Blood flow imaging in transesophageal echocardiography during atrial septal defect closure: a comparison with the current references.

BACKGROUND: Flow visualization before transcatheter atrial septal defect (ASD) closure is essential to identify the number and size of ASDs and to map the pulmonary veins (PV). Previous reports have shown improved visualization of ASD and PV using blood flow imaging (BFI), which supplements color Doppler imaging (CDI) with angle-independent information of flow direction. In this study, we compared transesophageal BFI with the current references in ASD sizing (balloon stretched diameter, BSD) and PV imaging (pulmonary angiography). METHODS: In this prospective study, 28 children were examined with transesophageal echocardiography (TEE) including BFI of the secundum ASD and the PV before interventional ASD closure. The maximum ASD diameter measured with BFI by 4 observers was compared to the corresponding BSD and CDI measurements. The repeatability of the BFI measurements was calculated as the residual standard deviation. BFI of the PV was compared to PV angiography. RESULTS: The mean maximum diameter measured by BFI was 12.1 mm (±SD 2.4 mm). The corresponding BSD and CDI measurements were 15.9 mm (±SD 3.0 mm) and 11.8 mm (±SD 2.5 mm), respectively. The residual standard deviation was 1.2 mm. Compared to PV angiography, the sensitivity of BFI in detecting the correct entry of the PV was 0.96 (95% CI: 0.82-1.0). CONCLUSION: Transesohageal echocardiography with BFI of the PV agreed well with pulmonary angiography. BFI had lower estimates for ASD size than BSD, but with acceptable 95% limits of agreement. The repeatability of the BFI measurements was close to the inherent ultrasound measurement error.

High prevalence of subclinical rheumatic heart disease in pregnant women in a developing country: an echocardiographic study.

OBJECTIVES: Pregnant women with rheumatic heart disease (RHD) carry a high risk of morbidity and mortality. In this study the prevalence of subclinical RHD in pregnant women in Keren, Eritrea was assessed using echocardiography. METHODS AND RESULTS: A prospective cross sectional survey of pregnant women attending a midwife consultation was carried out by two specially trained medical students and an experienced cardiologist. The women were screened by the medical students using echocardiography. All recordings were reviewed and evaluated by the experienced cardiologist before a final diagnosis was given. Eight of the 348 screened women had definite RHD. This corresponds to a prevalence of 2.3%, 95% CI (0.7-3.9). CONCLUSION: 2.3% of the pregnant women in Keren were found to have subclinical RHD.

Outcome of patients with low-gradient "severe" aortic stenosis and preserved ejection fraction.

BACKGROUND: Retrospective studies have suggested that patients with a low transvalvular gradient in the presence of an aortic valve area < 1.0 cm² and normal ejection fraction may represent a subgroup with an advanced stage of aortic valve disease, reduced stroke volume, and poor prognosis requiring early surgery. We therefore evaluated the outcome of patients with low-gradient "severe" stenosis (defined as aortic valve area < 1.0 cm² and mean gradient ≤ 40 mm Hg) in the prospective Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. METHODS AND RESULTS: Outcome in patients with low-gradient "severe" aortic stenosis was compared with outcome in patients with moderate stenosis (aortic valve area 1.0 to 1.5 cm²; mean gradient 25 to 40 mm Hg). The primary end point of aortic valve events included death from cardiovascular causes, aortic valve replacement, and heart failure due to aortic stenosis. Secondary end points were major cardiovascular events and cardiovascular death. In 1525 asymptomatic patients (mean age, 67 ± 10 years; ejection fraction, ≥ 55%), baseline echocardiography revealed low-gradient severe stenosis in 435 patients (29%) and moderate stenosis in 184 (12%). Left ventricular mass was lower in patients with low-gradient severe stenosis than in those with moderate stenosis (182 ± 64 versus 212 ± 68 g; P < 0.01). During 46 months of follow-up, aortic valve events occurred in 48.5% versus 44.6%, respectively (P = 0.37; major cardiovascular events, 50.9% versus 48.5%, P = 0.58; cardiovascular death, 7.8% versus 4.9%, P = 0.19). Low-gradient severe stenosis patients with reduced stroke volume index (≤ 35 mL/m²; n = 223) had aortic valve events comparable to those in patients with normal stroke volume index (46.2% versus 50.9%; P = 0.53). CONCLUSIONS: Patients with low-gradient "severe" aortic stenosis and normal ejection fraction have an outcome similar to that in patients with moderate stenosis.

