The impact of right atrial ischemia on inferior myocardial infarction with extension to right ventricle: transesophageal echocardiographic examination

BACKGROUND: The role of the right atrium in adaptation to the hemodynamic changes produced by extension of myocardial infarction (MI) of the left ventricular inferior wall to the right ventricle is fundamental. HYPOTHESIS: The aim of this study was analyze a group of patients with MI with extension of right chambers, and particularly right atrial alterations, by transesophageal echocardiography and to correlate it with clinical and angiographic variables. METHODS: Thirty patients with right ventricular (RV) MI involving obstruction of the right coronary artery without stenosis of the left coronary artery were included; 18 underwent early reperfusion. Transesophageal echocardiography was performed on all within 5 days of coronary angiography. Follow-up was continued from hospitalization to the present. RESULTS: When patients with right atrial ischemia were compared with those with normal right atrium, the RV wall movement score was significantly greater in the group with right atrial ischemia, severe RV dilatation was more frequent, and association with proximal occlusion of the artery responsible for the MI, as well as absence of right atrial branches and poor collateral circulation, were significant. Hospitalization was more prolonged in this group, and there was a higher incidence of arrhythmias, complete atrioventricular block, and mortality. CONCLUSIONS: Right atrial ischemia associated with RV infarction leads to a higher incidence of complications and higher mortality. Transesophageal echocardiography is a safe, reproducible technique that provides detailed anatomic information about right chambers and aids in the determination of prognosis and therapeutic decisions.     

Intraoperative monitoring of regional wall motion abnormalities for detecting myocardial ischemia by transesophageal echocardiography

Transesophageal two-dimensional echocardiography has been used for intraoperative monitoring of regional wall motion of the left ventricle. Regional wall motion abnormality is a sensitive indicator of myocardial ischemia and the use of two-dimensional transesophageal echocardiography may have a substantial advantage for early detection of myocardial infarction and thus for initiating timely and appropriate therapy in preventing postoperative myocardial ischemia. With an expected increase in the use of intraoperative transesophageal echocardiography for monitoring regional wall motion, we described the practical aspects of transesophageal echocardiography: (1) insertion technique of transesophageal echocardiographic probe; (2) the technique for obtaining an optimal short-axis view of the left ventricle; and (3) the method for evaluating regional wall-motion abnormality and myocardial ischemia. Regional wall motion abnormality is best monitored at the mid-papillary muscle level where all three coronary arteries meet. In obtaining this view, the transesophageal echocardiographic probe was found to be predominantly located in the stomach. Failure in obtaining short-axis view of the left ventricle at this level occurred in patients with left ventricular dilatation or obesity. Because of the anatomical reason, the echocardiographic transducer cannot reach a proper plane. In anesthetized patients, air can be pushed into the stomach during induction and may disturb the visualization. The pitfalls in examining regional wall motion abnormalities include: (1) shifting of the center of left ventricular contraction; (2) inadequate direction of the scanning plane; and (3) paradoxical septal movement. Three cases are presented to demonstrate the usefulness of transesophageal echocardiography in managing coronary artery surgical patients.     

Transesophageal echocardiography for the evaluation and management of patients with cerebral ischemia.

To prevent recurrent strokes and transient ischemic attacks, considerable attention is devoted to investigating the etiology of acute cerebral ischemia in the large subpopulation of patients without an easily identifiable cause. In general, transthoracic echocardiography is an insensitive tool for the evaluation of patients with cerebral ischemia, unless clinical signs and/or symptoms of cardiac disease are present. Transesophageal echocardiography (TEE), because of its increased sensitivity for aortic arch atheromata, atrial septal pathology, left atrial thrombi, and valvular abnormalities, is the preferred cardiac imaging modality, especially in young patients, older patients with hypertension or systemic atherosclerosis, and patients with prosthetic heart valves. This paper reviews the prognostic and therapeutic impact of TEE in patients with cerebral ischemia, specifically focusing on the ability of information obtained by this technique to alter patient management and improve risk stratification.     

Transesophageal echocardiography: Increased risk by repeated attempts to insert the transducer in patients with coronary artery disease?

