Hidetoshi Yoshitani

Comparison of acute and chronic impact of adaptive servo-ventilation on left chamber geometry and function in patients with chronic heart failure.

The aim of this study was to determine differences in the acute and chronic impact of adaptive servo‐ventilation (ASV) on left chamber geometry and function in patients with chronic heart failure (CHF).

Assessment of Coronary Flow Velocity With Transthoracic Doppler Echocardiography During Dobutamine Stress Echocardiography

OBJECTIVES The purpose of this study was to evaluate the feasibility of measuring coronary flow velocity (CFV) by transthoracic Doppler echocardiography (TTDE) in the left anterior descending coronary artery (LAD) during contrast-enhanced dobutamine stress echocardiography (DSE). We also assessed the value of TTDE for detecting stress-induced myocardial ischemia in the LAD territory. BACKGROUND Noninvasive assessment of both CFV and wall motion during DSE would enhance the diagnostic accuracy of DSE. METHODS One hundred forty-four consecutive patients underwent CFV recording in the distal LAD by TTDE during contrast-enhanced DSE. Regional wall motion score index (WMSI) in the LAD territory and CFV ratio at peak stress (CFV ratio peak), defined as a ratio of CFV at peak stress to basal CFV, were obtained. RESULTS Coronary flow velocity was successfully recorded in 129 patients (90%) at baseline and during dobutamine infusion. Mean value of CFV ratio peak was 2.39 +/- 0.83 (range: 0.84 to 4.40). There was good correlation between WMSI at peak stress and CFV ratio peak (r = 0.62, p < 0.001). Coronary flow velocity ratio peak was significantly lower in patients who developed stress-induced wall motion abnormality (WMA) in the LAD territory than it was in those patients without WMA (1.51 +/- 0.51 vs. 2.76 +/- 0.65, p < 0.001). A CFV ratio peak <2.1 had a sensitivity of 92% and a specificity of 86% for detecting the presence of stress-induced WMA. CONCLUSIONS Assessment of CFV in the distal LAD during DSE is feasible in the majority of cases and provides a CFV ratio for detecting stress-induced myocardial ischemia in the LAD territory.

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.

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.

Automated Assessment of Left Atrial Function From Time-Left Atrial Volume Curves Using a Novel Speckle Tracking Imaging Method

BACKGROUND Using a novel speckle-tracking imaging method, time-left atrial (LA) volume curves (TLAVCs) can be automatically obtained. The aim of this study was to evaluate whether this method can be used for the measurement of LA function with TLAVCs. METHODS In 10 normal subjects and 20 patients, apical 4-chamber images were obtained. Maximum volume, reservoir volume, conduit volume, booster pump volume, and minimum volume were measured from TLAVCs. The results were compared with those obtained by the manual tracing method on every frame during 1 cardiac cycle. RESULTS There was good agreement between the speckle-tracking imaging and manual methods for maximum LA volume (r = 0.98, P < .001), reservoir volume (r = 0.82, P < .001), conduit volume (r = 0.87, P < .001), booster pump volume (r = 0.80, P < .001), and minimum volume (r = 0.98, P < .001). The time to obtain TLAVCs was significantly shorter with the speckle-tracking imaging method (64 +/- 22 seconds) than with the manual method (22 +/- 4 minutes). CONCLUSION TLAVCs obtained using the speckle-tracking imaging method can be used for the rapid and noninvasive automated quantitation of LA function.

Prognostic value of LA volumes assessed by transthoracic 3D echocardiography: comparison with 2D echocardiography.

OBJECTIVES The hypothesis of this study was that minimal left atrial volume index (LAVImin) by 3-dimensional echocardiography (3DE) is the best predictor of future cardiovascular events. BACKGROUND Although maximal left atrial volume index (LAVImax) by 2-dimensional echocardiography (2DE) is a robust index for predicting prognosis, the prognostic value of LAVImin and the superiority of measurements by 3DE over 2DE have not been determined in a large group of patients. METHODS In protocol 1, we assessed age and sex dependency of LAVIs using 2DE and 3DE in 124 normal subjects and determined their cutoff values (mean + 2 SD). In protocol 2, 2-dimensional (2D) and 3-dimensional (3D) LAVImax/LAVImin were measured in 556 patients with high prevalence of cardiovascular disease. After excluding patients with atrial fibrillation, mitral valve disease, and age <18 years, 439 subjects were followed to record major adverse cardiovascular events (MACE). Patients were divided into 2 groups by the cutoff criteria of LAVI in each method. RESULTS In protocol 1, there was no significant age and sex dependency for each 2D and 3D LAVI. In protocol 2, during a mean of 2.5 years of follow-up, MACE developed in 88 patients, including 32 cardiac deaths. Kaplan-Meier survival analyses showed that all 4 LAVI cutoff criteria had significant predictive power of MACE. After variables were adjusted for clinical variables and left ventricular ejection fraction, all 4 methods were still independently and significantly associated with MACE, but 3D-derived LAVImin had the highest risk ratio. 3D LAVImin also had an incremental prognostic value over 3D LAVImax. CONCLUSIONS LAVIs by both 2DE and 3DE are powerful predictors of future cardiac events. 3D LAVImin tended to have a stronger and additive prognostic value than 3D LAVImax.

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.

