated backscatter during transesophageal atrial pacing.

BACKGROUND: [corrected] Subendocardial thickening is greater than subepicardial thickening and acute myocardial ischemia mainly impairs the former. Integrated backscatter cyclic variations (IBScv) reflect regional myocardial contractility and are blunted during myocardial ischemia. We hypothesized that stress-induced myocardial ischemia mainly affects subendocardial IBScv. METHODS AND RESULTS: Multiplane transesophageal echocardiography and simultaneous atrial pacing were performed in 12 patients without coronary artery disease (CAD) and in 25 with significant CAD. In a transgastric 2-chamber view, we calculated IBScv in subendocardium and subepicardium and a heterogeneity index, both at rest and at peak-pacing. In 27 myocardial segments of patients with normal coronary arteries, and in 16 myocardial segments supplied by coronary artery without significant stenosis in patients with CAD, there was a transmural gradient of IBScv at rest and the heterogeneity index did not change during all the protocol steps. In the 53 myocardial segments related to a significantly narrowed coronary artery, the transmural gradient of IBScv, present at rest, significantly decreased at peak-pacing because of subendocardial blunting, but promptly recovered 5 seconds after pacing interruption. Moreover, the myocardial thickening at rest and peak pacing correlated with the subendocardial IBScv behavior and not with the subepicardial one. CONCLUSIONS: IBScv are greater in the subendocardium than in the subepicardium. Atrial pacing stress test does not affect IBScv in segments supplied by nonstenotic coronary arteries, whereas it affects segments supplied by diseased coronary arteries, blunting exclusively subendocardial IBScv. Heterogeneity of IBScv intramyocardial changes caused by stress-induced ischemia must be taken into account when using IBScv for investigating myocardial ischemia.

Acute Disease↗
PubMed1999

Validation of a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) for the evaluation of coronary flow reserve: comparison with intracoronary Doppler flow wire.

OBJECTIVES: We tested the hypothesis that coronary flow reserve (CFR) in the left anterior descending coronary artery (LAD) as assessed by a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) is in agreement with CFR measurements assessed by intracoronary Doppler flow wire. BACKGROUND: Contrast-enhanced transthoracic second harmonic echo Doppler is a novel noninvasive method to detect blood flow velocity and reserve in the LAD. However, it has not yet been validated versus a gold-standard method. METHODS: Twenty-five patients undergoing CFR assessment in the LAD by Doppler flow wire were also evaluated by contrast-enhanced transthoracic Doppler to record blood flow in the distal LAD at rest and during hyperemia obtained by adenosine i.v. infusion. In five patients CFR was evaluated twice (before and after angioplasty). RESULTS: As a result of the combined use of i.v. contrast and second harmonic Doppler technology, feasibility in assessing coronary flow reserve equaled 100%. The agreement between the two methods was high. In fact, in all but five patients the maximum difference between the two CFR measurements was 0.38. Overall, the prediction (95%) interval of individual differences was -0.69 to +0.72. Reproducibility of CFR measurements was also high. The limits of the agreement (95%) between the two measurements were -0.32 to +0.32. CONCLUSIONS: Coronary flow reserve in the LAD as assessed by contrast-enhanced transthoracic echo Doppler along with harmonic mode concurs very closely with Doppler flow wire CFR measurements. This new noninvasive method allows feasible, reliable and reproducible assessment of CFR in the LAD.

Adenosine↗
PubMed1999

[Coronary reserve].

Explore the source record for details and available documents.

Angioplasty, Balloon↗
PubMed1995

Echocardiographic assessment of aortic valve replacement with stentless porcine xenografts.

