CASE REPORTS. The Use of Small Personal Ultrasound Devices by Internists Without Formal Training in Echocardiography

Transcription

1 Eur J Echocardiography (2003) 4, doi: /euje CASE REPORTS The Use of Small Personal Ultrasound Devices by Internists Without Formal Training in Echocardiography J. M. DeCara, R. M. Lang, R. Koch, R. Bala, J. Penzotti and K. T. Spencer Department of Medicine, Section of Cardiology, University of Chicago Medical Center, Chicago, IL 60637, U.S.A. Aims: Hand-held ultrasound devices will probably be used for bedside cardiac diagnoses by internists without formal training in echocardiography. We compared the accuracy of hand-held ultrasound devices studies performed by expert echocardiographers vs internal medicine residents with brief training in echocardiography. Methods and Results: Three internal medicine residents participated in an organized training program in echocardiographic principles, image acquisition, and interpretation. Subsequently, these residents and three echocardiographers imaged 300 patients with a hand-held ultrasound device. Sensitivity, specificity, positive and negative predictive values for internist- and echocardiographerperformed studies for the detection of cardiac abnormalities were compared using a full-featured exam as the gold standard. Resident- and echocardiographer-performed scans had similar overall sensitivity and specificity. There was a higher positive predictive value for the echocardiographer-performed scans. For clinically important findings (likely to affect patient care), sensitivity was slightly but significantly higher for the echocardiographerperformed scans. Clinically important findings most often missed by residents included regional wall motion abnormalities, intra-cardiac thrombus, right ventricular dysfunction and non-trivial pericardial effusions. Conclusion: Hand-held ultrasound devices provide useful screening tools for cardiac disease but should not replace a standard platform study. Training guidelines and competency evaluation are needed if these devices are to be used by non-echocardiographers for clinical decision-making. (Eur J Echocardiography 2003; 4: ) 2002 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved. Key Words: hand-held ultrasound device; training; internists; accuracy. Introduction Recent decades have been marked by substantial advances in echocardiography including the development of three-dimensional, stress, and contrast echocardiography. In addition to improving upon the diagnostic Address for correspondence and reprints: Jeanne M. DeCara, MD, University of Chicago Medical Center, 5841 S. Maryland Ave. MC 5084, Chicago, IL 60637, U.S.A. Tel: (773) ; Fax: (773) ; jdecara@medicine.bsd.uchicago.edu Received 19 April 2002; revised manuscript recived 8 August 2002; accepted 13 August capabilities of echocardiography, there has also been a thrust to make current two-dimensional technology more widely accessible by developing hand-held ultrasound devices, thereby redefining the notion of a portable echocardiogram. The first description of such a device for clinical use was by Roelandt in 1978 [1]. This linear array machine, the Minivisor (Organon, Teknika), weighed only 1.5 kg but had limited imaging capability, a single gain control, and a display format of only 2 4 cm [2]. The next generation of such devices arrived in the 1980s, providing a 5-lb mechanical sector scanner with two-dimensional imaging and a larger display screen. Though lacking in freeze-frame, M-mode, /03/$30.00/ The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved.

