左室重量与左心功能不全相关性的研究

目的：研究可否用左室重量表达并判定左心功能不全的可能性。方法：将左心功能不全按NYHA标准分成4个级别,每级1组,并设正常对照组,用超声心动图测量同一个病人的左室射血分数（LVEF）和左室重量。用SAS统计软件做方差分析。结果：LVEF与左心功能不全高度负相关（R＝－0．77270）,左室重量与左心功能不全高度正相关（R＝0．73421）。LVEF、左室重量各级指标间差别显著（n＝153,F＝64．85,P＜0．01;n＝153,F＝53．39,P＜0．0001）。各级与对照组比统,LVEF指标从Ⅱ级开始方有显著差别（P＜0．05）;而左室重量指标从Ⅰ级开始就有显著差别（P＜0．05）。结论：LVEF与左室重量指标均与左心功能不全高度相关,但心功能Ⅰ级的病人,左室重量指标更为敏感。     

急性心肌梗塞心肌缺血再灌注损伤18例临床分析

目的：利用间接指标的方法,观察急性心肌梗塞（ＡＭＩ）后心肌再灌注损伤（ＭｙｏｃａｒｄｉａｌＲｅｐｅｒｆｕｓｉｏｎＩｎｊｕｒｙ,ＭＲＩ）的临床表现,了解ＭＲＩ对左室射血功能及梗塞后心绞痛的影响。方法：对尿激酶静脉溶栓后３２例冠脉再通者和１０例冠脉未再通者进行心电图和心肌酶学动态监测,ＡＭＩ后３周所有患者接受心脏彩超检查。结果：临床判断冠脉再通者中ＭＲＩ发生率为５６２５％（１８／３２）,心电图主要表现为突发短暂性ＳＴ段明显抬高,其次是再灌注心律失常,束支或房室传导阻滞最少见。ＭＲＩ时血清ＣＰＫ峰值时间为１３８６±４２６小时,较冠脉再通而无ＭＲＩ组１９１７±５３６小时显著前移（Ｐ＜００５）。ＭＲＩ组ＬＶＥＦ（４５２５±１０７７％）显著高于冠脉未再通组（３８６０±９２５％）（Ｐ＜００５）,但与无ＭＲＩ组（５３２８±１２７７％）相比,Ｐ＞００５。ＭＲＩ组梗塞后心绞痛发生率为２７２８％,与无ＭＲＩ组４２８０％和冠脉未再通组１０００％相比,Ｐ均＞００５。结论：ＡＭＩ静脉溶栓后部分患者发生再灌注损伤,ＭＲＩ对ＬＶＥＦ和梗塞后心绞痛发作无显著影响。     

Ventricular fibrillation related to reversal of the neuromuscular blockade in a patient with long QT syndrome

The long QT syndrome (LQTS) is associated with syncopal attacks or even sudden death at a young age due to ventricular fibrillation. We report a patient with an undiagnosed LQTS who had an episode of cardiac arrest during the final part of general anesthesia, immediately after the drugs for reversal of the neuromuscular blockade were given. We suggest that the administration of glycopyrronium might have been the provoking factor in this patient.     

Intracapsular Hip Fracture: Increased Cortical Remodeling in the Thinned and Porous Anterior Region of the Femoral Neck