The question of whether several attempts at transducer insertion increase the risk of performing transesophageal echocardiography (TEE) in patients with coronary artery disease (CAD) has not been addressed to date. In the course of performing TEE in 45 patients with CAD, two or more attempts to insert the transducer were necessary in 9 cases. During various attempts, heart rate, blood pressure and ST-segment depression were recorded and correlated with the findings of the exercise electrocardiogram (ECG) and coronary angiography. Insertion was successful in six patients after two attempts and in three other patients after three, four, and five attempts, respectively. Heart rate rose significantly (p<0.005) with the increase of insertion attempts. In one patient, it continued to rise at the fourth attempt, reaching 216% compared with the initial heart rate. Systolic blood pressure rose by 5%, whereas there was hardly any change in diastolic blood pressure. As the number of insertion attempts increased, we recorded a continuous ST-segment depression in eight patients with angiographic changes of the coronary artery system. The depression was already significant at the first attempt (p<0.05). Compared with the initial reading (0.053 mV), the increase was 335% (p<0.01) after the second attempt (0.231 mV). One patient whose angiographic findings were normal had no ST-segment depression during TEE. In all eight patients with CAD ST-segment depression during TEE was > 0.2 mV. Since none of the patients complained of angina pectoris, the ST-segment depressions satisfied all the criteria of silent myocardial ischemia. Thus, in the performance of TEE in patients with CAD, ST-segment depression is consistently intensified with each additional attempt to insert the transducer and must be taken as an indicator of myocardial ischemia. Investigators should consider systemic analgesia (conscious sedation) when performing TEE in patients with CAD.     

The Role of Intraoperative Transesophageal Echocardiography in Heart Transplantation

The number of centers that perform heart transplants has increased rapidly in recent years. Although transthoracic and transesophageal echocardiography (TTE and TEE) are utilized frequently to diagnose and manage cardiac complications commonly found in this population postoperatively, little has been written about the routine use of intraoperative TEE. Intraoperative echo is ideally suited to identify acute complications during cardiac transplantation. This can include immediate signs of rejection, valvular abnormalities, and mechanical complications related to the surgical procedure. Many of these patients might require ventricular assist devices (VAD) to provide circulatory support, and intraoperative TEE can be used to verify correct positioning of the VAD hardware. In addition, many of the chronic complications that patients with heart transplants are at risk for may be serious yet asymptomatic. Therefore, a high quality, complete intraoperative echocardiographic study might serve as an important baseline to compare postoperative changes.     

Intraoperative assessment of myocardial perfusion using contrast echocardiography

Myocardial contrast echocardiography is a new technique capable of assessing regional myocardial perfusion in vivo in real time. This article reviews the background, principles, experimental validation, and clinical uses of intraoperative myocardial contrast echocardiography. Data can be derived both for online visual and computer analyses. The technique can be useful in determining the sequence of bypass graft placement and the success of graft anastamoses. Anastamoses can be revised immediately if needed. It is hoped that this technique will improve intraoperative myocardial preservation and will diminish the rate of perioperative myocardial infarction.     

超声心动图观察高原右心室急性心肌梗死溶栓治疗效果

目的:探讨超声心动图诊断高原地区右心室心肌梗死和判断溶栓治疗效果的价值。方法:高原地区（西藏日喀则,海拔3890 m）右心室心肌梗死患者23例,在溶栓治疗前和治疗后23 h进行床旁经胸超声心动图检查,10 d后再次随访。结果:溶栓治疗前后超声心动图测值比较,差异有显著性意义。右心室前后径由30.9±2.1 mm减小至22.8±2.6 mm（P<0.01）,三尖瓣反流速度由2.96±0.32 m/s减低至1.95±0.40 m/s,反流量由3.9±0.5 m l减少至1.6±0.4 m l,房间隔和室间隔的运动分析显示大部分恢复正常。结论:急性心肌梗死时出现右心系统异常,包括严重的三尖瓣反流和房室间隔运动异常,提示超声心动图对诊断右心室心肌梗死及评判溶栓治疗的效果有重要价值。     

