Acute hyperglycemia reduces myocardial blood flow reserve and the magnitude of reduction is associated with insulin resistance: a study in nondiabetic humans using contrast echocardiography.

The effect of acute hyperglycemia per se on coronary perfusion in humans is undefined. We evaluated the effects of short-term hyperglycemia on myocardial blood flow reserve (MBFR) in healthy nondiabetic volunteers. Twenty-one nondiabetic volunteers (76 % females, mean ± SD, age 48 ± 5 years) had noninvasive MBFR assessment while exposed to pancreatic clamp with somatostatin and replacement glucagon and growth hormone infusions, with frequent interval plasma glucose (PG) monitoring. Insulin was infused at 0.75 mU/kg/min to mimic postprandial plasma insulin concentrations, and glucose was infused to maintain euglycemia (PG 93.9 ± 7.3 mg/dl) followed by hyperglycemia (PG 231.5 ± 18.1 mg/dl). Myocardial contrast echocardiography (MCE) was performed during each glycemic steady state using continuous infusion of Definity at rest and during regadenoson (Lexiscan 5 ml (400 µg) intravenous bolus) infusion to quantify myocardial blood flow (MBF) and determine MBFR. Insulin resistance (IR) was assessed by glucose infusion rate (GIR; mg/kg/min) at euglycemia. Median stress MBF, MBFR, and ß reserve were significantly reduced during acute hyperglycemia versus euglycemia (stress MBF 3.9 vs 5.4, P = 0.02; MBFR 2.0 vs 2.7, P < 0.0001; ß reserve 1.45 vs 2.4, P = 0.007). Using a median threshold GIR of 5 mg/kg/min, there was a correlation between GIR and hyperglycemic MBFR (r = 0.506, P = 0.019). MBFR, as determined noninvasively by MCE, is significantly decreased during acute hyperglycemia in nondiabetic volunteers, and the magnitude of this reduction is modulated by IR.

Diagnostic accuracy of contrast echocardiography during adenosine stress for detection of abnormal myocardial perfusion: a prospective comparison with technetium-99 m sestamibi single-photon emission computed tomography.

Myocardial contrast echocardiography (MCE) utilizes compressible microbubbles behaving similarly to red blood cells. Destruction of microbubbles and observation of the gradual refill into the myocardium are key to evaluating perfusion using real-time MCE. We aimed to assess the feasibility and diagnostic accuracy of qualitative MCE utilizing a 17-segment model for localization of myocardial perfusion abnormalities compared with simultaneous technetium-99 m sestamibi single-photon emission computed tomography (SPECT). From July 2005 through August 2007, 97 patients with known or suspected coronary artery disease underwent simultaneous SPECT and realtime MCE during adenosine stress. Qualitative MCE and tracer uptake were analyzed visually using a 17-segment model in a blinded manner. Diagnostic accuracy and 95% confidence interval (CI) were determined. Myocardial contrast echocardiography was completed in 91 patients (age, mean [SD], 69.3 [10.9] years; body mass index, 30.0 [6.3]; 59 males [65%]). Myocardial contrast echocardiography analysis was feasible in 88 (97%) patients (261 of 264 [99%] territories; 1299 of 1497 [87%] segments). At patient level, MCE sensitivity was 88% (95% CI, 79%-94%); specificity was 85% (77%-90%). For disease detection in individual coronary territories, sensitivity and specificity were 84% (71%-92%) and 79% (72%-84%) for the left anterior descending artery; 62% (38%-80%) and 88% (83%-91%) for the left circumflex artery; and 73% (57%-82%) and 94% (89%-97%) for the right coronary artery. For MCE combined with wall-motion analysis, concordance with SPECT improved from 80% to 86%. Myocardial contrast echocardiography interobserver concordance was 81% (kappa [SE], 0.611 [0.78]). Myocardial contrast echocardiography accuracy was comparable in patients classified in accordance with presence of diabetes mellitus, myocardial infarction, hypertension, or percutaneous coronary intervention. Improved MCE specificity in detecting perfusion defects was seen in patients with no history of coronary bypass graft surgery (P = 0.005). Real-time MCE with a 17-segment model for analysis has good feasibility and accuracy in evaluation of myocardial perfusion during adenosine stress.

Assessment of myocardial perfusion during adenosine stress using real time three-dimensional and two-dimensional myocardial contrast echocardiography: comparison with single-photon emission computed tomography.