2 142 J. M. DeCara et al. Doppler, or recording features, initial clinical experience with this hand-held machine was promising [3,4]. In recent years, these miniature devices have become increasingly sophisticated, now allowing colour flow Doppler, freeze-frame, and two-dimensional measurements as well as limited storage capability. While the hand-held cardiac ultrasound devices do not have all of the technological features of the standard full-featured systems, their immediate availability to answer targeted clinical questions with regard to pericardial effusions, wall motion, and LV systolic function provides the clinician with the potential to make clinical decisions at the bedside without delay [5 8]. Though it is clear that sonographers may be better skilled at image acquisition, particularly in the US, recent investigation has demonstrated that these handheld devices, when used by cardiologists with at least level II training, serve as useful adjuncts to the physical exam and assist in bedside diagnoses [9]. As these machines become more widely available, potential users could include cardiologists without expertise in echocardiography, emergency room physicians, nursepractitioners, cardiac surgeons, and internists among others. This raises the question as to how much echocardiographic training among hand-held ultrasound users will ensure competency when employing these devices for clinical decision-making. The aim of the present study is to determine the diagnostic accuracy of the hand-held ultrasound device when used by fully trained echocardiographers compared to senior internal medicine residents who have undergone a limited but organized instructional programme in echocardiography. Study Design Study Population Three hundred adult inpatients and outpatients referred to the non-invasive cardiac imaging laboratory for clinically indicated studies were recruited into the study. Patients with limited echo windows were not excluded from the study. ICU patients and patients on ventilators were not included in the study population. Methods All study participants underwent a sonographerperformed exam using the full-featured echocardiographic imaging system (Sonos 5500, Agilent). The patients were then scanned with the Optigo machine by one of three cardiologists with level III training in echocardiography (n=149) or one of three internal medicine residents (n=151). The residents first completed an echocardiographic training programme consisting of 20 h of didactic instruction. This instruction included information on the basic principles of cardiac Table 1. Criteria for clinically important echocardiographic findings. Echocardiographic findings LAE/RAE LVH LV dysfunction RV dysfunction RWMA TR PR MR AI AS PS MS MVP Pericardial effusion Thrombus Congenital defect HCM SBE Severity Severe Severe Mild Moderate Moderate Mild Mild Small LAE=left atrial enlargement; RAE=right atrial enlargement; LVH=left ventricular hypertrophy; LV=left ventricular; RV=right ventricular; RWMA=regional wall motion abnormalities; TR=tricuspid regurgitation; PR=pulmonic regurgitation; MR=mitral regurgitation; AI=aortic regurgitation; AS=aortic stenosis; PS=pulmonic stenosis; MS=mitral stenosis; MVP=mitral valve prolapse; congenital defect=atrial septal defect, patent foramen ovale, ventricular septal defect; HCM=hypertrophic cardiomyopathy; SBE=subacute bacterial endocarditis. ultrasound, the standard views needed to answer specific clinical questions, how to optimize imaging conditions, and echocardiogram reading with experienced readers focusing on the evaluation of global and regional wall motion and valvulopathies. In addition, each resident had one-on-one instruction on image acquisition with a sonographer and performed 20 transthoracic echocardiograms under sonographer supervision prior to scanning patients enrolled in this study. In all physicianperformed studies the clinicians performing the study were blinded to the results of the sonographerperformed study. The only patient information provided to the physician was the indication for the study. All physician-performed studies were interpreted by the physician at the time of the scan. A datasheet listing common echo-derived findings was provided to each clinician in order to document the study interpretation. The listed findings were noted by the physician to either be present or absent. Abnormalities were then graded on a scale of zero to three according to increasing severity (0=trace, 1=mild, 2=moderate, 3=severe). After the physicians recorded their findings, an experienced echocardiographer uninvolved with the study read the complete, sonographer-performed studies and the findings were entered on to the same datasheet. For each clinical finding, the severity that was deemed to be clinically significant (likely to affect patient care) was defined (Table 1). The sensitivity, specificity, positive predictive value, and negative predictive value were

