Exogenous insulin-like growth factor II enhances post-infarction regional myocardial function in swine

OBJECTIVES: Insulin-like growth factor II (IGF-II) promotes cardiac myocytegrowth and contractility in vitro. This study was designed toinvestigate the effect of exogenous IGF-II on regional myocardialfun ction at the area of infarct in the pig. METHODS: Myocardial infarction was induced in 12 female anoesthetizedpigs by affigel blue beads, embolizing microvessels of the leftanterior descending coronary artery distribution. In the experimentalgroup (n=6), IGF-II (0.12 µg. kg^–1 in two animalsand 0.6 µg. kg^–1 in four) was incorporated intothe beads and delivered by them to the infarct area. Myocardialfunction was followed echocardiographically, and the excisedheart was analysed immunohistochemically and histopathologically. RESULTS: Myocardial function in injured zones, inversely related to anechocardiographic segmental wall motion score (mean ±SEM), was similar between the two groups at baseline, but at4 weeks post-infarction was significantly (P=0.008) reducedin the control group (0.58± 0.38 vs 3.42 ± 0.84),in contrast to nearly baseline values in the experimental group(0.58 ± 0.33 vs 1.17 ± 0.42, P=0.41). Cardiacperformance in injured segments was sign better after myocardialinjury in the experimental group (P=0.04). Tissue samples fromboth groups (4 weeks post-infarction), stained with haematoxylinand eosin demonstrated pen-infarct myocyte hypertrophy, correspondingto regions selectively stained by an antibody for CD56, whichhighlights growing cardiac myocytes. By image analysis semi-quantification,staining for CD56 was significantly (P=0.04) higher in the peri-infarctregion of the experimental group, as compared with controls(106.5 ± 2.8 vs 92 ± 4.4 gray level units). Microvesselsstained for von-Willebrand factor were similar in nwnber inboth groups (P=0.8), as were mesenchymal cells stained for vimentin(P=0.7). CONCLUSIONS: Exogenous IGF-II, delivered to the infarct area amelioratesregional cardiac function in the pig, perhaps by inducing peri-infarctmyocyte growth.     

Pulmonary venous flow as assessed by Doppler echocardiography: potential clinical applications

During the past few years Doppler assessment of pulmonary venous flow has gained increasing interest. The growing experience with the use of transesophageal echocardiography, the approach that nearly always yields registrations adequate for quantitative analysis, has markedly contributed in this respect. The Doppler-derived pulmonary venous flow pattern can be regarded as a measure of left atrial inflow and it augments the clinical significance of Doppler transmitral flow in the evaluation of diastolic left ventricular function. This article summarizes physiological background, possible applications, and limitations of Doppler echocardiography of pulmonary venous flow in clinical cardiology.     

The assessment of left ventricular filling dynamics using an online automatic border detection algorithm: comparison with cineventriculography

An echocardiographic system has been developed that performs automatic endocardial border detection and instantaneously calculates and displays a waveform of left ventricular cavity area versus time. The purpose of this study was to compare measurements of left ventricular filling dynamics from automatic border detection echocardiography with similar measurements from cineventriculography. Thirty-three patients undergoing cardiac catheterization had automatic border detection echocardiography performed within 45 minutes of cineventriculography. Ten patients had normal catheterization findings and 23 had cardiac disease. The automatic border detection waveforms generated from two echocardiographic views were measured to determine the fraction of filling occurring during the early diastolic rapid filling phase and during the filling phase resulting from atrial contraction. Similar fractions were derived from curves generated from frame-by-frame measurements of cineangiographic volumes. Results were analyzed by correlating echocardiographic and cineventriculographic results, and by a limits of agreement analysis (limits of agreement were +/- 2 standard deviations of the mean difference between echocardiography and cineventriculography). There were significant correlations between echocardiography and cineventriculography for each of the parameters studied. The best results were obtained for the apical four-chamber view (rapid filling fraction r = 0.72, P < 0.0001, atrial filling fraction r = 0.56, P < 0.001). Differences in filling patterns between normal and abnormal patient groups detected by cineventriculography were also detected by automatic border detection echocardiography. However, broad limits of agreement were observed, that may limit the ability of the automatic border detection system to reliably predict cineventriculographic results in an individual patient. Automatic border detection echocardiography can provide information about left ventricular filling dynamics that is similar to that obtained from frame-by-frame analysis of cineventriculograms. However, the variability in the results may limit the application of the technique in individual patients.     