Impact of baseline severity of aortic valve stenosis on effect of intensive lipid lowering therapy (from the SEAS study).

Retrospective studies have suggested a beneficial effect of lipid-lowering treatment on the progression of aortic stenosis (AS) in milder stages of the disease. In the randomized, placebo-controlled Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study, 4.3 years of combined treatment with simvastatin 40 mg and ezetimibe 10 mg did not reduce aortic valve events (AVEs), while ischemic cardiovascular events (ICEs) were significantly reduced in the overall study population. However, the impact of baseline AS severity on treatment effect has not been reported. Baseline and outcomes data in 1,763 SEAS patients (mean age 67 years, 39% women) were used. The study population was divided into tertiles of baseline peak aortic jet velocity (tertile 1: ≤ 2.8 m/s; tertile 2: > 2.8 to 3.3 m/s; tertile 3: > 3.3 m/s). Treatment effect and interaction were tested in Cox regression analyses. The rates of AVEs and ICEs increased with increasing baseline severity of AS. In Cox regression analyses, higher baseline peak aortic jet velocity predicted higher rates of AVEs and ICEs in all tertiles (all p values < 0.05) and in the total study population (p < 0.001). Simvastatin-ezetimibe treatment was not associated with a statistically significant reduction in AVEs in any individual tertile. A significant quantitative interaction between the severity of AS and simvastatin-ezetimibe treatment effect was demonstrated for ICEs (p < 0.05) but not for AVEs (p = 0.10). In conclusion, the SEAS study results demonstrate a strong relation between baseline the severity of AS and the rate of cardiovascular events but no significant effect of lipid-lowering treatment on AVEs, even in the group with the mildest AS.

Mechanical dispersion assessed by myocardial strain in patients after myocardial infarction for risk prediction of ventricular arrhythmia.

OBJECTIVES: The aim of this study was to investigate whether myocardial strain echocardiography can predict ventricular arrhythmias in patients after myocardial infarction (MI). BACKGROUND: Left ventricular (LV) ejection fraction (EF) is insufficient for selecting patients for implantable cardioverter-defibrillator (ICD) therapy after MI. Electrical dispersion in infarcted myocardium facilitates malignant arrhythmia. Myocardial strain by echocardiography can quantify detailed regional and global myocardial function and timing. We hypothesized that electrical abnormalities in patients after MI will lead to LV mechanical dispersion, which can be measured as regional heterogeneity of contraction by myocardial strain. METHODS: We prospectively included 85 post-MI patients, 44 meeting primary and 41 meeting secondary ICD prevention criteria. After 2.3 years (range 0.6 to 5.5 years) of follow-up, 47 patients had no and 38 patients had 1 or more recorded arrhythmias requiring appropriate ICD therapy. Longitudinal strain was measured by speckle tracking echocardiography. The SD of time to maximum myocardial shortening in a 16-segment LV model was calculated as a parameter of mechanical dispersion. Global strain was calculated as average strain in a 16-segment LV model. RESULTS: The EF did not differ between ICD patients with and without arrhythmias occurring during follow-up (34 +/- 11% vs. 35 +/- 9%, p = 0.70). Mechanical dispersion was greater in ICD patients with recorded ventricular arrhythmias compared with those without (85 +/- 29 ms vs. 56 +/- 13 ms, p < 0.001). By Cox regression, mechanical dispersion was a strong and independent predictor of arrhythmias requiring ICD therapy (hazard ratio: 1.25 per 10-ms increase, 95% confidence interval: 1.1 to 1.4, p < 0.001). In patients with an EF >35%, global strain showed better LV function in those without recorded arrhythmias (-14.0% +/- 4.0% vs. -12.0 +/- 3.0%, p = 0.05), whereas the EF did not differ (44 +/- 8% vs. 41 +/- 5%, p = 0.23). CONCLUSIONS: Mechanical dispersion was more pronounced in post-MI patients with recurrent arrhythmias. Global strain was a marker of arrhythmias in post-MI patients with relatively preserved ventricular function. These novel parameters assessed by myocardial strain may add important information about susceptibility for ventricular arrhythmias after MI.