3 Use of Small Personal Ultrasound Devices 143 Table 2. Baseline echocardiographic findings on highend platform studies. Echocardiographic finding Patient group Echocardiographer Resident AI 36 (24) 50 (33) AS 6 (4) 5 (3) Congenital defect 1 (0 6) 2 (1 3) HCM 1 (0 6) 0 (0) LAE 92 (61) 71 (47)* LV dysfunction 46 (31) 50 (33) LVH 71 (47) 51 (34) MR 89 (59) 102 (68) MS 2 (1 3) 1 (0 6) MVP 1 (0 6) 2 (1 3) Normal 5 (3 3) 2 (1 3) Pericardial effusion 17 (11) 31 (20) PI 38 (25) 47 (31) PS 0 (0) 0 (0) RAE 47 (31) 40 (27) RV dysfunction 1 (13) 27 (18) RWMA 14 (9 3) 20 (13) SBE 1 (0 6) 0 (0) Thrombus 3 (2) 2 (1 3) TR 105 (70) 125 (83) ()=percentage of the total Sonos finding per patient group, *P=0 03, P=0 02. Abbreviations as in Table 1. calculated for each clinically significant finding for both the resident-performed and echocardiographerperformed studies. The sonographer-performed Sonos 5500 studies were considered the gold standard for comparison. Statistics The resident-performed and echocardiographerperformed results were compared statistically using a z-test (SigmaStat, Jandel). Differences in the prevalence of baseline and clinically important findings between echocardiographer and resident patient groups were compared using the Fisher exact test. P values less than 0.05 were considered statistically significant. Results The vast majority of the patients had abnormal studies. There were only five (3.3%) completely normal studies in the echocardiographer patient group and two (1.3%) normal studies in the resident patient group. There were a similar number of echocardiographic abnormalities noted on the full-featured studies in both the echocardiographer and resident-patient groups. As shown in Table 2, the populations were comparable with respect to pathology with the exception of a greater number of patients with left atrial enlargement in the resident group and more patients with left ventricular hypertrophy in the echocardiographer group. As seen in Fig. 1, resident-performed studies with the Optigo machine resulted in similar overall sensitivity compared to echocardiographer-performed studies for the detection of echocardiographic abnormalities (63% and 65% respectively; P=ns). The specificity of the Optigo to identify abnormal findings was high for studies performed by echocardiographers and residents alike. Resident-performed studies resulted in slightly lower overall specificity of 92% compared to 95% for the echocardiographer-performed Optigo studies, but this Figure 1. (a) Sensitivity and specificity comparisons between echocardiographer-performed studies and residentperformed studies demonstrated moderate overall sensitivity and high specificity for both groups. (b) Comparisons between echocardiographer-performed and resident-performed scans showed a significantly higher overall positive predictive value but similar negative predictive value for echocardiographer-performed studies.

4 144 J. M. DeCara et al. Table 3. Clinically important findings detected by highend platform studies. Echocardiographic finding Patient group Echocardiographer Resident AI 10 (7) 21 (14) AS 6 (4) 5 (3) Congenital defect 1 (0 6) 2 (1 3) HCM 1 (0 6) 0 (0) LAE 4 (2 6) 4 (2 6) LV dysfunction 38 (25) 47 (31) LVH 1 (0 6) 0 (0) MR 52 (35) 47 (31) MS 2 (1 3) 1 (0 6) MVP 1 (0 6) 2 (1 3) Normal 5 (3) 2 (1 3) Pericardial effusion 9 (6) 7 (5) PI 1 (0 6) 4 (2 6) PS 0 (0) 0 (0) RAE 2 (1 3) 4 (2 6) RV dysfunction 19 (13) 27 (18) RWMA 14 (9) 20 (13) SBE 1 (0 6) 0 (0) Thrombus 3 (2) 2 (1 3) TR 23 (15) 12 (8)* ()=percentage of the total Sonos finding per patient group, *P=0 03. Abbreviations as in Table 1. was not statistically significant (Fig. 1). Similarly, the negative predictive value of Optigo scans for detecting echocardiographic abnormalities was 91% for echocardiographer-performed scans compared to 90% for resident scans, P=ns (Fig. 1). Positive predictive values were higher for echocardiographer scans compared to resident scans with values of 75% and 67%, respectively. This was statistically significant with a P value of (Fig. 1). Table 3 demonstrates the distribution of clinically important findings, as determined by the Sonos 5500 study for both patient groups. There were 83 patients with clinically significant abnormalities on the fullfeatured study in the echocardiographer group and 86 patients with clinically significant findings in the resident group. Overall, in the patients scanned by echocardiographers, there were 193 echocardiographic findings on the Sonos 5500 studies that were deemed clinically important. Similarly, in patient group scanned by residents, 207 echocardiographic findings identified on the Sonos 5500 scan were labelled clinically important. There were more patients with significant tricuspid regurgitation in the echocardiographer group, but otherwise the distribution of important findings in both patient groups was similar. In contrast to the results for all observations, for these major findings echocardiographer-performed studies had a sensitivity of 88%, which was significantly higher than the 80% sensitivity of resident-performed studies (Fig. 2). The specificity to detect clinically important findings was similar between groups, with echocardiographers achieving a specificity of 98% compared to 97% for resident scans. There were no significant differences in the positive and negative predictive values for the detection of clinically important findings noted between patient groups (Fig. 2). In total, there were 18 categories of echocardiographic abnormalities identified by the sonographer-performed gold-standard studies that were deemed clinically Figure 2. (a) When analysis is limited to clinically important findings only, sensitivity and specificity values increased in both groups but scans performed by echocardiographers had a significantly higher sensitivity compared to those performed by residents. (b) Positive and negative predictive values increased in both patient groups when only clinically important findings were analysed. PPV=positive predictive value; NPV=negative predictive value.