Transesophageal echocardiography in diagnosing cardioembolic stroke

Stroke is a disease with high morbidity and mortality that afflicts older people. The most common type of stroke is ischemic, and 15–20% of these strokes are cardioembolic. Because clinical features are not very specific for the type of stroke, diagnostic aides are needed to identify the mechanism of stroke so that appropriate therapy can be initiated. Numerous studies have shown that transesophageal echocardiography (TEE) is a more sensitive tool for diagnosing cardioembolic stroke than transthoracic echocardiography (TTE). However TTE and TEE are still considered complementary as they both provide unique information. The many abnormalities that can be identified by TEE and their therapy are discussed in this review, along with indications and complications of TEE. TEE has demonstrated that cardioembolic causes of stroke are much more common than previously thought. With a more precise diagnosis, appropriate therapy can be provided to help prevent cardiogenic stroke.     

The increasing role of transesophageal echocardiography in unexplained cerebral ischemia

Cerebrovascular disease is a leading cause of morbidity and mortality in the United States. A significant number of cerebral infarctions are due to a cardiac source of embolus. Transesophageal echocardiography (TEE) is being used with increasing frequency to study patients with potential cardiac causes of cerebral ischemia. TEE has a higher sensitivity for detecting left atrial and left atrial appendage thrombi and for visualizing abnormalities of the atrial septum such as patent foramen ovale and aneurysm. Abnormalities of the aorta and native and prosthetic valves can now be clearly identified by TEE. Preliminary data suggest that TEE may influence clinical management in patients with unexplained stroke.     

Usefulness of dipyridamole transesophageal echocardiography in the evaluation of myocardial ischemia and coronary artery flow

High-dose dipyridamole transesophageal stress echocardiography has recently been proposed as a useful and safe method to assess myocardial ischemia in patients with a poor transthoracic acoustic window. It has also been shown that transophageal echocardiography (TEE) allows the study of coronary blood flow reserve (CBFR) in the left anterior descending artery (LAD).The aim of our study was to assess whether the morphologic information and pathophysiologic data on CBFR and myocardial ischemia can be collected by a single stress TEE without comprimising its feasibility, safety and accuracy. We studied, 29 patients with known or suspected CAD (previous myocardial infarction or angina) (Group A), and as a control group, we studied 11 patients with mitral disease or mitral prostheses (Group B).All patients underwent the coronary angiography. None of Group B patients showed significant coronary artery stenosis (>70%). In baseline conditions left ventricular wall motion and LAD coronary blood flow velocity (CBFV) were also evaluated. The following CBFV parameters were measured: maximal diastolic velocity (MaxDV), mean diastolic velocity (MnDV), maximal systolic velocity (MaxSV), mean systolic velocity (MnSV). The ratios of dipyridamole to rest maximal and to mean to diastolic velocities (MaxDV-Dip/Max DV-rest; MnDv-Dip/MnDV-rest) were measured as indexes of CBFR.No side effects were observed and the test could be completed in all patients (feasibility 100%). Wall motion analysis was adequate in all patients (feasibility 100%). Comparison between wall motion analysis was obtained and angiographic findings showed that the overall sensitivity and specificity of TEE were 84% and 93% respectively. Sensitivity for one, two and three vessel disease was 60%, 70% and 100%, respectively. LAD CBFV was adequately recorded in 85% of patients. CBFR parameters showed a significant difference between the two groups (Max DV-Dip/Max DV-rest; 1.67±0.7 vs. 2.73±0.6,P<0.001); comparison between Group B patients and those of Group A with angiographically documented LAD stenosis showed a statistically significant difference in CBFR parameters (MaxDV-Dip/MnDV-rest, 2.73±0.6 vs. 1.65±0.7,P<0.001, MnDV-Dip/MnDV-rest, 2.56±0.5 vs. 1.69±0.6 P<0.001). We conclude that transesophageal stress echocardiography is a useful method to study CAD and that it is possible to assess both morphologic and pathophysiologic information during a single examination.     