OBJECTIVES: To evaluate diagnostic accuracy of adenosine two-dimensional and three-dimensional myocardial contrast echocardiography (2D- and 3D-MCE) compared with single-photon emission computed tomography (SPECT) for assessing myocardial perfusion. METHODS: From January through August 2007, patients with known or suspected CAD who were referred for SPECT underwent simultaneous adenosine 2D-MCE and 3D-MCE (live and full volume [FV]). Perfusion and wall motion in 17 segments in the left anterior descending, left circumflex, and right coronary artery territories were analyzed. RESULTS: We studied 30 patients: mean (SD) age, 72.6 (8.2) years; 19 (63%) men. Perfusion by SPECT was abnormal in 13 patients (43%). When comparing MCE with SPECT, sensitivity was comparable for 2D-MCE, 92%; live 3D-MCE, 91%; and FV 3D-MCE, 90%. Specificity was comparable for 2D-MCE, 75%; live 3D-MCE, 69%; and FV 3D-MCE, 79%. Agreement between live 3D-MCE and 2D-MCE was 92% (kappa[SE], 0.83 [0.17]) and between FV 3D-MCE and 2D-MCE, 88% (kappa[SE], 0.76 [0.13]). For eight patients in whom SPECT showed reversible defects, live 3D-MCE correctly identified defects in seven (88%), whereas FV 3D-MCE correctly identified them in five (63%) (P = 0.57). CONCLUSION: Myocardial perfusion assessment is feasible by 3D-MCE with the advantage of rapid, facile acquisition and offline image manipulation.

Integrating research into clinical practice: development of an echocardiography research unit.

Introducing a research program into an echocardiography clinical practice can pose many challenges. Some initial factors to consider are the possible effects on the current clinical schedule and the equipment and personnel resources required to support the research projects. More importantly, how can an organization successfully complete reliable and accurate research projects? Here, we describe our experience with establishing an echocardiography research center within our clinical echocardiography practice. In addition, we identify key staff roles, highlight our current research practice methods, and suggest essential components that may prove advantageous when incorporating echocardiography research into a clinical practice.

Prognostic Utility of Stress Testing and Cardiac Biomarkers in Menopausal Women at Low to Intermediate Risk for Coronary ARTery Disease (SMART Study): 5-Year Outcome.

BACKGROUND: In women with low to intermediate risk of coronary artery disease (CAD), prognostic detection strategies have been controversial. We present the follow-up data of the SMART trial in peri/postmenopausal women at low to intermediate risk of CAD. OBJECTIVES: To determine the value of contrast stress echocardiography (CSE), stress electrocardiogram (sECG), and serum biomarkers for prediction of cardiovascular events (CE) in peri/postmenopausal women at low to intermediate risk of CAD. MATERIALS AND METHODS: From January 2004 to August 2007, 400 peri/postmenopausal women were prospectively enrolled. All women had detailed risk factor assessment, and underwent simultaneous CSE (Definity®, Lantheus Medical Imaging) and sECG. Laboratories included brain natriuretic peptide (BNP), atrial natriuretic peptide, endothelin, and high sensitivity C-reactive protein. Wall motion score index was based on a 16-segment model. Abnormal CSE was defined as new or worsening wall motion abnormality at stress, while abnormal sECG was ≥1 mm horizontal/downsloping ST segment depression/elevation (80 mseconds duration). Self-reported outcome data were collected from a mailed Women's Heart Clinic Questionnaire. CE outcomes included all-cause mortality, nonfatal myocardial infarction (MI), heart failure, chest pain hospitalization or development of typical angina (CP), and revascularization (REVASC). Adjusted Cox proportional hazard ratios (HR; 95% confidence intervals) were reported. RESULTS: A total of 366 women (54.4 ± 5.5 years, Framingham risk 6.5% ± 4.4%) completed simultaneous CSE and sECG. Forty-two (11.5%) had abnormal CSE, while sECG was abnormal in 22 (6%) women. Follow-up (4.4 ± 1.2 years) was available in 315/366 (86%) women (78% exercise-CSE, 22% dobutamine-CSE). In those who completed follow-up, CSE was abnormal in 33 women (10.5%) and sECG was abnormal in 21 (6.7%). In 33 women with abnormal CSE, sECG was abnormal in 7 (21.2%) and normal in 26 (79%), p = 0.0004. CE occurred in 27 (8.6%) women: 8 all-cause mortality, 2 nonfatal MI, 13 CP, and 4 REVASC. CE occurred in 21% versus 7% of women with abnormal versus normal CSE, p = 0.014 and 38% versus 6% of women with abnormal versus normal sECG, p < 0.0001. Rest BNP was higher in women with CE versus those without (p = 0.018). Abnormal sECG and abnormal CSE were associated with CE, while only abnormal sECG was an independent predictor of CE (adjusted HR 10.3 [1.9-61.4], p = 0.007). Of the laboratory results, only BNP was associated with CE (adjusted HR 2.9 [1.1-7.3], p = 0.028). CONCLUSIONS: sECG and rest BNP were independent predictors of subsequent CE within 5 years in peri/postmenopausal women at low to intermediate risk of CAD.