[A young woman with cardiac arrest]. / Ung kvinne med hjertestans.

A 20-year-old woman presented with dyspnoea in the Emergency department and subsequently suffered a cardiac arrest. The initial rhythm was PEA (pulseless electrical activity). She had intermittent return of spontaneous circulation. Transthoracic echocardiography showed a dilated hypokinetic right ventricle and a collapsed left ventricle. The tentative diagnosis was pulmonary embolism, but she remained hemodynamically unstable despite thrombolysis. 90 min after the collapse she was put on cardiopulmonary bypass and surgical embolectomy was performed. Large masses of thrombotic material were collected from central parts of the right and left pulmonary artery. Therapeutic hypothermia was applied for 24 hours postoperatively. The remaining hospital stay was uneventful and ten days after the presentation she was transferred to her local hospital. At this point she was without neurological sequelae. The patient had used oral contraceptives (ethinyl estradiol/ drospirenone).

Quantification of mitral regurgitation using high pulse repetition frequency three-dimensional color Doppler.

BACKGROUND: The aim of this study was to validate a novel method of determining vena contracta area (VCA) and quantifying mitral regurgitation using multibeam high-pulse repetition frequency (HPRF) color Doppler. METHODS: The Doppler signal was isolated from the regurgitant jet, and VCA was found by summing the Doppler power from multiple beams within the vena contracta region, where calibration was done with a reference beam. In 27 patients, regurgitant volume was calculated as the product of VCA and the velocity-time integral of the regurgitant jet, measured by continuous-wave Doppler, and compared with regurgitant volume measured by magnetic resonance imaging (MRI). RESULTS: Spearman's rank correlation and the 95% limits of agreement between regurgitant volume measured by MRI and by multibeam HPRF color Doppler were r(s) = 0.82 and -3.0 +/- 26.2 mL, respectively. CONCLUSION: For moderate to severe mitral regurgitation, there was good agreement between MRI and multibeam HPRF color Doppler. Agreement was lower in mild regurgitation.

Intensive lipid lowering with simvastatin and ezetimibe in aortic stenosis.

BACKGROUND: Hyperlipidemia has been suggested as a risk factor for stenosis of the aortic valve, but lipid-lowering studies have had conflicting results. METHODS: We conducted a randomized, double-blind trial involving 1873 patients with mild-to-moderate, asymptomatic aortic stenosis. The patients received either 40 mg of simvastatin plus 10 mg of ezetimibe or placebo daily. The primary outcome was a composite of major cardiovascular events, including death from cardiovascular causes, aortic-valve replacement, nonfatal myocardial infarction, hospitalization for unstable angina pectoris, heart failure, coronary-artery bypass grafting, percutaneous coronary intervention, and nonhemorrhagic stroke. Secondary outcomes were events related to aortic-valve stenosis and ischemic cardiovascular events. RESULTS: During a median follow-up of 52.2 months, the primary outcome occurred in 333 patients (35.3%) in the simvastatin-ezetimibe group and in 355 patients (38.2%) in the placebo group (hazard ratio in the simvastatin-ezetimibe group, 0.96; 95% confidence interval [CI], 0.83 to 1.12; P=0.59). Aortic-valve replacement was performed in 267 patients (28.3%) in the simvastatin-ezetimibe group and in 278 patients (29.9%) in the placebo group (hazard ratio, 1.00; 95% CI, 0.84 to 1.18; P=0.97). Fewer patients had ischemic cardiovascular events in the simvastatin-ezetimibe group (148 patients) than in the placebo group (187 patients) (hazard ratio, 0.78; 95% CI, 0.63 to 0.97; P=0.02), mainly because of the smaller number of patients who underwent coronary-artery bypass grafting. Cancer occurred more frequently in the simvastatin-ezetimibe group (105 vs. 70, P=0.01). CONCLUSIONS: Simvastatin and ezetimibe did not reduce the composite outcome of combined aortic-valve events and ischemic events in patients with aortic stenosis. Such therapy reduced the incidence of ischemic cardiovascular events but not events related to aortic-valve stenosis. (ClinicalTrials.gov number, NCT00092677.)

