Instant telemedicine ECG consultation with cardiologists using pocket wireless computers

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AMERICAN JOURNAL OF EMERGENCY MEDICINE • Volume 19, Number 3 • May 2001

4. Mason JW: Amiodarone. N Engl J Med 1987;316:455-466 5. Vitolo E, Tronci M, Larovere MT, et ah Amiodarone versus quinidine in the prophylaxis of atrial fibrillation. Acta Cardiol 1981; 36:431-444 6. Blevins RD, Kerin NZ, Benaderet D, et ah Amiodarone in the management of refractory atrial fibrillation. Arch Intern Med 1987; 147:1401-1404 7. Nemec J, Shen W-K: Pharmacotherapy of atrial fibrillation. Exp Opin Pharmacother 1999;1:81-96 8. Jackrnan WM, Friday KJ, Anderson JL, et al: The long QT syndromes: A critical review, new clinical observations and a unifying hypothesis. Prog Cardiovasc Dis 1988;31:115-172 9. Curry P, Fitchett D, Stubbs W, et ah Ventricular arrhythmias and hypokalaemia. Lancet 1976;2:231-233 10. Brown MA, Smith WM, Lubbe WF, et al: Amiodarone-induced torsades de pointes. Eur Heart J 1986;7:234-239 11. Moro C, Romero J, Corres Peiretti MA: Amiodarone and hypokalemia. A dangerous combination. Int J Cardiol 1986;13:365368 12. Shen W-K, Terzic A, Stanton MS: Triggered activity and arrhythmogenesis: A clinical update. ACC Curr J Rev 1997 July/ August:l 6-19 13. Sclarovsky S, Lewin RF, Kracoff O, et ah Amiodarone-induced polymorphous ventricular tachycardia. Am Heart J 1983;105: 6-12 14. Jorens PG, van den Heuvel PA, Ranquin RE, et al: Amiodarone induced torsades de pointes. Report of three cases and review of literature. Acta Cardiol 1989;44:411-421 15. Seizer A, Wray HW: Paroxysmal ventricular fibrillation occurring during treatment of chronic atrial arrhythmias. Circulation 1964; 30:17-26 16. Keren A, Tzivoni D, Gottlieb S, et al: Atypical ventricular tachycardia (torsade de pointes) induced by amiodarone: arrhythmia previously induced by quinidine and disopyramide. Chest 1982; 81:384-386 17. Herings RM, Stricker BH, Leufkens HG, et ah Public health problems and the rapid estimation of the size of the population at risk. Torsades de pointes and the use of terfenadine and astemizole in The Netherlands. Pharm World Sci 1993;15:212-218 18. Martin AB, Garson A Jr, Perry JC: Prolonged QT interval in hypertrophic and dilated cardiomyopathy in children. Am Heart J 1994;127:64-70

INSTANT TELEMEDIClNE ECG CONSULTATION WITH CARDIOLOGISTS USING POCKET WIRELESS COMPUTERS To the Editor:--Telemedicine potentially improves access to specialists, but it is underused because it is expensive and technically complex to operate. Additionally, access to consultants requires them to be at a telemedicine unit (acceptable for elective consultations only). Here, we describe the feasibility of pocket wireless telemedicine access to a consultant's (cardiologist) expertise in interpreting electrocardiograms (ECGs). Although most ECGs are satisfactorily interpreted by primary care and emergency physicians, some ECGs may benefit from cardiology consultation. We used a Hewlett-Packard (Palo Alto, CA) Jornada 680 pocket computer (18.5 x 9.5 x 3.0 cm, 521 grams), containing a Sierra Wireless (Richmond, BC, Canada) AirCard 300 wireless card modem (46 grams a 6.6 cm antenna telescoping to 11 cm) giving it wireless internet access through a digital cellular telephone network, was used. Seventeen 12-lead ECGs were collected for study using 2 methods: Method 1: ECGs were digitized using a scanner and uploaded into a web server as a JPEG t i l t (a method of compressing an image file roughly 10-fold). A cardiologist was asked to review the ECG on the pocket wireless computer's (PWC) web browser, and

Copyright © 2001 by W.B. Saunders Company 0735-6757/01/1903-0024535.00/0 doi:l 0.1053/ajem.2001.22661

provide a consultation interpretation. The cardiologist, who had not used this PWC before, was given a 5 minute orientation on its rise.

