Cardiac transplantation: noninvasive detection of rejection by echocardiography

The main objective of follow-up of cardiac transplant patients is early recognition of acute rejection of the allogenic myocardium. Two patients followed up by the usual protocol also underwent routine M-mode and 2D echocardiography. The data was digitalized and memorized to allow systematic study of the pericardial and cardiac structures, and a comparison of their evolution. Acute rejection was associated with an increase in the acoustic density of the myocardium, especially of the interventricular septum, and an increase in myocardial mass as calculated from M-mode data; an increase of 5 p. 100 of this parameter with respect to an average reference value was judged to be significant. Comparisons were made with electrocardiographic data, especially with an index of voltage. The variability of this index which may be unrelated to rejection was apparent; in addition, there was an interval of about 5 days between the echocardiographic changes and the recording of significant reductions of the electrocardiographic index. Previously reported histological changes explain the precocity and reliability of the echocardiographic results obtained by a non-invasive and reproducible method.     

Cardiac echinococcal cyst: diagnosis by two-dimensional echocardiography

A case of an intracardiac echinococcal cyst is presented. The diagnosis was made by two-dimensional echocardiography, which clearly identified a large multiseptated cystic structure in the right ventricular outflow tract. The findings were verified at surgery. It is suggested that two-dimensional echocardiography may be the procedure of choice in the diagnosis of cardiac echinococcal disease.     

Doppler echocardiography for the diagnosis of acute cardiac allograft rejection

To evaluate the changes in left ventricular filling associated with acute cardiac rejection, serial Doppler echocardiographic examinations were prospectively performed on the same day as endomyocardial biopsy in 55 consecutive patients who successfully underwent orthotopic transplantation and were free of a previous episode of rejection. On average, 8.6 Doppler studies per patient were performed within a 6 month period after transplantation. Recordings of mitral flow were made with pulsed Doppler and two-dimensional echocardiography from an apical four chamber view; isovolumic relaxation time, peak early mitral flow velocity and pressure half-time were measured. The patients were classified into two groups on the basis of the histopathologic findings: group I (25 patients with at least one episode of mild or moderate rejection) and group II (30 patients without rejection). In group I, rejection was associated with a significant decrease of isovolumic relaxation time (p less than 0.005) and especially pressure half-time (p less than 0.0005) with no change in heart rate and peak early mitral flow velocity. In group II, Doppler indexes remained unchanged. These changes were not associated with alterations in left ventricular systolic function assessed by echocardiography. Isovolumic relaxation time and pressure half-time both returned to values similar to baseline values after immunosuppressive therapy (p less than 0.05 and p less than 0.0005, respectively). With 20% decrease in pressure half-time as a criterion for acute rejection, sensitivity was 88%, specificity 87% and positive predictive value 85%. Thus, Doppler echocardiographic evaluation of left ventricular diastolic function provides an excellent tool for early detection of acute rejection and noninvasive monitoring of the cardiac transplant recipient.     

超声新技术在心脏再同步治疗中的应用

慢性充血性心力衰竭是临床上常见的综合征,相当一部分患者合并房室传导或室内传导延迟,导致室壁运动的不同步,引起心功能的进一步恶化。从上一世纪90年代初,心脏再同步治疗(cardiac resynchronization therapy,CRT)开始用于治疗药物难治性心力衰竭,它通过起搏系统刺激左、右心室, 可改善心室的不同步收缩。超声新技术如组织速度显像、组织追踪显像、应变率显像、组织同步化显像可以直接测量心室机械同步性,识别理想的入选者,预测治疗效果,以及识别室壁运动最延迟的部位。这篇综述回顾了CRT的机制和超声新技术在CRT中的应用进展。     

Cardiac rejection following transplantation in dogs: transmural myocardial blood flow changes

In cardiac allografts acute rejection produces deleterious effects on blood flow adjustments. In order to differentiate the role of rejection over that of denervation cardiac denervated and cardiac transplanted dogs were compared. A canine model of orthotopic cardiac transplantation was utilized. Electronic devices were implanted for chronic hemodynamic studies. Regional myocardial blood flow distribution was assessed by radioactive microspheres (15 micron in diameter). Studies were carried out when animals had fully recovered (two to three days postoperatively), then in the 'early rejection' stage (five to six days post transplant) and in the 'severe rejection' stage (24 h before death). No significant difference in hemodynamic data or blood flow values were observed between groups in the recovery stage. In the denervated group, adequate cardiac function and myocardial blood perfusion was maintained throughout the study. In the transplanted group, significant loss of function was observed at the severe rejection stage. This was combined with significant decrement in blood flow to all areas of the myocardium. No selective area of underperfusion nor an early reduction in total blood flow could be observed. This study indicates that within cardiac rejection there is a parallel impairment in function and transmural myocardial blood flow which is unrelated to denervation or interruption of lymphatics.     

