Effects of complete heart block on myocardial function, morphology, and energy metabolism in the rat.

AIMS: Severe sustained bradycardia may cause acute and possibly chronic congestive heart failure (CHF). The aim of this study was to investigate acute and chronic effects of complete heart block (CHB) on cardiac function, morphology, and creatine (Cr) metabolism. METHODS AND RESULTS: CHB was induced in male Sprague-Dawley rats (approximately 250 g, n = 11) by means of electrocautery applied to the region of AV node and were compared with controls (n = 15). The rats were investigated at 1, 3, and 12 weeks after CHB induction with transthoracic echocardiography. Invasive haemodynamic assessment of left and right ventricular pressures was performed at 12 weeks. After the sacrifice, the hearts were freeze-clamped for analysis of myocardial Cr, and high energy phosphometabolites. The efficacy of operative procedure was 54%. The peri-operative mortality rate was 20%. Heart rate (HR) decreased by approximately 50% (P < 0.01) while stroke volume (SV) increased 2.5 times (P < 0.01) in the CHB rats. Cardiac index remained unchanged. The rats with CHB grew normally and were in no apparent distress. Filling pressures in left and right ventricles were normal. The CHB rats developed marked cardiomegaly with biventricular dilatation and eccentric left ventricular hypertrophy (P < 0.01). There was no change in the myocardial content of Cr and high energy phosphometabolites. CONCLUSION: Rats with CHB are compensating for reduction in HR with increased SV without haemodynamic and biochemical characteristics of CHF. This model may be useful to study the effects of CHB and bradycardia on myocardial structure, function, electrophysiology, and metabolism as well as for studies of cell therapy for reparation of AV conductance.     

三维数字减影血管造影在颅内动脉瘤诊疗中的应用价值

目的：探讨3D—DSA在颅内动脉瘤诊断和治疗中的应用价值。方法：对蛛网膜下腔出血患者常规行DSA检查，发现病变或可疑病变后行3D—DSA检查。结果：26例颅内动脉瘤中检出动脉瘤31枚，其中后交通9枚，C1段3枚，C2段5枚，C3段3枚，前交通6枚，大脑中3枚。椎动脉动2枚。3例2D—DSA未见病变3D—DSA确诊，5例因血管重叠3D—DSA排除了动脉瘤。6枚GDC栓塞，5枚手术夹闭，2枚颈内动脉可脱性球囊封阻术。结论：3D—DSA极大提高了脑血管造影检查的准确性和可靠性，为动脉瘤的介入治疗和手术夹闭提供了可靠保障，在临床诊疗中具有很高的应用价值。     

64排螺旋CTA早期诊断颅内动脉瘤的临床探讨

目的 探讨64排螺旋CT血管造影(CTA)对颅内动脉瘤早期诊断的临床意义. 方法 选取疑似颅内动脉瘤的蛛网膜下腔出血患者42例,在病情允许条件下首先进行64排螺旋CTA检查,随后进行DSA检查,采用自身配对四格表卡方检验,分析CTA与DSA检查结果的差异性. 结果 39例患者经CTA检查证实为颅内动脉瘤(瘤体直径2～26mm),1例患者CTA检查疑似动脉瘤,1例患者CTA检查阴性.41例患者经DSA检查发现动脉瘤,1例患者DSA检查阴性.CTA与DSA动脉瘤检出率比较差异无统计学意义(X2=0.263,P=0.608). 结论 CTA对于直径不小于2 mm动脉瘤的早期诊断较准确.     

颈内动脉狭窄或闭塞侧支循环途径的DSA和MR血管成像研究

目的　研究DSA、MR血管成像 (MRA)对颈内动脉狭窄或闭塞后侧支循环途径评价的意义。方法　颈内动脉狭窄或闭塞者 74例 ,DSA和MRA上脑血管正常表现者各 6 0例为对照组 ,分析其DSA和MRA表现。结果　 74例患者均有颈内动脉分叉以上狭窄或闭塞。病变同侧后交通动脉在DSA上的出现率 ,疾病组低于对照组 (P =0 0 2 5 ) ;在时间飞跃 (TOF)法MRA上的出现率 ,疾病组明显高于对照组 (P =0 0 0 0 )。后交通动脉DSA、MRA测量值均较对照组增大 (P =0 0 0 0 )。眼动脉直径DSA测量值较对照组增大 (P =0 0 0 3)。疾病组后交通动脉出现率在DSA上高于MRA (P <0 0 5 )。结论　DSA对本病侧支途径评价有重要意义 ,为术前必要检查。MRA安全 ,可从形态和功能上评价侧支循环 ,可做为首选方法     

