Dobutamine stress echocardiography: initial experience of a Canadian centre.

OBJECTIVE: To investigate the diagnostic accuracy, electrocardiogram and hemodynamic effects and safety of dobutamine stress echocardiography. SUBJECTS: Sixty-one patients with suspected coronary artery disease. All patients underwent coronary arteriography. MAIN RESULTS: The sensitivity of dobutamine stress echocardiography in diagnosis of coronary artery disease in the whole group was 91%. In patients with left anterior descending it was 97%; right 85%; circumflex 76%; three vessel 100%; two vessel 95%; single vessel 77%. Specificity, positive predictive value and accuracy of dobutamine stress echocardiography in diagnosis of coronary disease (whole group) was 57, 94 and 87%, respectively. ST depression of more than 1 mm occurred in 11 patients, ST elevation of more than 1 mm in three patients, T wave inversion in one and T normalization in nine. Significant differences of the effects of beta-blockers were noted on the peak effects of dobutamine as follows: heart rate increase of 46 +/- 22 versus 20 +/- 13 beats/min (P less than 0.0001); systolic pressure increase of 4 +/- 26 versus 22 +/- 19 mmHg (P less than 0.01); diastolic pressure decrease of 18 +/- 16 versus 10 +/- 12 mmHg (P less than 0.03) for patients without or with beta-blockers, respectively. Unifocal ventricular premature beats were noted in 10 patients, atrial premature beats in five and ventricular couplets in one. Angina occurred in 11 patients. Atypical chest pain occurred in seven patients, tingling in 11 and nausea in four. Thirty-six patients were totally asymptomatic. CONCLUSIONS: In this population with high prevalence (85%) of coronary artery disease, dobutamine stress echocardiography had high sensitivity and positive predictive value for coronary disease detection particularly in patients with left anterior descending or three vessel disease. The specificity and accuracy were not as good, but this may reflect the small number of normal patients. Dobutamine was well tolerated and conveniently administered.     

Transesophageal echocardiography using cypress-miniaturized echocardiogram unit: initial clinical experience

Transesophageal echocardiography (TEE) was introduced clinically in the United States in 1987. Recent technologic advances have resulted in the creation of a small portable hand-carried ultrasound (HCU) device that can be easily carried throughout the hospital with greater flexibility for cardiac imaging. These HCU devices have harmonic, color, and spectral Doppler (continuous/pulsed wave). Siemens Medical Solutions USA, Inc. has incorporated a TEE connector, which connects to its Cypress (highly miniaturized echocardiogram unit) and allows the performance of a TEE with this unit, which is mildly heavier than a typical HCU. We describe our initial clinical experience with this unit. The image quality is comparable to routine TEEs, with the advantages of shorter duration, portability, affordable cost, avoiding the use of high-end machine from the echo lab, availability of non-HCU units for other studies, and preventing the need for an echo technician to be involved in the procedure.     

Transesophageal echocardiography in children with congenital heart disease: an initial experience

Transesophageal echocardiography with a single plane (transverse axis), dedicated pediatric probe was performed prospectively in 25 anesthetized children undergoing routine cardiac catheterization or intracardiac surgery, to assess the potential role of this technique in the initial diagnosis, perioperative management and postoperative follow-up of children with congenital heart disease. The group ranged in age from 1 year to 14.8 years (mean 6.1) and weight from 6.5 to 52 kg (mean 22.4). Studies were successful in all patients and no complications were encountered. The results of the transesophageal studies (combined imaging, color flow mapping and pulsed wave Doppler sampling) were correlated both with the results of prior precordial studies and the information obtained at cardiac catheterization. Transesophageal echocardiography provided a more detailed evaluation of the morphology and function of systemic and pulmonary venous return, the atria, interatrial baffles, atrioventricular valves and the left ventricular outflow tract. Additional information was obtained in 15 patients (60%). Problem areas for single plane transesophageal imaging were the apical interventricular septum, the right ventricular outflow tract and the left pulmonary artery. The intraoperative use of transesophageal echocardiography allowed assessment of the surgical repair and monitoring of ventricular function and volume status while the patient was weaned from cardiopulmonary bypass. Transesophageal echocardiography in pediatric patients is of additional value in three main areas: 1) the precise morphologic diagnosis of congenital heart disease, 2) perioperative monitoring, and 3) postsurgical follow-up.     