Intraoperative transesophageal echocardiography of ventricular septal defect

The accuracy and limitations of intraoperative two-dimensional (2-D) and color Doppler flow mapping transesophageal echocardiography (TEE) of ventricular septal defect (VSD), before and after cardiopulmonary bypass, were analyzed in 62 children. Twenty-one patients had an isolated VSD, and 41 had a VSD plus additional cardiac anomalies. Two-dimensional and color Doppler flow mapping TEE were performed with a miniaturized 5-MHz single (transverse) plane transducer in the 51 of 62 patients weighing less than 20 kg. The remaining 11 were monitored using a single plane adult probe (n = 4) and a biplane (transverse plus longitudinal) probe (N = 7). Prebypass TEE provided a correct diagnosis in 57 of 62 cases (92%) and corrected an erroneous preoperative transthoracic echocardiographic diagnosis in three of 62 cases (5%). Single plane TEE diagnosis was erroneous in five patients: four with doubly-committed subarterial VSD and one with multiple small apical muscular defects and pulmonary hypertension. Biplane TEE (transverse longitudinal) provided clear and complete imaging of the right ventricular outflow tract in all seven cases in whom it was used. Postbypass TEE showed absence of a hemodynamically significant residual VSD in 30 of 40 patients (95%) who underwent VSD patch closure, prospectively identified two of 40 with significant residual VSD, and accurately measured the color Doppler jet width of all residual VSDs. We conclude that hemodynamically significant VSDs can be identified immediately after cardiopulmonary bypass based on the width of the residual VSD color Doppler flow map jet. Therefore, 2-D and color Doppler flow mapping TEE provide an accurate diagnosis in most cases of VSD but may miss doubly-committed subarterial and apical muscular VSD unless biplane TEE is used.     

Transesophageal echocardiography for congenital heart disease

Surface echocardiographic imaging of small children is routinely successful in defining anatomical details and Doppler flow patterns with even the most complex congenital cardiac malformations. However, in larger children or adults, imaging is frequently limited. A recent expansion of the role of echocardiography is intraoperative epicardial imaging. Epicardial and postoperative imaging, however, have significant limitations. To avoid some of these limitations, transesophageal echocardiography has increasingly been used in the arena of congenital heart disease. The more recent development of small sized gastroscopic probes has allowed transesophageal echocardiographic assessment of congenital heart disease in children down to newborn size. As detailed studies of individual lesions are reported, it has become clear that the mere presence of a congenital heart defect is not an indication for transesophageal echocardiography in most children if imaging can be accomplished by surface examination. However, transesophageal echocardiography may be indicated for the intraoperative or postoperative assessment of that defect, particularly when repair has been difficult or is known to be associated with significant residual abnormalities. Cardiac structures encountered with horizontal and vertical imaging plane transducers have been described and should be completely familiar to the examining echocardiographer.     

Complex ventricular septal rupture with dissection of the right ventricular wall in ischemic context

A 72-year-old man was admitted to the local hospital with non-ST elevation myocardial infarction. In the first 24 hours, a new onset apical murmur was heard. Transthoracic and transesophageal echocardiography showed interventricular septal (IVS) rupture and dissection of the right ventricle (RV) wall forming an echolucent pseudocavity that partially occupied the RV and communicated with the true RV cavity. Multislice computed tomography characterized in detail the IVS and RV wall dissection, and further showed the right coronary artery in the outer border of the RV and pseudocavity, excluding pericardial fluid. Despite surgical correction, progression to cardiogenic shock and death occurred 33 days after admission.     

Transesophageal echocardiography in NeoChord procedure

Background:

Transapical off-pump mitral valve intervention with neochord implantation for degenerative mitral valve disease have been recently introduced in the surgical practice. The procedure is performed under 2D-3D transesophageal echocardiography guidance.

Methods:

The use of 3D real-time transesophageal echocardiography provides more accurate information than 2D echocardiography only in all the steps of the procedure. In particular 3D echocardiography is mandatory for preoperative assessment of the morphology of the valve, for correct positioning of the neochord on the diseased segment, for the final tensioning of the chordae and for the final evaluation of the surgical result.