5 Use of Small Personal Ultrasound Devices 145 Table 4. Undetected clinically important findings: echocardiographer vs resident Optigo comparison. Abnormality Number Optigo missed/ Total number of important Sonos findings Echocardiographer important yet missed by either the echocardiographer or the resident in the Optigo scans. Table 4 lists these missed echocardiographic findings and compares the relative distribution of missed diagnoses on the Optigo scans performed by echocardiographers vs those performed by residents. Fourteen percent of clinically important echocardiographic findings were missed by echocardiographers as compared with 23% of important findings missed by residents, P=0 02. As shown, in comparison to echocardiographer-performed scans, resident-performed scans tended to miss substantially more pericardial effusions graded more than trace in severity (57% vs 22%), right ventricular dysfunction (56% vs 26%), and left ventricular regional wall motion abnormalities (45% vs 21%). Though intra-cardiac thrombus was less commonly noted, the residents missed all such findings using the hand-held device. In addition, clinically important AI was uncommon but never missed on the echocardiographer-performed scans in contrast to the resident-performed scans. Aortic stenosis, which was detected based upon two-dimensional visual assessment of leaflet movement and valve calcification, was missed nearly equally in both patient groups. None of the comparisons in Table 4 reached statistical significance. Discussion Resident AI 0/10 (0) 4/21 (19) AS 3/6 (50) 3/5 (60) Atrial enlargement 1.6 (17) 5/8 (63) Congenital defect 1/1 (100) 0/2 (0) HCM 0.1 (0) 0/0 (0) LV dysfunction 4/38 (3) 2/47 (4) LVH 0/1 (0) 0/0 (0) MR 5/52 (9) 6/47 (13) MS 0/2 (0) 0/1 (0) MVP 0/1 (0) 1/2 (100) RV dysfunction 5/19 (26) 15/27 (56) RWMA 3/14 (21) 9/20 (45) Pericardial effusion 2/9 (22) 4/7 (57) PR 1/1 (100) 1/1 (100) PS 0/0 (0) 0/0 (0) SBE 0/1 (0) 0/0 (0) Thrombus 0/4 (0) 2/2 (100) TR 1/23 (6) 0/12 (0) ()=percentage of the clinically important Sonos findings per patient group, P=ns for all comparisons. Abbreviations as in Table 1. Currently, certification by the National Board of Echocardiography requires a physician to be a cardiologist with at least level II training in echocardiography. This entails a minimum of six months of focused echocardiography training and the performance and interpretation of 300 transthoracic studies [10 12]. Such intense lengthy training among practising clinicians may not be practical for limited exams with hand-held devices. Other diagnostic modalities such as flexiblesigmoidoscopy, limited emergency room echocardiography, and office stress testing are often taught in organized short courses comprised of didactic and manual instruction. The adequacy of these brief courses is controversial [13 20]. It has not previously been demonstrated that this degree of training would be sufficient for responsible use of miniature echocardiographic devices amongst non-echocardiographers. The results of the present study suggest that nonechocardiographers can be trained in a limited but organized fashion to perform and interpret hand-held ultrasound studies for the detection of cardiac abnormalities with similar overall sensitivity to studies performed by fully trained echocardiographers. Of note in this study however, were the substantial differences in the sensitivity of hand-held devices when used by physicians with limited training to detect clinically important findings, particularly those that are often urgent indications for echocardiograms such as regional wall motion abnormalities, significant pericardial effusions, and RV dysfunction. Failure for these and other differences noted in Table 4 to reach statistical significance may be due to low event rates for each individual abnormality. Nonetheless, the significant differences in the total number of missed yet important findings between the patient groups and the individual trends for each finding are concerning in that significant cardiac events may be under-diagnosed and, therefore, not treated if the diagnostic work-up ends with the Optigo study. Furthermore, there are significant differences in overall positive predictive value, which suggests that physicians with brief training are likely to overcall abnormalities, leading to false positive results, which may then result in inappropriate