Method 2: ECGs were faxed (using a standard fax machine) to an internet fax intermediary so that a fax could be received as an image file by intemet e-mail on the PWC. Method 1 (web browser): Image download times averaged 119 seconds -+ 44. Interpretation times averaged 73 seconds +- 28. Image quality was rated as "good." All the cardiologists' interpretations were consistent with the original interpretations of record. Reliability was good, but not perfect. Occasional disconnections required reestablishing communication with the wireless network. Download speeds averaged 9000 baud (bits per second) or 900 bytes per second (compare this to a telephone modem with a top speed of 56,000 baud). Method 2 (fax e-mail): The visual quality of the images were highly dependent on the resolution used for faxing (standard, fine, superfine, photo, and so on). Higher resolution methods improved the quality of the ECG fax, but these took longer to fax and to view on the PWC. This method took substantially longer to view on the PWC because the files were not compressed using JPEG, 1 resulting in much larger image files to download. These files could be viewed easily on a desktop computer with a fast internet connection, but the slower wireless connection made viewing the ECGs with this method excessively slow. In theory, this method could be made faster if the images were smaller (as with JPEG~). This study shows that immediate telemedicine access to a consultant is feasible using wireless internet pocket devices. There are 3 barriers to the routine use of telemedicine2-3: (1)high cost, (2)high complexity, and (3) lack of access to consultants. The PWC is $600 and the wireless modem is $400 putting this in the affordable range. Complexity is minimal. Lack of access is eliminated if the consultant carries the PWC. This PWC used CDPD (cellular digital packet data), a wireless digital communication method. Other wireless methods (CDMA, TDMA, ARDIS, CDPD, GSM, and so on) are discussed elsewhere, 4 but they are all relatively new and slow. Although the specific task studied here will be ECG interpretation, pocket wireless access could be used for other types of telemedicine consultations as well. In summary, PWCs provide a simple and affordable means to gain access to specialty consultants. PWCs can improve tertiary and rural access to specialty consultants. Compared with computed tomography and magnetic resonance imaging, ECGs are simpler to transmit, however with advancing wireless technologies, more telemedicine applications for PWCs will be developed. With future technology, real time video will be available on PWCs. Special thanks to Verizon Wireless for providing digital wireless network services. Supported by grant no. 1-996000354-A1 from the Division of Disadvantaged Assistance, Bureau of Health Professions, Health Resources and Services Administration. Its contents are solely the responsibility of the Author(s) (Institution) and do not necessarily represent the official views of the Health Resources and Services Administration.

PATRICEM. TIM SING, MD Department of Pediatrics Native Hawaiian Center of Excellence

LORENG. YAMAMOTO,MD, MPH, MBA LANCEK. SHIRALMD, FAAP Department of Pediatrics Universi~ of Hawaii John A. Burns School of Medicine Honohdu, HI

References 1. Yamamoto LG: Using JPEG image compression to facilitate telemedicine. Am J Emerg Med 1995;13:55-57

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2. Yamamoto LG, Toma CS, Bell CK: Telemedicine in a box (-riB): Overcoming complexity and high cost telemedicine barriers using self-contained videoconferencing units. Ped Emerg Care (submitted for publication) 3. Toma CS, Yamamoto LG, Bell CK, et al: Immediate telemedicine consultations by e-mail (store and forward) using a telemedicine in a box (TIB) laptop to reduce cost/complexity and improve consultant availability. Office Emerg Pediatr 2000;13:134-138 4. Yamamoto LG, Williams DR: A demonstration of instant pocket wireless ct teleradiology to facilitate stat neurosurgical consultation and future telemedicine implications. Am J Emerg Med 2000;18; 423-426

Was diagnosis made in the emergency department ?

yes

J

Was there a discrepancy between admission and discharge diagnosis?

