完全型房室间隔缺损合并法洛四联症心内矫正术

目的总结心内矫正术治疗完全型房室间隔缺损合并法洛四联症(CAVSD-TOF)的经验. 方法从1985年1月至2002年5月,共行CAVSD-TOF心内矫正术12例,年龄6～16岁(11.1±2.8岁),采用右心房、右心室纵切口,前7例采用三片法补片,后5例用二片法补片修补房室间隔缺损,左侧房室瓣裂隙采用间断缝合,右心室流出道用跨瓣补片加宽. 结果术后早期死亡4例,前7例死亡3例,后5例死亡1例,死亡原因为严重低心排血量3例,灌注肺1例.长期随访6例,随访时间3个月至13.5年,无任何症状,NYHA心功能Ⅰ级或Ⅱ级. 结论 CAVSD-TOF采用右心房、右心室纵切口,二片法补片修补房室间隔缺损,常规间断缝合左侧房室瓣裂隙,跨瓣补片加宽右心室流出道能取得较良好的效果.     

A randomized trial comparing two different approaches of pacemaker selection.

AIMS: DDD-pacemakers are favoured in patients with sick-sinus-syndrome or AV-block. However, AAI-pacemakers for sick-sinus-syndrome or VDD-pacemakers for AV-block may provide similar benefit with lower costs. The aim is to show that a tailored approach (TA) with arrhythmia-specific pacemaker selection was equal to a standard approach (SA) regarding quality of life (QoL) at lower costs. METHODS AND RESULTS: The study was prospective and randomized with QoL as primary endpoint. Secondary endpoints were a combined endpoint of all-cause mortality, worsening heart failure or angina, atrial fibrillation (AF), stroke, these endpoints individually and costs. Of 198 patients (age 77 +/- 10 years, 43% female, ejection fraction 54 +/- 12%, follow-up 38 +/- 15 months), 94 were randomized to SA and 104 to TA. Thirty-two patients (34%) died in the SA group vs. 25 (24%) in the TA (P= ns). QoL showed no differences in all dimensions. The combined secondary endpoint was reached more frequently with SA (51%) compared to TA (37%, P = 0.045). There was no difference regarding all single secondary endpoints. Hardware costs were reduced by 15% (P < 0.0001). CONCLUSION: In long-term follow-up, a TA is equal to SA regarding the primary endpoint QoL and secondary endpoints as AF and mortality. Depending on the healthcare system, it may significantly reduce costs.     

房室传导阻滞的希氏束电图研究

研究了19例AVB的希氏束电图(HBE)。经皮穿刺股静脉将三极导管送至心脏希氏束部位,记录HBE。一度AVB5例,其中4例阻滞于房室结内,1例在希氏束内;二度AVB4例,3例阻滞于房室结,1例在希浦系;三度AVB10例,5例阻滞于房室结内,4例在希氏束,1例在希浦系。HBE能确定房室传导的阻滞部位,对指导安装起搏器和判断预后有一定意义。     

房室间隔缺损的形态学诊断——二维超声心动图与心血管造影,手术的比较

为了评估二维超声心动图（２ＤＥ）对房室间隔缺损（ＡＶＳＤ）的诊断和手术方法选择价值，对８７例ＡＶＳＤ的２ＤＥ，心血管造影及手术结果进行回顾对照研究，病例年龄自３月至１１月（平均３．９岁）。部分型ＡＶＳＤ４６例，过渡型１２例，完全型２９例（Ａ型２１例，Ｂ型４例，Ｃ型４例）２ＤＥ诊断与手术诊断符合率在部分型ＡＶＳＤ中为９７％，在过渡型及完全型ＡＶＳＤ中为８４％，２ＤＥ诊断与手术诊断不符合大多为过渡型与     

KOCH三角的解剖

本实验解剖了110例人心标本(成人70、儿童40)的Koch三角区,观察和测量了房室结的形态、大小、毗邻和标志。房间隔及冠状窦口上、下方均有肌束连于房室结。Todaro腱在儿童多全部为腱性;在成人,其后部为肌性。三角区的深面为左、右心房壁和室间隔顶所构成的锥形间隙,其内为进入房室结区的血管和神经。根据构成不同,可将三角区分为5个区,即前上角的纤维支架区和房室结区,其余部分自上向下分别为房间隔区、右房壁区和室间隔区。本文还讨论了这些形态结构的功能及外科意义。     

Changes in endocardial cell morphology during development of the endocardial cushions

Summary This paper presents a scanning electron microscope study of the morphologic changes undergone by the endocardium during development of the atrioventricular (A-V) endocardial cushions. Prior to cell seeding into the cushions, endocardial cells show a regular, uniform morphology, many of them appearing to be oriented in the direction of the blood flow. Concomitant with the appearance of cells in the A-V cushions, endocardial cells lose their elongated appearance, become more flattened and adopt a variable morphology. Endocardial cells at this stage develop filopodia and lamellipodia, overlap each other and show a variable number of microvilli and different degrees of flattening. After completion of endocardial migration, the endocardial cells that remain in the plane of the endocardium become extremely flattened, the degree of overlapping decreases and the cells adopt a polygonal morphology. These changes in endocardial cell morphology appear to be related to endocardial cell activity. It is suggested that the whole endocardial cushion, not just the cells that migrate into the cushions, is involved in cushion development. The activity of the endocardial cells may be related to the maintenance of the integrity of the endocardium.     