Usefulness of real-time intravenous myocardial contrast echocardiography in predicting left ventricular dilation after successfully reperfused acute myocardial infarction.

The ability of real-time intravenous myocardial contrast echocardiography to predict left ventricular remodeling after reperfused acute myocardial infarction was assessed in 47 patients. Intravenous myocardial contrast echocardiography was an independent predictor of left ventricular dilation after acute myocardial infarction. In particular, normal contrast opacification within dyssynergic segments indicated a very low risk of remodeling.

Comparison of intravenous myocardial contrast echocardiography and low-dose dobutamine echocardiography for predicting left ventricular functional recovery following acute myocardial infarction.

Akinesia after acute myocardial infarction (AMI) may be reversible or irreversible. Distinguishing these 2 entities early after AMI is difficult, but clinically important. Previous studies have shown that myocardial contrast echocardiography (MCE) and low-dose dobutamine echocardiography (DE) may both be useful in this setting. However, there are few data regarding the relative and combined value of these techniques. The aim of this study was to compare the utility of real-time intravenous MCE and low-dose DE in the early prediction of functional recovery of akinetic myocardium after AMI. Thirty-seven patients were studied 3 +/- 2 days after an AMI. Each subject underwent real-time MCE using an intravenous infusion of perflutren microbubbles. Immediately after this, low-dose DE was performed. Contrast opacification and wall motion were determined by experienced observers blinded to clinical data. Repeat echocardiograms were obtained 51 +/- 19 days later and wall motion at rest was scored by an observer blinded to clinical data. Normal contrast opacification predicted functional recovery with a positive predictive value of 63%, a negative predictive value of 73%, and an accuracy of 66%. Residual contractility during low-dose DE had a positive predictive value of 82%, a negative predictive value of 72%, and a predictive accuracy of 76%. When the 2 tests were concordant (64%), they had a positive predictive value of 81%, a negative predictive value of 85%, and a predictive accuracy of 83%. Low-dose DE was superior to intravenous MCE in the prediction of functional recovery of akinetic myocardium after AMI, but the combination of both maximizes predictive accuracy.

Strain rate and strain: a step-by-step approach to image and data acquisition.

The advent of strain and strain rate imaging in clinical echocardiography prompted an examination of proper techniques for image acquisition and analysis. For this promising and relatively new method of assessing myocardial performance to be successful in diagnostic echocardiography, close adherence to a standardized method is imperative. This article provides the echocardiographer with a step-by-step approach.

Contrast echocardiography using intravenous octafluoropropane and real-time perfusion imaging predicts functional recovery after acute myocardial infarction.

Akinesia after acute myocardial infarction (MI) may be reversible, secondary to stunning, or irreversible, as a result of extensive myocyte necrosis. Distinguishing these 2 entities soon after MI is difficult, but has important clinical implications. The current study assessed the use of intravenous myocardial contrast echocardiography (MCE) in this setting. A total of 35 patients were studied 2 (+/- 1) days after an acute MI. Of these, 31 (91%) underwent myocardial revascularization. Perfusion was assessed using real-time MCE and an intravenous infusion of octafluoropropane microbubbles. Repeated echocardiograms were obtained 56 (+/- 29) days later. Normal perfusion predicted functional recovery with a positive predictive value of 66% and a negative predictive value of 81%. The accuracy of the technique was superior in myocardial segments supplied by the left anterior descending coronary artery (positive and negative predictive value: 70% and 90%, respectively). In multivariable analysis, the mean MCE perfusion score in akinetic segments was the most powerful independent predictor of functional recovery (odds ratio 8.6, P =.02). These data suggest that real-time intravenous MCE is a useful predictor of functional recovery of akinetic myocardium after acute MI.

