This study was designed to investigate if tissue synchronization imaging (TSI) is useful to identify regional wall delay and predict left ventricular (LV) reverse remodeling after cardiac ...resynchronization therapy (CRT).
Echocardiographic assessment of systolic asynchrony is helpful to predict a positive response to CRT. Tissue synchronization imaging is a new imaging technique that allows quick evaluation of regional systolic delay.
Tissue synchronization imaging was performed in 56 heart failure patients at baseline and three months after CRT. Regional wall delay was identified on TSI images and the time to regional peak systolic velocity (Ts) in LV was measured by the six-basal-six-mid-segmental model. Eight TSI parameters of systolic asynchrony were computed when Ts was measured in ejection phase or also included postsystolic shortening.
Severe lateral wall delay occurred in 17 patients, which predicted LV reverse remodeling (chi-square = 8.13, p = 0.004). Among the eight quantitative parameters of asynchrony, the predictive values were higher for parameters that measured Ts in ejection phase than in postsystolic shortening. The standard deviation of Ts of 12 LV segments in ejection phase (Ts-SD-12-ejection) was most powerful to predict reverse remodeling (r = −0.61, p < 0.001) and gain in ejection fraction (r = 0.53, p < 0.001). The area of the receiver-operating characteristic (ROC) curve was the largest for Ts-SD-12-ejection (0.90, p < 0.001), with a sensitivity of 87% and specificity of 81% at a cutoff of 34.4 ms. The combination of lateral wall delay with Ts-SD-12-ejection gave a sensitivity and specificity of 82% and 87%.
Tissue synchronization imaging allows quick evaluation of regional wall delay, and combined with Ts-SD-12-ejection provides a reliable way of predicting reverse remodeling after CRT.
In patients with severe heart failure and dilated cardiomyopathy, cardiac resynchronization therapy (CRT) improves left ventricular (LV) systolic function associated with LV reverse remodeling and ...favorable 1-year survival. However, it is unknown whether LV reverse remodeling translates into a better long-term prognosis and what extent of reverse remodeling is clinically relevant, which were investigated in this study.
Patients (n=141) with advanced heart failure (mean+/-SD age, 64+/-11 years; 73% men) who received CRT were followed up for a mean (+/-SD) of 695+/-491 days. The extent of reduction in LV end-systolic volume (LVESV) at 3 to 6 months relative to baseline was examined for its predictive value on long-term clinical outcome. The cutoff value for LV reverse remodeling in predicting mortality was derived from the receiver operating characteristic curve. Then the relation between potential predictors of mortality and heart failure hospitalizations were compared by Kaplan-Meier survival analysis, followed by Cox regression analysis. There were 22 (15.6%) deaths, mostly due to heart failure or sudden cardiac death. The receiver operating characteristic curve found that a reduction in LVESV of > or =9.5% had a sensitivity of 70% and specificity of 70% in predicting all-cause mortality and of 87% and 69%, respectively, for cardiovascular mortality. With this cutoff value, there were 87 (61.7%) responders to reverse remodeling. In Kaplan-Meier survival analysis, responders had significantly lower all-cause morality (6.9% versus 30.6%, log-rank chi2=13.26, P=0.0003), cardiovascular mortality (2.3% versus 24.1%, log-rank chi2=17.1, P<0.0001), and heart failure events (11.5% versus 33.3%, log-rank chi2=8.71, P=0.0032) than nonresponders. In the Cox regression analysis model, the change in LVESV was the single most important predictor of all-cause (beta=1.048, 95% confidence interval=1.019 to 1.078, P=0.001) and cardiovascular (beta=1.072, 95% confidence interval=1.033 to 1.112, P<0.001) mortality. Clinical parameters were unable to predict any outcome event.
A reduction in LVESV of 10% signifies clinically relevant reverse remodeling, which is a strong predictor of lower long-term mortality and heart failure events. This study suggests that assessing volumetric changes after an intervention in patients with heart failure provides information predictive of natural history outcomes.
Currently, a clear definition of response to cardiac resynchronization therapy (CRT) is still lacking, and clinical and echocardiographic end points are used. It is also unclear whether patients with ...clinical responses also improve in echocardiographic end points (and vice versa). To better understand and define response to CRT, the relation between improvement in clinical and echocardiographic parameters was evaluated in 144 patients.
