左束支传导阻滞的核素心肌显像

目的探讨左束支传导阻滞的核素心肌显像并对照冠状动脉造影诊断冠心病的临床意义。方法15例左束支传导阻滞患者与10例正常人对照,先行多巴酚丁胺负荷试验再静脉注射201TI和99mTc-MIBI双核素心肌显像并与9例冠状动脉造影者进行比较,分析诊断冠心病的可靠性。在核素心肌显像中,分别对图像的中间短轴断层面进行定量分析,画感兴趣区(ROI)测定间壁/侧壁比值(S/LR)。结果①15例左束支传导阻滞201TI和99mTc-MIBI的S/LR分别为0.65±0.09和0.46±0.10,明显低于对照组(0.89±0.08和0.88±0.09)(P<0.01)。②5例多谱勒超声心动描记术显示前间壁、前壁收缩运动减弱。③9例冠状动脉造影者2例正常,7例显示冠状动脉狭窄>50%。结论①15例左束支传导阻滞显示间壁201TI和99mTc-MIBI摄取的显著不匹配(99mTc-MIBI>201TI)。②冠状动脉造影提示有冠状动脉狭窄的表现。因此,左束支传导阻滞行核素心肌显像是明确有无冠心病的有效检测方法之一。     

Systematic Performance Evaluation of a Cross-Correlation-Based Ultrasound Strain Imaging Method

Estimation of tissue motion in the lateral direction remains a major challenge in 2-D ultrasound strain imaging (USI). Although various methodologies have been proposed to improve the accuracy of estimation of in-plane displacements and strains, the fundamental limitations of 2-D USI and how to choose optimal algorithmic parameters in various tissue deformation paradigms to retrieve the full strain tensor of acceptable accuracy are scattered throughout the literature. Thus, this study attempts to provide a systematic investigation of a 2-D cross-correlation-based USI method in a theoretical framework. Our previously developed cross-correlation-based USI method was revisited, and additional estimation strategies were incorporated to improve in-plane displacement and strain estimation. The performance of the presented method using different matching kernel sizes (axial: from 1λ to 14λ, where λ = wavelength; lateral: from 1 to 13 pitches) and two data formats (radiofrequency and envelope) in various kinematic scenarios (normal, shear or hybrid deformation) was investigated using Field II simulations, in which coherent plane wave compounding with 64 steered angles was realized. For radiofrequency-based USI, smaller axial and larger lateral kernel sizes were preferred in scenarios with normal strains, whereas larger kernel sizes along the shearing direction and smaller ones orthogonal to the shearing direction were more suitable in scenarios with shear strains. For envelope-based USI, in contrast, the kernel size requirement was relatively relaxed. A compromise between optimal kernel sizes and estimation accuracy of various strain components was required in complex kinematic scenarios. These practical strategies for accurate motion estimation using 2-D cross-correlation-based USI were further tested in a tissue-mimicking phantom under quasi-static compression and in a preliminary in vivo examination of a normal human median nerve at the wrist during active finger motion.     

超声引导和神经电生理监测下小儿臂丛神经阻滞的临床观察

目的比较采用超声引导和神经电生理监测下进行小儿臂丛神经阻滞的临床效果。方法 60例美国麻醉师协会(ASA)Ⅰ级的闭合尺、桡骨骨折患儿,随机等分为传统解剖定位组(C组)和超声引导组(US组),均行神经电生理监测肌肉复合动作电位(CMAP)监测,局部麻醉采用0.2%左布比卡因0.4mL/kg肌间沟臂丛神经阻滞。观察两组麻醉操作完成时间、桡神经阻滞起效时间、麻醉术中氯胺酮的用量、术后麻醉恢复室停留时间,及并发症发生情况。结果 US组麻醉操作完成时间[(4.42±0.47)min]高于C组[(2.78±0.53)min],差异有统计学意义(P0.05)。US组桡神经阻滞起效时间[(7.63±1.56)min]低于C组[(9.89±1.67)min],差异有统计学意义(P0.05)。US组氯胺酮的用量[(31.3±10.6)mg]低于C组[(60.6±11.7)mg],差异有统计学意义(P0.01)。US组术后麻醉恢复室停留时间[(18.7±6.9)min]低于C组[(30.6±10.7)min],差异有统计学意义(P0.05)。结论超声引导小儿臂丛神经阻滞能明显减少全身麻醉药量,临床效果更好;CMAP是神经阻滞的客观和量化的观察指标,有临床应用价值。     