It has been shown previously that the antero-inferior cortex is subjected to maximal tensile stress during a fall onto the greater trochanter. We have recently shown that in cases of femoral neck fracture, cortical thinning and porosity is greatest in the anterior and antero-inferior region of the femoral neck. To investigate whether this is due to increased remodeling, we have quantified surface-based parameters associated with Haversian remodeling in femoral neck biopsies from women with intracapsular hip fracture and post-mortem controls. Cryostat sections of chilled biopsies were reacted for either tartrate-resistant acid phosphatase (TRAP) or alkaline phosphatase (ALP) activity. Proportions of active canals were determined in each quadrant (inferior, anterior, superior, posterior) of the femoral neck. The biopsies were then embedded in methacrylate to permit histomorphometry using Goldner’s and Solochrome sections. In the cases there was no significant increase in the proportion of canals undergoing remodeling in the cortex as a whole (p = 0.846), but the regional distribution of remodeling was markedly different from that in the controls. In the anterior cortex, the proportion of canals undergoing remodeling was increased by 56% (p = 0.0087); in contrast there was a relative decrease of 35% in the superior region (p = 0.0047). In the anterior cortex of cases there were 76% and 42% increases in the proportions of eroded (p = 0.019) and osteoid-bearing (p = 0.041) canals, respectively. In the superior region, the decrease in the proportion of remodeling sites was due to a marked decrease in canals with an osteoid surface (51%; p = 0.0031). Covariance analysis with cortical porosity as the dependent variable showed that porosity was significantly dependent on the regional distribution of eroded (p = 0.033) but not on the distribution of forming (p = 0.153) canals (R ²adj = 0.51). Cellular levels of TRAP and ALP were significantly elevated in the anterior region of cases compared with the controls (TRAP 55%, p = 0.006; ALP 36%, p = 0.003). For the posterior and inferior regions there were no marked differences in cellular TRAP and ALP levels compared with control values. These data show that the increased cortical thinning and increased porosity we have previously observed in the anterior cortex in cases of hip fracture are associated with increased indices of Haversian remodeling. These findings are consistent with the hypothesis that, in cases of hip fracture, remodeling imbalance in the anterior cortex is a continuing process up to the time of fracture and is due to increased osteoclastic cellular activity associated with an osteoblastic response that is inadequate to prevent bone loss. Received: 16 November 1998 / Accepted: 17 February 1999     

Ultracompact, completely implantable permanent use electromechanical ventricular assist device and total artificial heart

An ultracompact, completely implantable permanent use electromechanical ventricular assist device (VAD) and total artificial heart (TAH) intended for 50-60 kg size patients have been developed. The TAH and VAD share a miniature electromechanical actuator that comprises a DC brushless motor and a planetary roller screw. The rotational force of the motor is converted into the rectilinear force of the roller screw to actuate the blood pump. The TAH is a one piece design with left and right pusher plate type blood pumps sandwiching an electromechanical actuator. The VAD is one half of the TAH with the same actuator but a different pump housing and a backplate. The blood contacting surfaces, including those of the flexing diaphragm and pump housing, of both the VAD and TAH were made of biocompatible polyurethane. The diameter, thickness, volume, and weight of the VAD are 90 mm, 56 mm, 285 cc, and 380 g, respectively, while those of the TAH are 90 mm, 73 mm, 400 cc, and 440 g, respectively. The design stroke volume of both the VAD and TAH is 60 cc with the stroke length being 12 mm. The stroke length and motor speed are controlled solely based on the commutation signals of the motor. An in vitro study revealed that a maximum pump flow of 7.5 L/min can be obtained with a pump rate of 140 bpm against a mean afterload of 100 mm Hg. The power requirement ranged from 4 to 6 W to deliver a 4-5 L/min flow against a 100 mm Hg afterload with the electrical-to-hydraulic efficiency being 19-20%. Our VAD and TAH are the smallest of the currently available devices and suitable for bridge to transplant application as well as for permanent circulatory support of 50-60 kg size patients.     

Acute clinical deterioration in a patient with end-stage dilated cardiomyopathy and left ventricular thrombus formation

The case of a 17-year-old male patient with severe end-stage dilated cardiomyopathy and a large thrombus formation within the cavum of the left ventricle is reported. After an acute thrombectomia combined with a partial left ventriculectomy (Batista procedure), the patient was successfully treated with an appropriate left ventricular assist device (LVAD) system using a centrifugal nonocclusive pump (Biomedicus, Medtronic, Anaheim, CA, U.S.A.). Mechanical support was removed on Day 9, and the patient was discharged from the hospital on Day 19. The effectiveness of emergency mechanical support in patients with very unfavorable prognoses is discussed.     

