二尖瓣置换术患者左心室整体及局部节段心肌收缩功能的初步定量化研究

目的应用经食管超声心动图(TEE)的常规技术和组织多普勒超声心动图(TDE)技术评价二尖瓣置换术(MVR)患者心肺转流(CPB)前后左心室整体与局部心肌的收缩功能。方法择期CPB下行MVR的患者20例,ASAⅡ或Ⅲ级,心功能NYHA分级2或3级,EF≥45%。于麻醉诱导后锯胸骨前(T0)和停CPB后30min(T2)、90min(T2)时采用TEE常规技术和TDE技术,记录患者左心室射血分数(LVEF)和左室前、后壁等容收缩期速度平均值(Sm1)和射血期速度平均值(Sm2)等。结果 T0、T2时,Sm1明显大于Sm2(P0.01或P0.05);而T1时Sm1与Sm2差异无统计学意义。结论通过TDE技术评价二尖瓣置换术患者CPB后早期左心室整体及局部心肌收缩功能,并未明显受损害,但是等容收缩期心肌运动速度大于射血期。     

Aortic Dissections Complicating Open Cardiac Surgery: Report of Three Cases

Between June 1991 and February 1999, three patients suffered ascending aortic dissection as a complication of cardiopulmonary bypass operations with aortic cannulation at our hospital. The dissection occurred during the operation in two of the three patients and several months after the operation in one. Among a total of 2 207 cardiac operations performed during this period, the incidence of perioperative ascending aortic dissection was 0.14%. In addition to visual inspection and palpation, either epicardial or transesophageal echocardiography proved extremely useful for establishing an intraoperative diagnosis of ascending aortic dissection as a complication of open cardiac operation. One of the three patients underwent closed plication but subsequently died of vital organ ischemia. In this case, failure of reapproximation of the injured intima by closed plication might have led to extension of the dissection. Despite prolonged cardiopulmonary bypass and myocardial ischemic time, graft replacement of the ascending aorta was successfully carried out in the other two patients. Thus, we believe that graft replacement of the ascending aorta should be performed for patients with extensive aortic dissection complicating an open cardiac operation. Received: August 12, 1999 / Accepted: May 30, 2000     

超声心动图介入心包置管在延迟性心脏压迫中的应用(附64例报告)

目的探讨超声心动图介入心包腔直接置管引流对延迟性心脏压迫（late cardiac tamponade，LCT）患者的治疗效果。方法LCT患者64例，行二维超声引导下心包腔直接置管引流。结果穿刺成功率为100％，心包内置管引流15h～4个月，治疗效果满意。结论二维超声引导下施行心包穿刺置管引流能有效缓解症状，成功率高，可替代传统穿刺方法。     

Pericardial Complications of Cardiac Surgery: Emphasis on the Diagnostic Role of Echocardiography

Pericardial effusions are common following cardiac surgery; uncommonly they are large in size and may cause tamponade, either in the early or late postoperative period. Such effusions causing tamponade may be circumcardiac, but are frequently loculated, in which case one or more cardiac chambers is selectively compressed. Fortunately, echocardiography is capable of imaging not only the presence, location, and size of the pericardial effusion, but also indicating the presence of tamponade. Constrictive pericarditis resulting from cardiac surgery is being recognized with increasing frequency and has been associated with various echocardiographic abnormalities. This review also discusses certain other pericardial complications of cardiac surgery including supraventricular arrhythmias, chylopericardium, and posttransplant problems.     

Usefulness of echocardiography in the long-term follow-up study after surgical treatment of annuloaortic ectasia

From July, 1979 to August, 1987, 10 patients at our institution underwent a repair of annuloaortic ectasia (AAE), either with a separate aortic graft and valve or with Bentall’s operation. There were no hospital deaths, although there were two late deaths from unrelated accidental causes. In nine of the patients, echocardiograms were recorded to evaluate the postoperative cardiac function and possible complications. M-mode echocardiography facilitated the evaluation of cardiac function, and two-dimensional echocardiography was better suited to studying the postoperative structures. On the other hand, the real time two-dimensional Dopper flow mapping ensured the diagnosis of dissecting aneurysms through the blood flow pattern. Although the postoperative hemodynamics improved significantly, pseudoaneurysms between the native aortic wall and the graft were detected in three patients, with compression to the composite conduit in one, and residual distal aortic dissection was noted in another three patients. It was thus concluded that the composite graft replacement of the ascending aorta and aortic valve in patients with AAE can be accomplished with a low risk, but pseudoaneurysm formation at the coronary ostial or aortic suture line may be observed late after surgery. Regular postoperative follow-up study is therefore of great importance, and echocardiography would be the most pertinent, non-invasive method of meeting this purpose.     

Left ventricular hypertrophy persists after successful treatment for coarctation of the aorta

Objectives. To evaluate cardiac size and function in patients with coarctation of the aorta (CoA) before and after treatment. Design. Ventricular size and function were examined by 2- and 3-dimensional echocardiography, and concentrations of natriuretic peptides measured in 15 paediatric patients before repair, and one, 6, and 12 months thereafter. Controls comprised 15 children. Results. Before repair, mitral inflow velocities and left ventricular (LV) size and wall thickness were higher in patients. Thicknesses of interventricular septum and LV posterior wall decreased after repair but increased to initial level one year thereafter. The LV end-diastolic diameter remained larger than in controls despite successful repair. The size of right ventricle increased and levels of natriuretic peptides decreased during follow-up. Levels of natriuretic peptides correlated with the smallest diameter of CoA segment and diastolic indices of LV function. Conclusion. LV hypertrophy persists and LV size remains larger than in controls after successful repair even in normotensive patients with normal growth of CoA segment. This may be due to remodelling of ventricles and the aorta caused by CoA.     

