钙增敏剂MCI-154对内毒素休克大鼠左心室肌原纤维ATP酶活性的影响

目的　研究钙增敏剂MCI 15 4对内毒素休克大鼠左心室肌原纤维ATP酶活性的影响。方法　利用心室肌原纤维制备 ,测定其在不同钙浓度的激活液中的ATP酶活性。结果　内毒素休克组心肌肌原纤维在不同pCa(-log[Ca2 +] )溶液中的ATP酶活性及最大ATP酶活性均明显低于假休克组 ,ATP酶 pCa曲线向右移位约 0 .35个pCa单位 ,曲线的中位值pCa50 (产生 5 0 %最大ATP酶活性所对应的pCa)明显降低。 5×10 -5mol/L甲腈吡酮对上述异常无明显的纠正作用。内毒素休克大鼠心室肌原纤维经含 1× 10 -5mol/L的MCI 15 4的激活液处理后 ,各pCa点ATP酶活性及最大ATP酶活性均明显增加 ,显著高于内毒素休克组和甲腈吡酮组 ;ATP酶 pCa曲线向左移位约 0 .4个pCa单位 ,pCa50 值增加 ,显著高于内毒素休克组和甲腈吡酮组值 ,与假休克组值无明显差别。结论　内毒素休克后 ,心肌肌原纤维活力下降 ,ATP酶活性降低 ;钙增敏剂MCI 15 4可通过增加心肌收缩蛋白对钙的敏感性而提高心肌肌原纤维活力 ,增加ATP酶活性     

同浓度不同用量的乙醇对家兔左心室内压的影响

采用静脉内注射 5 0 %乙醇的方法 ,观察同浓度不同用量乙醇对家兔左心室内压的影响。结果显示给予乙醇后 ,大多数左心室内压降低 ,个别左心室内压不变。随着乙醇量的增加 ,左心室内压下降愈明显 (P <0 .0 5 )。提示高浓度乙醇可降低左心室内压 ,由于个体差异 ,乙醇对左心室内压的效应也略有不同     

Left ventricular function in children with the Marfan syndrome

Aortic dilatation and heart valve lesions are common in theMarfan syndrome but whether primary alterations occur in leftventricular (LV) function has not been studied hitherto. LVsize, mass and systolic as well as diastolic function were studiedby M-mode and Doppler echocardiography and cine magnetic resonanceimaging in 22 Marfan children aged 3.0–15.4 years andin 22 age-matched healthy children. No child had significantvalve disease. Heart rate and systolic blood pressure were comparablein the groups but diastolic blood pressure was higher in thecontrols (67 ± 7 mmHg vs 62 ± 8 mmHg, P=0.030).No statistically significant differences were found in LV size,mass or systolic function. The Marfan children had slower LVpeak diameter lengthening rates (106 ± 27 mm s^–1vs 132 ± 29 mm. s^–1, P=0.004), prolonged relaxationtimes (155 ± 22 ms vs 140 ± 19ms, P=0.023), slowerdeceleration of the early transmitral velocity (580 ±144 cm.s^–2 vs 720 ± 160 cm. s^–2, P=0.006),and smaller early-to-late peak velocity ratios (1.99 ±0.40 vs 2.29 ± 0.46, P=0.031). These data indicate thatI.V early diastolic function (relaxation) is impaired in theMarfan syndrome. Weakened elastic recoil due to the underlyingconnective tissue abnormality may best explain this novel observation.     

动态血压正常高限者的左室肥厚

目的：观察动态血压为正常高限者的左室肥厚情况,为该患者群靶器官损害的防治策略提供依据。方法：根据２４小时动态血压监测结果将病人分为３组：Ｎ组（正常血压组）、ＮＨ组（血压正常高限组）和Ｈ组（高血压组）。以超声心动图检测左室舒张末期内径,舒张末期室间隔和左室后壁厚度等,计算左室重量指数（ＬＶＭＩ）。结果：Ｈ组（１２９±４１）和ＮＨ组（１１５±３２）的ＬＶＭＩ明显高于Ｎ组（９７±２３,Ｐ＝０．００００１和０．００５）,Ｈ组和ＮＨ组间无统计学差异。结论：动态血压正常高限者左室肥厚程度明显重于血压完全正常者。对该人群亦应积极采取措施预防和治疗靶器官损害     

Automatic Border Detection to Assess Right Ventricular Function Following Surgical Treatment of Thromboembolic Pulmonary Hypertension

