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.     

Septal Flash-like Motion of the Earlier Activated Ventricular Wall Represents the Pathophysiology of Mechanical Dyssynchrony in Single-Ventricle Anatomy

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Atrio-ventricular block during left atrial flutter ablation

We present a case of a patient treated with catheter ablation for atrial fibrillation aiming to pulmonary veins isolation. During ablation, atrial fibrillation organized into a left atrial flutter. Electroanatomic and electrophysiologic mapping revealed the anterior left atrium area between the mitral annulus and left atrium septum as a critical region for flutter ablation. After a few pulses of radiofrequency, complete atrio-ventricular block appeared. Finally, we propose pace mapping of the mitral annulus to detect left dislodgment of the compact atrio-ventricular node.     

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.     

带状疱疹治疗中神经阻滞联合紫外线照射的应用

目的 研究神经阻滞联合紫外线照射治疗带状疱疹的方法及护理.方法 将我院2008年6月至2009年6月收治的145例带状疱疹患者随机分为两组,Ⅰ组65例患者行神经阻滞联合紫外线照射治疗;Ⅱ组80例患者在行神经阻滞联合紫外线照射治疗的基础上给予综合加强护理,观察两组患者止疱时间、结痂时间、疼痛消失时间以及患者满意度情况.结果 止疱时间、结痂时间、疼痛消失时间Ⅱ组和Ⅰ组相比明显缩短,Ⅱ组的患者满意度明显优于Ⅰ组的患者满意度,两组之间比较具有显著性差异(P＜0.05).结论 在神经阻滞联合紫外线照射治疗带状疱疹基础上辅以综合加强护理可缩短患者症状缓解时间,增加患者满意度.     

超声引导下星状神经节阻滞促进胃肠功能恢复的探讨

目的:采用星状神经节阻滞改善胃肠神经及内分泌功能,以此促进胃肠功能恢复,观察比较子宫切除术(全切或次全切)后2种促肛门排气方法的疗效。方法:试验组与对照组均为硬膜外麻醉,试验组术后6h即行星状神经节阻滞,双侧交替进行,每日1次;对照组采用术后6h进行足三里注射,每日2次。结果:观察组患者术后排气时间为(24.5±8.5)h,对照组术后排气时间为(33.2±9.0)h,两组差异有显著性(P<0.01)。结论:子宫切除术后进行星状神经节阻滞对促进胃肠功能恢复有较好疗效。     

Cushing's mechanism maintains cerebral perfusion pressure in experimental subarachnoid haemorrhage

Mortality following subarachnoid haemorrhage (SAH) is high, especially within the first 48 h. Poor outcome is predicted by high intracranial pressure which causes diminished cerebral perfusion pressure unless a compensatory increase in mean arterial blood pressure occurs. Therefore blood pressure elevation can be protective following subarachnoid haemorrhage despite the potential for rebleeding. This study investigated blood pressure responses to SAH and the impact on cerebral perfusion pressure and outcome, as demonstrated by two experimental models. Various blood pressure responses were demonstrated, both at the ictus and within the following 5 h. Elevated MABP at the ictus and at 2 h following experimental SAH was associated with maintenance of CPP in the presence of raised ICP. Poor outcome (arrest of the cerebral circulation) was predicted by failure of MABP to increase significantly above sham levels within 2 h of SAH. Rat SAH provides relatively inexpensive models to investigate physiological mechanisms that maintain cerebral perfusion in the presence of intracranial hypertension.     

Random Poly(methyl methacrylate‐co‐styrene) Brushes by ATRP to Create Neutral Surfaces for Block Copolymer Self‐Assembly

Random copolymer brushes of styrene and methyl methacrylate (MMA) on silicon wafers by atom transfer radical polymerization (ATRP) are synthesized using CuCl/CuCl₂/HMTETA. It is found that with increasing amount of styrene the thickness of the brush layer could no longer be well controlled by the amount of free (sacrificial) initiator in the reaction. At constant concentration of free initiator a constant thickness is obtained for various ratios of MMA to styrene. Within 30–70% MMA in the monomer feed the composition of the free polymer corresponds well to the monomer feed ratio, displaying a water contact angle in agreement with the theoretical value for a random copolymer. These copolymers are shown to create a neutral surface directing spin‐coated poly(styrene‐b‐MMA) into a perpendicular lamellae orientation.     

Self‐Assembly of Amphiphilic Block Copolymers in Ternary Solvent Mixtures: Lyotropic Liquid Crystalline Phase Behavior and Structure

The effects of the simultaneous addition of two organic solvents (glycerol and ethanol) on the lyotropic liquid crystalline (LLC) phase behavior and structure formed by PEO–PPO–PEO amphiphilic block copolymers in water are examined. Glycerol and ethanol have been selected because of their opposite effect: structure promoting and structure dissolving, respectively. Lattice parameters of Pluronic P105 (EO₃₇PO₅₈EO₃₇) and F127 (EO₁₀₀PO₇₀EO₁₀₀) LLC samples in the presence of any type and amount of E+G solvents decrease with increasing volume fraction of the PPO‐rich domains. Lattice parameters for the two block copolymers fall on the same line when normalized with the square root of polymer molecular weight, suggesting weak block segregation.