A multicenter, prospective study to evaluate the use of contrast stress echocardiography in early menopausal women at risk for coronary artery disease: trial design and baseline findings.

AIMS: This multisite prospective trial, Stress Echocardiography in Menopausal Women At Risk for Coronary Artery Disease (SMART), aimed to evaluate the prognostic value of contrast stress echocardiography (CSE), coronary artery calcification (CAC), and cardiac biomarkers for prediction of cardiovascular events after 2 and 5 years in early menopausal women experiencing chest pain symptoms or risk factors. This report describes the study design, population, and initial test results at study entry. METHODS: From January 2004 through September 2007, 366 early menopausal women (age 54±5 years, Framingham risk score 6.51%±4.4 %, range 1%-27%) referred for stress echocardiography were prospectively enrolled. Image quality was enhanced with an ultrasound contrast agent. Tests for cardiac biomarkers [high-sensitivity C-reactive protein (hsCRP), atrial natriuretic protein (ANP), brain natriuretic protein (BNP), endothelin (ET-1)] and cardiac computed tomography (CT) for CAC were performed. RESULTS: CSE (76% exercise, 24% dobutamine) was abnormal in 42 women (11.5%), and stress electrocardiogram (ECG) was positive in 22 women (6%). Rest BNP correlated weakly with stress wall motion score index (WMSI) (r=0.189, p<0.001). Neither hsCRP, ANP, endothelin, nor CAC correlated with stress WMSI. Predictors of abnormal CSE were body mass index (BMI), diabetes mellitus, family history of premature coronary artery disease (CAD), and positive stress ECG. Twenty-four women underwent clinically indicated coronary angiography (CA); 5 had obstructive (≥50%), 15 had nonobstructive (10%-49%), and 4 had no epicardial CAD. CONCLUSIONS: The SMART trial is designed to assess the prognostic value of CSE in early menopausal women. Independent predictors of positive CSE were BMI, diabetes mellitus, family history of premature CAD, and positive stress ECG. CAC scores and biomarkers (with the exception of rest BNP) were not correlated with CSE results. We await the follow-up data.

Rapid detection of coronary artery stenoses with real-time perfusion echocardiography during regadenoson stress.

BACKGROUND: Real-time myocardial contrast echocardiography permits the detection of myocardial perfusion abnormalities during stress echocardiography, which may improve the accuracy of the test in detecting coronary artery stenoses. We hypothesized that this technique could be used after a bolus injection of the selective A2A receptor agonist regadenoson to rapidly and safely detect coronary artery stenoses. METHODS AND RESULTS: In 100 patients referred for quantitative coronary angiography, real-time myocardial contrast echocardiography was performed during a continuous intravenous infusion of 3% Definity at baseline and at 2-minute intervals for up to 6 minutes after a regadenoson bolus injection (400 µg). Myocardial perfusion was assessed by examination of myocardial contrast replenishment after brief high mechanical index impulses. A perfusion defect was defined as a delay (>2 seconds) in myocardial contrast replenishment in 2 contiguous segments. Wall motion was also analyzed. The overall sensitivity/specificity/accuracy for myocardial perfusion analysis in detecting a >50% diameter stenosis was 80%/74%/78%, whereas for wall motion analysis it was 60%/72%/66% (P<0.001 for differences in sensitivity). Sensitivity for myocardial perfusion analysis was highest on images obtained during the first 2 minutes after regadenoson bolus (P<0.001 compared with wall motion), whereas wall motion sensitivity was highest at the 4-to-6-minute period after the bolus. No significant side effects occurred after regadenoson bolus injection. CONCLUSIONS: Regadenoson real-time myocardial contrast echocardiography appears to be a feasible, safe, and rapid noninvasive method for the detection of significant coronary artery stenoses.

Safety of contrast agent use during stress echocardiography in patients with elevated right ventricular systolic pressure: a cohort study.