Fracton topological order (FTO) is a new classification of correlated phases in three spatial dimensions with topological ground-state degeneracy (GSD) scaling up with system size and fractional ...excitations which are immobile or have restricted mobility. With the topological origin of GSD, FTO is immune to local perturbations, whereas a strong enough global external perturbation is expected to break the order. The critical point of the topological transition is either characterized by the broken GSD or the appearance of topologically distinct states with lower energy. In this work, we propose to characterize quantum phase transition of the type-I FTOs induced by external terms, when the transition can be characterized by the breaking down of GSD, and develop a theory to study analytically the critical points. In particular, for the external perturbation term creating lineon-type excitations, we predict a generic formula for the point of the quantum phase transition, characterized by the breaking down of GSD. This theory applies to a board class of FTOs, including X-cube model, and for more generic FTO models under perturbations creating two-dimensional (2D) or 3D excitations, we predict the upper and lower limits of the critical point. Our work makes a step in characterizing analytically the quantum phase transition of generic fracton orders.
Hypertension is common in patients with obstructive sleep apnea (OSA). However, the effect of OSA on ventricular function, especially diastolic function, is not clear. Therefore, we have assessed the ...prevalence of diastolic dysfunction in patients with OSA and the relationship between diastolic parameters and severity of OSA.
Sixty-eight consecutive patients with OSA confirmed by polysomnography underwent echocardiography. Diastolic function of the left ventricle was determined by transmitral valve pulse-wave Doppler echocardiography. Various baseline characteristics, severity of OSA, and echocardiographic parameters were compared between patients with and without diastolic dysfunction.
There were 61 male and 7 female patients with a mean age of 48.1 ± 11.1 years, body mass index of 28.5 ± 4.3 kg/m2, and apnea/hypopnea index (AHI) of 44.3 ± 23.2/h (mean ± SD). An abnormal relaxation pattern (ARP) in diastole was noted in 25 patients (36.8%). Older age (52.7 ± 8.9 years vs 45.1 ± 11.3 years, p = 0.005), hypertension (56% vs 20%, p = 0.002), and a lower minimum pulse oximetric saturation (Spo2) during sleep (70.5 ± 17.9% vs 78.8 ± 12.9%, respectively; p = 0.049) were more common in patients with ARP. By multivariate analysis, minimum Spo2 < 70% was an independent predictor of ARP (odds ratio, 4.34; 95% confidence interval, 1.23 to 15.25; p = 0.02) irrespective of age and hypertension. Patients with AHI ≥40/h had significantly longer isovolumic relaxation times than those with AHI < 40/h (106 ± 19 ms vs 93 ± 17 ms, respectively; p = 0.005).
Diastolic dysfunction with ARP was common in patients with OSA. More severe sleep apnea was associated with a higher degree of left ventricular diastolic dysfunction in this study.
ABSTRACT Recent observations of protoplanetary disk have reported spiral structures that are potential signatures of embedded planets, and modeling efforts have shown that a single planet can excite ...multiple spiral arms, in contrast to conventional disk-planet interaction theory. Using two and three-dimensional hydrodynamics simulations to perform a systematic parameter survey, we confirm the existence of multiple spiral arms in disks with a single planet, and discover a scaling relation between the azimuthal separation of the primary and secondary arm, and the planet-to-star mass ratio q: for companions between Neptune mass and 16 Jupiter masses around a 1 solar mass star, and for brown dwarf mass companions. This relation is independent of the disk's temperature, and can be used to infer a planet's mass to within an accuracy of about 30% given only the morphology of a face-on disk. Combining hydrodynamics and Monte-Carlo radiative transfer calculations, we verify that our numerical measurements of are accurate representations of what would be measured in near-infrared scattered light images, such as those expected to be taken by Gemini/GPI, Very Large Telescope/SPHERE, or Subaru/SCExAO in the future. Finally, we are able to infer, using our scaling relation, that the planet responsible for the spiral structure in SAO 206462 has a mass of about 6 Jupiter masses.
