I'Accid Emerg Med 1996;13:395-397 395 J Accid Emerg Med: first published as 10.1136/emj.13.6.395 on 1 November 1996. Downloaded from Interpretation of the emergency electrocardiogram by junior hospital doctors

Neil D Gillespie, Charles T F Brett, William G Morrison, Stuart D Pringle

Abstract Methods Objective-To assess the ability ofa cohort The study was performed in the departments of junior hospital doctors to interpret of accident and emergency, medicine, and sur- ECGs which have immediate clinical gery in a teaching hospital. Fifty seven medical relevance and influence subsequent man- staff were selected at random and provided agement ofpatients with a questionnaire containing eight ECGs for Methods-57 junior hospital doctors were interpretation. Each subject was interviewed interviewed and asked to complete a by one of the investigators. The study was per- standard questionnaire which included formed over a 48 h period, and to prevent cir- eight ECGs for interpretation and a culation of the correct answers those partici- supplementary question relating to the pating were asked not to divulge the answers of administration of thrombolytic treat- the questionnaire to colleagues. The ECGs ment. Each doctor was assessed over a offered for interpretation had one major 48 h period while they performed their clinically significant abnormality from among daily clinical duties. the following: (1) acute anterior myocardial Results-The major abnormality of ante- infarction, (2) atrial flutter with variable heart rior myocardial infarction was recognised block, (3) left bundle branch block, (4) atrial by almost all doctors. There was difficulty fibrillation with a slow ventricular response, (5) in the interpretation of posterior myocar- posterior myocardial infarction, (6) second dial infarction and second degree heart degree heart block, (8) supraventricular tachy- block. Most myocardial infarctions would cardia. There was also a normal ECG. have been given satisfactory thromboly- The doctors included in the survey were sis, but there was a reluctance to use this selected as being the most likely to be treatment in patients with posterior myo- interpreting large numbers of ECGs in emer- cardial infarction and left bundle brach gency admissions. We asked the doctors: (1) to block. A few patients without myocardial describe the relevant ECG abnormalities, and infarction would have received thrombo- (2) which ECGs had indications for throm-

lytic treatment. bolysis, given a normal previous ECG and a http://emj.bmj.com/ Conclusions-There is varying ability 2 h history of cardiac chest pain suggestive of among junior hospital doctors in the myocardial infarction. The study was per- interpretation of the emergency electro- formed during the working day while the cardiogram. The results are of concern as respondents were performing their normal poor interpretation of the ECG can result clinical duties. Model answers were provided in inappropriate management. As a result by two consultant cardiologists.