Criteria for the diagnosis of endocarditis and the role of echocardiography

When infective endocarditis is a diagnostic possibility, echocardiography permits noninvasive imaging of cardiac structures. As involvement of the endocardium is a sine qua non of endocarditis, echocardiography may assist in its diagnosis by demonstrating such involvement. The ability of echocardiography to detect the intracardiac manifestations of infective endocarditis has continued to improve, especially with the introduction of transesophageal imaging. This article will discuss some of the echocardiographic findings in endocarditis and elucidate the incorporation of these findings in the new Duke criteria for the diagnosis of endocarditis.     

Cost-benefit analysis of transesophageal echocardiography in cardiac surgery

This article evaluates the costs and outcomes associated with TEE during and after cardiac surgery. The costs include the direct and indirect costs--the complications of TEE. The outcomes include the positive consequences or the benefits: money and lives saved. The article uses liberal (high) estimates of the direct and indirect costs of TEE and conservative (low) estimates of the benefits. The exact cost or benefit depends on the number of cases performed. The analysis shows that patients having surgery for congenital heart disease derive the greatest overall benefit: around $600 per case studied. Patients having valvular repair surgery derive the next greatest benefit: around $450 per case studied. In contrast patients having valve replacement have an overall cost of around $150 per case studied. Patients having surgery for coronary artery disease also derive an overall benefit: around $100-$300 per case studied, depending upon assumptions regarding TEE's role in prevention of intraoperative strokes. This analysis indicates that the financial benefits of TEE are substantial and frequently outweigh costs in patients requiring cardiac surgery.     

Value of antenatal echocardiography in high risk patients to diagnose congenital cardiac defects in fetus

Results of fetal echocardiography in 1062 high risk pregnant patients are described. It was performed before 28 weeks of gestation in 770 cases. These were 38 abnormal scans (3.6%). A fetal arrhythmia was diagnosed in 14 cases and structural abnormality of the heart in 24. Complete atrioventricular block was commonest (n=12), structural heart disease associated in two of these cases. Other lesions identified were atrioventricular septal defect (n=5), hypoplastic left heart syndrome (n=4), ventricular septal defect (n=4), Ebstein’s anomaly (n=3), coarctation of aorta (n=2) and others (n=9). Postnatal confirmatory echocardiography is available in a total of 993 babies including 36 of 38 abnormal cases. There were eleven neonatal deaths amongst babies with abnormal scans. Errors in interpretation were observed in six instances. An anomaly was missed in five cases; in two of these, the main cardiac malformation was picked up but secondary lesions were missed. In one case, a false positive diagnosis of atrial septal defect was made. These errors did not influence the management of the pregnancy. Fetal echocardiography is a very sensitive (91.6%) and specific (99.9%) tool for antenatal diagnosis of congenital heart disease in high risk pregnancies. The information so obtained helps in guiding the optimal obstetric and neonatal management of these cases.     

