Low-dose Dobutamine Stress Echocardiography Research Articles

Value of mitral annular plane systolic excursion in the assessment of contractile reserve in patients with ischemic cardiomyopathy before cardiac revascularization

BackgroundMitral annular plane systolic excursion (MAPSE) is an M-mode derived echocardiographic marker of left ventricular longitudinal function, the aim of this study is to evaluate the value of MAPSE in assessment of contractile reserve in patients with ischemic cardiomyopathy before cardiac revascularization. MethodsThe study included 50 patients with ischemic cardiomyopathy with ejection fraction (EF) ≤35%, the patients presented to echocardiography laboratory for dobutamine stress echocardiography (DSE) to assess viability and contractile reserve before revascularization, patients with primary valvular disease, and those with significant mitral annular calcifications were excluded from the study. A low dose DSE was done to all patients using standardized incremental infusions of 5, 10, and 20 μg/kg/min and the following parameters were measured at both baseline and peak dose, (EF, wall motion score index(WMSI) and MAPSE). Contractile reserve was measured as the difference between the low dose and baseline values of the EF and WMSI. ResultsThe study included 50 patients aged 55.08±7.15 years, 94% were males, the DSE protocol was complete in all patients without serious side effects. A total of eight hundred segments were analyzed, at baseline 65% were dysfunctional including 31.2% hypokinetic, 28.8% were akinetic, and 5% were dyskinetic. At low dose study 70% of the dysfunctional myocardium showed viability, EF increased significantly from 30.84±4.56 to 42.24±8.15%, p <0.001, the WMSI reduced significantly from 1.92±0.33 to 1.47±0.39, and MAPSE increased significantly from 1.02±0.23 to 1.30±0.30mm. MAPSE showed a significant positive correlation with EF at both baseline and low dose study (r=0.283, p=0.046 & r=0.348, p=0.013) respectively and a significant negative correlation with WMSI at both baseline and low dose study (r=−0.3, p=0.034 & r=−0.409, p=0.003), respectively. By ROC curve analysis we found that Δ MAPSE ≥2mm can predict contractile reserve at Δ EF >10% (AUC=0.6, sensitivity 67.86, specificity 59.09), and Δ MAPSE ≥1.8mm can predict contractile reserve at ΔWMSI ≤0.20 (AUC=0.61, sensitivity 65.5, specificity 75.6). ConclusionsMAPSE is a rapid simple quantitative echocardiographic method that can asses contractile reserve in patients with ischemic cardiomyopathy before cardiac revascularization.

SY2-1 - Assessment and Treatment for Secondary Mitral Regurgitation

The assessment and treatment for secondary mitral regurgitation (MR) are based on the concepts different from those for primary MR. The main etiology of traditional secondary MR is mitral leaflet tethering-tenting occurring from left ventricular dilatation and systolic dysfunction. The origin of secondary MR usually takes a transverse direction along the mitral leaflets' coaptation. Consequently, the Doppler-derived volumetric method should be selected for the echocardiographic quantitative analysis of the secondary MR rather than the proximal isovelocity surface area method. In general, the strong medical therapies are required in heart failure patients with significant secondary MR. Mitral valve surgery may be also considered for patients with severe secondary MR with heart failure symptoms despite the optimal medical therapies. Concomitant mitral valve surgery is more reasonable in patients with coronary artery disease and severe secondary MR at the time of coronary artery bypass grafting (CABG). It is still controversial whether concomitant mitral valve surgery should be performed in patients with coronary artery disease and moderate secondary MR at the time of CABG. Low-dose dobutamine stress echocardiography or exercise stress echocardiography may be helpful to address this issue. For secondary MR seen in patients with atrial fibrillation and left atrial dilatation despite havinf preserved left ventricular ejection fraction, mitral annuloplasty would be the primary treatment.