Objectives We sought to determine whether early assessment of left ventricular (LV) dyssynchrony by tissue Doppler imaging may predict progressive ventricular enlargement and cardiac dysfunction ...after acute myocardial infarction (MI). Methods Forty-seven patients (mean age 59.9 ± 11.6 years) with normal QRS duration underwent tissue Doppler imaging and contrast-enhanced cardiac magnetic resonance imaging (Ce-MRI) at days 2 to 6, 3 months, and at 1 year after the index MI. Systolic dyssynchrony index (Ts-SD) was calculated from 12 LV segments, and infarct size (IS) by Ce-MRI. Results The remodeling group (n = 16) (defined as an increase in end-systolic volume ≥10% between 1 year and baseline) had greater initial IS (27.2 ± 9.6 vs 13.7 ± 4.1%, P < .001) and Ts-SD (50.9 ± 12.8 vs 33.6 ± 7.7 milliseconds, P < .001) than nonremodeling group (n = 31). At 1 year, the remodeling group had progressive increase in Ts-SD and decrease in LV ejection fraction (57.3 ± 18.5 and 36.0 ± 7.6%, respectively; both P < .05 vs baseline). Both Ts-SD (odds ratio 1.19 1.07-1.32, P = .001) and IS (odds ratio 1.65 1.19-2.29, P = .003) were shown to be independent predictors of progressive LV remodeling. A cutoff value of Ts-SD ≥45 milliseconds predicted LV remodeling at 1 year (sensitivity 90.5%, specificity 90.9%, Area-under-curve 0.907) ( P = .0005). Conclusions Left ventricular systolic dyssynchrony is a newly identified predictor of chronic LV remodeling after acute MI, which is independent and incremental to conventional assessment and IS as measured by Ce-MRI.
Improvement of Atrial Function and Atrial Reverse Remodeling After Cardiac Resynchronization Therapy for Heart Failure Cheuk-Man Yu, Fang Fang, Qing Zhang, Gabriel W. K. Yip, Chun Mei Li, Joseph ...Yat-Sun Chan, LiWen Wu, Jeffrey Wing-Hong Fung Echocardiographic technologies, including tissue Doppler and strain imaging, were used to assess biatrial function in 107 patients with heart failure who received cardiac resynchronization therapy and were followed up for 3 months. The left atrial (LA) pump function was significantly improved after cardiac resynchronization therapy, leading to LA reverse remodeling as reflected by the reduction in LA area/volume before and after atrial systole. Atrial strain was also increased, suggesting improvement of atrial compliance. However, these favorable changes in atrial function were mainly observed in the responders of left ventricular reverse remodeling.
Background: Intensive statin therapy has been shown to improve prognosis in patients with coronary heart disease (CHD). It is unknown whether such benefit is mediated through the reduction of ...atherosclerotic plaque burden. Aim: To examine the efficacy of high-dose atorvastatin in the reduction of carotid intimal–medial thickness (IMT) and inflammatory markers in patients with CHD. Design: Randomised trial. Setting: Single centre. Patients: 112 patients with angiographic evidence of CHD. Interventions: A high dose (80 mg daily) or low dose (10 mg daily) of atorvastatin was given for 26 weeks. Main outcome measures: Carotid IMT, C-reactive protein (CRP) and proinflammatory cytokine levels were assessed before and after therapy. Results: The carotid IMT was reduced significantly in the high-dose group (left: mean (SD), 1.24 (0.48) vs 1.15 (0.35) mm, p = 0.02; right: 1.12 (0.41) vs 1.01 (0.26) mm, p = 0.01), but was unchanged in the low-dose group (left: 1.25 (0.55) vs 1.20 (0.51) mm, p = NS; right: 1.18 (0.54) vs 1.15 (0.41) mm, p = NS). The CRP levels were reduced only in the high-dose group (from 3.92 (6.59) to 1.35 (1.83) mg/l, p = 0.01), but not in the low-dose group (from 2.25 (1.84) to 3.36 (6.15) mg/l, p = NS). A modest correlation was observed between the changes in carotid IMT and CRP (r = 0.21, p = 0.03). Conclusions: In patients with CHD, intensive atorvastatin therapy results in regression of carotid atherosclerotic disease, which is associated with reduction in CRP levels. On the other hand, a low-dose regimen only prevents progression of the disease.
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