BACKGROUND: Microbubble safety concerns led to changes in product recommendations for patients with pulmonary hypertension. Noninvasive estimation of right ventricular systolic pressure (RVSP) is equivalent to pulmonary artery systolic pressure in the absence of pulmonary outflow obstruction. We analyzed the short- and long-term outcomes of patients who received microbubble contrast and those who did not during stress echocardiography (SE) according to resting RVSP. METHODS AND RESULTS: From November 2003 to December 2007, 26,774 patients underwent SE. RVSP (mean, 32.6+/-9.6 mm Hg) was measured in 16 434 patients. Of these, 6164 (37.5%) received contrast for left ventricular opacification and 10 270 (62.5%) did not. Short-term (< or =72 hours and < or =30 days) and long-term (4.3 years) end points were death and myocardial infarction. Analysis was done for rest RVSP cut-points > or =35, > or =50, and > or =60 mm Hg and tricuspid regurgitant velocities > or =2.7 ms(-1) and > or =3.5 ms(-1). Adjusted Cox regression models were used. The contrast cohort comprised older patients (age, 67+/-12 versus 64+/-14 years; P<0.001), who were more likely to have positive SE results (35% versus 30%, P<0.001) compared with the noncontrast cohort. Using RVSP > or =50 mm Hg, there was no significant difference in short-term events between the contrast and noncontrast cohorts. For long-term events, there was no significant difference between both cohorts (adjusted hazard ratios [95% confidence intervals] for death, 1.10 [0.80 to 1.50], P=0.56; and myocardial infarction, 0.34 [0.11 to 1.03], P=0.06). Similar results were obtained at different RVSP and tricuspid regurgitant cut-points. Contrast agent-related adverse effects occurred in <1% of patients. CONCLUSIONS: RVSP had no impact on predisposition to adverse outcomes in patients undergoing contrast SE in the population studied.

Safety of contrast agent use during stress echocardiography: a 4-year experience from a single-center cohort study of 26,774 patients.

OBJECTIVES: We evaluated the short- and long-term safety of contrast agents during stress echocardiography (SE). BACKGROUND: Concerns about contrast agent safety led to revised recommendations for product use in the U.S. METHODS: We studied 26,774 patients who underwent SE between November 1, 2003, and December 31, 2007. The 10,792 patients who comprised the contrast cohort received second-generation perfluorocarbon-based agents for left ventricular opacification during SE. The noncontrast cohort comprised 15,982 patients who had their first SE in the same period but without contrast agents. Short-term (< or = 72 h and < or = 30 days) and long-term (up to 4.5 years) end points were death and myocardial infarction (MI). Cox regression models were used. Immediate contrast agent-related adverse effects were also reported. RESULTS: The contrast cohort had older patients (mean [SD] age, 65.8 [12.1] years vs. 62.6 [14.1] years; p < 0.001), a higher percentage of males (57.4% vs. 52.8%, p < 0.001), and higher-risk patients compared with the noncontrast cohort. In addition, dobutamine SE patients had greater cardiac risk than exercise SE patients. Abnormal SE findings in patients who received contrast agents were more frequent (32.4% vs. 27.9%, p < 0.001). The 2 cohorts had no statistical difference in the incidence of short-term events (death and MI). Within 72 h, 1 patient in the contrast cohort and 2 patients in the noncontrast cohort died (p = 0.54); 3 in the contrast cohort and 7 in the noncontrast cohort had MI (p = 0.92). Within 30 days, 37 patients (0.34%) in the contrast cohort and 57 patients (0.36%) in the noncontrast cohort died (p = 0.85); 17 patients (0.16%) in the contrast cohort and 16 patients (0.10%) in the noncontrast cohort had MI (p = 0.19). Adjusted hazard ratios were not different between cohorts for death (0.99; 95% confidence interval: 0.88 to 1.11) or MI (0.99; 95% confidence interval: 0.80 to 1.22). CONCLUSIONS: The use of contrast agents during SE was not associated with an increased short-term or long-term risk of death or MI.

Microvascular function in Takotsubo cardiomyopathy with contrast echocardiography: prospective evaluation and review of literature.

