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Query: UMLS:C0599766 (functional recovery)
 13,441 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microvascular perfusion is a prerequisite for ensuring viability early after acute myocardial infarction (AMI). For adequate assessment of myocardial perfusion, both myocardial blood volume and velocity need to be evaluated. Due to its high frame rate, low-power continuous myocardial contrast echocardiography (MCE) can rapidly assess these parameters of myocardial perfusion. We hypothesized that the technique can accurately differentiate necrotic from viable myocardium after reperfusion therapy in AMI. Accordingly, 50 patients underwent low-power continuous MCE using intravenous Optison (Amersham Health, Amersham, Middlesex, United Kingdom) 7 to 10 days after AMI. Myocardial perfusion (contrast opacification assessed over 15 cardiac cycles after the destruction of microbubbles with high energy pulses) and wall thickening were assessed at baseline. Regional and global left ventricular (LV) function was reassessed after 12 weeks. Out of the 297 dysfunctional segments, MCE detected no contrast enhancement during 15 cardiac cycles in 172 segments, of which 160 (93%) failed to show improvement. MCE demonstrated contrast opacification during 15 cardiac cycles in 77 segments, of which 65 (84%) showed recovery of function. The greater the extent and intensity of contrast opacification, the better the LV function at 3 months (p <0.001, r = -0.91). Almost all patients (94%) with <20% perfusion in dysfunctional myocardium (assessing various cut-offs) failed to demonstrate an improvement in LV function. MCE and peak creatine kinase proved to be independent predictors of functional recovery (p <0.001). In conclusion, low-power continuous MCE is an accurate and rapid bedside technique to identify microvascular perfusion after AMI. This technique may be utilized to reliably predict late recovery of function in dysfunctional myocardium after AMI.
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PMID:Usefulness of myocardial contrast echocardiography using low-power continuous imaging early after acute myocardial infarction to predict late functional left ventricular recovery. 1294 65

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.
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PMID:[Myocardial contrast echography. History, methodology and clinical applications]. 1467 50