Superior cardiovascular effect of aerobic interval training versus moderate continuous training in heart failure patients: a randomized study.

BACKGROUND: Exercise training reduces the symptoms of chronic heart failure. Which exercise intensity yields maximal beneficial adaptations is controversial. Furthermore, the incidence of chronic heart failure increases with advanced age; it has been reported that 88% and 49% of patients with a first diagnosis of chronic heart failure are >65 and >80 years old, respectively. Despite this, most previous studies have excluded patients with an age >70 years. Our objective was to compare training programs with moderate versus high exercise intensity with regard to variables associated with cardiovascular function and prognosis in patients with postinfarction heart failure. METHODS AND RESULTS: Twenty-seven patients with stable postinfarction heart failure who were undergoing optimal medical treatment, including beta-blockers and angiotensin-converting enzyme inhibitors (aged 75.5+/-11.1 years; left ventricular [LV] ejection fraction 29%; VO2peak 13 mL x kg(-1) x min(-1)) were randomized to either moderate continuous training (70% of highest measured heart rate, ie, peak heart rate) or aerobic interval training (95% of peak heart rate) 3 times per week for 12 weeks or to a control group that received standard advice regarding physical activity. VO2peak increased more with aerobic interval training than moderate continuous training (46% versus 14%, P<0.001) and was associated with reverse LV remodeling. LV end-diastolic and end-systolic volumes declined with aerobic interval training only, by 18% and 25%, respectively; LV ejection fraction increased 35%, and pro-brain natriuretic peptide decreased 40%. Improvement in brachial artery flow-mediated dilation (endothelial function) was greater with aerobic interval training, and mitochondrial function in lateral vastus muscle increased with aerobic interval training only. The MacNew global score for quality of life in cardiovascular disease increased in both exercise groups. No changes occurred in the control group. CONCLUSIONS: Exercise intensity was an important factor for reversing LV remodeling and improving aerobic capacity, endothelial function, and quality of life in patients with postinfarction heart failure. These findings may have important implications for exercise training in rehabilitation programs and future studies.

Design and baseline characteristics of the simvastatin and ezetimibe in aortic stenosis (SEAS) study.