BACKGROUND: Takotsubo cardiomyopathy (TC) mimics ST-elevation myocardial infarction without substantial angiographic stenosis. Coronary microvascular dysfunction has been proposed as a possible mechanism in TC. The aim of this study was to evaluate microvascular function in TC using real-time myocardial contrast echocardiography (MCE). METHODS: Real-time MCE was performed within 24 hours of coronary angiographic diagnosis of TC. Myocardial perfusion was evaluated through qualitative and quantitative myocardial contrast echocardiographic analyses comparing normal segments with segments with dysfunctional wall motion (WM). RESULTS: From January 2007 to January 2008, 11 patients received diagnoses of TC. Of these patients, 9 were prospectively enrolled (mean age, 70.9 +/- 17.5 years; 8 women). Qualitative and quantitative myocardial contrast echocardiographic analyses were feasible in 87% and 81% of segments. Overall, concordance between qualitative MCE and WM for normal versus abnormal analysis was observed in 71% of segments (kappa = 0.442, SE = 0.08). Significantly lower myocardial blood flow velocity (beta) and lower myocardial blood flow (Abeta) were detected in segments with dysfunctional WM compared with those with normal WM (beta = 0.55 +/- 0.39 vs 0.90 +/- 0.77, P = .009; Abeta = 5.31 +/- 3.92 vs 12.38 +/- 13.47, P = .002). In the discordant segments between qualitative MCE and WM, the quantitative perfusion parameters beta and Abeta were significantly lower in segments with dysfunctional WM compared with those with normal WM (beta = 0.22 +/- 0.20 vs 1.79 +/- 0.57, P = .01; Abeta = 1.90 +/- 1.1 vs 24.29 +/- 19.9, P = .02). Recovery of WM abnormalities was detected in all patients during follow-up echocardiography (mean, 60.3 +/- 66.0 days). No contrast-related side effects were reported. During mean follow-up of 5.9 +/- 4.6 months, there were no cardiac events, but 1 noncardiac death (from lung cancer) occurred. CONCLUSION: TC is associated with abnormal myocardial perfusion detected with qualitative and quantitative MCE, indicative of microvascular dysfunction.

Regional diastolic contour abnormalities during contrast stress echocardiography: improved detection of coronary artery disease.

BACKGROUND: Use of contrast improves detection of systolic regional wall motion abnormalities (RWMAs) during stress echocardiography. We evaluated regional diastolic contour abnormalities (RDCAs) that were associated with coronary artery disease (CAD). METHODS: From August of 2003 to September of 2004, we evaluated 89 patients who underwent contrast stress echocardiography (CSE) and coronary angiography within a 3-month period ("invasive" group) and 17 patients with lower CAD risk who underwent CSE only ("reference" group). RESULTS: RDCAs were present in 73 patients in the invasive group and were associated with higher Framingham risk scores (relative risk, 3.6; 95% confidence interval, 1.9-6.6). RDCAs were present in 1 patient in the reference group. When combined with RWMA, RDCA improved sensitivity of CSE from 78% to 97% and specificity from 26% to 59% (diagnostic threshold for CAD was 70% stenosis). CONCLUSION: RDCAs were a novel observation associated with higher CAD risk and improved the diagnostic accuracy of CSE.

American Society of Echocardiography Consensus Statement on the Clinical Applications of Ultrasonic Contrast Agents in Echocardiography.

UNLABELLED: ACCREDITATION STATEMENT: The American Society of Echocardiography (ASE) is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The ASE designates this educational activity for a maximum of 1 AMA PRA Category 1 Credit.trade mark Physicians should only claim credit commensurate with the extent of their participation in the activity. The American Registry of Diagnostic Medical Sonographers and Cardiovascular Credentialing International recognize the ASE's certificates and have agreed to honor the credit hours toward their registry requirements for sonographers. The ASE is committed to resolving all conflict-of-interest issues, and its mandate is to retain only those speakers with financial interests that can be reconciled with the goals and educational integrity of the educational program. Disclosure of faculty and commercial support sponsor relationships, if any, have been indicated. TARGET AUDIENCE: This activity is designed for all cardiovascular physicians, cardiac sonographers, and nurses with a primary interest and knowledge base in the field of echocardiography; in addition, residents, researchers, clinicians, sonographers, and other medical professionals having a specific interest in contrast echocardiography may be included. OBJECTIVES: Upon completing this activity, participants will be able to: 1. Demonstrate an increased knowledge of the applications for contrast echocardiography and their impact on cardiac diagnosis. 2. Differentiate the available ultrasound contrast agents and ultrasound equipment imaging features to optimize their use. 3. Recognize the indications, benefits, and safety of ultrasound contrast agents, acknowledging the recent labeling changes by the US Food and Drug Administration (FDA) regarding contrast agent use and safety information. 4. Identify specific patient populations that represent potential candidates for the use of contrast agents, to enable cost-effective clinical diagnosis. 5. Incorporate effective teamwork strategies for the implementation of contrast agents in the echocardiography laboratory and establish guidelines for contrast use. 6. Use contrast enhancement for endocardial border delineation and left ventricular opacification in rest and stress echocardiography and unique patient care environments in which echocardiographic image acquisition is frequently challenging, including intensive care units (ICUs) and emergency departments. 7. Effectively use contrast echocardiography for the diagnosis of intracardiac and extracardiac abnormalities, including the identification of complications of acute myocardial infarction. 8. Assess the common pitfalls in contrast imaging and use stepwise, guideline-based contrast equipment setup and contrast agent administration techniques to optimize image acquisition.

