Reference values of right atrial longitudinal strain imaging by two-dimensional speckle tracking

Background: The role of speckle tracking in the assessment of right atrial (RA) deformation dynamics has not been established yet. The reference ranges of RA longitudinal strain indices were measured by speckle tracking in a population of normal subjects. Methods: In 84 healthy individuals, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and time to peak longitudinal strain (TPLS) were measured using a six‐segment model for the RA. Strain rate (SR) was also measured starting from the QRS‐wave onset, peak positive (x‐wave), first peak negative (y‐wave), and second negative peak (z‐wave). The time from the QRS onset was measured to each wave peak. Results: Adequate tracking quality was achieved in 64% of segments analyzed. Inter‐ and intraobserver variability coefficients of measurements ranged between 6% and 11%. Global PALS was 49 ± 13%, global TPLS was 363 ± 59 msec, x‐wave was 2.12 ± 0.58 sec^?1, y‐wave was ?1.91 ± 0.63 sec^?1, and z‐wave was ?2.18 ± 0.78 sec^?1. Conclusion: Speckle tracking is a feasible technique for the assessment of longitudinal myocardial RA deformation. Reference ranges of strain indices were reported. (Echocardiography 2012;29:147‐152)     

Semantic organisation and handedness: Mixed-handedness is associated with more diffuse activation of ambiguous word associates

Research indicates that there are individual differences in the flexibility and ease with which one retrieves and uses concepts stored in memory. Based on prior research suggesting that mixed-handedness is associated with greater cognitive flexibility, it was hypothesised that mixed-handers have access to a relatively diffuse associative network, where link strengths for closely related and distantly related concepts are not as disparate as in the case of strong-handers. This idea was explored using ambiguous words for stimuli, as ambiguous words are known to have both strong (concepts related via dominant meaning) and weak associates (concepts related via subordinate meaning). Consistent with the prediction, mixed-handers showed equal ease in accessing both strongly and weakly related concepts. In Experiment 1 mixed-handers exhibited equivalent priming for dominant and subordinate associates, while strong-handers exhibited priming for dominant associates only. In Experiment 2 ratings of strength of association for dominant versus subordinate associates were examined. Mixed-handedness was associated with lesser disparity of dominant and subordinate association ratings.     

The lighter side of advertising: Investigating posing and lighting biases

People tend to display the left cheek when posing for a portrait; however, this effect does not appear to generalise to advertising. The amount of body visible in the image and the sex of the poser might also contribute to the posing bias. Portraits also exhibit lateral lighting biases, with most images being lit from the left. This effect might also be present in advertisements. A total of 2801 full-page advertisements were sampled and coded for posing direction, lighting direction, sex of model, and amount of body showing. Images of females showed an overall leftward posing bias, but the biases in males depended on the amount of body visible. Males demonstrated rightward posing biases for head-only images. Overall, images tended to be lit from the top left corner. The two factors of posing and lighting biases appear to influence one another. Leftward-lit images had more leftward poses than rightward, while the opposite occurred for rightward-lit images. Collectively, these results demonstrate that the posing biases in advertisements are dependent on the amount of body showing in the image, and that biases in lighting direction interact with these posing biases.     

左右侧大脑中动脉急性脑梗死后白细胞变化及预后的比较

目的 探讨不同侧大脑中动脉(MCA)急性脑梗死对免疫系统的不同影响. 方法 选择中山医科大学附属第三医院自2006年1月至2013年2月收治的99例急性MCA大面积梗死患者,按梗死部位分为左侧脑梗死组(n=51)和右侧脑梗死组(n=48),分别对2组患者起病后第1天、第3天、第7天的外周血白细胞计数及各分类白细胞比例、1周内肺部感染情况、1周内体温、1个月或出院时患者美国国立卫生研究院卒中量表(NIHSS)评分和改良Rankin评分等进行比较. 结果 2组患者肺炎感染率、1周内体温情况、1月内NIHSS评分及改良Rankin评分差异均无统计学意义(P＞0.05).未按肺炎分层时2组患者白细胞数量差异无统计学意义(P＞0.05);按肺炎分层后,2组无肺炎患者中性粒细胞及淋巴细胞1周内变化趋势呈现出明显不同. 结论 未感染肺炎的左侧和右侧MCA脑梗死患者急性期白细胞变化趋势不完全相同,提示不同侧MCA脑梗死引起免疫抑制的机制可能不同.     