The relationship between myocardial perfusion and left ventricular longitudinal systolic function in patients with coronary slow flow

Objective To investigate whether myocardial perfusion impairment and left ventricular(LV) longituadinal systolic dysfunction had happened in patients with coronary slow flow(CSF), and to assess the relationship between them by myocardial contrast echocardiography(MCE) and speckle tracking imaging(STI). Methods A total of 55 patients underwent coronary angiography for angina were enrolled, of those 35 with coronary slow flow phenomenon as CSF group, 20 patients with normal coronary angiography as control group. STI and MCE were performed from the apical 4-, 3-and 2-chamber views at baseline and after low-dose dobutamine stress echocardiography (LDDSE) in CSF group and control group. STI derived LV global longitudinal strain(GLS) and GLS amplitude of variation(ΔGLS), and MCE derived myocardial blood flow(MBF), and myocardial flow reserve(MFR) were obtained. And the correlation between GLS/ΔGLS and MBF/MFR was analyzed. Results At baseline, the GLS and MBF were similar between CSF group and control group(P>0.05). After LDDSE, both GLS and MBF were significantly increased in two groups(P<0.05). The GLS, ΔGLS, MBF, and MFR in CSF group were significantly lower than those in control group(P<0.05). There was no significant correlation between GLS and MBF at baseline in the CSF group(r=-0.274, P=0.111). However, after LDDSE significant correlation existed between GLS and MBF(r=-0.630, P=0.000). Conclusions LV longituadinal systolic function is impaired in patients with CSF under dobutamine stress test, the impairment of MBF and MFR could be an important contributor to the decrease of LV longituadinal systolic function. Key words: Echocardiography; Microbubbles; Dobutamine; Coronary disease; Ventricular function, left; Speckle tracking imaging

P3351Cardiac magnetic resonance deformation analysis and low-dose dobutamine stress echocardiography for assessment of myocardial viability

P3351Cardiac magnetic resonance deformation analysis and low-dose dobutamine stress echocardiography for assessment of myocardial viability

124 Stroke volume determined flow reserve does not predict the true severity of low-flow low-gradient aortic stenosis and is not a robust marker of contractile reserve in patients undergoing low-dose dobutamine echocardiography

BackgroundDuring low-dose dobutamine stress echocardiography (LDDSE) in low-flow low-gradient aortic stenosis (LFLGAS), both the aortic stenosis (AS) severity and the presence of contractile reserve (CR) are conventionally assessed based on...

Low-flow/low-gradient aortic stenosis-Still a diagnostic and therapeutic challenge.

Aortic stenosis (AS) is the most frequently observed valvular heart disease. During the symptomatic stage, the rate of death increases dramatically, so that a precise diagnostic approach is taken to guide therapeutic options. Of patients with severe AS, 30% to 50% present with low-flow/low-gradient AS (LF/LGAS) status. This review focuses on LF/LGAS and the best diagnostic and therapeutic management in either classic LF/LGAS with reduced left ventricular ejection fraction (LVEF) or paradoxical LF/LGAS with preserved LVEF. Current literature demonstrates that in classic LF/LGAS it is crucial to rule out a pseudo-severe AS, because reduced LVEF may result in an incomplete opening of the valve. This can be done by low-dose dobutamine stress echocardiography. Classic LF/LGAS has poor clinical outcomes when managed conservatively; therefore, surgical or interventional aortic valve replacement should be performed. In paradoxical LF/LGAS, the LVEF is preserved (>50%), but impaired filling of the concentric hypertrophied ventricle leads to reduced stroke volume. Therefore, diagnostic and therapeutic decisions in paradoxical LF/LGAS are even more challenging. It is a heterogeneous disease entity, and it is crucial to rule out any diagnostic errors because numerous potential confounders might lead to misdiagnosis. As in classic stenosis, pseudo-severe stenosis must be ruled out as well. Evaluation via multidetector computed tomography or transesophageal echocardiography can help to evaluate the morphologic alterations of the valve (eg, calcification). Further studies are necessary to understand this disease entity and to evaluate the optimal diagnostic and therapeutic approach for these patients.

STROKE VOLUME DETERMINED FLOW RESERVE DOES NOT PREDICT THE TRUE SEVERITY OF LOW-FLOW LOW-GRADIENT AORTIC STENOSIS AND IS NOT A ROBUST MARKER OF CONTRACTILE RESERVE IN PATIENTS UNDERGOING LOW-DOSE DOBUTAMINE ECHOCARDIOGRAPHY

Background: During low-dose dobutamine stress echocardiography in low-flow low-gradient aortic stenosis (LFLGAS), both the aortic stenosis severity and the presence of contractile reserve are conventionally assessed based on stroke volume flow reserve (SVFR) (stroke volume increase ≥20%). However

Multidimensional contractile reserve predicts adverse outcome in patients with severe systolic heart failure: a 4-year follow-up study.