Automatic border detection (ABD) has been developed as a potentially useful means for evaluating ventricular function on line in an automatic fashion. Its success with tracking left ventricular function is established, but little is known about its ability to assess right ventricular (RV) function. Accordingly, 20 patients with severe pulmonary hypertension due to chronic thromboembolic disease underwent standard two-dimensional echocardiography and imaging with ABD before and after pulmonary thromboendarterectomy to correct pulmonary hypertension. ABD-derived results were compared to manually planimetered RV areas calculated from the apical four-chamber view. Doppler tricuspid regurgitant velocity fell significantly with surgery from 4.4 ± 0.6 to 2.9 ± 0.7 m / sec (P < 0.001). The mean values for RV areas derived by manual planimetry and ABD were similar, as was fractional area shortening, which improved significantly with surgery (manual 0.24 ± 0.01 preoperative vs 0.31 ± 0.11 postoperative, P < 0.05; and ABD 0.19 ± 0.05 preoperative vs 0.32 ± 0.15 postoperative, P < 0.001). There was, however, very little correlation between the individual values for ABD versus manually derived RV areas and fractional area shortening, with the best correlation being the RV end-diastolic areas after surgery (y = 0.684x + 7.9, r = 0.564, P = 0.01). These results demonstrate that both manually planimetered RV areas and those determined by ABD can adequately follow changes in ventricular function over time. However, variability within each technique may prevent direct comparison of the absolute values of the two techniques.     

Huge colloid cyst of the third ventricle associated with calcification in the cyst wall

Giant or huge colloid cysts of the third ventricle up to of more than 3 cm in diameter are extremely rare. The patient presented with symptoms of increased intracranial pressure, including headache, vomiting, and papilledema. Computerized tomographic (CT) scan revealed a hypodense, huge colloid cyst of the third ventricle associated with calcification in the cyst wall. Both hypodensity and calcification are uncommon roentgenological findings for colloid cysts of the third ventricle. The patient was operated on by the transcortical/transventricular approach and the colloid cyst was completely excised.     

5-Hydroxytryptamine-induced increase in left ventricular dP/dtmax does not suggest the presence of ventricular 5-HT4 receptors in the pig

Summary Although 5-hydroxytryptamine (5-HT) increases porcine atrial force and rate via 5-HT₄ receptors, its effect on left ventricular contractility is not known. Therefore, using the maximum rate of rise of left ventricular pressure (LVdP/dt_max) as an index of cardiac contractility, we have attempted to analyze the possible role of ventricular 5-HT₄ receptors in the anaesthetized pig. The full agonists at 5-HT₄ receptors, 5-HT and 5-methoxytryptamine (each 3, 10 and 30 g · kg^–1), and the -adrenoceptor agonist, isoprenaline (0.01, 0.03 and 0.1 g · kg^–1), increased heart rate, LVdP/dt_max and cardiac output. For a given degree of tachycardia, the increase in LVdP/dt_max by isoprenaline was substantially more than that observed with either 5-HT or 5-methoxytryptamine. The 5-HT₄ receptor partial agonist, renzapride (3, 10, 30, 100 and 300 g · kg^–1), also increased heart rate and LVdP/dt_max dose-dependently. When the heart was paced at 150 beats · min^–1, increases in LVdP/dt_max as well as cardiac output (except with the highest doses) by 5-HT, 5-methoxytryptamine and isoprenaline were clearly attenuated. However, the magnitude of attenuation of LVdP/dt_max responses by cardiac pacing was more marked in the case of 5-HT and 5-methoxytryptamine than with isoprenaline.The effects of renzapride (300 g · kg^–1) and tropisetron (0.3 and 3 mg · kg^–1) on increases in heart rate and LVdP/dt_max by 5-HT, 5-methoxytryptamine and isoprenaline were also studied. In the absence of atrial pacing, both renzapride and tropisetron (3 mg · kg^–1) effectively antagonized the responses to 5-HT and 5-methoxytryptamine; except for some decrease in the LVdP/dt_max response by tropisetron, the effect of isoprenaline remained essentially unchanged after the antagonists. During atrial pacing, renzapride significantly antagonized the responses to the first two doses of 5-HT, but the responses to the highest 5-HT dose and to 5-methoxytryptamine remained unaffected. Though, particularly after its higher dose, tropisetron reduced the responses to 5-HT and 5-methoxytryptamine, isoprenaline responses were also affected.The above results show that a significant part of the increase in LVdP/dt_max by 5-HT receptor agonists in the anaesthetized pig is a consequence of tachycardia elicited by these compounds via 5-HT₄ receptors. Since the increase in LVdP/dt_max, compared to tachycardia, was much less with 5-HT and 5-methoxytryptamine than with isoprenaline, and since the antagonism by renzapride and tropisetron against 5-HT and 5-methoxytryptamine during atrial pacing was relatively weaker and/or unspecific, it appears unlikely that the increase in LVdP/dt_max, during atria] pacing is mediated by ventricular 5-HT₄ receptors. This view is substantiated by our recent in vitro experiments where 5-HT (0.01 to 100 mol/l) failed to significantly increase contractions of porcine left ventricular trabeculae.Correspondence to P. R. Saxena at the above address     

