Hiromi Nakai

Subclinical left ventricular dysfunction in asymptomatic diabetic patients assessed by two-dimensional speckle tracking echocardiography: correlation with diabetic duration

AIMS Early detection of diabetic heart disease is important for the timely interventions resulting in the prevention for the future development of heart failure. Subclinical left ventricular (LV) systolic dysfunction may be identified by a reduction in longitudinal function, which can be assessed using 2D speckle tracking echocardiography (STE). METHODS AND RESULTS To determine longitudinal, radial, and circumferential function, three LV short-axis and three LV apical views were acquired in 60 asymptomatic diabetic patients with normal LV ejection fraction (EF) and 25 age-matched healthy volunteers. Using 2D strain software, end-systolic longitudinal strain (LS), radial strain (RS), and circumferential strain (CS) were measured in 18 LV segments. No significant differences in LVEF were noted between two groups. Diabetic patients had more advanced diastolic dysfunction and increased LV mass compared with normal subjects. Basal, middle, and apical LSs were significantly lower in diabetic patients compared with control subjects, with 43% (26/60) of the diabetic patients showing abnormal global LS values (cut-off value: -17.2, mean - 2SD in control subjects). Basal RS and apical CS were also significantly lower in diabetic patients. Multivariate linear regression analysis showed that diabetic duration was the only independent confounder for the reduction of LS (t = 2.22, P = 0.0313). CONCLUSION In addition to diastolic dysfunction, subclinical LV longitudinal dysfunction is preferentially and frequently observed in asymptomatic diabetes patients with normal LVEF. The decrease in LS correlated with duration of diabetes. 2DSTE has the potential for detecting subclinical LV systolic dysfunction and might provide useful information of the risk stratification in an asymptomatic diabetic population.

Effects of aging on left atrial function assessed by two-dimensional speckle tracking echocardiography.

BACKGROUND Aging affects left atrial (LA) function, which can be assessed by two-dimensional (2D) speckle tracking echocardiography (STE). The aim of this study was to determine (1) the feasibility and accuracy of measuring LA volume with 2DSTE and (2) the effects of aging on LA function. METHODS 2DSTE of the LA was acquired from the apical 4-chamber view (frame rate: 63 +/- 11 /sec, iE33) using prototype speckle tracking software (QLAB, Philips Medical Systems, Andover, MA) in 140 healthy volunteers (3-79 years, 74 men). LA wall was tracked on a frame-by-frame basis, and LA volume waveforms were generated. Maximum LA volume (LAVmax) and minimal LA volume (LAVmin), and the LA volume before atrial contraction (LAVpre-a) were measured. Passive emptying percent of total emptying (LA conduit function) and active emptying percent of total emptying (booster function) were calculated as ([LAVmax-LAVpre-a]/[LAVmax-LAVmin]) x 100 and ([LAVa-LAVmin]/[LAVmax-LAVmin]) x 100. RESULTS Adequate LA volume waveforms were obtained in all subjects. A good correlation was obtained between speckle tracking-derived LA volume measurements and manually traced LA volume measurements of the identical 2D image (LAVmax: r = 0.93, P <.001, LAVmin: r = 0.88, P <.001, LAVpre-a: r = 0.92, P <.001). Passive and active emptying indices had a significant age dependency (r = 0.80, P <.001). Overall, passive emptying accounted for 67% of the total LA emptying ranging from 83% in the youngest to 42% in the oldest decade. CONCLUSION Aging significantly affects LA conduit and booster function. 2DSTE can effectively and easily measure LA volume and has a potential for the noninvasive assessment of LA function.

Age- and Gender-Dependency of Left Ventricular Geometry Assessed with Real-Time Three-Dimensional Transthoracic Echocardiography

BACKGROUND Aging and gender may affect left ventricular (LV) mechanics. The aim of this study was to determine the age and gender dependency of LV mechanical indices obtained from real-time three-dimensional echocardiography (RT3DE). METHODS RT3DE was performed in 280 healthy subjects (age range, 1-88 years; 137 men). From full-volume data sets, LV endocardial and epicardial borders were semiautomatically traced using quantitative software. LV volumes and corresponding long-axis diameter were measured throughout the cardiac cycle. Sphericity index was defined as the ratio of LV volume and spherical volume, calculated as 4/3 × π × (long-axis diameter/2)(3). LV mass was calculated as (LV epicardial volume - LV endocardial volume) × 1.05. The ratio of LV mass to LV volume was also calculated. RESULTS The mean value of LV ejection fraction did not change with age. However, LV volumes, mass, sphericity index, and LV mass/volume ratio were altered by age: (1) sphericity index was highest in the first decade of age and then declined until the fifth decade, (2) LV mass/volume ratio significantly increased in older age, and (3) LV mass/volume ratio was significantly higher in aged women compared with age-matched men. CONCLUSIONS Age has heterogeneous effects on LV shape and LV mass/volume ratio, potentially due to the growing process of myocardial fibers and the surrounding architecture in the younger population, as well as the aging process, with an increase in vascular stiffness and a loss of myocytes in older populations. Higher LV mass/volume ratios in older women might be a contributor to the preferential development of diastolic heart failure in this population.

