Noriaki Sato

Quantitative validation of left atrial structure and function by two-dimensional and three-dimensional speckle tracking echocardiography: a comparative study with three-dimensional computed tomography.

BACKGROUND The aim of this study was to validate the accuracy of three-dimensional (3D) speckle tracking echocardiography (STE) and two-dimensional (2D)-STE for the assessment of left atrial (LA) volume and function by comparison with 3D-computed tomography (CT) performed on the same day as STE. METHODS LA phasic volume and emptying function (EF) were measured in 28 patients with paroxysmal atrial fibrillation undergoing catheter ablation (62±11 years old) using both 3D-STE and 2D-STE during sinus rhythm. LA phasic volume and function measured by 3D-STE and 2D-STE were validated using 3D-CT as a gold standard. RESULTS The intraobserver correlation coefficient and variability in maximum LA volume assessed by 3D-STE were 0.99 and 1.4±6.0%, respectively. The interobserver correlation coefficient and variability in maximum LA volume assessed by 3D-STE were 0.99 and 0.2±4.5%, respectively. There were strong correlations between LA phasic volume measured by 3D-CT and those measured by 3D-STE (r=0.98, p<0.001). There were correlations between LA phasic function measured by 3D-CT and those measured by 3D-STE (r=0.85-0.88, p<0.001). There was a better agreement between 3D-CT and 3D-STE in the assessment of LA phasic volumes and function than between 3D-CT and 2D-STE in apical 2- and 4-chamber view. CONCLUSIONS 3D-STE allows more accurate measurement of LA volume and function than 2D-STE and has high reproducibility.

Left ventricular layer function in hypertension assessed by myocardial strain rate using novel one-beat real-time three-dimensional speckle tracking echocardiography with high volume rates

We recently developed novel software to measure phasic strain rate (SR) using automated one-beat real-time three-dimensional speckle tracking echocardiography (3D-STE) with high volume rates. We tested the hypothesis that left ventricular (LV) systolic function and relaxation analyzed by SR with the novel 3D-STE in hypertension (HTN) with hypertrophy may be impaired in the endocardium before there is LV systolic dysfunction. We measured LV longitudinal, radial and circumferential SR in patients with HTN (n=80, 69±7 years) and age-matched normotensive controls (n= 60, 69±10 years) using 3D-STE. HTN patients were divided into four groups according to LV geometry: normal, concentric remodeling, concentric hypertrophy and eccentric hypertrophy. We measured SR during systole as an index of systolic function, SR during isovolumic relaxation (IVR) as an index of relaxation and E/e’ as an index of filling pressure. Endocardial SR during systole in HTN with concentric and eccentric hypertrophy decreased compared with that in controls despite no reduction in ejection fraction or epicardial SR. Endocardial radial SR during IVR decreased even in normal geometry, and it was further reduced in concentric remodeling and hypertrophy despite no reduction in epicardial SR. LV phasic SR assessed by 3D-STE with high volume rates is a useful index to detect early decreases in LV systolic function and to predict subclinical LV layer dysfunction in patients with HTN.