Aortic valve stenosis and atherosclerotic disease have several risk factors in common, in particular, hypercholesterolemia. Histologically, the diseased valves appear to have areas of inflammation much like atherosclerotic plaques. The effect of lipid-lowering therapy on the progression of aortic stenosis (AS) is unclear, and there are no randomized treatment trials evaluating cardiovascular morbidity and mortality in such patients. The Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) Study is a randomized, double-blind, placebo-controlled, multicenter study of a minimum 4 years' duration investigating the effect of lipid lowering with ezetimibe/simvastatin 10/40 mg/day in patients with asymptomatic AS with peak transvalvular jet velocity 2.5 to 4.0 m/s. Primary efficacy variables include aortic valve surgery and ischemic vascular events, including cardiovascular mortality, and second, the effect on echocardiographically evaluated progression of AS. The SEAS Study randomly assigned 1,873 patients (age 68+/-10 years, 39% women, mean transaortic maximum velocity 3.1+/-0.5 m/s) from 173 sites. Other baseline characteristics were mean blood pressure of 145+/-20/82+/-10 mm Hg (51% hypertensive); 55% were current or previous smokers; and most were overweight (mean body mass index 26.9 kg/m2). At baseline, mean total cholesterol was 5.7+/-1.0 mmol/L (222 mg/dl), low-density lipoprotein cholesterol was 3.6+/-0.9 mmol/L (139 mg/dl), high-density lipoprotein cholesterol was 1.5+/-0.4 mmol/L (58 mg/dl), and triglycerides were 1.4+/-0.7 mmol/L (126 mg/dl). The SEAS Study is the largest randomized trial to date in patients with AS and will allow determination of the prognostic value of aggressive lipid lowering in such patients.

Choosing apical long-axis instead of two-chamber view gives more accurate biplane echocardiographic measurements of left ventricular ejection fraction: a comparison with magnetic resonance imaging.

BACKGROUND: We sought to evaluate whether the use of apical long-axis (APLAX) rather than two-chamber (2CH) view, in combination with four-chamber (4CH) view, improved accuracy of biplane echocardiographic measurements of left ventricular (LV) ejection fraction (EF), using magnetic resonance imaging (MRI) as a reference standard. METHODS: One hundred consecutive cardiac patients underwent cardiac MRI and 2D-echocardiography. Standard apical LV views were digitally acquired with baseline tissue harmonic imaging and low-power contrast echocardiography. Echo and MRI LV volumes were calculated by manual tracing and disc summation methods. RESULTS: Feasiblity for biplane volume measurements increased with the use of APLAX. Precontrast limits of agreement (LOA) for EF compared to MRI were -19.1 to 9.0 % (EF units) using 2CH, narrowing to -14.6 to 6.7% using the APLAX. With contrast, corresponding LOAs narrowed from -10.5 to 6.1%, to -7.3 to 3.8%, respectively. The improved accuracy with APLAX was evident regardless of image quality, previous MI and regional LV dyssynergy. Both intra- and interobserver variability improved by substituting 2CH with APLAX view. CONCLUSION: Using APLAX rather than 2CH in combination with 4CH view improved feasibility, accuracy and reproducibility of biplane echocardiographic EF measurements in cardiac patients, even with optimisation of endocardial borders by contrast.

Accurate and reproducible measurement of left ventricular volume and ejection fraction by contrast echocardiography: a comparison with magnetic resonance imaging.

OBJECTIVES: We evaluated the accuracy and reproducibility of contrast echocardiography versus tissue harmonic imaging for measurements of left ventricular (LV) volumes and ejection fraction (EF) compared to magnetic resonance imaging (MRI). METHODS: Digital echo recordings of apical LV views before and after intravenous contrast were collected from 110 consecutive patients. Magnetic resonance imaging of multiple short-axis LV sections was performed with a 1.5-T scanner. Left ventricular volumes and EF were calculated offline by method of discs. Thirty randomly selected patients were reanalyzed for intraobserver and interobserver variability. RESULTS: Compared with baseline, contrast echo increased feasibility for single-plane and biplane volume analysis from 87% to 100% and from 79% to 95%, respectively. The Bland-Altman analysis demonstrated volume underestimation by echo, but much less pronounced with contrast. Limits of agreement between echo and MRI narrowed significantly with contrast: from -18.1% to 8.3% to -7.7% to 4.1% (EF), from -98.2 to -11.7 ml to -59.0 to 10.7 ml (end-diastolic volume), and from -58.8 to 21.8 ml to -38.6 to 23.9 ml (end-systolic volume). Ejection fraction from precontrast echo and MRI differed by > or =10% (EF units) in 23 patients versus 0 after contrast (p < 0.001). At intraobserver and interobserver analysis, limits of agreement for EF narrowed significantly with contrast. CONCLUSIONS: The two-dimensional echocardiographic evaluation of LV volumes and EF in non-selected cardiac patients was found to be more accurate and reproducible when adding an intravenous contrast agent.

