Presentation on theme: "Assessment of left ventricular function"— Presentation transcript:
1Assessment of left ventricular function The InGenious HyperCare European Network Excellence in phenotyping:Assessment of left ventricular functionTatiana KuznetsovaUniversity of Leuven, Belgium
2LVF Outline Systolic function Diastolic function Echocardiographic protocol (JRP A3)
3LVFSystolic functionConventional echocardiography enables the assessment of LV dimensions, volumes, sphericity index, and severity of mitral regurgitation;HF due to systolic dysfunction is relatively easy to diagnose by echocardiography (dilated left ventricle with a reduced ejection fraction)
4LVF Components of regional function Radial function Longitudinal CircumferentialWithout the longitudinal component, sarcomere shortening would lead to an EF < 30%.
5LVF Tissue Doppler imaging Tissue Doppler Imaging (TDI) makes it possible to specifically evaluate the longitudinal and radial components of regional LV systolic function.Measurements of myocardial deformation with the Doppler technique have been validated using microcrystals and MRI (Urheim S, Circulation 2000; Edvardsen T, Circulation 2002).
6Basal segments of inferior and infero-lateral walls LVFOff-line analysisStrain rateStrainAVCMVOTimeintegrationAVCMVOBasal segments of inferior and infero-lateral wallsPeak systolic SREnd-systolic SSPEQLE: Software Package for Echocardiographic Quantification, Leuven; version 4.06
7LVFInter-observer differences in percent versus average of two readingsMean of 2 readingsBland and Altman, 1986
8LVF Longitudinal S and SR by RWT Mean values are adjusted; * P 0.05 ***P0.001
9LVF Regional LV geometry Wall stress related to: σ = P x R / 2WT Pressure ↑ → σ ↑Shape, cavity size ↑ → σ ↑Wall thickness ↑ → σ ↓σ = P x R / 2WTSince R curvature is larger in longitudinal direction, the stress on longitudinal fibres is higher, they show decreased deformation first.
10LVFSystolic functionTDI, compared with conventional echocardiography, is a more sensitive method for the detection of LV systolic dysfunction, particularly in subjects with LV remodelling and normal EF.Our observations underscore the importance of normal long axis function in maintaining a coordinated ventricular contraction.The clinical utility of strain and strain rate in risk stratification or as therapeutic target remains to be established.
11LVF Diastolic function About 50% of patients with new onset of HF do have a normal EF (HF with preserved EF).HF with preserved EF is associated with a high mortality rate, comparable to that of patients with reduced EF (Bhatia R.S., N Engl J Med 2006; Bursi F., JAMA 2006)Assessment of diastolic function requires conventional and Tissue Doppler Imaging
12LVFTransmitral blood flow vs pulsed Tissue Doppler ImagingAEEaAa
13LVFInter-observer differences in percent versus average of two readingsMean of 2 readingsBland and Altman, 1986
15Echo Echocardiographic performance protocol A single observer performs all echocardiographic examinations by means of Vivid 7 ultrasound scanner (GE Vingmed, Horten, Norway)Standardized echocardiography scanning sequence (about 40 min, page MOP JRP A3)Correct orientation of the ultrasound beam and imaging planes to LV structure and blood flow is essentialAll echocardiographic examinations in a digital format are stored on a local network for off-line reading by two independent observers (EchoPack, GE and SPEQLE, University of Leuven)
16Echo Methods to limit echocardiographic measurement variability Use echocardiography central reading laboratory:a. Minimize number of readers,b. Monitor reader variability,c. Rapid communication with study sites on study quality.Standardized “hands-on” training of sonographers onsite.Monitoring of sonographers for technical quality; encode study quality in database.American Society of Echocardiography Recommendations for Use of Echocardiography in Clinical Trials. J Am Soc Echocardiogr 2004;17:
17Echo Methods to limit echocardiographic measurement variability Reading off-line strategies:Batch read when possible to minimize systematic temporal drifts;Average multiple beats (minimum of 3);Single reader preferable.Establish acquisition and reader variability:Test-retest of small sample of participants, ie, same participant repeated over small interval, same machine, same sonographer, same reader;Blind duplicates for inter-reader and intra-reader variability assessment.
18JRP A3Echo-centersKatholieke Universiteit Leuven, B JA Staessen, T Kuznetsova, T RichartJagiellonian University Cracow, PL K Kawecka-Jaszcz, K Stolarz, M LosterMedical University of Gdansk, PL K Narkiewicz, W Sakiewicz, A RojekUniversitá degli Studi di Padova, I E Casiglia, V TikhonoffHospital Universitari Valencia, SP E Lurbe, J AlvarezInstitute of Internal Medicine, RU Y Nikitin, S Malyutina, A Ryabikov