定量组织速度成像对右室起搏患者左室收缩运动的研究

目的　应用定量组织速度成像 (QTVI)评价右室心尖起搏 (RVAP)VVI型对左心收缩功能的影响。方法　应用GEVivid 7彩色多普勒超声显像仪对 2 0例RVAP患者和 2 0例正常人的心尖四腔切面的室间隔和左室外侧壁速度和位移曲线进行观察 ,测量心电图Q波分别至室间隔和左室外侧壁收缩期峰速度的时间 ,并除以R R间期进行校正。结果　QTVI显示右室起搏器置入者的室间隔与左室外侧壁速度曲线的收缩期S波非同步出现。Q波至室间隔收缩期峰速度的时间短于Q波至左室外侧壁收缩期峰速度的时间 ,两者分别为 ( 0 .12± 0 .0 2 )s和 ( 0 .14± 0 .0 2 )s,P <0 .0 5。结论　右室起搏后早期的左室整体收缩功能虽未见明显下降 ,但QTVI可以发现室间隔与左室壁收缩明显的不协调 ,可作为早期分析左室收缩运动的定量方法。     

经导管封闭治疗小儿继发孔房间隔缺损

目的探讨应用经导管封闭治疗小儿房间隔缺损的临床效果.方法 16例ASD患儿.男6例,女10例;年龄2～14(8±4)岁,体重10～40(23±9)Kg.先行右心导管用球囊导管测量ASD大小,选择适合的封堵器,在X线及超声引导下释放封堵器堵闭ASD,术后随访疗效,追踪残余分流率和并发症.结果应用此法封闭16例ASD,全部成功.手术时间为(70±30)血n,透视时间(13±8)min,术中无明显并发症.术后随访右房、右室径较术前明显缩小,恢复正常(P＜0.05);无残余分流发生.结论经导管封闭治疗小儿房间隔缺损术具有创伤小,成功率高,安全性好的优点,但其长期疗效需进一步随访观察.     

左主干起源于右冠状动脉窦（附2例报告并文献复习）

目的:分析左主干起源于右冠状动脉窦的临床特征,提高对左主干起源于右冠状动脉窦的认识和诊断.方法:回顾分析2例左主干起源于右冠状动脉窦的临床病例并对文献进行回顾分析.结果:左主干起源于右冠状动脉窦是一种罕见的先天性冠脉畸形,这种畸形可分为良性或恶性,主要根据异常左冠状动脉与主动脉和肺动脉之间的关系.对于可能引起猝死或严重心肌缺血患者,应进行冠状动脉旁路移植术.2例患者左主干起源于右冠状动脉窦,其中1例左主干走行于主动脉与肺动脉之间,1例走行于主动脉前方,这2例未进行预防性外科手术,目前预后良好.结论:左主干起源于右冠状动脉窦是罕见的冠脉畸形,应注意鉴别是良性或是恶性,确定下一步治疗方案.     

ELECTRICAL REMODELLING OF CHRONIC ATRIAL FIBRILLATION

1. It is now recognized that atrial fibrillation (AF) is not a benign condition, as it is associated with a 40% increase in mortality and a doubling of the risk of stroke. 2. The development of AF leads to mechanical, electrophysiological and cellular changes in the atria that tend to sustain AF. This process is known as atrial remodelling. 3. The three electrophysiological elements in the atria that initiate and sustain AF are: (i) shortening of the refractory period and an increase in dispersion; (ii) slowing of conduction velocity; and (iii) the presence of triggerin. foci. 4. As AF is a heterogeneous disorder, therapeutic strategies include the use of devices (pacemakers and atrial defibrillators), radiofrequency ablation (focal ablation or the creation of linear lines) and drug therapy that may reverse a remodelle. atrium.     

Incremental Value of Three-Dimensional Echocardiography Over Transesophageal Multiplane Two-Dimensional Echocardiography in Qualitative and Quantitative Assessment of Cardiac Masses and Defects

In the present study, we compared three-dimensionally (3-D) reconstructed images with multiplane two-dimensional (2-D) transesophageal echocardiographic (TEE) images in 17 patients with various cardiac masses and defects. To overcome the problem of making measurements from 3-D reconstructed images, we carefully "dissected" the 3-D dataset using paraplane and anyplane 2-D sections, which were then used to obtain the maximum sizes of the cardiac masses and defects. Of the 15 vegetations and 9 abscesses detected by 3-D TEE in 7 patients, only 8 (53%) vegetations and 4 (44%) abscesses were detected by multiplane 2-D TEE (P < 0.02). Also, the exact anatomical location, shape, geometry, and extent of various cardiac masses and defects were more clearly delineated by 3-D than 2-D TEE. The maximum dimensions of cardiac masses and defects were larger by 3-D than by 2-D TEE in 17 (89%) of the 19 lesions available for comparison (P < 0.002). In addition, 3-D TEE correlated more closely than 2-D TEE when compared to surgical measurements in three patients in whom they were available. Thus, it would appear that in several instances, the exact size of the cardiac lesion could only be assessed by analysis of the 3-D volumetric dataset. Out preliminary study has demonstrated the superiority of transesophageal 3-D reconstruction over multiplane 2-D TEE in both qualitative and quantitative assessment of various cardiac mass lesions and pathological defects.     