Effect of Through-Plane and Twisting Motion on Left Ventricular Strain Calculation: Direct Comparison between Two-Dimensional and Three-Dimensional Speckle-Tracking Echocardiography

BACKGROUND The aim of this study was to investigate the effect of out-of-plane motion on discrepancies in strain measurements between two-dimensional (2D) and three-dimensional (3D) echocardiography. METHODS Two-dimensional and 3D data sets were acquired in 54 patients. Using 2D and 3D speckle-tracking software, global circumferential strain (CS) and longitudinal strain (LS) as well as CS and LS at three left ventricular (LV) levels was measured. The effect of through-plane motion was assessed by mitral annular displacement. RESULTS Although a good correlation of global CS was noted between the two methods (r = 0.80, P < .01), mean values of global CS were significantly higher on 3D compared with 2D echocardiography. Correlations of CS and their mean differences were 0.65 and -4.61 at the basal level, 0.76 and -4.17 at the midventricular level, and 0.60 and -2.23 at the apical level, respectively. Correlation of global CS between the two methods was higher in patients who showed mitral annular displacement < 9.4 mm (r = 0.81) compared with those with mitral annular displacement ≥ 9.4 mm (r = 0.61). A good correlation of global LS (r = 0.89, P < .01) was noted, with no significant bias. Correlations of LS and their mean differences were 0.52 and 1.59 at the basal level, 0.89 and -1.17 at the midventricular level, and 0.73 and 1.46 at the apical level, respectively. Correlation of LS between the two methods was higher in patients who showed LV twist < 12.2° (r = 0.94) compared with patients with LV twist ≥ 12.2° (r = 0.68). CONCLUSIONS Through-plane motion produced discrepancies in CS measurements, especially at the LV basal level. Larger bias of LS at the basal and apical LV levels compared with the midventricular level between the two methods suggests that LV twisting also affects the calculation of 2D LS.

Comparative Diagnostic Accuracy of Multiplane and Multislice Three-Dimensional Dobutamine Stress Echocardiography in the Diagnosis of Coronary Artery Disease

BACKGROUND Although real-time three-dimensional echocardiography (RT3DE) is useful for delineating the extent and severity of stress-induced wall motion abnormalities during dobutamine stress echocardiography (DSE), it also provides simultaneous multiple two-dimensional cut planes, which may potentially improve the detection of stress-induced wall motion abnormalities. The aim of this study was to determine the comparative diagnostic accuracy of RT3DE in multiplane and multislice modes for the diagnosis of coronary artery disease (CAD) during DSE against coronary angiography reference. METHODS Multiplane and multislice cut planes (3 V, GE Healthcare, Milwaukee, WI) at rest and peak dose of dobutamine were acquired in 71 patients with known or suspected CAD. In multiplane mode, matrix array transducer allowed the simultaneous visualization of parasternal long and short-axis views or apical 4-, 2-, and 3-chamber views. From full-volume datasets, 9 equidistant 2-dimensional short-axis images from LV base to apex were extracted and simultaneously displayed (multislice mode). Visual assessment of regional wall motion was performed. Coronary angiography was performed within 48 hours and used as a reference. RESULTS Abnormal findings (new or worsened wall motion abnormalities or fixed wall motion abnormalities) were noted in 36 patients by multiplane mode and 28 patients by multislice mode. Coronary angiography showed significant stenosis in 32 of 71 patients in 49 of 213 coronary arteries. On a patient basis, sensitivity was not different, but specificity was significantly higher in multislice mode (95%) compared with multiplane mode (77%, P < .05). Diagnostic accuracy for detecting right CAD was also significantly higher in multislice mode (93% vs 80%, P < .05). CONCLUSION Assessment of LV wall motion from multiple short-axis slices extracted from full-volume RT3DE datasets improves the diagnosis of CAD and is thus a useful addition to DSE tools.

Evidence of a Vicious Cycle in Mitral Regurgitation With Prolapse Secondary Tethering Attributed to Primary Prolapse Demonstrated by Three-Dimensional Echocardiography Exacerbates Regurgitation

Background— In patients with mitral valve prolapse, nonprolapsed leaflets are often apically tented. We hypothesized that secondary left ventricular dilatation attributed to primary mitral regurgitation (MR) causes papillary muscle (PM) displacement, resulting in this leaflet tenting/tethering, and that secondary tethering further exacerbates malcoaptation and contributes to MR severity. Methods and Results— Three-dimensional transesophageal echocardiography was performed in 25 patients with posterior mitral leaflet prolapse with an intact anterior mitral leaflet (AML) and 20 controls. From 3D zoom data sets, 11 equidistant antero-posterior cut planes of the mitral valve at midsystole were obtained. In each plane, tenting area of nonprolapsed leaflet and prolapse area of prolapsed leaflet were measured. Prolapse/tenting volume of each region was obtained as the product of interslice distance and the prolapse/tenting area. AML tenting volume and whole leaflet prolapse/tenting volume were then obtained. The PM tethering distance between PM tips and anterior mitral annulus was measured from 3D full-volume data sets. The severity of MR was quantified by vena contracta area extracted from color 3D transesophageal echocardiography data sets. AML tenting volume was significantly larger in patients with posterior mitral leaflet prolapse compared with that in controls (1.2±0.5 versus 0.6±0.2 mL/m2; P<0.001). Multivariate regression analysis identified independent contribution to AML tenting volume from an increase in PM tethering distance. Multivariate regression analysis identified independent contributions to MR severity (vena contracta area) from both whole leaflet tenting volume (r=0.44; P<0.05) and prolapse volume (r=0.44; P<0.05). AML tenting volume decreased along with left ventricular volume and PM tethering distance postrepair (n=8; P<0.01). Conclusions— These results suggest that primary mitral valve prolapse with MR causes secondary mitral leaflet tethering with PM displacement by left ventricular dilatation, which further exacerbates valve leakage, constituting a vicious cycle that would suggest a pathophysiologic rationale for early surgical repair.