Stentless porcine xenografts (SPXs) implanted in the aortic position have potential hemodynamic advantages over traditional valve prostheses because of the lack of a rigid stent. Twenty-four patients (mean age 59 years) who underwent aortic valve replacement with SPXs were studied by echocardiography early after and 26 +/- 10 months (range 8 to 40) after operation. Peak and mean gradients, as well as aortic valve area, did not change significantly from baseline (16.3 +/- 8 and 9.8 +/- 5.6 mm Hg, and 1.78 +/- 0.63 cm2, respectively) to follow-up study (12.5 +/- 5 and 7.7 +/- 3 mm Hg, and 1.8 +/- 0.65 cm2, respectively). At baseline, color flow Doppler imaging showed aortic valve regurgitation where the leaflets coapted centrally in 17 of 24 patients (trivial, n = 14; mild, n = 3). Besides the central leak, paravalvular regurgitation was seen in 4 patients (trivial, n = 3; mild, n = 1). At follow-up, 18 of 24 patients had aortic valve regurgitation (trivial, n = 11; mild, n = 6; and moderate, n = 1). New valvular regurgitation (graded as trivial, n = 2; mild, n = 2; and moderate, n = 1) was detected in 5 patients, and new paravalvular regurgitation (graded as mild) developed in 1 patient. Two patients underwent repeat operation for valve-related complications: (1) rupture of a valve cusp with acute pulmonary edema, and (2) fibrotic stenosis of the left coronary ostium with unstable angina. In conclusion, this study demonstrates good hemodynamic performance of the SPX in the aortic position.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Intraoperative echocardiography by a new miniaturized epicardial probe: preliminary findings.

Miniaturized probes constitute recent progress in the field of epicardial echocardiography. We recently used a new miniaturized probe, derived from a standard transesophageal probe, in a series of 12 adult patients who underwent cardiac surgery in order to test the possibility of obtaining new views for epicardial imaging. This study demonstrates the feasibility and safety of performing intraoperative echocardiography when using a miniaturized epicardial probe. This probe may be placed on a broader epicardial and vascular area, thus overcoming the size limitations of the commonly used epicardial probes. The major limitation found with the miniaturized probe, however, was the inability to obtain a true four-chamber view from the ventricular apex, due to the difficulty of holding the probe motionless between the apex and the diaphragm while the heart is beating. Although extensive experience with larger groups of patients and different pathologies will be required to define the full potential of this new probe, the advent of the miniaturized probe may further expand the applicability of epicardial echocardiography in pediatric patients during surgery for congenital heart disease.

Adolescent↗
PubMed1993

The role of transesophageal echocardiography in the monitoring of cardiac mass removal: a review of 17 cases.

Intraoperative transesophageal echocardiography (TEE) was used to monitor the removal of intracardiac masses in 17 patients. Prebypass TEE was used to confirm the preoperative diagnosis. It gave a clear image and anatomical definition of the mass in 16 cases. Moreover, in 11 of these patients, prebypass TEE provided information not obtained previously by traditional exams. This information was judged either useful or indispensable for a successful outcome in 10 of these patients. However, in one of the remaining six patients, TEE did not clearly visualize a flat thrombus in the left atrium. Postbypass TEE was used in each case to monitor the surgical results of the mass removal and the associated procedures. In one patient, it disclosed a progressively expanding hematoma in the left atrial wall, which was interfering with mitral valve function. From this experience, we consider intraoperative TEE the best monitoring device during cardiac mass removal because it usually provides a more complete diagnosis and anatomical definition of the mass than the traditional preoperative methods and permits monitoring of the surgical results before chest closure. Some limitations to this method may exist.

Adult↗
PubMed1991

[Echocardiography-guided endomyocardial biopsy].

We have performed 20 echocardiography-guided endomyocardial biopsies in 16 patients, totalling 98 bioptic samples. In each case fluoroscopy was available to supplement the echocardiographic findings. The right ventricle was biopsied in 17 cases, the left ventricle in 3. All 3 left ventricular biopsies and 14 out of 17 right ventricular biopsies were satisfactorily guided by echocardiography. An adequate echocardiographic window was not obtained in 3 cases of right ventricular biopsies and the procedures were carried out under fluoroscopy. In 5 cases (25%), totalling 10 samples, echocardiography showed a somewhat different position of the bioptome from that suggested by fluoroscopy, thus guiding a significant repositioning of it. Finally, in one patient, echocardiography promptly visualized a severe pericardial effusion, due to cardiac perforation, thus allowing its immediate drainage.

Adult↗