Xing Sheng Yang

Quantification of left ventricular regional myocardial function using two-dimensional speckle tracking echocardiography in healthy volunteers — A multi-center study

BACKGROUND Although two-dimensional speckle tracking (2DST) has been validated in animal and early clinical studies for quantitative evaluation of myocardial motion and contractility, there are only limited measurements in large healthy population to be used as reference data, which severely restricts its clinical application. This study aimed at determining the age-specific normal values of left ventricular (LV) longitudinal, circumferential and radial strain in healthy adults. METHODS We studied 228 healthy subjects (109 males, mean age 44 ± 15 years, range 18-78 years). Their LV longitudinal, circumferential and radial strains were measured by 2DST at basal, middle and apical levels of parasternal short-axis and apical 2-, 4- and 3-chamber views. The effects of age, gender and echocardiographic machines (52 patients had measurements obtained by both GE and Philips machines) on these parameters were also evaluated. RESULTS The longitudinal and circumferential strains were -20.4 ± 3.4% and -22.9 ± 3.1%, respectively with higher values being observed at basal than apical segments. On the contrary, the radial strain which ranged 42.6 ± 12.9% decreased towards apical segments. The longitudinal strain declined, the circumferential strain rose and the radial strain remained similar during aging. Adult females had slightly higher circumferential and longitudinal strains than males (23 ± 3% vs -22 ± 3%, -21 ± 3% vs -20 ± 3% respectively; both p<0.01). Strains measured by the 2 different echo machines had good correlations but Phillips-assessed strains (longitudinal and circumferential) were 10% higher than GE measurements. Inter- and intra-observer variabilities were acceptable. CONCLUSIONS Strain measurements by 2DST echocardiography varies with age, gender and echocardiographic vendors in healthy adults. These findings are important to differentiate between health and disease and to assess the severity of disease.

Left atrial regional phasic strain, strain rate and velocity by speckle-tracking echocardiography: Normal values and effects of aging in a large group of normal subjects

BACKGROUND Two-dimensional (2D) speckle tracking echocardiography (STE) is a new tool for evaluation of LA function. The aims of this study are to establish the normal range of LA function measured by 2DSTE in different age groups and to evaluate the relations between the parameters of 2DSTE and Doppler echocardiography in evaluating LA and LV diastolic function in healthy adults. METHODS A total of 121 healthy volunteers (62 males, aged 47±15) were studied. The LA STE curves were obtained using R-wave onset of the electrocardiogram as a reference point. The LA strain during systolic, early and late diastole (εs, εa and εe = εr - εa); strain rate (SRs, SR, SRe and SRa); velocity (Vs, Ve and Va) were analyzed by commercialized software (EchoPAC). The differences between these parameters were analyzed in different age groups (≤35, 36-55 and ≥55 years) in both genders and compared with the corresponding Doppler echocardiographic indices. RESULTS Global LA εs, εe, and εa were 46.8±7.7, 27.3±6.4 and 19.6±4.2%; SRs, SRe, and SRa were 2.4±0.5, -2.4±0.7 and -2.8±0.6 1/s; Vs, Ve and Va were -5.3±0.9, 5.8±1.2 and 5.2±1.1cm/s respectively. The global LA 2DSTE parameters significantly correlated with Doppler echocardiographic indices which represented LA or LV diastolic function. Moreover, the STE LA parameters correlated significantly with age but not gender. CONCLUSIONS This study provides the normal range of LA strain, strain rate and velocity in 3 age groups, which are closely correlated with LA and LV function. The detailed assessment of LA phasic mechanics by 2DSTE may prove to be an important tool for future clinical studies.