双能量CT头颅血管成像的影像质量、辐射剂量及初步临床应用

Objective To assess the clinical value of dual-energy intracranial CT angiography (CTA).Methods Forty-one patients suspected of intracranial vascular diseases underwent dual-energy intracranial CT angiography, and 41 patients who underwent conventional subtraction CT were enrolled as the control group.Image quality of intracranial and skull base vessels and radiation dose between dual-energy CTA and conventional subtraction CTA were compared using two independent sample nonparametrie test and independent-samples t test, respectively.Prevalence and size of lesions detected by dual-energy CTA and digital subtraction CTA were compared using paired-samples t test and Spearman correlative analysis. Results The percentage of image quality scored 5 was 70.7% (29/41) for dual-energy CTA and 75.6% (31/41) for conventional subtraction CTA.There was no significant difference between the two groups(Z= -0.455, P=0.650).Image quality of vessels at the skull base in conventional subtraction CTA was superior to that in dual-energy CTA, especially for the petrosal and syphon segment (Z=-4.087, P= 0.000).Radiation exposure of dual energy CTA and conventional CTA were (396.54±17.43) and (1090.95±114.29) mGy · cm respectively.Radiation exposure was decreased by 64% (t=-38.52, P=0.000) by dual energy CTA compared with conventional subtraction CTA.Out of the 41 patients,19 patients were diagnosed as intracranial aneurysm, 2 patients as arteriovenous malformation (AVM), 3 patients with Moya-moya's disease, and the remaining 17 patients with negative results.Nine patients with intracranial aneurysm, 2 patients with AVM, 3 patients with Moya-moya's disease, and 2 patients with negative findings underwent DSA or operation, with concordant findings from both techniques.Diameter of aneurysm neck, long axis and minor axis by dual-energy CTA was (2.90±1.61), (5.23±1.68) and (3.83±1.69) nun, respectively; Diameter of aneurysm neck, long axis and minor axis by DSA was (2.95±1.71), (5.10±1.60) ,(3.83±1.65) nan,respectively.There was no significant difference for the diameters of aneurysm between dual energy CTA and DSA ((t=-0.734,1.936,0.12.5 respectively, P=0.482,0.085,0.903 respectively), and good correlation was found between diameter measurements using the two techniques(r=0.964,0.976,0.973, respectively, all P=0.000) Conclusions Compared with conventional subtraction CTA, dual energy CTA has good image quality for intracranial vessels; however, image quality of the skull base vessels is worse, especially for the petrosal and syphon segment.Dual energy CTA has decreased radiation dose and a high diagnostic accuracy, being a practical imaging madality for diagnosis of intracranial vascular lesions.     

肝动脉解剖变异影像学研究

目的用数字减影血管造影(DSA)和CT血管造影(CTA)进一步探讨肝动脉解剖变异的种类、发生率及特点。方法回顾分析1000例因肝脏疾病而行DSA检查患者的临床资料、肝动脉的DSA,以及其中的32例肝动脉解剖变异的CTA表现。观察肝动脉的起源、走行、分布情况,并分别统计其变异类型和发生率。结果1000例肝动脉造影中,正常型727例,占72.7%;肝动脉变异273例,占27.3%。273例肝动脉变异中属于Michels分型的148例,占14.8%。Michels分型未包括在内者为125例,占12.5%。其中肝总动脉分叉变异54例,占5.4%,肝动脉起源变异214例,占21.4%,肝总动脉分叉 肝动脉起源变异5例,占0.5%。以上变异合并多种变异共存21例,占2.1%。结论肝动脉解剖变异的种类具有多样性、复杂性。除DSA外,CTA亦可显示肝动脉解剖变异。肝胆外科和影像科医师了解肝动脉解剖变异对于术前制定手术方案、提高诊断准确性等有重要意义。     

双能量胸部DR对筛查冠状动脉钙化的意义:与多排螺旋CT的比较性研究

目的探讨胸部双能量DR骨骼像在筛查冠脉钙化中的意义。方法35例患者分别行右前斜位胸部双能量DR检查及多排螺旋CT(MDCT)冠状动脉扫描并记录照射后射线的体表入射剂量ESD(mGy)。2位高年资放射科医师及2位低年资医师分析双能量胸片骨骼像,对LAD、LCX、RCA共105条血管的钙化情况进行评估。CT扫描图像进行钙化积分分析。以钙化积分>300为金标准,对双能量DR的结果进行ROC分析。结果DR胸片平均阳性率27.6%(29/105),其中LAD阳性率48.5%(17/35);LCX22.8%(8/35);RCA 11.4%(4/35)。4位医师的ROC结果显示曲线下面积分别为0.866、0.854、0.725、0.642。胸部DR照射平均体表入射剂量为(0.469±0.22)mGy;多排CT入射剂量为(12.29±1.40)mGy。两者经配对t检验有显著差异。结论DR骨骼片可以检出较明显的冠状动脉钙化,对冠心病的筛查和病情的检测有一定的临床意义。     

动脉数字减影血管造影的临床应用

本文报告８０例动脉数字减影血管造影（ＩＡＤＳＡ）的初步经验，特别着重影像质量的评价。在本组病例，ＩＡＤＳＡ主要用于头颅、颈部、肺、腹部以及先天性心脏病的诊断。本组未发生重大并发症。ＩＡＤＳＡ的优点是：（１）影像质量好；（２）用于ＩＡＤＳＡ的剂量和浓度以及导管的直径均较用于常规血管造影的小得多，因此其副作用和并发症显著减少；（３）检查时间显著缩短，因此，ＩＡＤＳＡ对介入放射学治疗特别有用；（４）ＩＡＤＳＡ现已大部取代常规血管造影来诊断多种疾病。     

急性大脑中动脉栓塞的动静脉联合溶栓治疗的实验研究

目的:评价动静脉联合溶栓治疗实验兔急性脑梗死的疗效。方法:采用兔自体血栓栓塞大脑中动脉制成急性脑梗死模型,随机分为动、静脉联合溶栓组(IA+IV组)、静脉溶栓组(IV组)及对照组,分别给予以动脉+静脉、静脉内注射尿激酶及静脉内注射生理盐水。采用DSA观察血管再通率、核磁共振弥散成像观察相对表观系数(rADC)、改良Bederson评分法观察神经功能缺损。结果:IA+IV组血管再通率为83.3%、rADC值(0.918±0.144)及神经功能缺损评分(0.80±0.84)均优于IV组和对照组。结论:动静脉联合溶栓治疗急性脑梗死优于静脉内溶栓治疗。