Vasodilator effects of C-type natriuretic peptide on cerebral arterioles in rats

The vasodilator effects of C-type natriuretic peptide (CNP) were investigated in isolated rat cerebral arterioles. CNP caused dose-dependent vasodilation, maximally by 10.0±2.2% at 10⁻⁶ M. The median effective concentration (EC₅₀) was 5.2×10⁻¹⁰ M. In contrast, atrial natriuretic peptide and B-type natriuretic peptide, other members of the natriuretic peptide family, produced little or no vasodilation. Pretreatment with methylene blue (10⁻⁴ M) abolished CNP-induced vasodilation, whereas pretreatment with N^G-monomethyl-

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-arginine or indomethacin did not inhibit vasodilation. Thus, CNP is suggested to cause significant vasodilation in cerebral arterioles via a cyclic guanosine monophosphate-dependent mechanism. © 1997 Elsevier Science B.V. All rights reserved.     

Mechanical emergency recanalization of the left main coronary artery

Acute occlusion of the left main coronary artery is normally fatal. According to the literature, only a few cases have been treated by intracoronary thrombolysis; the prolonged period of ischemia, however, resulted in severe left ventricular dysfunction and numerous complications. Therefore, effort should be directed to recanalize the left main coronary artery within the shortest possible interval. We followed this approach in a case of acute occlusion of a subtotal stenosis of the left main coronary artery which could be mechanically reopened and dilated within a few minutes. The intervention resulted in immediate reversal of profound cardiogenic shock and complete restoration of normal left ventricular function. At hospital discharge, the patient was asymptomatic with a negative bicycle stress test. Immediate mechanical recanalization and angioplasty appear to be a feasible approach in life-threatening coronary occlusion.     

老年心功能不全血浆心钠素浓度的变化

采用放射免疫法测定31例老年心功能不全患者血浆心钠素(ANP)浓度,发现老年心功能不全组ANP明显低于对照组(P<0.01)。血浆ANP含量随心功能不全的严重程度而明显减少(P<0.05)。病程与ANP浓度呈负相关 (r=-0.441,P<0.05)。不同病种、不同受累部位及有或无房颤之间ANP差异无显著性(P<0.05)。     

Persistence of Mammary Artery Branches and Blood Supply to the Left Anterior Descending Artery

Background. Partial harvesting of the left internal mammary artery (LIMA) is a widespread technique used during minimally invasive coronary operations performed through a left anterior small thoracotomy. The influence of persisting LIMA branches was investigated to evaluate their effect on the blood flow of the left anterior descending artery.

Methods. Thirty patients, 15 with totally (group A) and 15 with partially (group B) harvested LIMAs, were evaluated. All the patients underwent postoperative angiography, during which a flow map of the LIMA was performed. The average peak velocity and the diastolic-to-systolic peak velocity ratio were recorded. The LIMA graft flow pattern was recorded in the proximal and distal thirds of the artery. Intramammary adenosine (12 to 14 μg) was injected and the average peak velocities before and after injection were calculated.

Results. The average peak velocity was similar in both groups in the proximal and distal thirds of the LIMA (25 ± 7 and 26 ± 5 cm/sec, respectively, in group A versus 27 ± 5 and 25 ± 5 cm/sec, respectively in group B; p = NS). The diastolic-to-systolic peak velocity ratio was similar proximally (0.78 ± 0.3 in group A versus 0.69 ± 0.3 cm/s in group B; p = NS), but not distally (1.72 ± 0.1 in group A versus 0.97 ± 0.3 in group B; p < 0.0005). The LIMA graft flow reserve was similar both proximally and distally (2.6 ± 0.6 and 2.5 ± 0.3 cm/s, respectively, in group A versus 2.6 ± 0.5 and 2.6 ± 0.3 cm/s, respectively, in group B; p = NS).

Conclusions. The persistence of LIMA branches does not influence the blood flow of the left anterior descending artery after acute adenosine-induced myocardial hyperemia. If a left anterior small thoracotomy is used in left anterior descending artery direct revascularization, complete LIMA harvesting is not mandatory and depends on the personal preference of the surgeon.     

心电图短P-R间期观测研究

目的：探讨和鉴别心电图短Ｐ－Ｒ间期的产生原因，为临床诊断、治疗提供依据。方法：检测１１５例受检者的常规导联心电图（ＲＬＥＣＧ）、头胸导联心电图（ＨＣＥＣＧ）、食管导联心电图（ＥＬＥＣＧ），对其中５５例临床可疑心律失常和ＲＬＥＣＧ示短Ｐ－Ｒ间期者行食管心房调搏电生理检查。结果：①Ｐ波出现率和振幅均值比较ＥＬＥＣＧ＞ＨＣＥＣＧ＞ＲＬＥＣＧ（Ｐ＜０．０１），出现率分别为１００％、９５％、９１％。②ＨＣＥＣＧＰ－Ｒ段均值（Ｐ＜０．０１）及变异系数＜ＲＬＥＣＧ。③ＲＬＥＣＧ波幅低、图形多变是产生心电图短Ｐ－Ｒ间期的主要原因。结论：作为无创伤性检查方法，ＨＣＥＣＧ和ＥＬＥＣＧ可以对短Ｐ－Ｒ间期者进行初步筛选，而经食管心房调搏能检测ＥＣＧ短Ｐ－Ｒ间期的电生理特性，对鉴别诊断有肯定价值。