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Heart, Lung and Circulation Abstracts S532008;17S:S1–S209

121Left Atrial Contraction in Thalassaemia Major—Relationwith Iron overload

Bon Chou 1,∗, Lesley Donelan 1, Don K. Bowden 2, RogerE. Peverill 1

1 Monash Cardiovascular Research Centre, MonashHeart &Monash University, Department of Medicine (MMC), Clayton,Victoria, Australia; 2 Medical Therapy Unit, Southern Health,Clayton, Victoria, Australia

Background: Iron overload causes left ventricular dysfunc-tion in patients with thalassaemia major (TM), but whetherleft atrial (LA) function is also affected in TM is unknown.Methods: Fifty-eight TM patients with preserved left ven-tricular ejection fraction (age 30 ± 7 years, 24 men) werecompared to 58 age and sex-matched controls. Long axisLA contraction was assessed at the septal and lateral wallsusing pulsed wave tissue Doppler imaging (TDI) by mea-surement of the peak LA contraction velocity (A′) andmitral annular excursion during LA contraction (LAExc).LA volume was calculated and indexed to body surfacearea (BSA; LAVI). The transmitral A velocity was also mea-sured. The average ferritin level over 5 years was calculatedfor the TM patients.Results: TM patients had a higher heart rate (HR) anda lower body surface area (BSA; p < 0.05 for both). TMpatients also had a larger LAVI (p < 0.001) and a higherAbtreawrCbiop

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impact on myoT2*, its reproducibility and relationshipwith left ventricular function.Methods: Mid-septum short-axis segmented FLASHimages with 11 TE values (3.6–18 ms) were acquired on30 patients with congenital haemoglobinopathy managedby transfusion and chelation therapy. Mean pixel valuesat the inter-ventricular septum were graphed against TE.myoT2* was derived from exponential regression anal-ysis. Comparison between 11 and standard 9 TE values(5.6–18 ms), and the inclusion/exclusion of myocardialsignal indistinguishable from background noise (noisetest: signal-1S.D. < noise + 1S.D.) was performed by Bland-Altman analysis. Intra-, inter-observer and inter-studyvariability were assessed by % coefficient of variation(%CV) and Bland-Altman analysis.Results: Observed myoT2* was 16.4 ± 12.2 ms(mean ± S.D.). 11 versus 9 TE demonstrated a myoT2*mean difference (95% limits of agreement) of −0.4 ms(−6.2, 5.4 ms), and with/without noise test of 0.3 ms (−2.6,3.2 ms). With 11 TE and noise test, intra-, inter-observerand inter-study %CV were 6.4%, 8.1% and 5% respec-tively; mean difference (95% limits of agreement) betweenobservations were 0.3 ms (−5.0 to 5.7 ms), 0.5 ms (−3.6to 4.7 ms) and 0.1 ms (−4.0 to 4.3 ms) respectively. LognmyoT2* correlated with LVEF (P = 0.021, R = 0.433).Conclusions: This myoT2* methodology including 11 TEand noise test demonstrated high reproducibility and cor-r

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(p < 0.05). LAExc was 27–30% lower at both annularorders in TM (p < 0.001 for both), but A′ was similar

o controls. After adjusting for HR, BSA and LAVI, TMemained a significant predictor of lower septal and lat-ral LAExc (p < 0.001 for both). In TM subjects ferritin wasn inverse correlate of septal and lateral LAExc, and thisas independent of age, HR and BSA (β = −0.49 and −0.42,

espectively, p < 0.01 for both).onclusion: Long axis LA contraction is reduced in TM,ut this is not reflected in a reduction in A′. The reduction

n LA contraction in TM is related to the degree of ironverload and is not likely to be due to a reduction in LAreload.

oi:10.1016/j.hlc.2008.05.122

22yocardial T2* Estimation Techniques in Iron Overloadisease: Relationship with Left Ventricular Function

ichael Leung ∗, Angelo Carbone, Greg Brown, Stephenorthley

Royal Adelaide Hospital and Adelaide University, Adelaide,outh Australia, Australia

bjectives: Myocardial T2* relaxometry has been pro-osed as a measure of myocardial iron accumulation.yocardial T2* estimate (myoT2*) has been associ-

ted with fatal heart failure in transfusion-induced ironverload disease. However, limited discussion of theethodology exists in the literature. We developed explicit

ules for data acquisition and analysis and assessed their

elated with left ventricular function.

oi:10.1016/j.hlc.2008.05.123

23chocardiography Velocity Vector Imaging for Assessingight Ventricular Function and its Relation to MRI Volu-etric and Visual Assessment

hiew Wong ∗, Michelle Butler, Heinz Pluger, Andrewaylor

Alfred Hospital and Baker Heart Research Institute, Melbourne,ustralia

ackground: Right ventricular (RV) function assessmenty 2D echocardiogram is limited in providing an accu-ate measure of RV ejection fraction (RVEF). Quantitative

easurement of RV function is needed for serial measure-ents.bjective: We sought to determine if the new Velocityector Imaging (VVI) can be used to provide accurateuantitative measures of the RV function. Comparisonsere made with an MRI-derived RVEF and echo visual

ategorization of the RV function.ethods: We analyzed RV function in 32 patients

ncluding 13 patients who had cardiac MRI studiesnd echocardiograms within a 3-month period. Veloc-ty vector-derived RVEF, averaged tissue velocity; strainnd strain rate were obtained from the four-chamberiew. RVEF by MRI were derived from volumetric recon-truction. RV function was categorized as normal, mild,oderate and severe.