Left ventricular contractile reserve is a prognostic indicator for adverse outcome in patients with severe chronic heart failure with reduced ejection fraction (HFrEF). We investigated the dobutamine-induced changes of LV multidimensional deformation and their predictive value for cardiac mortality of patients with severe chronic HFrEF. In this prospective study, out of 130 patients with severe HFrEF who underwent a low-dose dobutamine stress echocardiography (LDSE) study using speckle tracking imaging, 100 patients were followed up for the occurrence of cardiac death over a period of 4 years. Compared with survivors, non-survivors (n = 32) had lower radial strain (RS) and strain rate (RSR) (10.7 ± 5.9 vs. 20.1 ± 8% and 0.5 ± 0.2 vs. 0.8 ± 0.3 L/s, P < 0.001), a smaller increase of global longitudinal strain (GLS) and strain rate after LDSE (0.9 ± 1.5 vs. -3.3 ± 3.5% and -0.1 ± 0.1 vs. -0.3 ± 0.3 L/s, P < 0.001), and a lack of change in the circumferential and radial deformation. The dobutamine-induced changes of all speckle tracking indices predicted cardiac mortality, while, among resting echocardiographic parameters, only RS and RSR predicted survival, after adjusting for age, sex, cardiomyopathy aetiology, NYHA class, AF, BNP levels, resting LVED, and LV outflow tract velocity-time integral, and their respective changes produced by dobutamine (P < 0.05). The dobutamine-induced change of GLS and resting RS were the best additive predictors of mortality with a net reclassification improvement of 0.518 (P = 0.022) CONCLUSION: In severe chronic HFrEF, resting RS and the dobutamine-induced change of GLS are independent predictors of cardiac mortality.

Prediction of left ventricular contractile recovery using tissue Doppler strain and strain rate measurements at rest in patients undergoing percutaneous coronary intervention.

The aim of the study was to assess the ability of tissue Doppler (TD) deformation analysis at rest to predict left ventricular contractile recovery in patients undergoing percutaneous coronary intervention (PCI). This prospective cohort enrolled 67 patients with segmental wall motion abnormality. Assessment of each segment was performed at rest and during low dose Dobutamine stress echocardiography (DSE) using a 4 point scoring system, TD peak systolic strain (PSS) and peak systolic strain rate (PSSR). The study followed up the patients for contractile improvement after 6months of successful PCI by echocardiography. Of a 319 dysfunctional segments, 155 (49%) showed contractile recovery and 164 (51%) did not. PSS and PSSR at rest were significantly higher in recovered segments compared to segments without recovery (PSS: -7.27 ± 0.8 Vs. -6.14 ± 0.7%, PSSR: -0.34 ± 0.13 Vs. -0.24 ± 0.1/s. p < 0.0001 both). Similarly, both parameters were significantly higher in the contractile recovery group at follow up (p 0.001). Resting PSSR as well as PSS and PSSR during DSE were significant independent predictors of contractile recovery (p < 0.001 each). For predicting segmental contractile recovery, resting PSSR with a -0.31/s cut-off point had 76% sensitivity and 59% specificity (AUC 0.74), DSE qualitative viability assessment had asensitivity of 75% and specificity of 77%, DSE PSS with a cut-off point of -9.1% had 74% sensitivity and 63% specificity (AUC 0.77) and DSE PSSR with a cut-off point of-0.72/s had 78% sensitivity and 77% specificity (AUC 0.81). Resting PSSR is a modest predictor of segmental contractile recovery after PCI while PSSR during DSE has a comparable diagnostic performance to subjective wall motion scoring. Recovered segments show improvement of deformation parameters after PCI.

The detection of viable myocardium by low-dose dobutamine stress speckle tracking echocardiography in patients with old myocardial infarction.

To explore the significance and value of speckle-tracking echocardiography (STE) associated with low-dose dobutamine stress echocardiography (LDDSE) for the detection of viable myocardium (VM) in patients with old myocardial infarction (OMI). We performed STE with LDDSE in 33 hospitalized patients with OMI and left ventricular systolic dysfunction. QLAB software was used to analyze strain (S) and strain rate (Sr). Percutaneous coronary intervention (PCI) was subsequently performed. The movement of each wall segment was observed by routine echocardiography before and after 1, 3, and 6 months of PCI, and improvement was regarded as the gold standard for diagnosing VM. Compared with semi-quantitative wall-motion analysis combined with LDDSE, the sensitivity, specificity, and accuracy of c-STE (combining the three directions of S and Sr) at LDDSE were 91.6%, 79.5%, and 87.5%, respectively (p < 0.02). Among the deformation parameters, longitudinal strain (LS) and longitudinal strain rate (LSr) had the highest sensitivity, specificity, and accuracy. Upon combining LS and LSr at LDDSE to parallel tests, the sensitivity, specificity, and accuracy were 91.7%, 90%, and 90.6%, respectively. Compared with baseline, LVEF after PCI increased from 43.3% ± 2.6% to 47.3% ± 2.9% (p < 0.001). Global strain at LDDSE is superior to semi-quantitative wall-motion analysis with LDDSE for the assessment of VM. When the multivariable analysis and the parallel tests are combined, LS combined with LSr can be considered an independent predictor of VM. LVEF is improved after PCI in patients with VM and OMI. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:545-554, 2016.