Feasibility of single-beat full-volume capture real-time three-dimensional echocardiography for quantification of right ventricular volume: Validation by cardiac magnetic resonance imaging

BACKGROUND The lack of an accurate noninvasive method for assessing right ventricular (RV) volume and function has been a major deficiency of two-dimensional (2D) echocardiography. The aim of our study was to test the feasibility of single-beat full-volume capture with real-time three-dimensional echo (3DE) imaging system for the evaluation of RV volumes and function validated by cardiac magnetic resonance imaging (CMRI). METHODS Sixty-one subjects (16 normal subjects, 20 patients with hypertension, 16 patients with pulmonary heart disease and 9 patients with coronary heart disease) were studied. RV volume and function assessments using 3DE were compared with manual tracing with CMRI as the reference method. RESULTS Fifty-nine of 61 patients (96.7%; 36 male, mean age, 62 ± 15 years) had adequate three-dimensional echocardiographic data sets for analysis. The mean RV end diastolic volume (EDV) was 105 ± 38 ml, end-systolic volume (ESV) was 60 ± 30 and RV ejection fraction (EF) was 44 ± 11% by CMRI; and EDV 103 ± 38 ml, ESV 60 ± 28 ml and RV EF 41 ± 13% by 3DE. The correlations and agreements between measurements estimated by two methods were acceptable. CONCLUSION RV volumes and function can be analyzed with 3DE software in most of subjects with or without heart diseases, which is able to be estimated with single-beat full-volume capture with real-time 3DE compared with CMRI.

Effect of age and gender on left ventricular rotation and twist in a large group of normal adults — A multicenter study

BACKGROUND The newly developed 2-dimensional speckle tracking imaging (2D-STI) allows assessment of left ventricular (LV) rotation and twist. The aims of the present study are to establish normal values and to examine the effect of aging and gender on these parameters. METHODS We studied 228 healthy subjects (109 males, mean age 44 ± 15 years, ranged 18-78 years). LV longitudinal and circumferential strain, rotation and twist were assessed by 2D-STI at basal, middle and apical levels of parasternal short-axis and apical 2-, 4- and 3-chamber views. RESULTS The mean global LV longitudinal and circumferential strains were -20.4 ± 3.4% and -22.9 ± 3.1%, respectively. Of the 2,736 segments analyzed, 110 (8%) and 128 (9.4%) segments did not have optimal images for the assessment of basal and apical rotation. The basal rotation (-9.6 ± 2.5°) was significantly lower than apical rotation (11.2 ± 4.3°, p<0.0001) with a mean LV twist of 20.5 ± 4.5°. The longitudinal strain decreased with aging, which was accompanied by significant augmentations in circumferential strain, LV rotation and twist. There was no gender difference for rotational and twist measurements which had acceptable inter and intra-observer variabilities. CONCLUSIONS Evaluation of LV rotation and twist are feasible with 2D-STI. Older age rather than gender seems to augment global LV rotation and twist. This may be the compensatory mechanism as a result of aging-related decline in subendocardial function. These data can serve as the references for further evaluation of pathological myocardial motions in various cardiovascular diseases.

Three-dimensional speckle strain echocardiography is more accurate and efficient than 2D strain in the evaluation of left ventricular function

BACKGROUND Two-dimensional speckle tracking echocardiography (2DSTE) has been used widely in research, but rarely in clinical practice because data acquisition and analysis are time-consuming. By reducing the acquisition and analysis time, 3-dimensional STE may improve clinical impact. We investigated the feasibility of 3DSTE myocardial deformation, with comparison to 2DSTE. METHODS Transthoracic 3DSTE and 2DSTE were performed in 230 adults (138 men, 51 ± 14 years, and 142 hypertension, 10 heart failure and 78 normotensive subjects). The variables of LV deformation were analyzed using EchoPAC software. RESULTS The 3D LV longitudinal (LS) analysis was feasible in 84.9% of the study subjects, which was lower than the 2D analysis (97.2%). The success rates for circumferential strain (CS) and radial strain (RS) were similar between the 2D and 3D techniques. All magnitude of strains measured by 2DSTE and 3DSTE were significantly correlated. The magnitude of 3D LS and CS was lower, but the 3D RS is higher than that of 2DSTE (-18.5 ± 2.8 vs. -21.2 ± 3.5; 20.8 ± 4.1 vs. 21.7; and 50.0 ± 11.2 vs. 37.7 ± 12.6, respectively). Strains measured by 3DSTE exhibited stronger correlation with LV ejection fraction (EF) than that by 2DSTE. In inter- and intra-observer reproducibility for 3D LS, CS, RS and AS were acceptable. The mean time of analysis for LV volume, EF and strains was 116s by 3DSTE, which was significantly shorter than that by 2DSTE (5 min, P<0.0001). CONCLUSIONS Three-dimensional STE is feasible and reproducible in the estimation of LV function, requires substantially less time than 2DSTE and is a more feasible technique for LV function assessment in clinical practice.