To the Editor.'--The value of consistent, systematic follow-up of the clinical outcomes of hospitalized emergency department (ED) patients has received little attention in the emergency medicine literature. How frequently, for example, is clinically relevant information generated beyond what is initially available in the ED? Are diagnoses commonly or infrequently amended after hospitalization? In several different scenarios clinical information is necessarily generated after the ED phase of a patient's evaluation. For example, when ED patients are hospitalized for further evaluation of a symptom complex (eg, abdominal pain or syncope) useful diagnostic information is typically developed later in a patient's hospitalization. Alternatively, a diagnosis may be posited in the ED that, because of time or other constraints, cannot be confirmed until later in the hospitalization (eg, suspected ruptured appendicitis, confirmed at exploratory laparotomy). Finally, a diagnosis "made" in the ED may simply turn out to be wrong (eg, pneumonia which, during hospitalization, is recognized to be parynchymal changes secondary to a new diagnosis of sarcoidosis). If no system for routine review of patient outcomes exists, the emergency physician may remain ignorant of relevant clinical information in each of the above 3 circumstances. This study is an initial attempt to compare the admission diagnoses, developed in the ED, with the discharge diagnoses of a group of hospitalized patients. The frequencies of discrepancy between admission and discharge diagnoses are noted, as are the reasons for the discrepancies. The hospital records of 100 hospitalized patients, selected at random, were surveyed. The ED records, including the emergency physicians' dictated notes and any ancillary studies were first reviewed. A determination was made as to whether a causative diagnosis had been assigned on admission (see Fig 1). Symptom complexes, eg, chest pain, syncope, and so on were not considered causative diagnoses. The remainder of the hospital records, including the discharge summary, progress notes, consultants' notes, and ancillary studies, were then reviewed to identify the diagnostic impressions developed during hospitalization. If a causative diagnosis was proposed at admission, a judgment was made as to whether there was a discrepancy between the admission and the discharge diagnoses (Fig 1). If there was a discrepancy between the admission diagnosis and the discharge diagnosis, the chart was reviewed to determine whether, based on information available in the ED, there was a:

no

yes

ED FOLLOW-UP: A COMPARISON OF ADMISSION AND DISCHARGE DIAGNOSES

no

Was E.D. diagnosis impossible because of:

MISSED Dx

UNAVAILABLE Dx

Was the discrepancy a result of:

MISDx

MISSED Dx

UNAVAILABLE Dx

FIGURE 1. Flow chart for classification of discrepancies, if any observed between admission and discharge diagnoses.

(3) Unavailable diagnosis: if the diagnosis could not be made without information generated later in the hospitalization (Fig 1). If no causative diagnosis was assigned at admission, the charts were reviewed to determine whether, based on information available in the ED, there was a: (1) Missed diagnosis: if the diagnosis should have been possible but was overlooked, or an (2) Unavailable diagnosis: if the diagnosis could not be made without information generated later in the hospitalization (Fig 1). Seventy-seven out of 100 patients (77%) were admitted with a proposed diagnosis (Fig 2). In 23 out of the 100 patients (23%) no causative diagnosis was thought possible in the ED. These 23 patients were typically admitted for further evaluation of a symptom, eg, chest pain, abdominal pain, and so on.

e" ,m

II.

(1) Misdiagnosis: if the ED diagnosis was simply in error, or a (2) Missed diagnosis: if the diagnosis should have been possible but was overlooked, or an

YES Copyright © 2001 by W.B. Saunders Company 0735-6757/01/1903-0025535.00/0 doi:l 0.1053/ajem.2001.22673

FIGURE 2. ment?

NO

Was a "diagnosis" made in the emergency depart-