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Role of Three‐Dimensional Speckle Tracking Echocardiography in the Quantification of Myocardial Iron Overload in Patients with Beta‐Thalassemia Major
Author(s) -
Li Shujuan,
Hwang Yuyan,
Ha Shauyin,
Chan Godfrey C.F.,
Mok Amanda S.P.,
Wong Sophia J.,
Cheung Yiufai
Publication year - 2016
Publication title -
echocardiography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 62
eISSN - 1540-8175
pISSN - 0742-2822
DOI - 10.1111/echo.13266
Subject(s) - ejection fraction , medicine , speckle tracking echocardiography , cardiology , receiver operating characteristic , cardiac magnetic resonance , twist , cutoff , magnetic resonance imaging , nuclear medicine , heart failure , radiology , mathematics , geometry , physics , quantum mechanics
Background The new three‐dimensional speckle tracking echocardiography (3D STE ) may enable comprehensive quantification of global left ventricular ( LV ) myocardial mechanics. Methods Twenty‐four patients aged 29.3 ± 5.2 years and 22 controls were studied. 3D STE was performed to assess LV 3D global strain, twist and torsion, ejection fraction, and systolic dyssynchrony index ( SDI ). The LV SDI was calculated as % of SD of times‐to‐peak strain of 16 segments/ RR interval. The global performance index ( GPI ) was calculated as (global 3D strain·torsion)/ SDI . Area under the receiver operating characteristic curve ( AUC ) was calculated to determine the capability of 3D STE parameters to discriminate between patients with (cardiac magnetic resonance T2* <20 ms) and those without myocardial iron overload. Results Compared with controls, patients had significantly lower LV global 3D strain (P < 0.001), twist (P = 0.01), torsion (P = 0.04), and ejection fraction (P < 0.001) and greater SDI (P < 0.001). The GPI was lower in patients than controls (P < 0.001). T2* value correlated positively with global 3D strain (r = 0.74, P < 0.001) and GPI (r = 0.63, P = 0.001), and negatively with SDI (r = −0.44, P = 0.03). The AUC s of GPI , global 3D strain, ejection fraction, torsion, and 1/ SDI were 0.94, 0.90, 0.87, 0.82, and 0.70, respectively. The GPI cutoff of 2.7°/cm had a sensitivity of 94.9% and a specificity of 88.9% of differentiating patients with from those without myocardial iron overload. Conclusions The LV composite index of strain, torsion, and dyssynchrony derived from 3D STE enables sensitive detection of myocardial iron overload in patients with thalassemia.