of the findings of this study it is proposed on October 1, 2021 by guest. Protected copyright. to introduce more formal training in the interpretation of clinically relevant ECG abnormalities for junior hospital doctors. Results (JAccidEmergMed 1996;13:395-397) The major findings of the study are summa- rised in tables 1 and 2. Most of the doctors Department of Key terms: ECG interpretation; junior hospital doctors; recognised acute anterior myocardial infarc- Cardiology, Ninewells accident and emergency tion with ease. This is reassuring, as these are Hospital, Dundee, United Kingdom the patients most likely to gain overall benefit N D Gillespie from the administration of thrombolytic treat- S D Pringle The treatment of acute myocardial infarction ment. However, there was difficulty in recog- by thrombolysis results in significant improve- nising posterior myocardial infarctions. This is A&E Department, ment in mortality.'2 The major clinical trials of concern as many of these patients have large Dundee Royal which have shown benefit from the administra- infarcts and thrombolysis is often given in the Infirmary, Dundee, United Kingdom tion ofthrombolytic treatment used electrocar- presence of ST depression. The other ECG C T F Brett diographic (ECG) criteria to allocate patients which proved difficult to interpret was second W G Morrison to treatment. Recent audits have shown poor degree heart block. In practice, this is an ability to interpret ECGs among hospital doc- important abnormality which should be recog- Correspondence to: tors.' However, these audits have been concen- nised early as patients may require cardiac pac- Dr N Gillespie, Department of Cardiology, Ninewells trated on ECG abnormalities oflimited clinical ing if this arrhythmia is associated with haemo- Hospital and Medical importance in the acute medical emergency dynamic upset. School, Dundee DD1 9SY, situation. We assessed the ability of a group of A consistent finding was that thrombolysis Scotland. hospital doctors to interpret clinically impor- would have been given appropriately to pa- Accepted for publication tant ECGs, where accurate assessment was tients with anterior myocardial infarction. 17 July 1996 essential for optimum patient management. However, there was a reluctance to give throm- 396 Gillespie, Brett, Morrison, Pringle J Accid Emerg Med: first published as 10.1136/emj.13.6.395 on 1 November 1996. Downloaded from Table 1 Percentage ofhospital doctors correcdy identifying importance as these patients are at risk of syn- ECG abnormalities cope and may require pacemaker insertion. Department/grade Our data suggest that there are gaps in the knowledge of junior doctors regarding the JHO Med SHO/Reg+A&E indications for thrombolysis. All of the patients ECG (n=26) (n=31) with acute anterior myocardial infarction were Anterior MI 88 97 given thrombolysis but only 40% of those with Atrial flutter 73 84 left bundle branch block (LBBB) would have LBBB 77 87 received it. This is concerning as there is an Normal 73 97 Slow AF 42 55 absolute mortality benefit of 49 lives saved per Posterior MI 8 29 1000 patients treated if patients with LBBB on 2:1 block 19 45 their presenting ECG are treated with throm- SVT 69 81 bolysis.6 JHO, junior house officer; SHO, senior house officer; Med, Several patients with atrial fibrillation, sec- medical; Reg, registrar; MI, myocardial infarction; LBBB, left ond degree heart block, and supraventricular bundle branch block; AF, atrial fibrillation; SVT, supraventricu- lar tachycardia. tachycardia would have received thrombolysis incorrectly in this study. This highlights the bolysis to patients with posterior infarctions problem that in the desire to give thrombolysis and those with new left bundle branch block. to patients with acute myocardial infarction A few doctors would have given thromboly- other patients may receive inappropriate sis to patients with atrial fibrillation, second thrombolysis. This exposes these patients to degree heart block, and supraventricular tachy- the risk of serious adverse effects such as cardia. cerebrovascular accident or major blood loss without any potential for benefit. The study confirms that there is a varying ability among junior hospital doctors in Discussion interpreting ECGs showing myocardial infarc- Electrocardiography is one of the most fre- tion or life threatening arrhythmias. Although quently used investigations in hospital practice. in practice doctors with difficulties in inter- Despite this, previous studies have suggested a preting ECGs are likely to get a second opinion poor ability among doctors to interpret the before giving thrombolytic treatment there is findings.34 This is alarming as the optimal nevertheless a need for formal teaching in management of a number of potentially life ECG interpretation in the same way that threatening conditions requires prompt accu- resuscitation skills are taught, as delays in giv- rate interpretation of the electrocardiogram. ing thrombolysis have survival implications for Some of these studies have analysed patients.7 Computer models may be of some interpretation of ECG abnormalities such as help but there is no substitute for clear the PR interval and QT interval which, recognition of abnormalities that require im- although important, have little influence on the mediate therapeutic intervention. There is a http://emj.bmj.com/ administration of emergency treatment. clear need for hospitals to issue guidelines for This present study focuses on ECG abnor- thrombolysis and standard protocols to aid malities which have immediate implications for inexperienced junior staff in decision making. patient management. Each ECG had only one A recent survey of the variation in the use of major abnormality, and the scoring system was thrombolytic treatment by junior hospital doc- such that the interpretation was either correct tors showed that less than a third of partici- or incorrect, thus eliminating the contribution pants worked in hospitals with local policies.8 of non-specific ECG findings. Ideally thrombolytic treatment should be given on October 1, 2021 by guest. Protected copyright. The study confirmed a satisfactory in accident and emergency departments so that interpretation and treatment of acute anterior the door-to-needle time is kept below 30 min- myocardial infarction. Posterior myocardial utes.7 In this region, decisions regarding infarction was identified poorly. Even though thrombolytic therapy are made by both medi- the established benefit of thrombolysis in pos- cal and accident and emergency staff and terior myocardial infarction is less clear, key treatment is started in accident and emergency. management includes treatment with aspirin, c Clearly continuing education is vital, as blockade, and admission to a coronary care there is a rapid turnover of junior hospital doc- unit.' The poor recognition of patients with tors in most hospitals. ALS (advanced life sup- second degree heart block is of particular port) schemes offer training in basic cardiovas- Table 2 Percentage ofpatients thrombolysed given 2 h history ofchest pain cular emergencies and life support, although places on such schemes are limited. Only two Departmentlgrade of the doctors questioned (both in A/E) in this survey were known to have ALS certification. JHO Med SHO/Reg+A&E (n=31) In the near future, there are plans to introduce (n=26) an induction programme for all junior house Anterior MI 92 97 officers before they start their jobs. This LBBB 31 39 programme would include ECG inter- Posterior 15 23 Slow AF 12 10 pretation. Following introduction of this pro- SVT/2nd degree heart block 8 3 gramme it is planned to repeat this study. In this shows a wide vari- JHO, junior house officer; SHO, senior house officer; Med, medical; Reg, registrar; MI, myocar- conclusion, survey dial infarction; LBBB, left bundle branch block; AF, atrial fibrillation; SVT, supraventricular ation in junior doctors' ability to interpret tachycardia. clinically important ECGs and to give throm- Interpretation of the emergency electrocardiogram 397

bolytic treatment appropriately. The wide- 3 Montgomery H, Hunter S, Morris S, Naunton-Morgan R, J Accid Emerg Med: first published as 10.1136/emj.13.6.395 on 1 November 1996. Downloaded from Marshall RM. Interpretation of electrocardiograms by spread introduction of ALS courses and the doctors. BMJ3 1994;309:1551-2. adoption of local guidelines may improve 4 Morrison WG. Swann IJ. Electrocardiograph interpretation by junior doctors. Arch Emerg Med 1990;7:108-10. training and guidance for junior hospital 5 Frishman WH, Furberg CD, Friedewald WT. f Blockade doctors in a key area of clinical practice. for survivors of acute myocardial infarction. N Engl J Med 1984;310:830-4. 6 Indications for fibrinolytic therapy in suspected acute myo- cardial infarction: collaborative overview of early mortality and major morbidity results from all randomised trials of 1 Gruppo Italiano Per Lo Studio Dela Streptokinase in over 1000 patients. FTT Collaborative Group. Lancet Infarto Miocardico (GISSI). Effectiveness of intravenous 1994;ii:311-22. thrombolytic treatment in acute myocardial infarction. 7 Guidelines for the early management of patients with myo- Lancet 1986;i:397-401. cardial infarction. British Heart Foundation working 2 ISIS-2 Collaborative group. Randomised intravenous strep- group. BMJ' 1994;308:767-71. tokinase, oral aspirin, both among 17,187 cases of 8 Hood S, Birnie D, Curzio J, Hillis WS. Wide variation in the suspected acute myocardial infarction. ISIS-2. Lancet use ofthrombolytic therapy among junior doctors in South 1988;ii:349-60. and Central Scotland. Health Bull (Edinb) 1996;4:131-9.

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