The vibratory innocent heart murmur in schoolchildren: A case-control Doppler echocardiographic study

Summary In 810 schoolchildren (aged 5–14 years) the prevalence of a grade 1–3/6 vibratory innocent heart murmur (VIHM) is 41%. Restricted to a grade 2 or 3 VIHM, the prevalence is 14%, decreasing from 21% in the age-class 5–6 years to 8% for children 13–14 years of age. The prevalence of a grade 3 VIHM is 1%. Together with a matched control, 84 children with a grade 2 or 3 VIHM underwent further cardiologic examination including electrocardiography, phonocardiography, and Doppler echocardiography. A positive correlation was found between the presence of a VIHM and higher left ventricular voltages on the ECG, but within the normal range; lower heart rate; smaller diameter of the ascending aorta (AAO); and higher blood flow velocity and higher maximal acceleration of the blood flow in the LVOT and the AAO. In 40% of the children with a VIHM, a systolic aortic valve vibration was seen with a frequency 100 Hz and an amplitude 1 mm, whereas this type of vibration was present in only one case control. No significant difference was found concerning the prevalence of false tendons in the left ventricle, systolic and diastolic diameter of the left ventricle, systolic time intervals, and shortening fraction of the left ventricle. The VIHM is strongly associated with a smaller AAO, with higher velocity and acceleration of the blood flow in the LVOT and AAO, and with a vibratory phenomenon of the aortic valve, pointing towards the LVOT-aortic valve region as the site of origin of the VIHM.     

应用脉冲多普勒估测右心室dp／dtmax方法的评价

目的通过动物实验及临床研究评价右心室射血期肺动脉脉冲多普勒频谱参数估测右心室收缩功能的可行性。方法6条健康犬及25例先心病患儿。1.在右心室正性肌力及改变前后负荷干预下,观察实验犬血流频谱最高速度（Vp）、加速时间（AT）、平均加速度（Am）及Vp2／AT等肺动脉射血期脉冲多普勒参数与右心室dp／dtmax的关系。2.测算先心病患儿上述各肺动脉射血期血流频谱参数并与心导管造影术中右室dp／dtmax测值比较。结果1．实验犬中仅Vp及Vp2／AT在右心室正性肌力及前后负荷干预下始终与右室dp／dtmax呈高度相关。2先心病患者肺动脉血流Vp、Am及Vp2／AT与右心室dp／dtmax成非常显著相关。结论右室Vp及Vp2／AT可用于右空心肌收缩力的估测。     

Infective endocarditis in paediatrics

Infective endocarditis is a result of infection of the endocardium, particularly of the heart valves (native or prosthetic valves). The most common causative organisms in the paediatric population are: Streptococci, Staphylococci and Enterococci. The classical signs of infective endocarditis like Roth spots, Janeway lesions, splinter haemorrhages and Osler's nodes are relatively rare in children. A high index of suspicion in a febrile child with a new murmur, detailed history, meticulous examination, repeated blood cultures, and echocardiography are essential in establishing the diagnosis. Management of infective endocarditis involves a prolonged course of antibiotics, at least for 4–6 weeks depending upon the causative organism and underlying heart condition. Complications of infective endocarditis include congestive heart failure resulting from valvular damage/regurgitation, infective emboli leading to abscesses in other organs and abnormal host immunological responses. Prophylactic antibiotics for dental and other medical procedures like genitourinary tract procedures are no longer recommended in the UK. The emphasis should be on educating children and their parents in early recognition of infective endocarditis. Children at high risk of developing endocarditis should be assessed urgently after clinical suspicion.     

超声心动图对扩张性心肌病患者左室舒张功能的评价

为评价超声心动图对扩张性心肌病（ＤＣＭ）患者左室舒张功能的诊断价值。方法：用超声心动图 和放射性核素显像（ＲＮＶ）对２０例ＤＣＭ患者和２０例同龄正常人的左室舒张功能进行对照分析。结果：ＤＣＭ组左室 舒张功能ＲＮＶ指标峰充盈率（ＰＦＲ）明显降低,同对照组比较差异有显著性（Ｐ＜０．０５）;超声指标二尖瓣血流频谱早 期充盈峰速度（νＥ）、晚期充盈峰速度（νＡ）、νＡ／νＥ等参数同对照组比较无明显差异（Ｐ＞０．０５）,表现为“正常”。结 论：超声心动图舒张功能指标νＥ、νＡ、νＡ／νＥ不能真实反映ＤＣＭ患者的左室舒张功能。