Transesophageal echocardiography as a quality control tool in thoracoscopic cardiac surgery:4-years' experience

Background The utilization value of intraoperative transesophageal echocardiography in cardiac surgery is more and more important. However,the role of intraoperative transesophageal echocardiography on quality control during thoracoscopic cardiac surgery has not been comprehensively studied. Methods A retrospective study of transesophageal echocardiography application on patients underwent thoracoscopic cardiac surgery from2012 to 2015 was conducted in a single cardiovascular center. General anesthesia and peripheral cardiopulmonary bypass were standardized for all patients. All procedures were performed through 3 holes made in the right chest wall. Transesophageal echocardiography monitoring was routinely utilized in each patient. Results A total of 1387 patients underwent thoracoscopic cardiac surgery were involved in the study. The mean age of patients was 42.8±15.3 years with a female predominance(60.6%). The most common procedures were mitral valve replacement(n=507,36.6%),atrial septal defect repair(n=425,30.6%),and mitral valve plasty(n=294,21.2%). Other main procedures included correction of partial anomalous pulmonary venous connection,cor triatriatum,ventricular septal defect or partial atrioventricular canal,removal of left or right atrial myxoma,and tricuspid valve plasty or replacement. Transesophageal echocardiography monitoring was useful at every stage of surgery without any major associated complications. Forty-four patients(3.2%)required surgical re-interventions immediately following transesophageal echocardiography evaluation. The reasons included unsatisfactory valve plasty,paravalvular leak,prosthetic dysfunction and residual shunting. The incidence of surgical re-intervention,as well as the mortality,decreased annually with increased surgical volume. Conclusions Intraoperative transesophageal echocardiography plays an important role in the quality control of thoracoscopic cardiac surgery.[S Chin J Cardiol 2019;20(2):69-78]     

Transesophageal echocardiography in myocardial ischemia: a review

This article reviews established as well as emerging fields in the application of transesophageal echocardiography (TEE) in the investigation of myocardial ischemia. TEE already has a well defined and established role in stress echocardiography in patients with poor transthoracic acoustic window, and in the detection of intraoperative myocardial ischemia in cardiac and noncardiac surgery. The evaluation of right ventricular ischemia and infarction and the assessment of coronary flow reserve (CFR) are relatively new fields in the application of TEE and the potential of this technique has not yet been fully evaluated. The evidence collected and reviewed in this article is still preliminary but it presupposes a significant role of TEE in the diagnosis and pathophysiological assessment of myocardial ischemia.     

Transesophageal cross-sectional echocardiography

A transesophageal cardiac imaging system is described. This system employs hand-held mechanical sector and linear scanners each having a flexible tube and a small ultrasonic transducer contained within a small oil bag easily swallowed by adults. In the sector scanner, a small transducer in the esophagus rotates alternately and horizontal heart images are displayed. In the linear scanner, a small transducer in the esophagus moves up and down and vertical heart images are displayed. The system was evaluated in 31 adult subjects. In all subjects, stable high quality heart images were observed continuously from base to apex as the transducer was being withdrawn or advanced in the esophagus. In horizontal scans, entire heart images were observed at the level of the atrioventricular valves. In vertical scans, the bifurcation of the pulmonary artery could be observed clearly. There was little difference in the image quality among subjects.     

Ergonovine stress echocardiography: Recent experience and safety in our centre

AIM: To study recent experience and safety of ergonovine stress echocardiography in our centre.METHODS: In this study we collected the clinical variables of patients referred since 2002 for ergonovine stress echocardiography, in addition to indications, the results of this test, complications, blood pressure and heart rate values during the test and the number and results of tests requested before this technique.RESULTS: We performed 40 tests in 38 patients, 2 tests were carried out to verify therapy efficacy. The prevalence of classic cardiovascular risk factors was low and the most frequent indication was chest pain (57.5%). Coronary angiography was performed in 32 patients, and showed normal coronary arteries in 27 patients and non-significant stenosis in 5 cases. In 16 patients, coronary angiography was carried out after a positive or inconclusive ischemia test. Another 6 patients had a normal stress test (5 exercise electrocardiography tests and 1 nuclear imaging test). Of the 40 ergonovine stress echocardiography tests, 6 were positive (4 in the right coronary artery territory and 2 in the circumflex coronary artery territory), all of them by echocardiographic criteria, and by electrocardiographic criteria in only 3 (50%). The presence of non-significant coronary artery stenosis was more frequent in patients with positive ergonovine stress echocardiography (50% vs 6%, P = 0.038), and were related to ischemic territory. During the maximum stress stage, there was a higher systolic (130.26 ± 19.17 mmHg vs 136.58 ± 27.27 mmHg, 95% CI: -12.77 to 0.14 mmHg, P = 0.055) and diastolic blood pressure (77.89 ± 13.49 mmHg vs 83.95 ± 15.73 mmHg, 95% CI: -10.41 to -1.69 mmHg, P = 0.008) than at the baseline stage, and the same was registered with heart rate (73 ± 10.96 beats/min vs 79.79 ± 11.72 beats/min, 95% CI: -9.46 to -4.11 beats/min, P < 0.01). Nevertheless, there were only 2 hypertensive reactions during the last stage, which did not force a premature end to the test, without sustained tachy or bradyarrhythmias, and the technique was well tolerated in 58% of cases. A unique complication (2.5%) of this test was a prolonged vasospasm with a slight increase in necrosis biomarkers, however, this was without repercussion.CONCLUSION: Ergonovine stress echocardiography can be performed with safety, is well tolerated in the majority of cases, and is useful for determining the ischemia mechanism in selected cases.     

