J. Geoffrey Stevenson

ACC/AHA clinical competence statement on echocardiography: A Report of the American College of Cardiology/American Heart Association/American College of Physicians–American Society of Internal Medicine Task Force on Clinical Competence Developed in Collaboration with the American Society of Echocardiography, the Society of Cardiovascular Anesthesiologists, and the Society of Pediatric Echocardiography

Preamble......688 References......708 The granting of clinical staff privileges to physicians is a primary mechanism used by institutions to uphold the quality of care. The Joint Commission on Accreditation of Health Care Organizations requires that the granting of continuing medical staff

Guidelines for optimal physician training in echocardiography Recommendations of the American Society of Echocardiography Committee for Physician training in Echocardiography

Over the past few years, the clinical use of echocardiography has continued to expand. Echocardiographic techniques are used widely to define normal and abnormal cardiac anatomy, evaluate cardiac chamber sizes and dynamics, assess valvular and pericardial diseases, detect intracavitary masses, measure pressure gradients across discrete stenoses, determine flow volumes, detect and assess the severity of valvular regurgitation, demonstrate and quantitate intracardiac shunts, and measure the timing of cardiac events. These and related applications have led to the increasing use of echocardiography in the diagnostic evaluation of many cardiac disorders. Echocardiography requires considerable theoretical knowledge, technical skill and practical experience to be used in an optimal manner. Previous publications have suggested guidelines for physician training in the techniques of M-mode and 2-dimensional echocardiography. The clinical applications of echocardiography continue to grow, however, and Doppler techniques for evaluating blood flow have become an established component of the echocardiographic evaluation of many disorders. This article presents the current recommendations of the American Society of Echocardiography as to the background knowledge, the nature and amount of practical experience, and the type of training site that are optimal for the training of physicians who take responsibility for the conduct and interpretation of echocardiographic studies.

Transesophageal Echocardiography During Repair of Congenital Cardiac Defects: Identification of Residual Problems Necessitating Reoperation

One advantage of intraoperative transesophageal echocardiographic (TEE) evaluation during surgery for congenital heart disease is detection of suboptimal repairs, thus providing the opportunity to return to cardiopulmonary bypass (CPB) to repair residual defects. The purpose of this study was to evaluate the impact of TEE on decisions to return to CPB. Two-hundred-thirty infants and children with a variety of defects were studied with size-appropriate TEE probes. Patients were grouped by anatomic defect or surgical procedure for which TEE was requested. After CPB, pre- and post-CPB TEE anatomic, functional, and flow evaluations were compared. TEE findings prompted a return to CPB to repair residual defects in 17 of 230 (7.4%) patients. By diagnosis, return to CPB occurred in 9 of 28 (32%) patients with left ventricular outflow tract obstruction, 5 of 78 (6.4%) patients with ventricular septal defect, 1 of 16 (6%) patients with switch-repaired transposition, 1 of 32 (3%) with aortic valve disease, and 1 of 3 with double outlet right ventricle. All post-CPB diagnoses were confirmed during reoperation. Although post-CPB TEE provided reassuring information in patients with other diagnoses, TEE impact on return to CPB appears to be significant in a small group of primary diagnoses. The sensitivity and specificity of TEE determination of the need for reoperation were 89% and 100%, respectively. By identifying the site, severity, and mechanism of residual problems, TEE offers substantial utility in detection of residual problems in need of reoperation.

Incidence of Complications in Pediatric Transesophageal Echocardiography: Experience in 1650 Cases☆☆☆

The purpose of this study was to tabulate the complications encountered in 1650 patients who underwent pediatric transesophageal echocardiography. The occurrence of complications and their type and severity were prospectively recorded. The patients had a mean age of 3.6 years (range 1 day to 21 years) and a mean weight of 17.2 kg (range 1.6 to 118 kg). Of the 1650 cases, 1534 were intraoperative. Most patients studied (97%) had congenital heart disease. Complications occurred in 52 (3.2%) of the 1650 patients. Failure to insert the probe occurred in 13 (0.8%) patients; if those cases are not counted as complications, the incidence of overall complications falls to 2.4%. Airway obstruction occurred in 14 (1%) patients, right mainstem advancement of the endotracheal tube in 3 (0.2%), inadvertent tracheal extubation in 8 (0.5%), vascular compression in 10 (0.6%), and single additional complications in 4 (0.2%). No significant bleeding, arrhythmias, esophageal injuries, or deaths occurred. Failure to insert the probe and airway complications occurred predominantly and significantly in smaller subjects. It is concluded that the incidence of complications during pediatric transesophageal echocardiography is low.

Comparison of Several Noninvasive Methods for Estimation of Pulmonary Artery Pressure

