Quantification methods in contrast echocardiography.

New technologies and the availability of new echo-contrast agents have resulted in advances of diagnostic and prognostic indications of left ventricular opacification (LVO) and myocardial perfusion. The clinical diagnostic value of ultrasound contrast media for LVO and its impact on the clinical decision-making process has been demonstrated in several studies. Recent research aims at developing new quantitative software to improve the delineation of the endocardial border, to assess 3D myocardial perfusion for more accurate regional/global LV function measurements, and to evaluate 4D intra-cardiac flow dynamics. Furthermore, a general consensus has been reached on the incremental value of myocardial contrast echocardiography (MCE) for obtaining additional information in both chronic and acute coronary artery disease (CAD) patients and on the possibility to make quantitative measurements of microvascular damage. Q-contrast is a new software system which provides quantitative measurements to generate parametric images of microcirculatory flow. In a research project including 120 patients, Q-contrast software has been tested to assess the role of contrast in AMI (Acute Myocardial Infarction Contrast Imaging (A.M.I.C.I. Study); good agreement between parametric MCE and SPECT has been found. Preliminary results further confirm that quantitative MCE may provide additional clinical value over qualitative information for the assessment of LV function and of the effects of coronary artery disease on the myocardial microcirculation (viability, ischemia or infarct).

[Myocardial contrast echography. History, methodology and clinical applications]. / Ecocontrastografia miocardica. Cenni storici, aspetti metodologici e applicazioni cliniche.

Recent studies have demonstrated the usefulness of myocardial contrast echocardiography (MCE) in studying myocardial perfusion. Several first and second generation contrast agent such as Levovist, Sonovue, Optison, Definity and Imagent are commercially available or close to be introduced into the market. Use of MCE allowed the clinical demonstration of no-reflow phenomenon in patients with acute myocardial infarction (AMI) after recanalization of the infarct related artery (IRA). Coronary angiography is unable to assess the microvascular damage as showed by the poor correlation between TIMI grading and perfusion score evaluated by MCE. Furthermore, the use of MCE is important to determine coronary stenosis, to identify microvascular damage during ischaemia-reperfusion and to evaluate the presence of collateral circulation in the area at risk. MCE seems to be the most effective technique for assessing microvascular integrity after reperfusion as compared to TIMI myocardial perfusion grade, nuclear myocardial perfusion imaging and magnetic resonance imaging. These techniques are expensive, invasive and not available in most of the hospitals. Furthermore, as compared to nuclear medicine and echo-dobutamine, MCE has greater specificity and higher accuracy in detecting coronary artery disease. Recent studies showed that not only primary percutaneous coronary intervention (PCI) but also rescue and delayed PCI reduced microvascular damage and that MCE play a key role in assessing myocardial salvage after reperfusion. The most exciting aspect of MCE is the independent role in predicting left ventricular (LV) remodelling and functional recovery. The extent on no-reflow is an important predictor of LV dysfunction and remodelling at follow-up. Several studies have demonstrated that the extent of infarct-zone viability is a powerful independent predictor of LV dilation. There is a close relationship between the extent of microvascular damage, the extension of necrosis, the site of AMI and LV remodelling. We demonstrated that MCE performed 24 hours after reperfusion, at 1 week and 6 months appears to provide important prognostic information. These data support the daily use of MCE in coronary care unit and could establish a strategy for clinical decision making in patients with AMI.

Assessment of no-reflow phenomenon after acute myocardial infarction with harmonic angiography and intravenous pump infusion with Levovist: comparison with intracoronary contrast injection.