Changes in diastolic function in heart rejection: role of Doppler echocardiography]

In acute cardiac rejection, left ventricular diastolic function is altered. To study these abnormalities and their utility in cardiac allograft rejection, we studied 56 cardiac transplant recipients. All patients were assessed with endomyocardial biopsy and Doppler echocardiography done in the same day. A total of 163 Doppler studies were recollected. Cardiac transplant recipients were excluded during the early 6 weeks postoperative period. Totally, 100 biopsies were normal, 48 positive for mild rejection (Billingham Gde I-II) and 15 positive for moderate or severe rejection (Billingham Gde III-IV). Compared to negative biopsies, during acute rejection left ventricular wald thickness significantly increased (p < 0.05); isovolumic relaxation period and pressure half-time significantly decreased (p < 0.05, p < 0.001 respectively). Nevertheless, increase in peak early mitral flow velocity was only significantly associated with severe rejection (p < 0.001). Correlating only progressive shortening of isovolumic relaxation period parameter in the diagnosis of graft rejection, we forward a high sensibility (85%) and low specificity (57%). Thus, Doppler echocardiographic evaluation of left ventricular diastolic function provides a non-invasive tool for early detection of acute rejection monitoring after the early postoperative period.     

肝移植急性排斥反应的生化诊断

目的　总结肝移植术后急性排斥反应 (AR)的诊断经验。方法　回顾性分析 70例肝移植患者术后AR的发生率 ;分析AR组、保存 再灌注损伤 (PRI)组移植肝活检前患者生化检测值。结果　 42例次移植肝活检 ,17次发生AR ,2 2次为PRI ;3次为药物中毒。生化检测AR组 ,随发病进展 ,ALT、AST逐渐增高 ,成正相关 (P <0 .0 5 ) ;PRI组随发病进展 ,ALT、AST逐渐降低 ,成负相关 (P <0 .0 5 )。结论　移植肝活检及活检前生化检测对于AR的诊断与鉴别诊断有重要意义。     

高频超声心动图对大鼠异位移植心脏急性排斥反应的评价

目的:探讨高频超声心动图评价大鼠颈部异位移植心脏急性排斥反应的价值。方法:建立27只大鼠颈部异位心脏移植模型,其中同种异体移植20只,同系移植7只。7只同系移植大鼠和10只同种异体移植大鼠,分别于移植术后第1、3、5天,应用高频超声心动图观察异位移植心脏,第5天观察完毕后处死并行病检。另10只同种异体移植大鼠,分别于移植术后第1、3天各观察1次,第3天观察完毕后处死行病检。超声观察指标包括左室心肌厚度、左室质量和左室射血分数。结果:同种异体移植术后,随着移植时间的延长,超声检查显示左室心肌厚度和左室质量逐渐增加,术后第3天,病理学提示轻中度排斥反应(1～2级)时,左室心肌厚度和左室质量明显高于同系移植组,差异有统计学意义(P<0.05),至术后第5天病理学提示严重排斥反应(3～4级)时,左室心肌厚度和左室质量较同系移植组进一步升高(P<0.01)。左室射血分数在严重排斥反应发生时才出现明显减低。同系移植大鼠各指标在术后连续观察中无明显改变。结论:高频超声心动图可动态显示大鼠异位移植心脏的结构及功能改变,为心脏移植实验研究提供了一种无创且简便可靠的观察方法,也为临床心脏移植的排斥反应的超声评价提供了实验依据。室壁厚度、左室质量可作为超声评价急性排斥反应发生的敏感指标。     

Cardiac resynchronization in congestive heart failure: role of Doppler echocardiography in patient selection

Cardiac echodoppler is an efficient tool to analyse cardiac mechanic loop. Diastolic and systolic desynchronisation criteria are analysed. It should allow a more efficient selection of patients who could take benefit of resynchronization therapy, but also to choose resynchronization system, to program optimal atrioventricular delay, interventricular delay and to evaluate resynchronization efficiency. However, this tool should be evaluated in large studies in order to compare it to electrocardiogram.     

Cardiac fibroma with tumor involvement of the mitral valve: diagnosis by cross-sectional echocardiography

The clinical, cross-sectional echocardiographic, haemodynamic,and angiographic features of a case of cardiac fibroma in anewborn with unexplained pulmonary hypertension, and directtumor involvement of the posterior leaflet of the mitral valve,are presented. The role of echocardiography in the pre-operativeevaluation of cardiac tumors is discussed.     

Early vectorcardiographic diagnosis of rejection in long-term follow-up of heart transplantation

A series of 194 transplant subjects was followed-up by over 2,600 vectorcardiograms. Several cases of rejection were chosen among the most patent and best documented cases (eight cases of acute rejection and seven cases of chronic rejection) and 15 control cases where all tests, including the vectorcardiogram, had always remained negative. Two criteria of rejection were used, i.e. the amplitude of the left maximum QRS vector less than 1.10 mV and relative right spatial area greater than 35 per cent. By accumulating all traces for each patient, recorded during and outside the rejection phase, it was found that the mean of the individual means was 0.96 mV for the left amplitude in cases of rejection versus 1.74 mV in the control group, and 44 versus 22 per cent for the right area. The first trace which, on the curves showing the progress of each patient, was likely to signal acute or chronic rejection always had a left amplitude less than 1 mV (mean 0.89 mV) and a right area greater than 33 per cent (mean 45%). The first suspicious trace always preceded the detection of signs by echography or biopsy (except in one case where it occurred at the same time). The interval varied from 16 to 112 days in five cases of rejection assessed as acute, and from 63 to 600 days in seven cases of chronic rejection. There was no echographic control in two other cases, but death occurred 45 and 63 days after the first vectorcardiographic signs. The vectorcardiogram improves after recovery from acute rejection.(ABSTRACT TRUNCATED AT 250 WORDS)