Transesophageal echocardiography and stroke

Only coronary artery disease and cancer kill more people than stroke in the United States. Transesophageal echocardiography (TEE) is a semi-invasive ultrasound cardiac imaging technique that provides superior anatomic detail as well as functional information. Searching for a cause of cerebral ischemia is the most common indication for TEE in cardiac ultrasound laboratories. Although TEE is not superior to transthoracic imaging for identifying all sources of cardiac embolism, its ability to more sensitively detect atrial septal aneurysm, patent foramen ovale, and aortic atheroma has been well described in recent years. Care must be exercised in using TEE to identify suspected cardiac sources of embolism, as potential etiologies described in the literature are not equally established by rigorous clinical trials. Confidence level in cause and effect for any cardiac pathology identified must be factored into therapeutic decisions.     

Transesophageal echocardiography in stroke

Fifteen to twenty percent of all ischemic strokes are of cardioembolic origin. Since the introduction of transesophageal echocardiography (TEE) in 1976, its clinical application in the diagnosis of cardioembolic stroke has expanded greatly. Comprehensive literature has accumulated showing TEE as an invaluable tool for the diagnosis of cardioembolic stroke because it allows superior visualization of established embolic stroke risk factors (apical thrombus, endocarditis) as well as the identification of newer factors (patent foramen ovale, aortic arch plaques, etc.). In this article, we summarize the present status of TEE in the diagnostic workup of stroke.     

Transesophageal echocardiography: procedures and clinical application

In existence for more than a decade, transesophageal echocardiography has gained renewed interest because of technologic advances including high resolution transducers, multiple imaging planes and Doppler color flow mapping. The heart is imaged from within the esophagus with a gastroscope-mounted transducer, obviating technical difficulties encountered in transthoracic echocardiography. Transesophageal echocardiography is utilized intraoperatively to monitor patients undergoing open heart surgery or high risk cardiac patients undergoing noncardiac surgery. In the ambulatory patient, the procedure facilitates imaging of many structures (including the left atrium and appendage, mitral and aortic native and prosthetic valves and thoracic aorta), with better resolution than that obtained by routine transthoracic echocardiography. Technical aspects of transesophageal echocardiography as well as its indications and limitations are reviewed.     

Transesophageal echocardiography: instrumentation and system controls

Transesophageal echocardiography (TEE) is a semi-invasive, monitoring and diagnostic tool, which is used in the perioperative management of cardiac surgical and hemodynamically unstable patients. The low degree of invasiveness and the capacity to visualize and assimilate dynamic information that can change the course of the patient management is an important advantage of TEE. Although TEE is reliable, comprehensive, credible, and cost-effective, it must be performed by a trained echocardiographer who understands the indications and the potential complications of the procedure, and has the ability to achieve proper acquisition and interpretation of the echocardiographic data. Adequate knowledge of the physics of ultrasound and the TEE machine controls is imperative to optimize image quality, reduce artifacts, and prevent misinterpretation of diagnosis. Two-dimensional (2D) and Motion (M) mode imaging are used for obtaining anatomical information, while Doppler and Color Flow imaging are used for information on blood flow. 3D technology enables us to view the cardiac structures from different perspectives. Despite the recent advances of 3D TEE, a sharp, optimized 2D image is pivotal for the reconstruction. This article describes the relevant underlying physical principles of ultrasound and focuses on a systematic approach to instrumentation and use of controls in the practical use of transesophageal echocardiography.