Myocardial contrast echocardiography (intracoronary application) has emerged as an accurate method to detect the "no-reflow phenomenon." To investigate the diagnostic value of harmonic angiography after intravenous infusion of Levovist in assessing "no-reflow," both intracoronary and intravenous contrast injections were performed in a group of patients with acute myocardial infarction. Seventeen consecutive patients with a successfully reperfused acute myocardial infarction within 6 hours of symptom onset were selected for this study. All patients underwent contrast echocardiography with harmonic angiography with Levovist (400 mg/mL, intravenous pump infusion, trigger intervals 1:4 to 1:8) and sonicated albumin (0.5 to 1 mL, intracoronary bolus) on day 1 after the achievement of a sustained coronary reflow. Myocardial perfusion was qualitatively assessed with a 12-segment model. The endocardial length of the residual contrast defect after reflow was also calculated. Forty-four of 204 segments were not analyzed after intravenous contrast echocardiography and 37 after intracoronary contrast echocardiography because of artifacts. Intracoronary and intravenous injections showed a perfusion defect in 31 (19%) segments, with a concordance of 89% (kappa coefficient, 0.72). Concordance in anteroseptal, anterolateral, and inferolateral segments was 95% (kappa = 0.92), 88% (kappa = 0.66), and 83% (kappa = 0.57), respectively. With intracoronary injection used as the reference method, intravenous injection had a sensitivity of 74% and a specificity of 93% for diagnosing contrast defects. The endocardial extent of no-reflow was 18 +/- 19 after intravenous and 21 +/- 17 after intracoronary contrast echocardiography (P = not significant). Intravenous contrast echocardiography with Levovist reliably identifies the no-reflow phenomenon after successful reperfusion, especially in acute anteroseptal myocardial infarction.

Non-invasive assessment of myocardial perfusion by intravenous contrast echocardiography: state of the art.

Many technical problems, related to both imaging instrumentation and contrast agents, have to be taken into account before attempting non-invasive evaluation of myocardial perfusion by intravenous contrast media injection. Potentials and pitfalls of first generation contrast agents (i.e. Levovist, Schering AG, Berlin, Germany) using intermittent harmonic angio imaging and of second generation contrast media (i.e. SonoVue, Bracco SpA, Milan, Italy) using real-time perfusion imaging in the non-invasive assessment of myocardial perfusion were described and discussed. We still need more solid data before introducing intravenous myocardial echocardiography into the clinical arena. However, convincing data from several research laboratories are paving the way for the widespread use of this new method in clinical practice.

Modification of cardiac function in cirrhotic patients with and without ascites.

OBJECTIVES: Abnormalities in cardiac function have been reported in liver cirrhosis, suggesting a latent cardiomyopathy in these patients. In this study we investigated cardiac function in cirrhotic patients and in controls. METHODS: A total of 20 cirrhotic patients without previous or ongoing ascites, 20 cirrhotic patients with moderate-to-severe ascites, and 10 healthy controls were studied by two-dimensional Doppler echocardiography. Cardiac dimensions and left and right ventricular function were evaluated. The left ventricular geometric pattern was calculated according to Ganau's criteria. Diastolic function was evaluated by the peak filling velocity of E wave and A wave, E/A ratio, and deceleration time of E wave. The pulmonary systolic arterial pressure was also estimated in patients with tricuspid insufficiency. RESULTS: Right and left atrium and right ventricle diameters were significantly enlarged in cirrhotic patients versus controls. E/A ratio was decreased (p < 0.05) in patients with ascites (0.9 +/- 0.2) versus those without ascites (1.3 +/- 0.4) and controls (1.3 +/- 1). The estimated pulmonary systolic arterial pressure was slightly elevated in patients with ascites (35 +/- 5 mm Hg, six patients) versus those with no ascites (28 +/- 5, 10 patients) and controls (27 +/- 8, 6 controls, analysis of variance, p < 0.05). The pattern of left ventricular geometry was normal in the majority of patients. Nitrite and nitrate levels were increased in cirrhotics irrespective of the presence of ascites. CONCLUSIONS: Liver cirrhosis is associated with enlarged right cardiac chambers. Diastolic dysfunction and mild pulmonary hypertension are evident in cirrhotic patients with ascites. These changes do not depend on variations in the left ventricular geometry.

Detection of residual tissue viability within the infarct zone in patients with acute myocardial infarction: ultrasonic integrated backscatter analysis versus dobutamine stress echocardiography.