Optimisation of atrioventricular delay during exercise improves cardiac output in patients stabilised with cardiac resynchronisation therapy

Background Atrioventricular (AV) delay in cardiac resynchronisation therapy (CRT) recipients are typically optimised at rest. However, there are limited data on the impact of exercise-induced changes in heart rate on the optimal AV delay and left ventricular function. Methods and results The authors serially programmed AV delays in 41 CRT patients with intrinsic sinus rhythm at rest and during two stages of supine bicycle exercise with heart rates at 20 bpm (stage I) and 40 bpm (stage II) above baseline. The optimal AV delay during exercise was determined by the iterative method to maximise cardiac output using Doppler echocardiography. Results were compared to physiological change in PR intervals in 56 normal controls during treadmill exercise. The optimal AV delay was progressively shortened (p<0.05) with escalating exercise level (baseline: 123±26 ms vs stage I: 102±24 ms vs stage II: 70±22 ms, p<0.05). AV delay optimisation led to a significantly higher cardiac output than without optimisation did during stage I (6.2±1.2 l/min vs 5.2±1.2 l/min, p<0.001) and stage II (6.8±1.6 l/min vs 5.9±1.3 l/min, p<0.001) exercise. A linear inverse relationship existed between optimal AV delays and heart rates in CRT patients (AV delay=241−1.61×heart rate, R2=0.639, p<0.001) and healthy controls (R2=0.646, p<0.001), but the slope of regression was significantly steeper in CRT patients (p<0.001). Conclusions Haemodynamically optimal AV delay shortened progressively with increasing heart rate during exercise, which suggests the need for programming of rate-adaptive AV delay in CRT recipients.

Prevalence of atrial septal pouch and risk of ischemic stroke

BACKGROUND It has been postulated that atrial septal pouch (ASP) may favor the stasis of blood and predispose to thromboembolic complications. We sought to evaluate the prevalence of ASP, and its association with ischemic stroke. METHODS We retrospectively studied 500 patients, who underwent transesophageal echocardiography (TEE) due to clinical indications. Seventy two patients due to image quality, and 104 patients with atrial septal defect or PFO were excluded. The remaining 324 patients were included in the analysis. The depth of ASP was measured. RESULTS ASP was detected in 98 patients [left side ASP (LASP) in 58 (59.2%), and right side ASP (RASP) in 40 (40.8%) patients]. LASPs were significant deeper than RASPs (10.1±5.2 vs 4.4±1.4mm, p<0.0001). Patient characteristics were categorized by the presence or absence of LASP. The age (61±12 vs 61±12), gender and stroke risk factors were no significant difference between patients with or without LAPS. Ischemic stroke occurred in 21 patients without LASP, 10 patients with LASP. The presence of a LASP was found to be associated with an increased risk of ischemic stroke, in either univariable analysis (17.2 vs. 7.9%, p=0.03; OR=2.43, 95% CI=1.1-5.5, p=0.033) or after adjustment for other stroke risk factors using multiple logistic regression analysis (OR=2.45, 95% CI 1.1-5.8, p=0.036). CONCLUSIONS This study demonstrated evidence of association between LASP and ischemic stroke. Among 324 patients, the risk of ischemic stroke was twice more among patients with LASP than cases without LASP.