Metoprolol CR/XL improves systolic and diastolic left ventricular function in patients with chronic heart failure.

AIMS: To investigate whether metoprolol controlled release/extended release (CR/XL) once daily would improve diastolic and systolic left ventricular function in patients with chronic heart failure and decreased ejection fraction. METHODS: In an echocardiographic substudy to the Metoprolol CR/XL Randomized Intervention Trial in Heart Failure (MERIT-HF), 66 patients were examined three times during a 12-month period blinded to treatment group, assessing left ventricular dimensions and ejection fraction, and Doppler mitral inflow parameters, all measured in a core laboratory. RESULTS: In the metoprolol CR/XL group left ventricular ejection fraction increased from 0.26 to 0.31 (P = 0.009) after a mean observation period of 10.6 months, and deceleration time of the early mitral filling wave (E) increased from 189 to 246 ms (P = 0.0012), time velocity integral of E-wave increased from 8.7 to 11.2 cm (P = 0.018), and the duration of the late mitral filling wave (A) increased from 122 to 145 ms (P = 0.014). No significant changes were seen in the placebo group regarding any of these variables. CONCLUSION: Metoprolol CR/XL once daily in addition to standard therapy improved both diastolic and systolic function in patients with chronic heart failure and decreased ejection fraction.

Systolic long axis function of the left ventricle. Global and regional information.

OBJECTIVE: To compare global systolic measurements of mitral annular motion by M-mode and tissue velocity time integral, and annular velocity by pulsed and colour Doppler for precision and bias. Secondly, to compare the ability of annular motion to identify regional dysfunction with segmental analysis by strain rate imaging. DESIGN: Nineteen normal subjects and 19 patients with myocardial infarction were studied with echocardiography. RESULTS: There were significant correlations between ejection fraction (EF) and annular motion/velocity by all methods, ranging from 60 to 80%. Measurements had 95% limits of agreement intervals between 7.7 and 15.6 mm for annulus excursion and 8.8 cm/s for annulus velocities with biases between methods of 0.7-1.9 mm and 2.6 cm/s. Annular motion and velocity were reduced in the patients compared with the control group, but were depressed at all points so the infarcted region could not be identified. Only segmental analysis could identify the region of dyssynergy. CONCLUSION: Annular motion and velocity measure global function, but have high variability and measurements are method dependent. Only segmental analysis can identify regional dyssynergy. This is possible with strain rate imaging, but the precision is still too low for clinical use.

Estimation of left ventricular ejection fraction from Doppler derived myocardial performance index in patients with acute myocardial infarction: agreement with echocardiographic and radionuclide measurements.

OBJECTIVE: The aim of the study was to validate a previously published method to calculate left ventricular ejection fraction (EF) from the myocardial performance index (MPI or Tei-index) in patients with acute myocardial infarction (MI). METHODS: Sixty-one patients in sinus rhythm without overt heart failure were examined between 2 and 7 days after the acute MI. Doppler tracings from mitral inflow and left ventricular outflow were recorded together with two-dimensional echocardiographic (2DE) recordings. MPI was calculated from the Doppler tracings, and EF measured with the biplane Simpson's method. From MPI the EF was calculated by the formula EF = 0.60 - (0.34 x MPI). Radionuclide angiographic (RNA) measurements of EF were performed within 1 day of the Doppler echocardiography. RESULTS: Compared with radionuclide EF, MPI derived EF significantly underestimated EF by 0.03 (+/-0.013; P = 0.027), whereas there was no significant difference in mean EF between 2DE and RNA. There was no statistically significant difference in the agreement between MPI derived EF relative to RNA, or 2DE relative to RNA. The agreement between the three methods was only moderate with wide limits of agreement (+/-0.17). The relationship expressed by the proposed formula for calculating EF from MPI was not statistically significant in regression analysis in this patient population. CONCLUSIONS: No statistically significant relationship was found between MPI and EF by radionuclide angiography. However, MPI derived EF was as accurate as biplane echocardiographic measurements of EF when compared with radionuclide EF, but the agreement between methods was only moderate.