Result and Conclusion:

This article is to outline the technical aspects of the transesophageal echocardiography guidance of the NeoChord procedure showing that the procedure can be performed only with a close and continuous interaction between the anesthesiologist and the cardiac surgeon.     

Transesophageal echocardiography in the evaluation of cardiac myxoma: A case of familial myxoma

The vast majority of atrial myxomas are readily apparent on standard transthoracic echocardiography. We present the case of a young woman with known history of familial myxoma, in whom a large left atrial mass was identified on transthoracic echocardiography. Transesophageal study more clearly delineated the extent and origin of the tumor. In addition, an unsuspected tumor in the right ventricle was also identified. These findings were confirmed at surgery, and both masses were excised. The advantages of transesophageal echocardiography in evaluation and management of this unusual subset of patients with cardiac tumor are discussed.     

Transesophageal Echocardiographic Study of Right Atrial Myocardial Infarction and Myocardial Viability

In order to determine the effects of dobutamine on right atrial wall movement, two groups were studied using transesophageal echocardiography. Group A included six patients without ischemic heart disease. Group B included six patients with infarction of the inferior wall of both ventricles and abnormal wall movement of the right atrium. In group A, an increase in the amplitude of right atrial movement was observed with dobutamine at doses of 5 and 10 μ/kg per minute. In group B, infusion of dobutamine did not modify wall akinesis in three patients with right atrial infarction; in the remaining three, alterations of segmental atrial movement were evident, and their responses to dobutamine were related to the patency of right atrial coronary branches. The following conclusions were reached: (1) dobutamine has a positive inotropic effect on atrial myocardium; (2) right atrial ischemia appears in the echocardiogram as altered segmental or global wall movement; (3) dobutamine can be used in the evaluation of atrial myocardial viability.     

Utilization of intraoperative transesophageal echocardiography during repair of congenital cardiac defects: a survey of North American centers

BACKGROUND: Intraoperative transesophageal echocardiography (TEE) has been increasingly utilized during repair of congenital cardiac defects. HYPOTHESIS: The aim of this study was to assess the practice of TEE in this setting. METHODS: A survey was sent to 70 centers in the United States and Canada; replies were obtained from 65 centers (93%). Responses were grouped into four categories: (1) Performance of intraoperative echocardiography, (2) performance practices, (3) equipment and probe issues, (4) billing and reimbursement. Data were available from all responding centers unless specified below. RESULTS: All responding centers employed intraoperative echocardiography, with 98% employing TEE. All responding centers employed intraoperative echocardiography. The majority of centers (72%) utilized intraoperative echocardiography in all cases or all open cases except atrial septal defects, while the remainder employed it selectively. The average duration of TEE experience at responding centers was 6.1 years. Transesophageal echocardiography was primarily the responsibility of cardiologists, with most centers having individuals meeting published TEE training guidelines. The large majority of centers performed both pre- and postbypass TEE studies. Equipment and probes were widely available. All centers disinfected the TEE probe between studies, but for longer times than recommended. CONCLUSION: Utilization of intraoperative TEE during surgery for congenital heart disease is widespread; the results of this survey may be useful to individual institutions as they evaluate their utilization of intraoperative echocardiography.     

Contrast echocardiography in the diagnosis of myocardial stunning

The identification of viable myocardium within dysfunctional myocardium has important clinical implications. By using a microvascular tracer, myocardial contrast echocardiography may have the potential for prediction of myocardial viability in the acute and subacute phases of myocardial infarction. In the case presented, the normal myocardial perfusion observed after intravenous injection of the contrast agent, combined with severe wall motion abnormality following prolonged chest pain, suggested myocardial stunning. This was confirmed by normal coronary angiography and by restoration of normal left ventricular function at 1-month follow-up echocardiography.     

Acute Myocardial Infarction During Transesophageal Echocardiography

We describe the occurrence of acute myocardial infarction during transesophageal echocardiography (TEE) in a patient with atrial fibrillation and underestimated angina. Such a case has not been previously reported in the literature. This case illustrates one of the possible complications of TEE, leading us to suggest systematic sedation in patients with angina in whom TEE is envisaged.