Early diastolic dyssynchrony in relation to left ventricular remodeling and function in hypertension

BACKGROUND Cardiac synchronization is important in maintaining myocardial performance, but the mechanism of diastolic dyssynchrony leading to failing myocardium is unclear. We aim to study the relation of left ventricular (LV) diastolic dyssynchrony with diastolic dysfunction in patients with hypertension. METHODS Two-D, three-D and Doppler echocardiography were performed using the GE Vivid E9 system on 230 subjects. Among them, 154 patients with hypertension were divided into group 1 (86 patients with mild to moderate hypertension, BP 152 ± 8/91 ± 11 mm Hg) and group 2 (68 patients with severe hypertension, BP 188 ± 12/105 ± 24 mm Hg), age 76, gender matched normotensive subjects (119 ± 6/76 ± 9 mm Hg) as control. The routine 2D and Doppler parameters were measured and LV systolic and diastolic dyssynchrony indices were determined as the standard deviation of the time interval from the peak R of the QRS complex to peak myocardial systolic strain rate (Ts-SD), and to early diastolic strain rate (Te-SD) of 12 LV segments. RESULTS LV relative wall thickness, mass index, and Te-SD were significantly higher in patients with hypertension than in control group (p<0.0001), but Ts-SD showed no significant differences. Te-SD and diastolic dysfunction worsened progressively with increasing severity of hypertension (p<0.05). Te-SD was significantly and independently associated with parameters of LV remodeling and diastolic function. CONCLUSION Our study demonstrated that LV diastolic dyssynchrony was associated with LV remodeling, which seems to contribute to diastolic dysfunction in hypertension. This diastolic dyssynchrony index derived from speckle tracking echocardiography can be used as a marker for studying the LV function and effects of therapy in hypertensive heart disease.

Layer-specific quantification of myocardial deformation may disclose the subclinical systolic dysfunction and the mechanism of preserved ejection fraction in patients with hypertension.

Abstract Background Systemic hypertension (HTN) leads to left ventricular (LV) remodeling, which results in diastolic dysfunction in the presence of preserved ejection fraction (EF). The goal of this study was to explore subclinical LV systolic dysfunction and the mechanism of preserved EF using layer-specific quantification of myocardial deformation in HTN patients. Methods One hundred and twenty HTN patients (mean blood pressure (BP) 165±20/ 96±16mmHg) and 120 age and gender matched volunteers (mean BP 120±10/76±8mmHg) were studied. Left ventricular echocardiographic parameters including LV ejection fraction (LVEF), global and regional peak longitudinal, circumferential 2D systolic layer strain and LV twist were measured. The associations between these parameters were studied against LV relative wall thickness (RWT) and LV mass index. Results LVEF was normal in all HTN patients. The RWT and LV mass index were higher in HTN group (0.40±0.06 vs 0.35±0.03, p Conclusions This study revealed that hypertension resulted in increased RWT and LV mass. Impairment in layer and global longitudinal strain found in HTN patients may indicate early systolic dysfunction due to impaired endomyocardial function. Enhancement of circumferential strain and LV twist may be a compensatory mechanism to maintain LVEF in these patients.

Doppler flow signals in small amount pericardial effusion after radiofrequency ablation

A 59-year-old man underwent radiofrequency ablation for chronic atrial fibrillation. The angiogram was normal. The left and right atriums is significantly dilated, no thrombi was detected in the atriums and atrial appendage by transesophageal echocardiography. Post-ablation, sinus rhythm was return. He was started on amiodarone. Approximately two weeks after ablation, the patient noted chest pain. A transthoracic echocardiogram showed a small amount of circumferential pericardial effusion. Color Doppler-flow examination revealed flow within both free walls of left and right ventricle side portion of the pericardial effusion directed toward the apical in systole (Fig. 1A,B). No communication with the left atrium or right ventricle was seen. The intrapericardial flow pattern could also be demonstrated by pulsed-wave Doppler examination (Fig. 1C). The contrast (Sonovue 0.3 ml dilated with 5 ml normal saline) test was negative (Fig. 2). The flowwithin the pericardium can rarely be demonstrated in the absence of a communication with cardiac chambers. To our knowledge, there is only one published case, who underwent quadruplevessel coronary artery bypass grafting for symptomatic severe triplevessel coronary artery disease. Approximately two weeks after surgery, the patient noted exertional shortness of breath that progressed. A transthoracic echocardiogram showed a large circumInternational Journal of Cardiology 171 (2014) 447–470