Characteristics of the delayed rectifier K current compared in myocytes isolated from the atrioventricular node and ventricle of the rabbit heart

The delayed rectifier potassium current (I _K) is known to be important in action potential repolarisation and may contribute to the diastolic pacemaker depolarisation in pacemaker cells from the heart. In this study, using whole-cell patch clamp, we investigated the characteristics of I _K in morphologically normal cells from the atrioventricular node (AVN) and ventricle of the rabbit heart. Cells were held at −40 mV and 5 μM external nifedipine was used to block L-type calcium current (I _Ca,L). Significant I _K was observed with pulses to potentials more positive than −30 mV. The steady-state activation curve in both cell types showed maximal activation at between + 10 and + 20 mV. Half-maximal activation of I _K occurred at −4.9 and −4.1 mV with slope factors of 8.3 and 12.4 mV in ventricular and AVN cells, respectively. Using pulses of increasing duration, significant I _K tails after repolarisation from + 40 mV were observed with pulses of 20 ms and increased with pulses up to 100–120 ms in both cell types. Pulses of longer duration did not activate further I _K and this suggested that only the rapid component of I _K, called I _Kr, was present in either cell type. Moreover, I _K tails after pulses to all potentials were blocked completely by E-4031, a selective blocker of I _Kr. The reversal potential of I _K varied with the concentration of external K. Superfusion of AVN cells with medium containing 4, 15 and 40 mM [K⁺]_o resulted in reversal potentials of −81, −56 and −32 mV, respectively, which are close to values predicted if the I _K channel were highly selective for K. The time constants for deactivation of I _K in ventricle and AVN on return to −40 mV after a 500-ms activating pulse to + 60 mV were 480 ms and 230 ms, respectively. The faster deactivation of I _K in AVN cells was a distinguishing feature and suggests that there may be differences in the I _Kr channel protein between ventricular and AVN cells. Received: 24 July 1995 /Received after revision: 20 October 1995 /Accepted: 23 October 1995     

Loss of lamin A/C expression revealed by immuno-electron microscopy in dilated cardiomyopathy with atrioventricular block caused by<Emphasis Type="Italic"> LMNA</Emphasis> gene defects

Mutations of the LMNA gene encoding the lamin A and C nuclear envelope proteins cause an autosomal dominant form of dilated cardiomyopathy (DCM) with atrioventricular block (AVB). The aim of this study was to investigate ultrastructural nuclear membrane changes by conventional electron microscopy and protein expression by immuno-electron microscopy in the heart of patients with DCM and AVB due to LMNA gene mutations. Four immunohistochemical techniques were used: pre-embedding and post-embedding in Epon-Araldite resin and London Resin White (LRW), with and without silver enhancement. Parallel light microscopy immunohistochemistry studies were performed. Conventional electron microscopy showed a loss of integrity of the myocyte nuclei with blebs of the nuclear membrane, herniations and delamination of the nuclear lamina and nuclear pore clustering. Post-embedding LRW was the most informative technique for morphology and immuno-labelling. Immuno-labelling was almost absent in the nuclear envelope of patients with LMNA gene mutations, but intensely present in controls. The loss of labelling selectively affected myocyte nuclei; the endothelial cell nuclei were immunostained in patients and controls. Light immunohistochemistry confirmed the results. These findings confirm the hypothesis that LMNA gene defects are associated with a loss of protein expression in the selective compartment of non-cycling myocyte nuclei.     

Pathological Aspects of Radiofrequency Catheter Ablation of the Canine Atrioventricular Node and Bundle of His

Radiofrequency catheter ablation of the atrioventricular (AV) node or bundle of His was performed in 12 adult mongrel dogs. The aim was to create chronic incomplete AV block (first- and second-degree AV block) and to examine the histopathology of the ablated lesions. However, the late electrophysiological results (2 4 weeks follow up) were various: normal in 2 dogs, mild PR prolongation (< 50%) in 2 dogs, first-degree AV block (PR prolongation a 50%) in 2 dogs, second degree AV block in 2 dogs, complete AV block in 4 dogs. The maximally ablated area (%) of the atrioventricular conduction system in serial histologic sections from dogs with these conditions was 69%, 75%, 89.5%, 95% and 99.5%, respectively. The number of intact conduction cells at the maximally ablated site varied from 6 to 30 in the four cases of incomplete AV block. The mean ablated volume (%) of either the AV node or penetrating His bundle correlated roughly with the degree of AV block. The ablated lesions were well demarcated and almost replaced by dense fibrous tissue at 4 weeks. Interruption (3 dogs) or thinning (1 dog) of the endocardial elastic lamellae was detected, in association with endocardial thickening (mean 913 μm). Endocardial thrombi were found in 3 dogs (2 fresh, 1 organized). We conclude that radiofrequency catheter ablation does not cause severe complicated lesions. Several possible conditions for creating chronic incomplete AV block are discussed. Acta Pathol Jpn 41: 487–498, 1991.     

永久起搏电极植入途径及起搏类型的探讨

目的评价起搏电极的植入途径及永久起搏器的类型.方法选择1987～1999年安置的80例永久起搏器患者.结果经颈外静脉植入电极6例,手术时间为256±75分;经头静脉植入电极48例,手术时间为247±65分(P＞0.05);经锁骨下静脉途径植入电极26例,手术时间为118±35分(P均＜0.01).其中,AAI型3例(4%),DDD型5例(6%),VVI型72例(90%).结论经锁骨下静脉植入起搏电极,方法简单,组织损伤小,手术时间短,优于其它途径.VVI型起搏器在我国仍然是主要使用的起搏器.