Concomitant mitral valve repair and left ventricular reconstruction in a patient with chronic ischemic mitral regurgitation and inferior left ventricular aneurysm

The surgical approach to ischemic mitral regurgitation with concomitant inferior left ventricular aneurysm remains uncertain in terms of the indication for operation and the short-and long-term outcomes. We performed concomitant mitral valve repair, left ventricular reconstruction, and aortic valve replacement on a 71-year-old male with severe ischemic mitral regurgitation, inferior left ventricular aneurysm, and degenerative aortic regurgitation. Postoperative status was in New York Heart Association functional class I without mitral regurgitation 8 months after operation. We discuss, and review the procedures reported in the literature.     

Torsades de pointes after intracoronary papaverine

Coronary blood flow velocity and coronary flow reserve can be assessed in humans using a coronary Doppler catheter and the vasodilator papaverine. Although it is a safe, elegant and reproducible technique, serious complications can occur. Coronary flow reserve assessment in a 49-year-old man with a critical stenosis in the proximal part of the circumflex artery was complicated by a papaverine-induced ventricular arrhythmia. Several features of the present case report support papaverine-induced disturbances of the repolarization phase as the pathophysiological mechanism: a 'torsade de pointes' pattern of the tachycardia, the lengthening of the QT-interval, the appearance of a new U-wave and the presence of additional risk factors (hypokalaemia and alcalosis). Patients presenting additional risk factors for this complication should be excluded from coronary flow reserve assessment.     

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。     

经导管同期封堵治疗膜周部室间隔缺损合并房间隔缺损

目的　探讨经导管介入同期治疗膜周部室间隔缺损 (VSD)合并房间隔缺损 (ASD)的可行性、方法及疗效。方法　 4例患者 ,年龄为 12～ 2 6岁。术前超声检查提示VSD合并ASD。VSD均为膜周部缺损 ,缺损直径 3～ 6mm ,缺损上缘距主动脉瓣 2～ 6mm。ASD均为继发孔型 ,缺损直径 5～ 8mm。4例患者均于术中先行左心室造影 ,确定VSD适合封堵后 ,先行VSD封堵 ,最后行ASD封堵。结果　 4例患者均经导管一次封堵治疗成功。左心室造影显示VSD呈囊袋型 3例 ,囊袋直径分别为 4、5和 10mm ,封堵器的直径分别为 4、8和 12mm。 1例缺损为管状 ,直径 3.5mm ,用 4mm的封堵器治疗成功。4例患者ASD伸展径为 6～ 10mm ,封堵器直径为 6～ 12mm。所有患者术中及术后无并发症。结论　经导管介入同期封堵治疗膜周部VSD合并ASD具有技术上的可行性、安全性和良好的治疗效果     

Non-invasive estimation of the diastolic elastic and viscoelastic properties of the left ventricle

The present study applies a non-invasive method to the quantitative evaluation of left ventricular stiffness in normal subjects and in patients with ischaemic heart disease (IHD). We have studied 20 patients with IHD and 25 healthy subjects. The third heart sound (S3) was detectable in all patients. We have correlated the energy spectrum of S3, divided into 15 Hz bands, with a series of echocardiographic parameters. The existence of a significant correlation between the spectrum energy and the diameter and thickness of the left ventricle at the moment of S3 allowed us to explore the possibility of interpreting the origin of S3 based on a mathematical model. Our hypothesis has been that, once the left ventricle starts vibrating, it behaves as a simple physical model composed of a mass and an elastic element. To this purely elastic model one can add a factor accounting for viscosity, with a damping effect, to obtain a more complex viscoelastic model. The stiffness coefficient 'k' was computed in both models from the peak frequency of S3 and the left ventricular mass at the moment of S3. Furthermore, in the viscoelastic model, the damping element 'c' was also computed. Both parameters--k and c--were significantly increased in the group with IHD compared with the control group. Although a simplification of the vibrating system, these models make it possible to obtain non-invasively information on the characteristics of the left ventricle through the combined use of echocardiography and spectral analysis of S3.     