Transcranial random noise stimulation (tRNS) over prefrontal cortex does not influence the evaluation of facial emotions

ABSTRACT

Cerebral asymmetries for emotion processing are controversial, the right hemisphere being considered either superior in the recognition of all emotions, or superior in the recognition of negative emotions (together with the left-hemispheric superiority for positive emotions). In a number of previous studies, tDCS was applied on the left/right prefrontal cortex (PFC) in order to disentangle this issue, but the results remain controversial. We applied hf-tRNS/sham stimulation over the left/right PFC, during the presentation of neutral, angry and happy faces presented as broadband images (supraliminal condition), and as “hybrid” stimuli in which an emotional face in low spatial frequency is superimposed to the neutral expression of the same individual in high spatial frequency (subliminal condition), during a friendliness evaluation task. The results showed that angry and happy unfiltered stimuli were judged as the most unfriendly and friendly, respectively. Importantly, we found that hf-tRNS applied over the left/right PFC did not influence friendliness evaluations for emotional faces.     

Right ventricular involvement in anterior myocardial infarction: a tissue Doppler-derived strain and strain rate study

OBJECTIVE:

Strain and strain rate imaging is currently the most popular echocardiographic technique that reveals subclinical myocardial damage. There are currently no available data on this imaging method with regard to assessing right ventricular involvement in anterior myocardial infarction. Therefore, we aimed to evaluate right ventricular regional functions using a derived strain and strain rate imaging tissue Doppler method in patients who were successfully treated for their first anterior myocardial infarction.

METHODS:

The patient group was composed of 44 patients who had experienced their first anterior myocardial infarction and had undergone successful percutaneous coronary intervention. Twenty patients were selected for the control group. The right ventricular myocardial samplings were performed in three regions: the basal, mid, and apical segments of the lateral wall. The individual myocardial velocity, strain, and strain rate values of each basal, mid, and apical segment were obtained.

RESULTS:

The right ventricular myocardial velocities of the patient group were significantly decreased with respect to all three velocities in the control group. The strain and strain rate values of the right mid and apical ventricular segments in the patient group were significantly lower than those of the control group (excluding the right ventricular basal strain and strain rate). In addition, changes in the right ventricular mean strain and strain rate values were significant.

CONCLUSION:

Right ventricular involvement following anterior myocardial infarction can be assessed using tissue Doppler based strain and strain rate     

阵发性心房颤动患者心房及肺静脉不应期离散度的变化

目的探讨阵发性房颤患者房颤相关组织的电生理特性改变情况。方法选取阵发性房颤患者10例(房颤组)和无房颤病史的左侧旁路有显性预激波患者15例(对照组)。将大头电极分别放置在两组患者左上肺静脉、左下肺静脉、右上肺静脉、右下肺静脉开口及左心房顶壁、前壁、后壁、高位右心房,分别测定各部位有效不应期(EPR)。结果①房颤组心房及肺静脉EPR离散度指数(DI)为0.117±0.028,对照组为0.074±0.029,两组比较,P<0.05。②房颤组左心房ERP为(234.00±28.72)ms,肺静脉ERP为(230.75±32.69)ms;对照组左心房ERP为(248.00±25.99)ms,肺静脉ERP为(244.33±26.78)ms,两组比较,P均<0.05。结论阵发性房颤患者DI明显增大,左心房、肺静脉ERP显著缩短。     