clinical decisionmaking and treatment. It is unclear whether the reason for such differences is due to inadequate image acquisition on the part of the non-echocardiographer or whether the problem lies in the interpretation of acquired images. Both are necessary in order for the non-echocardiographer to arrive at an accurate echocardiographic diagnosis; yet, skill in interpretation may perhaps be the most difficult goal to accomplish within the limitations of a brief training programme. Since echocardiographers undergo an extensive training process, it is possible that they were more attentive to subtle echocardiographic details during their study interpretations, resulting in a higher diagnostic yield. However, even expert echocardiographers missed 3% of cases of LV dysfunction and 21% of cases with regional wall motion abnormalities. This was likely due a combination of factors. The hand-held device used in this study did not have harmonic capabilities. For this reason, assessment of global and regional LV function

6 146 J. M. DeCara et al. was difficult in patients with poor acoustic windows. In addition, American cardiologists do not routinely image patients. Accordingly, their ability to obtain good images in all views may be lower than expected, particularly compared with cardiologists in other countries where it is customary for physicians to perform the scans. In any event, our data suggests that limited training in echocardiography prior to the use of the Optigo ultrasound device provides reasonably good information as a quick screening exam which would complement the physical exam but in no way should replace the standard full-featured study performed by a sonographer and interpreted by an experienced echocardiographer adept at detecting the subtle abnormalities important in making discriminating diagnoses. This is especially true when the decision to administer or withhold potential treatments such as pericardiocentesis, anticoagulation and antiplatelet agents for acute coronary syndrome, and percutaneous intervention for chest pain in the presence of uninterpretable electrocardiograms are heavily influenced by the echocardiographic examination. The exact degree of training required for responsible use of hand-held ultrasound devices is uncertain. Preliminary data from other investigators using much briefer durations of training targeted to the diagnosis of only a few echocardiographic abnormalities (i.e. LV dysfunction, the presence of pericardial effusion, the presence of mitral regurgitation) have resulted in moderately good agreement with standard echocardiograms using a full-featured imaging system [5,21]. The limited training that the residents received in our study was intense and more comprehensive than in other studies. In addition, since each resident scanned 50 patients, these physicians underwent significant learning curves. All of this suggests that the casual user of the hand-held device might perform less well than the residents in our study. Given that the residents in our study failed to discern subtle yet clinically important findings, perhaps a targeted approach to instruction in and use of handheld ultrasound devices by non-echocardiographers would be more appropriate. As a screening test, the Optigo machine holds promise: it has a moderately high sensitivity, is safe, relatively inexpensive, user friendly, and portable, thereby easily accessible. When used by clinicians with limited training, the lower sensitivity to detect clinically important findings indicates a need for structured training, competency guidelines, and quality assurance. Implicit in this is the need for either full level II echocardiographic training in accordance with the guidelines for the American Society of Echocardiography prior to using hand-held devices for clinical decision-making or use of such machines in consultation with an experienced echocardiographer. Hand-held machines currently available offer a variable degree of technology. For instance, Doppler, tissue harmonics and M-mode capabilities are not present on all types of hand-held devices. Such machines can be used to perform only directed studies and, evaluation of clinical problems such as diastolic dysfunction, valve stenosis and wall motion is limited. Secondly, there is one model of the hand-held ultrasound device that can be interfaced with a small VCR, though this limits the