Quantitative assessment of left ventricular volume and ejection fraction using two-dimensional speckle tracking echocardiography

AIMS Two-dimensional speckle tracking echocardiography (2DSTE) allows measurements of left ventricular (LV) volumes and LV ejection fraction (LVEF) without manual tracings. Our goal was to determine the accuracy of 2DSTE against real-time 3D echocardiography (RT3DE) and against cardiac magnetic resonance (CMR) imaging. METHODS AND RESULTS In Protocol 1, 2DSTE data in the apical four-chamber view (iE33, Philips) and CMR images (Philips 1.5T scanner) were obtained in 20 patients. The 2DSTE data were analysed using custom software, which automatically performed speckle tracking analysis throughout the cardiac cycle. LV volume curves were generated using the single-plane Simpsons formula, from which end-diastolic volume (LVEDV), end-systolic volume (LVESV), and LVEF were calculated. In Protocol 2, the 2DSTE and RT3DE data were acquired in 181 subjects. RT3DE data sets were acquired, and LV volumes and LVEF were measured using QLab software (Philips). In Protocol 1, excellent correlations were noted between the methods for LVEDV (r=0.95), ESV (r=0.95), and LVEF (r=0.88). In Protocol 2, LV volume waveforms suitable for analysis were obtained from 2DSTE images in all subjects. The time required for analysis was <2 min per patient. Excellent correlations were noted between the methods for LVEDV (r=0.95), ESV (r=0.97), and LVEF (r=0.92). However, 2DSTE significantly underestimated LVEDV, resulting in a mean of 8% underestimation in LVEF. Intra- and inter-observer variabilities of 2DSTE were 7 and 9% in LV volume and 6 and 8% in LVEF, respectively. CONCLUSIONS Two-dimensional speckle tracking echocardiography measurements resulted in a small but significant underestimation of LVEDV and EF compared with RT3DE. However, the accuracy, low intra- and inter-observer variabilities and speed of analysis make 2DSTE a potentially useful modality for LV functional assessment in the routine clinical setting.

Hypertrophic cardiomyopathy is associated with more severe left ventricular dyssynchrony than is hypertensive left ventricular hypertrophy.

Objective: To evaluate left ventricular (LV) dyssynchrony in patients with left ventricular hypertrophy (LVH), and to compare abnormalities associated with hypertrophic cardiomyopathy (HCM) and hypertensive heart disease (HHD) using 2D speckle tracking imaging. Methods: Basal, middle, and apical 2D LV short‐axis images were acquired in 43 patients with LVH including 20 with HCM and 23 with HHD, and in 15 age‐matched controls. Radial strain, circumferential strain, time interval from the R‐wave to peak radial strain (Trs), and time to peak circumferential strain (Tcs) were measured in six equidistant segments at each level of the 3 LV short‐axis views using 2D speckle tracking analysis. To assess LV dyssynchrony, Trs(cs)‐18SD, the standard deviation (SD) of Trs(cs) in all 18 segments, was calculated. Results: Regional radial strain in the middle and apical short‐axis segments was significantly less in patients with HCM than in those with HHD. Regional circumferential strain in the apical short‐axis segments was also less in HCM. Trs‐18SD and Tcs‐18SD were significantly longer in patients with HCM than in age‐matched controls and patients with HHD (Trs‐18SD: HCM: 88 ± 32 ms, HHD: 51 ± 20 ms, control: 45 ± 12 ms P < 0.001, Tcs‐18SD: HCM: 71 ± 27 ms, HHD: 46 ± 14 ms, control: 45 ± 14 ms P < 0.001). Conclusions: The presence of LVH is thus not always associated with LV dyssynchrony. However, the greater reduction of regional strain and severe LV dyssynchrony in HCM may contribute to the adverse cardiovascular outcomes associated with this disease.

Pitfalls of anatomical aortic valve area measurements using two-dimensional transoesophageal echocardiography and the potential of three-dimensional transoesophageal echocardiography.