Echocardiographic indices of increased left ventricular filling pressure and dilation after acute myocardial infarction.

The relationship between echocardiographic indicators of acute and chronic left ventricular (LV) filling pressure and LV dilation after acute myocardial infarction was assessed in 47 patients. The ratio of early transmitral flow velocity to early mitral annulus velocity (E/e') reflects acute LV filling pressure and the indexed volume of the left atrium is an indicator of chronic LV filling pressure. E/e' was higher (19 vs 10, P = .001) among patients who experienced a greater than 15% increase in indexed LV end-diastolic volume (remodeling group, n = 10). Receiver operating characteristic curve analysis confirmed that E/e' was a predictor of remodeling (area under the curve 0.83, P = .002). Patients with E/e' greater than 15 had a mean increase in indexed LV end-diastolic volume of 9.3 versus 1.7 mL/m2 in patients with E/e' 15 or less (P = .01). Multivariable regression analyses confirmed that E/e' was the strongest independent predictor of remodeling in this cohort (odds ratio 1.39, P = .01). There was no relationship between indexed volume of the left atrium and LV dilation. These data suggest that the E/e' ratio may be a useful predictor of LV dilation after acute myocardial infarction. In particular, an E/e' ratio greater than 15 identifies patients at increased risk.

An echocardiographic left ventricular wall area index for functional detection of myocardial injury in hemodynamically unloaded hearts.

Functional assessment of the left ventricle is affected by loading conditions. Detection of rejection-mediated myocardial injury in a heterotopic heart transplant model is a challenge for the echocardiographer because the heart is in an unloaded state. We examined the relationship of a novel left ventricular (LV) wall area index (LVWAI) and serum cardiac troponin T (cTnT) levels. The LVWAI, based on prior methods of determining LV mass, was defined as the difference between epicardial and endocardial areas divided by the epicardial area. The biphasic morphometric response of LVWAI reflected changes in the cTnT levels and allowed echocardiographic detection of myocardial injury in hemodynamically unloaded hearts.

Feasibility of continuous venous infusion of SonoVue for qualitative assessment of reversible coronary perfusion defects in stress myocardial contrast echocardiography.

OBJECTIVE: To study the feasibility of continuous intravenous SonoVue contrast echocardiography for qualitative assessment of reversible myocardial perfusion in dipyridamole stress tests. METHODS: Eleven patients (10 male and 1 female, mean age 66 years) with a history of chest pain and a clinical indication for stress sestamibi single photon emission computed tomography (SPECT) underwent concurrent SonoVue 99mTc myocardial contrast echocardiography (MCE). RESULTS: Of the total 176 segments obtained, 53 (30%) were regarded as indeterminate, 39 (22%) as discordant, and 84 (48%) as concordant between MCE and SPECT imaging. Two patients had abnormal SPECT results. The overall feasibility and specificity of MCE were 70 and 74%, respectively. The concordant (p = 0.59) and discordant (p = 0.55) segments were comparable with either MCE technique. However, continuous low-mechanical-index imaging produced fewer indeterminate segments (17 segments, 32%) than intermittent harmonic B-mode imaging (36 segments, 68%) (p = 0.04). Significantly more indeterminate segments were found in the left anterior descending artery territory. However, the overall concordance was similar (p = 0.5) in all three coronary artery territories. The concordance and discordance rates at different left ventricular levels (i.e., basal, mid, and apical) were similar (p = 0.50 and 0.08, respectively). CONCLUSION: Continuous-infusion SonoVue contrast echocardiography is feasible, with high specificity, for detecting myocardial perfusion defects as assessed by dipyridamole SPECT.