portability of the device and its ease of use at the point of care. For the majority of commercially available devices, however, there is limited ability to archive images and no associated reporting system. For this reason, a standard echocardiogram on a full-featured machine should be ordered in all cases where a focused echocardiogram has been done. Lastly, in the current era of medical economics, it is worthwhile noting that reimbursement for these relatively inexpensive devices is likely to be withheld unless a mechanism for quality assurance and documentation is established. Limitations The exclusion of ventilated ICU patients in this study introduces a degree of referral bias. However, hand-held devices in ICU ventilated patients have been shown to be of limited value. It is in such sick, and technically challenging, patients that a full-featured imaging system should be used to collect adequate images upon which to base clinical decisions [22]. Echocardiographer-performed and resident-performed studies were done on two separate patient groups. While all patients were taken from the pool of patients routinely referred to the echocardiography laboratory at our institution, it is conceivable that there might have been more patients with poor acoustic windows in one or the other group. Though this information was not formally collected, one would expect that a large disproportion of patients with limited acoustic windows between groups would be reflected in significant differences in overall sensitivity between patients groups, which were not seen here. It is also not possible to be entirely certain that the abnormalities found in each patient group were visually similar. For example, LV thrombi may be larger in patients from the echocardiographer group compared to patients from the resident group. Similarly, wall motion abnormalities may be subtler in one patient group compared to the other. While an alternative study design that included a full-featured echocardiogram in addition to two hand-held echocardiograms per patient (echocardiographers and residents scanning the same patients) would have allowed comparison of the exact same datasets, this was deemed logistically impractical in the setting of a busy clinical laboratory given time constraints and patient tolerance. To account for this limitation, we studied a rather large number of patients (n=300) in which echocardiographers scanned 149 patients and residents scanned 151 patients. Using this design, clinically important findings were randomly distributed between the two patient groups and were present in a similar, though not exactly equal, proportion in the two groups. The Optigo machine used in this study did not have the capacity for M-mode. Residents were not instructed

7 Use of Small Personal Ultrasound Devices 147 on the use of two-dimensional measurement features of the Optigo machine since this would require additional scanning time, obviating the potential benefit of a quick scan. In cases where the echocardiographic abnormalities were related to dimension, differences in the detection rates between groups may have been due to the largely subjective nature of assessment. For this reason, and also because typically only severe atrial enlargement or ventricular hypertrophy would be a clinically important indicator of significant disease, only severe abnormalities in dimensions were used for comparisons between echocardiographer- and resident-performed studies. Conclusion Limited instruction in echocardiography, consisting of the supervised performance of 20 echocardiograms along with 20 h of didactic teaching and reading alongside an experienced echocardiographer, allows physicians without formal training in echocardiography to perform a focused ultrasound examination with moderate overall sensitivity and high specificity, making it a useful screening tool. The significant differences in sensitivity between groups with varying levels of training to detect findings likely to impact patient care as well as lower overall positive predictive value of internistperformed hand-held ultrasound studies compared to echocardiographer-performed studies for the detection of abnormalities suggests that standardized training, competency testing, and quality assurance guidelines need to be established before these devices can be utilized for clinical decision-making by physicians without formal