微波消融犬室性心动过速的实验研究

观察微波消融犬室性心动过速（简称室速）疗效和微波消融对血液动力学的影响。健康犬４０只,随机分成５组,Ⅰ组（对照组,ｎ＝８）,Ⅱ、Ⅲ、Ⅳ和Ⅴ组（消融组,ｎ＝８）,由股动脉、股静脉穿刺进行血液动力学监测。用０．０１ｍｌ０．０３％乌头碱注入心室壁诱发室性心动过速。消融释放功率和时间Ⅱ组为４０Ｗ×３０ｓ,Ⅲ组为４０Ｗ×６０ｓ,Ⅳ组为８０Ｗ×３０ｓ,Ⅴ组为８０Ｗ×６０ｓ。结果：自发放微波能量至室速终止时间Ⅱ、Ⅲ组为（１０．１±２．４）ｓ,与对照组比,Ｐ＜０．００１;Ⅳ、Ⅴ组为（５．３±１．５）ｓ,与对照组比,Ｐ＜０．００１。消融前后血液动力学各项指标差异无统计学意义（Ｐ＞０．０５）,消融后组间血液动力学各项指标差异无统计学意义（Ｐ＞０．０５）。微波产生的心肌损伤,显微镜下观察均为凝固性坏死,与周围组织存在清晰的界限。结论：微波消融室速具有较好的疗效,消融能量与时间在一定范围内对血液动力学无明显影响,可望成为室速治疗的１种新方法。     

多普勒超声心动图评估左心室舒张末压的研究

目的探讨多普勒超声心动图评估左室舒张末压的有效方法与指标。方法对６８例病人采用左心导管测压及经胸多普勒超声心动图检测。结果对比研究显示,联合肺静脉与二尖瓣血流频谱分析优于二尖瓣血流频谱分析,肺静脉Ａ峰和二尖瓣Ａ峰时限差值（ＰＡｄ－Ａｄ）与左室舒张末压实测值呈最佳相关性（ｒ＝０．７２,Ｐ＜０．０１）。结论认为应用多普勒超声心动图测定ＰＡｄ与Ａｄ,并以其差值估测左室舒张末压,是一项简便、可靠的无创性评估左室舒张末压的方法。ＰＡｄ－Ａｄ≥０可作为临床判断左室舒张末压增高［≥２．０ｋＰａ（１５ｍｍＨｇ）］的一项半定量指标。     

右室舒张功能的衰老演变规律脉冲多普勒超声心动图研究

目的　检测右室舒张功能的随龄演变规律。方法　用脉冲多普勒超声心动图记录320例健康知识分子的三尖瓣血流频谱,年龄范围26～90岁。结果　右室舒张功能指标Er、EMVr、EDVr、Eir、13FFr、NPFRr、ErAr、随年龄增加分别降低,而EDTcr、Ar、Air、AFFr、随年龄增加而增加。EATcr、EAVr、在各年龄组中无变化。结论　右室的舒张功能年龄增长而减低     

洛沙坦抗高血压及左室肥厚的疗效观察

目的 :观察血管紧张素 受体拮抗剂—洛沙坦的降压效果及对高血压病合并左室肥厚的影响。方法 :4 6例合并左室肥厚的 期高血压病患者服用洛沙坦 5 0 mg/ d,观察其血压的变化及治疗前和 6个月后左室质量 (L VM)。结果 :用洛沙坦后 4 d～ 6d血压开始下降 ,2周血压趋向正常 ,4周血压继续缓慢下降 ,6周时达到最大降压效果。 L VM在 12周时无明显变化。 2 4周表现轻度 L VM减少。结论 :洛沙坦是抗高血压的一个有效治疗药物 ,对左心室肥厚有轻度逆转作用