VIEWING ONLY POSTERS1323Evaluation of right ventricular transverse strain and strain rate in patients with acute ST-segment elevation myocardial infarction: a cardiac magnetic resonance feature tracking study1333Cardiac resynchronization in ischemic heart failure patients: a comparison between therapy guided by cardiac magnetic resonance imaging and 2D-speckle tracking echocardiography1338Cardiac magnetic resonance versus bisphosphonate scintigraphy for diagnosis of cardiac amyloidosis1341Strain relaxation index, a novel

VIEWING ONLY POSTERS1323Evaluation of right ventricular transverse strain and strain rate in patients with acute ST-segment elevation myocardial infarction: a cardiac magnetic resonance feature tracking study1333Cardiac resynchronization in ischemic heart failure patients: a comparison between therapy guided by cardiac magnetic resonance imaging and 2D-speckle tracking echocardiography1338Cardiac magnetic resonance versus bisphosphonate scintigraphy for diagnosis of cardiac amyloidosis1341Strain relaxation index, a novel

Low-gradient aortic stenosis.

An important proportion of patients with aortic stenosis (AS) have a 'low-gradient' AS, i.e. a small aortic valve area (AVA <1.0 cm(2)) consistent with severe AS but a low mean transvalvular gradient (<40 mmHg) consistent with non-severe AS. The management of this subset of patients is particularly challenging because the AVA-gradient discrepancy raises uncertainty about the actual stenosis severity and thus about the indication for aortic valve replacement (AVR) if the patient has symptoms and/or left ventricular (LV) systolic dysfunction. The most frequent cause of low-gradient (LG) AS is the presence of a low LV outflow state, which may occur with reduced left ventricular ejection fraction (LVEF), i.e. classical low-flow, low-gradient (LF-LG), or preserved LVEF, i.e. paradoxical LF-LG. Furthermore, a substantial proportion of patients with AS may have a normal-flow, low-gradient (NF-LG) AS: i.e. a small AVA-low-gradient combination but with a normal flow. One of the most important clinical challenges in these three categories of patients with LG AS (classical LF-LG, paradoxical LF-LG, and NF-LG) is to differentiate a true-severe AS that generally benefits from AVR vs. a pseudo-severe AS that should be managed conservatively. A low-dose dobutamine stress echocardiography may be used for this purpose in patients with classical LF-LG AS, whereas aortic valve calcium scoring by multi-detector computed tomography is the preferred modality in those with paradoxical LF-LG or NF-LG AS. Although patients with LF-LG severe AS have worse outcomes than those with high-gradient AS following AVR, they nonetheless display an important survival benefit with this intervention. Some studies suggest that transcatheter AVR may be superior to surgical AVR in patients with LF-LG AS.

Right Ventricular Function and Prognosis in Patients with Low-Flow, Low-Gradient Severe Aortic Stenosis

Patients with low left ventricular ejection fractions and low-flow, low-gradient aortic stenosis (AS) represent a challenging cohort with high morbidity and mortality. The prevalence and clinical impact of right ventricular dysfunction (RVD) on risk stratification and prognosis in these patients is unknown. A retrospective analysis was performed of 65 patients with low-flow, low-gradient AS who underwent low-dose dobutamine stress echocardiography to determine AS severity and to ascertain flow reserve status (≥20% stroke volume increase). Clinical, demographic, and imaging data were prospectively collected. Per guidelines, RVD was defined as tricuspid annular plane systolic excursion<16mm in the apical four-chamber view and measured at baseline. Cox proportional hazards modeling was used to risk-adjust comparisons for the end point of all-cause mortality. The mean age was 74±9years, the mean left ventricular ejection fraction was 29±10%, the mean indexed aortic valve (AV) area was 0.49±0.1cm(2)/m(2), and the mean AV gradient 22±7mmHg. RVD was present in 37 patients (57% of the study cohort). After a median follow-up period of 13months (interquartile range, 5-30months), there were 29 AV replacements and 30 deaths. The presence of RVD (hazard ratio, 2.86; 95% CI, 1.21-6.75; P=.02) was an independent risk factor associated with all-cause mortality despite many adjustments for potential clinical and echocardiographic confounders such as AV replacement, Society of Thoracic Surgeons Predicted Risk of Mortality score, severity of tricuspid regurgitation, and left ventricular global longitudinal strain. Baseline RVD is prevalent in patients with low-flow, low-gradient AS undergoing dobutamine stress echocardiography. Quantification of right ventricular systolic function in these complex patients provides important prognostic value and risk stratification adjunctive to Society of Thoracic Surgeons Predicted Risk of Mortality score and should be incorporated into the decision-making process.