循证护理干预对神经根阻滞治疗带状疱疹的影响

目的：探讨循证护理干预神经根阻滞方法对带状疱疹治疗的临床效果。方法选择2013年2月至2014年2月在我院门诊就诊并诊断为带状疱疹的患者90例,取得知情同意后将其随机分为观察组和对照组各45例,对照组采用神经根阻滞治疗法(即在节段脊椎旁肌肉组织内静注混合液得宝松+利多卡因+维生素B1+B12)+常规护理,观察组患者采用神经根阻滞治疗法+循证护理。比较两组患者的临床效果、有效率和不良反应率的差异性。结果观察组患者的结痂时间、脱痂时间、疼痛开始缓解时间和持续时间均显著短于对照组,差异有统计学意义( P<0．05);观察组的优质睡眠时间显著多于对照组,差异有统计学意义( P<0．05);观察组患者的总有效率显著高于对照组,差异有统计学意义( P<0．05);两组患者不良反应率的比较,差异无统计学意义( P>0．05)。结论循证护理干预神经根阻滞用于带状疱疹患者治疗,疗效显著、安全性高,可以在门诊治疗中推广应用。     

老年人行走时躯干冠状面运动学变化对稳定性的影响及其与跌倒的关联性

目的:更好的理解老年人在行走时躯干冠状面的稳定性,及其与跌倒风险的联系。方法:12例健康老年人和12例健康年轻人在步行机上分别以1.0km/h、2.0km/h、3.0km/h、4.0km/h、5.0km/h 5个步速行走以观测他们的躯干运动。在确定步宽、步幅时间、局部动态稳定性和躯干冠状面运动幅度的同时,测量身体重心(centre of mass,Co M)投影到足部放置位置的距离(d Co M)和躯干运动与足跟着地时间的时序差别(d Time)。另外,测量髋最大外展肌力,受试者自述过去一年中跌倒次数。结果:老年人的髋外展肌力(1.0±0.05)N/kg比年轻人小,躯干局部动态稳定性降低,步宽(0.18±0.08)m增大,步幅(1.20±0.25)s减小,此外,老年人的d Co M(0.11±0.05)m比年轻人大,而d Time(0.42±0.13)s比年轻人短。老年人的髋外展肌力、步宽、步幅时间、d Co M、d Time均和跌倒次数相关联。结论:老年人在行走时步宽更大,步幅时间更短,而且d Co M也比年轻人大,这可能是为了稳定冠状面的平衡而采取的一种策略。老年人髋外展肌肌力降低,使d Time缩短,损害了冠状面的平衡,从而导致跌倒的发生。     

Heart Block and Idiopathic Pulmonary Hemosiderosis

A young woman with idiopathic pulmonary hemosiderosis (IPH) and advanced heart block below the atrioventricular node requiring pacemaker therapy is discussed. Thirteen years after the onset of IPH she is free of pulmonary symptoms despite having never received steroid or antimetabolite therapy.     

Optimal side of implant for single-lead VDD pacing: right-sided versus left-sided implantation

BACKGROUND: Atrial undersensing occurs in a considerable number of patients with single-lead VDD pacing. This study tried to determine the role of implant side in maintenance of the VDD mode in patients with isolated atrioventricular (AV) block. METHODS: Eighty-two patients with isolated AV block (46 females; mean age, 58 +/- 17 years) received a single-lead VDD pacemaker (Medtronic Kappa, n = 70 and St. Jude Medical Affinity, n = 12). The patients were randomly assigned to one of two implantation groups (group I: right-sided VDD and group II: left-sided VDD). In each group, the P-wave amplitudes were determined at implantation, predischarge, 2-month, and 6-month follow-up. At each follow-up visit, stored event histograms of pacemaker were also retrieved. The atrial sensing measurements were compared between two groups. RESULTS: Implantation was easier from right side (1.7 +/- 1.0 vs 2.8 +/- 1.7 attempts, P = 0.001). Implant P-wave was higher in group I compared to group II (4.2 +/- 1.7 vs 2.7 +/- 1.0 mV, P < 0.0001). During follow-up, higher P-wave amplitudes were obtained in group I both at predischarge (2.6 +/- 1.3 vs 1.4 +/- 1.1 mV, P < 0.0001), 2-month (2.8 +/- 1.8 vs 1.3 +/- 1.0 mV, P < 0.0001), and 6-month (2.9 +/- 1.7 vs 1.3 +/- 0.9 mV, P < 0.0001) evaluations but remained stable throughout the 6 months in both groups. After implantation, VDD function was better maintained in group I than group II (100% vs 90%, P = 0.026). Incidence of atrial undersensing was lower in group I than group II (P = 0.026) in last follow-up visit. CONCLUSIONS: Implant side has a significant influence on atrial sensing performance in single-lead VDD pacing. Thus, right-side implantation should be the preferred approach for the implantation of VDD single-lead systems.