AB

ST

RA

CT

S

S44 Abstracts Heart, Lung and Circulation2007;16:S1–S201

Table. Abstract 107

n = 42 LAD RCA LCx Overall

Sens Spec Sens Spec Sen Spec Sens Spec

2DE 88% 73% 60% 78% 46% 76% 86% 52%

3DE 27% 81% 38% 92% 36% 93% 46% 80%

p value <0.01 0.47 0.21 0.14 0.58 0.08 <0.01 0.06

doi:10.1016/j.hlc.2007.06.112

108The Accuracy of Regional Left Ventricular 3DE in Com-parison with MRI

C. Jenkins ∗, J. Chan, T.H. Marwick

University of Queensland, Brisbane, Australia

Objectives: Previous studies have shown that 3D echo(3DE) for follow-up of global volume is comparable tomagnetic resonance imaging (MRI) and could be used indaily practice. Regional volume (RVol) has yet to be vali-dated and therefore we sought to evaluate 3DE RVol versusMRI.Methods: 3DE and MRI RVol were assessed at baselineand at 1-year follow-up in 10 unselected patients (8 men,

109The Relative Atrial Index (RAI)—A Novel, Simple,Reliable and Robust Transthoracic EchocardiographicIndicator of Significant Atrial Defects

Natalie Kelly ∗, Lisa Walters, Darren Walters, DarrylBurstow, Jeffrey Presneill, Gregory M. Scalia

The Prince Charles Hospital, Brisbane, Qld., Australia

Background: Detection of atrial septal defects (ASDs)and other shunts is sometimes difficult by transthoracicechocardiography. Robust assessment of right heart vol-ume loading (as an indicator of significant shunting) hasbeen difficult to achieve with subjective estimation beingcommonly used. We review a novel transthoracic tool.Methods: The Relative Atrial Index (RAI) was derivedfrom standard apical four chamber views using theformula RAI = RA area (cm2)/LA area (cm2). The RAI forpatients with significant ASDs (n = 219) was comparedwith age-matched controls (n = 219) and with the generalpopulation (excluded significant intrinsic right heartpathology, n = 4897).

63 ± 14 years).Results: Measurements were taken at each RVol at end-diastole (EDV) and end-systole (ESV) and the change involume over follow-up for each were compared. The totalchange over all segments for EDV MRI was −0.11 ± 2.46 mland 3DE 0.46 ± 2.05 ml (r = −0.09 p = 0.24; F = 1.45 p = 0.01).For ESV, the total change over all segments for MRIwas 0.06 ± 3.17 ml and 3DE 0.39 ± 1.65 ml (r = 0.33 p = 0.68;F = 3.71 p < 0.01). There was no correlation and high vari-ation between RVol when left ventricular walls werecompared individually (Table).Conclusions: Although global 3DE volumes may comparewell to MRI, RVol image quality and automated softwareneeds more investigation if it is to be used in daily practice.

Table. Abstract 108*p < .05 Posterior AntSeptal Septal Lateral Anterior Inferior

EDV (ml) r = −0.3,p = 0.2,F = 1.39,p = 0.23

r = 0.30,p = 0.19,F = 2.74*

r = −0.3,p = 0.2,F = 1.3,p = 0.3

r = −0.10,p = 0.59,F = 2.47*

r = −0.28,p = 0.13,F = 2.15*

r = 0.08,p = 0.68,F = 0.62,p = 0.10

ESV (ml) r = 0.15,p = 0.5,F = 8.89*

r = 0.4,p = 0.07,F = 2.52*

r = −0.1,p = 0.2,F = 2.14*

r = 0.72*,F = 8.72*

r = −0.06,p = 0.9,F = 7.63*

r = 0.19,p = 0.31,F = 1.7,p = 0.08

doi:10.1016/j.hlc.2007.06.113

Results: The RAI in ASD patients (1.23 ± 0.23) was signifi-cantly higher than the matched normal controls (0.78 ± 0.1,p < 0.0001) and significantly higher than the general popu-lation (0.81 ± 0.15, p < 0.0001). ROC analysis suggested thata nominal cut-off value for RAI >1.0 predicated ASD versusmatched controls with a sensitivity of 96.8% and specificityof 100%. In the general population an RAI <1.0 excludedan ASD with a false negative rate of 3% and a false positiveof 11.8%.Conclusion: This novel and simple transthoracic parame-ter, RAI robustly identifies patients with significant atrialshunting. Prospective analysis of its diagnostic and prog-nostic utility warrants further investigation.

doi:10.1016/j.hlc.2007.06.114