Low-dose dobutamine stress echo for reverse remodeling prediction after cardiac resynchronization

PurposeCardiac resynchronization therapy (CRT) is a valuable option for patients with heart failure and wide QRS to reduce electromechanical dyssynchrony (DYS). High non-responders rate (30%) urges the need to improve selection of candidates for CRT. We hypothesized that low-dose dobutamine stress echocardiography (DSE) can help unmask dyssynchronous motion. The aim of this study is comparison between dyssynchrony index at rest and during low-dose dobutamine stress to predict left ventricular reverse remodeling after CRT. Patients and methodsProspectively, 57 consecutive patients (37 male) aged 61.8±9 who qualified for CRT according to current guidelines were enrolled. Two dimensional echocardiography and tissue Doppler imaging (TDI) were performed before and 6 month after CRT to assess reverse remodeling (rLV). Additionally DSE was performed before CRT. DYS was assessed at rest (DYSr) and peak DSE (DYSd) separately, as a difference between time to peak systolic velocity (Ts) of septum and lateral wall. Ts was corrected for heart rate. ResultsrLV defined as decrease ≥15% of LVESV at follow-up was found in 38 (67%) patients. DYSr and DYSd were independent predictors of rLV (OR=1.04, Cl ±1.02–1.06, p<0.02 and OR=1.05, Cl±1.03–1.08, p<0.0002 respectively). ROC analysis found that DYSr>42ms and DYSd>59ms had sensitivity of 70% and 87%, specificity of 61% and 78%, and accuracy of 70% and 84% respectively for prediction of reverse remodeling LV. Area under Receiver Operating Characteristic Curve for DYSd was higher than for DYSr (0.89 vs 0.71, p<0.007). ConclusionExercise intraventricular dyssynchrony assessed by dobutamine stress echo is a strong independent predictor of cardiac resynchronization therapy response.

Dobutamine-Induced Strain and Strain Rate Predict Viability Following Fibrinolytic Therapy in Patients with ST-Elevation Myocardial Infarction.

Background: Low-dose dobutamine stress echocardiography is increasingly used for identifying myocardial viability.Aim: We explored whether dobutamine-induced strain (S) and strain rate (SR) can identify myocardial viability following fibrinolytic therapy for ST-segment-elevation myocardial infarction (STEMI), taking 99mTc-sestamibi scintigraphy as the “gold standard” for diagnosis.Methods: We enrolled 60 consecutive patients presenting for myocardial viability assessment at least 4 weeks following STEMI. S and SR were measured by tissue Doppler imaging individually for all myocardial segments under low-dose dobutamine stress echocardiography. Patients underwent resting 99mTc-sestamibi scintigraphy using the standard imaging technique. Based on the results of 99mTc-sestamibi scintigraphy, the dobutamine-induced S and SR were compared between viable and non-viable segments. Receiver-operating characteristics curve was constructed to determine the cutoff value of the dobutamine-induced S and SR that best identifies viability.Results: The dobutamine-induced S and SR were significantly higher in viable compared with non-viable segments, a finding that was consistent for most individual myocardial segments (10 out of 16 for S and 11 out of 16 for SR). A cutoff value ranging from −8.5 to −9.6% for the S identified viability in apical and mid- segments, whereas a cutoff value ranging from −11.5 to −21.5% identified viability in basal segments. Similarly, a cutoff value ranging from −0.5 to −1.2 s−1 for the SR identified viability in apical and mid-segments, whereas a cutoff value ranging from −1.4 to −1.7/s−1 identified viability in basal segments.Conclusion: In patients undergoing viability assessment following fibrinolytic therapy for STEMI, the dobutamine-induced S and SR were higher in viable versus non-viable segments. A cutoff value of dobutamine-induced S and SR identified viability in most individual myocardial segments.