AIMS The aims of this study were to (i) investigate aortic annulus dynamics using two-dimensional (2D) speckle tracking echocardiography, (ii) determine optimal 2D short-axis view for the calculation of planimetric aortic valve area (AVA), and (iii) compare 2D planimetric AVA extracted from volumetric three-dimensional data sets using real-time 3DTEE (three-dimensional transoesophageal echocardiography) with standard 2DTEE planimetry. METHODS AND RESULTS We studied 60 patients with aortic stenosis (AS) and 10 control subjects. AVA was calculated by standard 2DTEE planimetry method, volumetric 3DTEE method, and continuity equation (CE) from transthoracic echocardiography. In addition, aortic annular motion was studied using 2D speckle tracking. Aortic annulus moves cranially during early systole and subsequently moves caudally during the remainder of systole and isovolumic relaxation. Annulus again moved in the cranial direction during diastole in both groups. Although AVA correlated well between 2DTEE and 3DTEE methods (r = 0.95), 2DTEE showed a significantly larger AVA compared with 3DTEE method (1.26 +/- 0.39 vs. 1.10 +/- 0.39 cm(2), P < 0.001). In patients in whom aortic cusps were visible in 2DTEE short-axis images during systole only (n = 45), AVA using 2DTEE was still larger than that measured with 3DTEE. However, the bias in AVA was significantly lower compared with the remaining 15 patients (-0.13 +/- 0.11 vs. -0.26 +/- 0.12 cm(2), P < 0.005). Although both methods showed moderate correlation with AVA by CE (r = 0.78, 0.75), mean differences were significantly smaller by 3DTEE than 2DTEE (-0.01 +/- 0.25 vs. -0.17 +/- 0.27 cm(2), P < 0.001). CONCLUSION Aortic annular motion affects the calculation of AVA using 2DTEE. Three-dimensional transoesophageal echocardiography has a potential for more accurate determination of anatomical AVA.

Continuous positive airway pressure ameliorates sleep-induced subclinical left ventricular systolic dysfunction: demonstration by two-dimensional speckle-tracking echocardiography

AIMS We hypothesized that continuous positive airway pressure (CPAP) therapy could improve sleep-induced left ventricular (LV) dysfunction in patients with obstructive sleep apnoea syndrome (OSA). The aim of this study was to investigate the effects of CPAP therapy on LV systolic dysfunction during overnight sleep in patients with OSA using two-dimensional speckle-tracking echocardiography (2DSTE). METHODS AND RESULTS 2D LV short-axis and apical views were acquired before and immediately after overnight sleeping in 32 patients with OSA and normal LV ejection fraction. Using 2D strain software, three-principal strains were measured. In a subset of 14 OSA patients who received chronic CPAP therapy, identical measurements were repeated 3 months after the therapy. Although no significant changes in global radial and circumferential strain were noted, global longitudinal strain was significantly reduced after overnight sleeping (-19.1 +/- 2.0) compared with before sleep (-20.7 +/- 1.8, P < 0.001). After CPAP therapy, improvements in apnoea-hypopnoea index and minimal oxygen saturation were accompanied by the disappearance of longitudinal strain reduction during overnight sleep. CONCLUSION Repetitive obstructive apnoea produces acute impairment of LV longitudinal function, suggesting the development of subendocardial ischaemia. CPAP therapy not only decreases the severity of OSA, but also ameliorates sleep-induced longitudinal LV dysfunction, which can be assessed by 2DSTE.

Possible link between strain ST-T change on the electrocardiogram and subendocardial dysfunction assessed by two-dimensional speckle-tracking echocardiography

AIMS Strain ST-T changes on surface electrocardiogram (ECG) may reflect subendocardial dysfunction. We hypothesized that strain ST-T changes are associated with (i) decrease in longitudinal strain, (ii) decrease in early systolic clockwise twist and early diastolic untwisting, and (iii) augmentation of peak twist due to subendocardial dysfunction. METHODS AND RESULTS Three levels of left ventricular (LV) short-axis views and three LV apical views were acquired in 46 hypertensive patients with LV hypertrophy and 23 age-matched control subjects using 2D echocardiography. Patients were divided into two groups according to the presence (n = 18) or absence (n = 28) of strain ST-T change on 12-lead ECG. Using 2D strain software, longitudinal, radial, and circumferential strain were measured. Early systolic clockwise twist, end-systolic twist, and untwisting at early diastole were measured from time-domain LV twist curves. No significant intergroup differences in LV ejection fraction were noted. Longitudinal strain was significantly reduced in hypertensive patients with strain ST-T changes compared with those without these changes or control subjects. Although LV twist at end-systole was similar between patients with and without strain ST-T changes, early systolic clockwise twist and untwisting was significantly reduced in strain ST-T change group compared with the no ST-T change group. Multivariate analysis revealed that not LV mass index but strain ST-T change was an independent predictor of global longitudinal strain. CONCLUSION The reduction in longitudinal strain, early systolic clockwise twist, and untwisting in hypertensive patients with strain ST-T changes suggests possible link between this ECG abnormality and subendocardial dysfunction, which can be assessed by 2D speckle tracking echocardiography.

Tornado-like appearance of spontaneous echo contrast assessed by real-time 3D transesophageal echocardiography

We report a case showing that real-time 3D transesophageal echocardiography provides unique information about the dynamic nature of spontaneous echo contrast (SEC) in 3D space and has the potential to provide better understanding of SEC.