心房颤动肺静脉前庭和左房内连续碎裂电位的电生理特点

目的探讨阵发性和持续性心房颤动(简称房颤)患者肺静脉前庭(PVO)和左房(LA)内连续碎裂电位(CFEAs)的电生理特点。方法入选24例药物治疗无效的房颤患者,依房颤节律分为阵发性房颤(PAF)组与持续性房颤(PeAF)组,每组各12例,根据距离肺静脉口远近,将肺静脉分成距肺静脉5～10 mm(Ⅰ区)与10～20 mm(Ⅱ区)两区。在房颤时,应用EnSite NavX标测系统高密度标测PVO和LA,比较两组平均CFE值(碎裂间期)≤70ms的CFAEs的电生理特点。结果①PeAF组LA内径大于PAF组(P<0.05),PAF组LA后壁CFAES分布比例最低,顶部最高,PeAF组前后壁最低,左心耳最高;PAF组PVO较LA高(P<0.05),PeAF组PVO和LA无差异。②两组间总PVO区域连续CFAEs比例无差异,PeAF组LA明显高于PAF组(P<0.05),PAF左下PVO连续CFAEs分布比例高于PeAF(P=0.02),另三支PVO无明显差别。除顶部PAF组连续CFAEs分布高于PeAF组(P=0.02)外,PeAF组下壁、左心耳及二尖瓣环均显著高于PAF组(P均<0.001)。③PAF组各支Ⅰ区连续CFAEs分布高于Ⅱ区(P<0.05),PeAF组左下PVOⅠ区高于Ⅱ区(P<0.05),右上PVOⅡ区高于Ⅰ区(P<0.05),另两支PVO无差异。④PAF组PVO平均CFE明显低于LA(P<0.0001),PeAF组两区域及两组间PVO则无差异;PeAF组LA平均CFE值较低,连续CFAEs数量较多,房颤周长较短。结论 LA电解剖重构在房颤维持中起重要作用,PeAF LA内连续CFAEs分布较PAF广泛,碎裂程度更高,房颤周长较短。PVO绝大多数连续CFAEs位于5～10 mm区域。     

Left atrial deformation imaging with ultrasound based two-dimensional speckle-tracking predicts the rate of recurrence of paroxysmal and persistent atrial fibrillation after successful ablation procedures

Predict AF. Objective: Since predictors of recurrence of atrial fibrillation (AF) after ablation procedures are poorly defined, this prospective study was conducted to assess the value of left atrial (LA) deformation imaging with two‐dimensional speckle‐tracking (2D‐ST) to predict AF recurrences after successful ablation procedures. Methods and results: One hundred and three consecutive patients (age 58.1 ± 16.6 years, 72.8% male) with AF (76 paroxysmal, 27 persistent) and 30 matched controls underwent transthoracic echocardiography and 2D‐ST‐LA‐deformation analysis with assessment of LA‐radial and LA‐longitudinal strain (Sr, Sl), and velocities derived from the apical 4‐ and 2‐chamber views (4CV, 2CV). AF recurrence was assessed during 6 months of follow‐up. For determination of AF‐related LA changes, AF patients were compared to controls and patients with AF recurrences after ablation procedures (n = 30, 29.1%) were compared with patients who maintained sinus rhythm (n = 73, 70.9%). Atrial deformation capabilities were significantly reduced (P < 0.0005) in patients with AF (4CVSl 17.8 ± 13.5%; 4CVSr 22.3 ± 14.9%; 4CV‐velocities 2.53 ± 0.97 seconds) when compared with controls (4CVSl 31.3 ± 12.4%; 4CVSr 30.3 ± 9.1%; 4CV‐velocities 3.48 ± 1.01 cm/s). Independent predictors for AF recurrence after ablation procedures were 2CV‐LA‐global‐strain (Sr, P = 0.03; Sl, P = 0.003), 4CV‐LA‐gobal‐strain (Sr, P = 0.03; Sl, P = 0.02), and regional LA‐septal wall‐Sl (P = 0.008). LA‐global‐strain parameters were superior to regional LA function analysis for the prediction of AF recurrences, with cutoff values (cov), hazard ratios (HR), positive and negative predictive values (PPV, NPV) were: 4CVSl cov, 10.79% (HR 27.8, P < 0.0005; PPV 78.8%, NPV 93.9%), 4CVSr cov, ?16.65% (HR 24.8, P < 0.0005; PPV 69.4%, NPV 96.6%), 2CVSl cov, 12.31% (HR 22.7, P < 0.0005; PPV 75.8%, NPV 95.3%), and 2CVSr cov, ?14.9% (HR 12.9, P < 0.0005; PPV 64.3%, NPV 93.2%). Conclusion: Compared with controls, AF itself seems to decrease LA deformation capabilities. The assessment of global LA strain with 2D‐ST identifies patients with high risk for AF recurrence after ablation procedures. This imaging technique may help to improve therapeutic guiding for patients with AF. (J Cardiovasc Electrophysiol, Vol. 23 p. 247‐255, March 2012.)