training in echocardiography. References [1] Roelandt J, Wladimiroff JW, Baars AM. Ultrasonic real time imaging with a hand-held scanner. Part II initial clinical experience. Ultrasound Med Biol 1978; 4(2): [2] Roelandt J, Bom K, Hugenholtz PG. The ultrasound cardioscope: a hand-held scanner for real-time cardiac imaging. J Clin Ultrasound 1980; 8(3): [3] Schwarz KQ, Meltzer RS. Experience rounding with a handheld two-dimensional cardiac ultrasound device. Am J Cardiol 1988; 62(1): [4] Xie F, Breese MS, Nanna M, Lichtenberg GS, Allen MN, Meltzer R. Blinded comparison of an ultrasound stethoscope and standard echocardiographic instrument. Chest 1988; 94(2): [5] Kimura BJ, Amundson SA, Willis CL, Gilpin EA, DeMaria AN. Briefly-trained physicians can use a hand-held ultrasound device to improve detection of LV dysfunction. Circulation 2001; II-334: Ref Type: Abstract. [6] Kirkpatrick AW, Simons RK, Brown R, Nicolaou S, Dulchavsky S. The hand-held FAST: experience with handheld trauma sonography in a level-i urban trauma center. Injury 2002; 33(4): [7] Lemola K, Yamada E, Jagasia DH, Kerber RE. A handcarried personal ultrasound device for rapid evaluation of left ventricular function: Use after limited echo training. Circulation 2001; II-496: Ref Type: Abstract. [8] Rugolotto M, Hu BS, Liang DH, Schnittger I. Rapid assessment of cardiac anatomy and function with a new handcarried ultrasound device (OptiGo): a comparison with standard echocardiography. Eur J Echocardiogr 2001; 2(4): [9] Spencer KT, Anderson AS, Bhargava A, Bales AC, Sorrentino M, Furlong K et al. Physician-performed point-ofcare echocardiography using a laptop platform compared with physical examination in the cardiovascular patient. J Am Coll Cardiol 2001; 37(8): [10] Pearlman AS, Gardin JM, Martin RP, Parisi AF, Popp RL, Quinones MA et al. Guidelines for optimal physician training in echocardiography. Recommendations of the American Society of Echocardiography Committee for Physician Training in Echocardiography. Am J Cardiol 1987; 60(1): [11] Popp RL, Winters WL, Jr. Clinical competence in adult echocardiography. A statement for physicians from the ACP/ ACC/AHA Task Force on Clinical Privileges in Cardiology. J Am Coll Cardiol 1990; 15(7): [12] Stewart WJ, Aurigemma GP, Bierman FZ, Gardin JM, Kisslo JA, Jr., Pearlaman AS et al. Guidelines for training in adult cardiovascular medicine Core Cardiology Training Symposium (COCATS). Task Force 4: training in echocardiography. J Am Coll Cardiol 1995; 25(1): [13] Statement on role of short courses in endoscopic training. Gastrointest Endosc 1988; 34(3) (Suppl): 4S 15S. [14] Guidelines for training non-specialists in screening flexible sigmoidoscopy. Gastrointest Endosc 2000; 51(6): [15] American College of Emergency Physicians. ACEP emergency ultrasound guidelines Ann Emerg Med 2001; 38(4): [16] Cash BD, Schoenfeld PS, Ransohoff DF. Licensure, use, and training of paramedical personnel to perform screening flexible sigmoidoscopy. Gastrointest Endosc 1999; 49(2): [17] Mateer J, Plummer D, Heller M, Olson D, Jehle D, Overton D et al. Model curriculum for physician training in emergency ultrasonography. Ann Emerg Med 1994; 23(1): [18] Schlant RC, Friesinger GC, Leonard JJ. A statement for physicians from the ACP/ACC/AHA Task Force on Clinical Privileges in Cardiology. J Am Coll Cardiol 1990; 16(5): [19] Stewart WJ, Douglas PS, Sagar K, Seward JB, Armstrong WG, Zoghbi W et al. Echocardiography in emergency medicine: a policy statement by the American Society of Echocardiography and the American College of Cardiology, Task Force on Echocardiography in Emergency Medicine of the American Society of Echocardiography and the Echocardiography and Technology and Practice Executive Committees of the American College of Cardiology. J Am Coll Cardiol 1999; 33(2): [20] Wigton RS, Nicolas JA, Blank LL. Procedural skills of the general internist. A survey of 2500 physicians. Ann Intern Med 1989; 111(12): [21] Alexander JH, Peterson ED, Chen AY, Harding TM, Adams D, Kisslo JA. Feasibility of point-of-care echo by non-cardiologist physicians to assess left ventricular function, pericardial effusion, mitral regurgitation, and aortic valvular thickening. Circulation 2001; II-334: Ref Type: Abstract. [22] Goodkin GM, Spevack DM, Tunick PA, Kronzon I. How useful is hand-carried bedside echocardiography in critically ill patients? J Am Coll Cardiol 2001; 37(8):