Noninvasive estimation of pulmonary artery pressure is an important component of cardiac ultrasound studies. A number of methods are available for estimation of pulmonary pressure, each with varying degrees of reported accuracy. To assess feasibility and accuracy, noninvasive pulmonary artery pressure estimates were performed in infants and children at the time of catheterization. Patients were examined prospectively until there were 50 patients, in whom each of six methods for estimation of pulmonary pressure had been accomplished. All patients had tricuspid and pulmonary regurgitation of less than severe degree and no structural, flow, or electrocardiographic abnormality known to compromise the six methods. Systolic pressure was estimated by the Burstin method and also from peak tricuspid regurgitation velocity. Mean pressure was estimated by acceleration time divided by ejection time from waveforms obtained from the right ventricular outflow tract and main pulmonary artery. Diastolic pressure was estimated by systolic time intervals and from end-diastolic pulmonary regurgitation velocity. Noninvasive estimates were compared with simultaneous or nearly simultaneous catheterization measurements. For systolic pressure Burstin estimates were accomplished in 89% with high accuracy (r = 0.97). Tricuspid regurgitation velocities were recorded in 82%, also with high accuracy (r = 0.96). Waveforms for mean pressure estimation were recorded in 98% to 100% of patients. Those from the right ventricular outflow tract corresponded well with catheterization pressures (r = 0.94), whereas those recorded from the main pulmonary artery offered poor prediction of pulmonary pressure (r = 0.63). Systolic time interval measurements were accomplished in only 65% and did not correlate highly with catheterization (r = 0.84). Diastolic pressure estimates based on pulmonary regurgitation velocity were recorded in 98% of subjects with high accuracy (r = 0.96). Each method had advantages and disadvantages. The Burstin method was accurate but technically demanding and is reported to be limited by heart rate and significant right-sided regurgitation. Peak tricuspid velocities proved unexpectedly difficult to record in some patients but when successful, provided excellent prediction of pressure. Recording of waveforms for ratios of acceleration time to ejection time proved easy, but accuracy was high only for outflow tract waveforms. Peculiarities of main pulmonary artery flow may have led to poor accuracy for ratios measured from that site. For diastolic pressure estimation, systolic time interval records were the most difficult to obtain and did not provide useful accuracy. In contrast, pulmonary regurgitation velocities were easily obtained and provided high accuracy results. This is a selected pediatric series, evaluating methods in nearly ideal circumstances.(ABSTRACT TRUNCATED AT 400 WORDS)

American College of Cardiology/American Heart Association Clinical Competence Statement on Echocardiography

Developed in Collaboration with the American Society of Echocardiography, the Society of Cardiovascular Anesthesiologists, and the Society of Pediatric Echocardiography

Noninvasive determination of pressure gradients in children: Two methods employing pulsed Doppler echocardiography

Pulsed Doppler echocardiography has been considered poorly suited for high velocity blood flow measurement, because of the problem of signal aliasing. Two methods for reduction of aliasing in a pulsed system were evaluated in an attempt to measure flow velocities characteristic of significant pressure gradients. With the angle correction method, carrier frequency, pulse repetition frequency and intercept angle were manipulated using a commercially available two-dimensional pulsed Doppler system. Forty children undergoing cardiac catheterization were studied. Gradients of 60 to 70 mm Hg were accurately predicted by this method, and gradients above 90 mm Hg were underestimated. Overall correlation (r) value was 0.95. The method is limited primarily by the introduction of potential error in measurement of intercept angle; it is advantageous in that it can be attempted using currently available pulsed Doppler echographic systems. With the multiple sample volume method, pulse repetition frequency was increased through the addition of extra sample volumes. Carrier frequency was minimized and angle correction was not employed. Thirty-nine children underwent cardiac catheterization using a prototype instrument. Excellent agreement between Doppler predictions and actual gradients was found for gradients up to 100 mm Hg (r = 0.99). Although this method requires new instrumentation, it is advantageous in that gradients are accurately predicted and cannot be overestimated. Both methods retain the advantages of pulsed Doppler study for comprehensive flow evaluation and reference their quantitative application within a two-dimensional echographic format. Neither method is simple, and each has been validated only in pediatric subjects.

Adherence to Physician Training Guidelines for Pediatric Transesophageal Echocardiography Affects the Outcome of Patients Undergoing Repair of Congenital Cardiac Defects

Intraoperative echocardiography is widely accepted as being useful during a variety of cardiac surgical procedures. Several applications have been reported during the repair of congenital cardiac defects. National organizations, including the Society of Pediatric Echocardiography and the American Society of Echocardiography, have published guidelines for the provision of at least minimum standards of training and quality for a variety of cardiac ultrasonography procedures. Few data exist concerning whether adherence to such guidelines affects the performance of ultrasonography studies or patient outcome. This study is an outcome-based analysis of intraoperative transesophageal echocardiography performed during repair of congenital cardiac defects during 5-month periods in 2 different years. In year 1, examinations were performed by physicians who met the guidelines for pediatric transesophageal echocardiography published by the American Society of Echocardiography. Those performing examinations in year 2 did not meet those guidelines. Significant differences between the years were found for adequacy of echocardiographic recordings, return to bypass for further surgery based on echocardiographic results, and prevalence and detection of significant residual problems by intraoperative echocardiography. It is concluded that patient outcome is affected beneficially when intraoperative transesophageal echocardiography is performed by physicians who meet the published guidelines, and whose sole responsibility is the performance of echocardiography.

ACC/AHA Clinical Competence Statement on Echocardiography

Preamble......688 References......708 The granting of clinical staff privileges to physicians is a primary mechanism used by institutions to uphold the quality of care. The Joint Commission on Accreditation of Health Care Organizations requires that the granting of continuing medical staff

Doppler echocardiography: Applications, limitations and future directions☆

On the basis of principles that are similar to (but differ slightly from) those that underlie M mode and two dimensional techniques, pulsed Doppler echocardiography permits evaluation of intracardiac blood flow noninvasively. This technique is helpful in the diagnosis and management of patients with valvular and congenital heart disease, and in some circumstances provides information not available from M mode or two dimensional imaging. Despite several notable limitations, pulsed Doppler echocardiography is a useful diagnostic technique whose clinical application is likely to increase as future technologic improvements occur.