OBJECTIVES: The goals of this study were to analyze temporal changes in cardiac cyclic variation of integrated backscatter (CVIB) in acute myocardial infarction (AMI) and to investigate the predictive value of CVIB normalization compared with that of dobutamine stress echocardiography (DSE) in the assessment of functional recovery after revascularization. BACKGROUND: The normal CVIB is blunted by ischemia and recovers early after reperfusion, faster than wall motion improvement. Analysis of CVIB has been widely investigated for its potential to detect viable myocardium in the early stage of infarction. No studies have compared CVIB analysis with other techniques for viability assessment in patients with acute ischemic. METHODS AND RESULTS: Integrated backscatter images were obtained in 12 patients with AMI on days 1, 3, and 7 after admission and 1 month after revascularization. On day 7, DSE was performed in all patients. On admission, 22 of 144 segments were dyssynergic. On day 1, CVIB was abnormal in all 22 infarcted segments, on day 3, in 16, and on day 7, in only 10 infarcted segments. Eight of 10 segments nonviable by CVIB (CVIB-nonviable) were also nonrespondent by DSE; whereas 12 of 14 segments viable by DSE (DSE-viable) were also CVIB-viable. At follow-up, 10 CVIB-viable segments and 1 CVIB-nonviable segment showed functional recovery; whereas 10 of 14 DSE-viable segments showed functional recovery. Thus the positive predictive value of CVIB and DSE was 83% and 72%, respectively, with a diagnostic agreement between techniques in 77% of segments. CONCLUSIONS: Our data suggest that the normalization in CVIB in the first week after AMI accurately predicts residual tissue viability within the infarct zone. We also observed that the initial pattern of cyclic variation may be predictive of functional recovery. Finally, we found a good correlation between the recovery of a normal CVIB in segments that were still dysfunctional and a more validated method to assess tissue viability, such as the dobutamine test.

Effects of angiotensin-converting enzyme inhibition on left ventricular geometric patterns in patients with essential hypertension.

Although angiotensin-converting enzyme inhibitors have been shown to affect left ventricular (LV) remodeling favorably in several conditions, it remains unclear whether they can influence LV geometric pattern in hypertension. To address this issue, 122 patients (71 men and 51 women; mean age = 51 +/- 10 years) with mild to moderate hypertension were studied prospectively. All underwent clinical evaluation and Doppler echocardiography at entry and more than 2 years of quinapril therapy (10-40 mg/day). According to either LV mass (normal if < 131 g/m2 for men or < 100 g/m2 for women) or the ratio of LV posterior wall thickness to diastolic diameter (RWT; normal if < 0.45) at baseline, 58 patients had normal mass and RWT, 18 patients had concentric remodelling (i.e., normal mass but increased RWT), 24 patients had eccentric hypertrophy (i.e., increased mass but normal RWT), and 22 patients had concentric hypertrophy (i.e., increase in both mass and RWT). After 6 months of quinapril therapy, all patients with normal left ventricles showed the maintenance of mass and RWT within normal limits. Patients with concentric remodeling showed no increase in mass but had a significant decrease in RWT. Patients with eccentric hypertrophy exhibited a significant reduction in mass with no substantial change in RWT. Patients with concentric hypertrophy had a significant reduction in both mass and RWT. Changes in LV mass and geometry were maintained during the 2-year period of treatment and were paralleled by improvements in Doppler indices of LV diastolic function in each group. It is concluded that quinapril, with its well-known effects on LV hypertrophy, modifies the LV geometric pattern of hypertensive patients favorably, regardless of the presence of an abnormal LV mass or RWT.

Noninvasive assessment of mitoxantrone cardiotoxicity in relapsing remitting multiple sclerosis.

Multiple sclerosis is the most common cause of neurologic disability in young adults. Recent reports have suggested that Mitoxantrone might be a candidate for clinical trials in multiple sclerosis patients. The authors studied 20 patients with relapsing remitting multiple sclerosis to evaluate cardiac toxicity during a one-year follow-up period. Patients were divided into 2 groups: group A, mitoxantrone treated patients (cumulative dose of 96 mg/m2); group B, placebo patients. The clinical course of multiple sclerosis was assessed using the Expanded Disability Status Scale and the number of relapses during the follow-up. Each patient had an electrocardiogram and a spectral and color flow Doppler echocardiographic examination at enrollment, and 6 and 12 months later, to investigate cardiac toxicity. The mean exacerbation rate was reduced significantly in group A patients. No significant differences in the electrocardiograms or the echocardiographic parameters of systolic and diastolic function were noted between the two groups or in group A during the follow-up. Mitoxantrone treatment seems able to improve the clinical course of relapsing remitting multiple sclerosis patients. It does not show any cardiac toxicity in selected patients at this dosage.