右室流出道顽固性室性早搏及室性心动过速射频消融的临床探讨

目的　采用导管法射频消融术治疗顽固性右室流出道室性早搏 (室早 )及室性心动过速 (室速 )并通过临床效果、安全、可靠等特点方面以探讨该术的可行性和必要性。方法　采用起搏标测的方法 ,以起搏 12导联心电图与室早及室速发作完全相同点为消融靶点。以即刻室早消失及右室心尖部和流出道不能诱发室速为消融终点。结果　 6例室早消融即刻早搏消失 ,5例无器质性心脏病室早。2 4 h动态心电图检查 :室性早搏消融前为 ( 16 72 8± 2 75 2 )次 / 2 4 h,消融后为 ( 2 16± 112 )次 / 2 4 h( P<0 .0 5 )。 1例先心室间隔修补术后室早消融前为 2 185 6次 / 2 4 h,消融后为 175 6 9次 / 2 4 h( P>0 .0 5 )。 1例右室心肌病右室流出道室速发作时 ,药物及食道调搏均未终止发作 ,行急诊射频消融即刻成功。2 d后再次发作右室流出道另一部位室速 ,再次行射频消融术成功 ,随访 1月无复发。结论　无器质性心脏病顽固性右室流出道室早的经导管射频消融术 ,是一种安全可靠的方法 ,对右室流出道且发作时血液动力学稳定的室速经导管射频消融已得到临床认可 ,值得进一步推广。     

血管紧张肽转换酶抑制剂对高血压病人心脏和大动脉的影响

目的 :评价血管紧张肽转换酶 (ACE)抑制剂对原发性高血压病人心脏和大动脉结构和功能的影响。方法 :应用二维超声、超声心动图及自动脉搏波传导速度 (PWV)测定仪观察 16例采用ACE抑制剂培哚普利治疗 (4mg ,po ,qd ;4wk后若血压 >18.6 / 12 .0kPa ,加服吲哒帕胺 2 .5mg ,po ,qd)的原发性高血压病人心脏、大动脉结构和功能的改变 ,分别在治疗前和治疗 12wk后进行上述检测。结果 :收缩压、脉压、颈动脉 股动脉PWV、颈总动脉内膜 中层厚度和左室后壁厚度在 12wk培哚普利治疗后显著降低 [分别为 (2 0 .4±s 1.4 )kPavs (18.0± 1.2 )kPa ,(7.5± 1.1)kPavs (6 .9± 1.2 )kPa ,(10 .5± 1.3)m·s- 1vs (8.6± 1.0 )m·s- 1,(0 .71± 0 .14 )mmvs (0 .5 9± 0 .14 )mm ,(10 .5± 1.0 )mmvs (9.8± 1.0 )mm ,P <0 .0 1或P <0 .0 5 ];颈总动脉横断面顺应性、容积扩张性在治疗前后无显著性差异(P >0 .0 5 )。结论 :培哚普利对心血管系统的影响不仅仅是与血压降低有关 ,药物引起动脉平滑肌松驰 ,对全身和局部肾素 血管紧张肽系统的抑制能有效地改善高血压导致的心脏、血管结构和功能的改变。     

Double Outlet Right Ventricle with Intact Atrial Septum and Restrictive Ventricular Septal Defect: An Analysis of Two Cases

Two cases of double outlet right ventricle with restrictive ventricular septal defect are described. This is an uncommon presentation that causes left ventricular dysfunction because of left ventricular outflow tract obstruction. The presence of an intact atrial septum leads to severe pulmonary hypertension, which tends to aggravate the right ventricular output. In the presence of a normal left ventricle, the authors suggest the possibility of enlargement of the ventricular septal defect in order to perform a biventricular repair. The association of a supramitral valve ring in both cases, and the isolation of the left subclavian artery and an aortopulmonary fenestration in one of these cases, are also discussed. In addition we explore factors that cause restrictive ventricular septal defects as well as the mechanisms that may lead to spontaneous closure of ventricular septal defect in a double outlet right ventricle.