Correction by oral adsorbent of abnormal digestive tract milieu in rats with chronic renal failure

In order to examine the mechanism by which the oral carbonaceousadsorbent, AST-120 delays the appearance of glomerular sclerosis,experiments were carried out in 120 male Sprague-Dawley ratsweighing 285–320 g. The rats were first subjected to 2/3,3/4, and 4/5 nephrectomy (n=40). The experiments were begunat 2 weeks after the surgery, and were performed over an 8-weekperiod. Half of each group (n=20) was administered 1 g/day ofliquid AST-120, and the other half received liquid vehicle solutionwith pair feeding in each group. In the 2/3 nephrectomized groupthe administration of AST-120 delayed the occurrence of glomerularhypertrophy and prevented the appearance of glomerular sclerosiswithout any significant differences in renal function, systemicblood pressure (SBP), and urinary protein excretion (U-P). Inthe 3/4 nephrectomized group the administration of AST-120 delayedthe appearance of glomerular hypertrophy and sclerosis withsignificant decreases in SBP and U-P. In the 4/5 nephrectomizedgroup the administration of AST-120 delayed the appearance ofglomerular sclerosis and prevented a decrease in renal function.It is concluded that administration of the oral adsorbent AST-120delays the occurrence of glomerular sclerosis by delaying theappearance of glomerular hypertrophy, systemic hypertension,and the increase in proteinuria. It can be therefore mentionedthat the accumulating substances in the digestive tract worsenthe abnormal milieu of chronic renal failure.     

Stability of the Defibrillation Probability Curve with the Development of Ventricular Dysfunction in the Canine Rapid Paced Model

Most patients with implantable defibrillators have diminished cardiac function. Progressive heart failure might impair defibrillation efficacy, leading to interpreted device, failure. This study sought to determine the effect of ventricular dysfunction on defibrillation energy using a biphasic endocardial system. Eleven dogs were ventricularly paced at 225 pulses/min for 2 weeks to induce ventricular dysfunction, and five control dogs remained unpaced. Dose response defibrillation probability curves were generated for each animal at baseline, after 2 weeks (at which time the pacemakers were turned off in the paced group), and then 1 week later. The defibrillation thresholds, ED₂₀, ED₅₀, and ED₈₀ (the 20%, 50%, and 80% effective defibrillation energies, respectively) were determined for each dog at each study. In the paced dogs, the mean ejection fraction fell from 55% to 25% after pacing (P < 0.0001), and rose to 46% after its discontinuation (P = 0.0002). The defibrillation threshold, ED20, ED₅₀, and ED80 remained unchanged in both the control and paced groups for all three studies, even after adjustment for dog weight or left ventricular mass. Rapid pacing produced no change in left ventricular mass. It induced ventricular cavity dilatation and wall thinning, which had opposing effects on defibrillation energy requirements, resulting in no net change of the ED₅₀ in heart failure. In conclusion, the defibrillation efficacy of a biphasic transvenous system is not changed by the development of heart failure using the rapid paced canine model.     

左心室造影功能成像的临床应用

为探讨左心室造影功能成像的价值与限度，我们选择冠脉及左心室造影者38例行左室功能成像，观察左室壁运动情况并与节段法室壁运动定量分析比较。结果示左室收缩正常18例，其各节段EF值平均39％，节段性收缩减弱7例，无收缩3例，矛盾收缩4例，普遍性收缩减弱6例，病变节段的EF值平均5～19％，明显低于正常者（P＜0．01）。结论：左室功能成像效果直观且客观，可作为室壁运动定量分析的一个重要补充。     

人左、右心室阻抗微分心动图的比较研究

作者利用Ⅱ导心电图、心音图、颈动脉搏动图、右（或左）心室阻抗微分心动图同步描记的方法。对人左、右心室阻抗微分心动图进行了比较分析。结果显示:人的左、右心室阻抗微分心动图图形相似，波形稳定，转折明显，均有清晰的生理标志点。两种图形各相应生理标志点在时相上存在着区别．且人的左、右心室阻抗微分心动图能分别反映人的左、右心室收缩和舒张过程，说明利用人的左、右心室阻抗微分心动图能分别测定人的左、右心室收缩时间间期与舒张时间间期值，鉴别和评定左、右心室的功能。