Post systolic shortening in nonobstructive hypertrophic cardiomyopathy with delayed emptying of the apex: a Doppler flow, tissue Doppler and strain rate imaging case study.

We report a case of a 92-year-old woman with syncope and exertional dyspnea, who on echocardiographic examination proved to have hypertrophic cardiomyopathy. Doppler flow revealed delayed emptying of the apex, extending into the early filling phase. Tissue Doppler and strain rate imaging illustrated postsystolic shortening corresponding to the apical ejection, demonstrating that the apical flow was due to wall thickening resulting in active ejection. The imaging methods and mechanics of post-systolic shortening are discussed.

Flow propagation velocity is not a simple index of diastolic function in early filling. A comparative study of early diastolic strain rate and strain rate propagation, flow and flow propagation in normal and reduced diastolic function.

BACKGROUND: Strain Rate Imaging shows the filling phases of the left ventricle to consist of a wave of myocardial stretching, propagating from base to apex. The propagation velocity of the strain rate wave is reduced in delayed relaxation. This study examined the relation between the propagation velocity of strain rate in the myocardium and the propagation velocity of flow during early filling. METHODS: 12 normal subjects and 13 patients with treated hypertension and normal systolic function were studied. Patients and controls differed significantly in diastolic early mitral flow measurements, peak early diastolic tissue velocity and peak early diastolic strain rate, showing delayed relaxation in the patient group. There were no significant differences in EF or diastolic diameter. RESULTS: Strain rate propagation velocity was reduced in the patient group while flow propagation velocity was increased. There was a negative correlation (R = -0.57) between strain rate propagation and deceleration time of the mitral flow E-wave (R = -0.51) and between strain rate propagation and flow propagation velocity and there was a positive correlation (R = 0.67) between the ratio between peak mitral flow velocity / strain rate propagation velocity and flow propagation velocity. CONCLUSION: The present study shows strain rate propagation to be a measure of filling time, but flow propagation to be a function of both flow velocity and strain rate propagation. Thus flow propagation is not a simple index of diastolic function in delayed relaxation.

Strain Rate Imaging by Ultrasound in the Diagnosis of Regional Dysfunction of the Left Ventricle.

BACKGROUND: Regional strain rate in the left ventricle can be assessed by tissue Doppler velocity gradient and color mapped in real time. Regional contractility thus can be visualized and graded. To validate the method, we made a comparison with standard echocardiography. METHODS AND RESULTS: Fifteen patients with recent myocardial infarction were examined with the use of strain rate imaging (SRI). Velocity gradients were mapped by color. Gray-scale imaging was performed using the second harmonic mode. Cine loops of two-dimensional echocardiography (2-D echo) and SRI images from three standard apical planes were analyzed off line. A four-grade scale in 16 segments was used to score wall motion by 2-D echo and by SRI. Of a total of 236 segments, 235 segments were analyzable by 2-D echo and 218 segments were analyzable by SRI. Correlation of wall motion score index with ejection fraction was - 0.84 by 2-D echo and - 0.92 by SRI. One hundred fourteen segments had an equal score by the two methods: 51 segments differed by 1 degree and 14 segments differed by 2 degrees (kappa = 0.45). CONCLUSIONS: SRI agrees well with echocardiography in grading regional wall function, and the method can be seen as validated in a clinical setting for assessment of regional systolic wall function and is demonstrated to be applicable for semiquantitative wall motion assessment. SRI has theoretical advantages and may be a valuable addition to standard echocardiography, especially in the field of stress echocardiography.