CRT-707 Value of Tissue Doppler Derived Velocity During Isovolumic Contraction in Assessment of Left Ventricular Viability After Low Dose Dobutamine Stress Echocardiography

Differentiation of dysfunctional but viable myocardium from irreversibly damaged scar tissue has important clinical implications for patients’ ischemic heart disease and impaired left ventricular function. We studied 27 male patients with ischemic cardiomyopathy (Age: 60±7 years) before and

Dobutamine stress for evaluation of right ventricular reserve in pulmonary arterial hypertension.

Right ventricular contractile response to pharmacological stress in pulmonary arterial hypertension (PAH) has not been characterised. We evaluated right ventricular contractile reserve in adults with PAH using dobutamine stress echocardiography. 16 PAH patients and 18 age-matched controls underwent low-dose dobutamine stress echocardiography. Contractile reserve was assessed by the change (Δ; peak stress minus rest value) in tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular systolic velocity (S'). A subgroup of 13 PAH patients underwent treadmill cardiopulmonary exercise testing for peak oxygen uptake (V'O2peak). At rest, TAPSE and S' were reduced in the PAH group compared with controls (1.7 ± 0.4 versus 2.4 ± 0.2 cm and 9.7 ± 2.6 versus 12.5 ± 1.2 cm · s(-1), respectively; p<0.05). Contractile reserve was markedly attenuated in PAH compared to controls (ΔTAPSE 0.1 ± 0.2 versus 0.6 ± 0.3 cm and ΔS' 4.6 ± 2.8 versus 11.2 ± 3.6 cm · s(-1); p<0.0001). In the sub-group of PAH patients with preserved right ventricular systolic function at rest, contractile reserve remained depressed compared to controls. V'O2peak was significantly correlated with ΔS' (r=0.87, p=0.0003) and change in stroke volume (r=0.59, p=0.03). Dobutamine stress can reveal sub-clinical reduction in right ventricular contractile reserve in patients with PAH. A correlation with exercise capacity suggests potential clinical value beyond resting measurements.

Clinical research of safflower injection on hibernating myocardial revascularization

Coronary artery disease (CAD) is one of the leading causes of death. Safflower attracts great attention owing to its anti-ischemia/reperfusion injury effect. Ninety-three patients with CAD were included and randomized into safflower treatment group, PCI group and control group. Low-dose dobutamine stress echocardiography (DSE) was performed to measure end-systolic volume (ESV), end-diastolic volume (EDV), left ventricular ejection fraction (LVEF) and wall motion score index (WMSI) to determine the recovery of hibernating myocardium and cardiac function in all patients before treatment and after 3-month follow-up. The study was to investigate the effects of safflower on hibernating myocardial revascularization and cardiac function. It was found that LVEF was significantly improved, while the ESV and WMSI were significantly reduced after 2-week treatment in safflower and PCI treatment groups. No significant differences were found between safflower and PCI treatment groups in ESV, EDV, WMSI and LVEF after treatment Safflower injection effectively improved hibernating myocardial function.

DOBUTAMINE STRESS ECHOCARDIOGRAPHY RISK-STRATIFIES WOMEN WITH LOW-GRADIENT AORTIC STENOSIS UNDERGOING TRANSCATHETER AORTIC VALVE REPLACEMENT

Patients with severe aortic stenosis and low mean transvalvular gradient have poor outcomes, with an estimated 30 day post-surgical Aortic Valve Replacement (AVR) mortality of 21%. Low Dose Dobutamine Stress Echocardiography (LD-DSE) is performed in these patients for further risk stratification by

VALIDITY OF AUTOMATED GLOBAL LONGITUDINAL STRAIN MEASUREMENTS WITH LOW-DOSE DOBUTAMINE STRESS ECHOCARDIOGRAPHY FOR THE ASSESSMENT OF MYOCARDIAL VIABILITY AFTER ACUTE MYOCARDIAL INFARCTION: COMPARISON WITH DELAYED ENHANCEMENT AND MICROVASCULAR OBSTRUCTION BY CARDIAC MAGNETIC RESONANCE IMAGING

Low-dose dobutamine stress echocardiography (DSE) assesses myocardial viability at the early stage of acute myocardial infarction (AMI), but its assessment is subjective and variable. Recently, automated function imaging (AFI) was shown to determine global longitudinal peak strain (GLPS) based on