Intraoperative contrast transesophageal echocardiography using Albunex

This study was designed to investigate the effect of administration of the contrast material Albunex on intraoperative contrast transesophageal echocardiography for patients with mitral valve disease or coronary artery disease. We studied nine patients scheduled for elective coronary artery bypass grafting (CABG group) and nine patients scheduled for elective mitral valve replacement (MVR group), and used a transesophageal echocardiography probe and an echocardiographic system. During the period of stable hemodynamics before the start of cardiopulmonary bypass, Albunex in doses of 0.1 ml·kg⁻¹ was injected at a rate of about 1 ml·s⁻¹ from either the peripheral venous line or the distal lumen of the pulmonary arterial catheter, and the effect on contrast was compared. This effect was semiquantitatively assessed by using a grading scale from 0 to 3, with 0 indicating an absence of opacification and 3, full opacification of the cavities examined. In the CABG group, contrast resulting from administration of Albunex from the pulmonary arterial catheter was significantly better than that from the peripheral venous line, whereas in the MVR group, no improvement was found. Furthermore, when it was administered into the pulmonary artery, the effect on contrast for the MVR group was significantly lower than that for the CABG group. The efficacy rate of intraoperative contrast transesophageal echocardiography using Albunex was relatively low, and appeared to be affected by pulmonary circulation or many other factors such as the method of administration, including the route and injection pressure.     

Effective systolic orifice area of the aortic valve: implications for Doppler echocardiographic cardiac output determinations

BACKGROUND: Substantial research using echocardiography has established that stroke volume (SV) or cardiac output (CO) can be measured non-invasively at the level of the aortic valve (AV) with high accuracy. Stroke volume is the product of the velocity time integral occurring at the sampling site and the effective systolic AV orifice area (AVOAeff). Nevertheless, a generally accepted method for the determination of AVOAeff is still lacking. METHODS: Aortic valve OAeff was measured in 228 consecutive patients scheduled for coronary artery surgery. Two widely adopted methods were applied to approximate the constantly changing orifice area of the AV: (1) the circular orifice model (AVOA-CM), and (2) the triangular orifice model (AVOA-TM). Aortic valve OA-CM assumes the shape of a circle as an appropriately time averaged geometrical model, and AVOA-TM takes the shape of an equilateral triangle for granted. RESULTS: The AV was easily imaged by echocardiography in both short- and long-axis views in all patients. Relying on AVOA-CM, AVOAeff was 3.49+/-0.77 cm2. AVOA-TM estimates were 2.80+/-0.55 cm2 (mean+/-SD). The results did not agree (bias analysis). CONCLUSIONS: The echocardiographic measurement of SV or CO at the level of the AV has to be reconsidered.     

Feasibility of color doppler tissue velocity imaging for assessment of regional timing of left ventricular longitudinal movement

Objective—The feasibility of color Doppler tissue velocity imaging (c‐TVI) with a high time resolution of 10?ms for simultaneous measurement of the temporal characteristics of regional left ventricular (LV) tissue velocities at different LV sites was examined.

Methods and results—In 20 subjects with structurally normal hearts, inter‐ and intraobserver agreement and the beat‐to‐beat variation were tested in c‐TVI profiles from basal and mid‐LV segments of the interventricular septum (IS) and of the lateral free wall (LFW). For peak tissue velocities a mean error of less than 1?cm/s was demonstrated. For systolic regional LV velocity time difference, the mean error was ±5?ms, with the best agreement when sampling from basal LV sites. For diastolic regional LV velocity time differences, the mean error was ±12?ms. The longitudinal LV movement pattern demonstrated a pattern of incremental tissue velocity from basal to mid‐LV, and from IS to LFW sites.

Conclusion—The c‐TVI method has acceptable inter‐ and intraobserver agreement and is sufficiently accurate to disclose regional time aspects of LV contraction and relaxation.     

Failure of clinical features of low probability endocarditis. The early echo remains essential

Abstract

Objective. To investigate if earlier reported retrospectively derived criteria for predicting absence of infective endocarditis (IE) on transthoracic echocardiography could be prospectively confirmed or improved with transoesophageal echocardiography (TOE). Design. Prospective analysis of the relationship between predefined clinical IE features and findings on TOE in 708 IE suspected patients. Results. The previously reported criteria were rejected as 1/10 of our confirmed IE patients fulfilled criteria for predicting absence of IE. However, our study generated another model of low probability of IE: This disease was absent in 99.4% of patients with negative blood cultures and absence of vascular phenomena and predisposing cardiac conditions. Such patients accounted for 25% of our population of patients suspected of IE. Conclusions. The utility of earlier reported clinical criteria for predicting absence of IE proved insufficient. Instead the study generated new simpler criteria of low probability of IE. However, these included negative blood cultures, but echocardiography must not be postponed while awaiting the results of blood cultures. Therefore the proposed new criteria only apply to patients with documented negative blood cultures when the suspicion of IE arises, in our study only 10% of the population. Accordingly, the study documented the essential role of early echocardiography in suspected IE.

Trial registration: ClinicalTrials.gov identifier: NCT00524212.