Differentiating ST-Elevation Myocardial Infarction from Nonischemic ST-Elevation in Patients With Chest Pain
2011; Elsevier BV; Volume: 108; Issue: 8 Linguagem: Inglês
10.1016/j.amjcard.2011.06.008
ISSN1879-1913
AutoresViet Tran, Henry D. Huang, José Gutiérrez Díez, Gerardo Kalife, Rajiv Goswami, David Paniagua, Hani Jneid, James M. Wilson, Scott R. Sherron, Yochai Birnbaum,
Tópico(s)Cardiovascular Function and Risk Factors
ResumoCurrent guidelines state that patients with compatible symptoms and ST-segment elevation (STE) in ≥2 contiguous electrocardiographic leads should undergo immediate reperfusion therapy. Aggressive attempts at decreasing door-to-balloon times have led to more frequent activation of primary percutaneous coronary intervention (pPCI) protocols. However, it remains crucial to correctly differentiate STE myocardial infarction (STEMI) from nonischemic STE (NISTE). We assessed the ability of experienced interventional cardiologists in determining whether STE represents acute STEMI or NISTE. Seven readers studied electrocardiograms of consecutive patients showing STE. Patients with left bundle branch block or ventricular rhythms were excluded. Readers decided if, based on electrocardiographic results, they would have activated the pPCI protocol. If NISTE was chosen, readers selected from 12 possible explanations as to why STE was present. Of 84 patients, 40 (48%) had adjudicated STEMI. The percentage for which readers recommended pPCI varied (33% to 75%). Readers' sensitivity and specificity ranged from 55% to 83% (average 71%) and 32% to 86% (average 63%), respectively. Positive and negative predictive values ranged from 52% to 79% (average 66%) and 67% to 79% (average 71%), respectively. Broad inconsistencies existed among readers as to the chosen reasons for NISTE classification. In conclusion, we found wide variations in experienced interventional cardiologists in differentiating STEMI with a need for pPCI from NISTE. Current guidelines state that patients with compatible symptoms and ST-segment elevation (STE) in ≥2 contiguous electrocardiographic leads should undergo immediate reperfusion therapy. Aggressive attempts at decreasing door-to-balloon times have led to more frequent activation of primary percutaneous coronary intervention (pPCI) protocols. However, it remains crucial to correctly differentiate STE myocardial infarction (STEMI) from nonischemic STE (NISTE). We assessed the ability of experienced interventional cardiologists in determining whether STE represents acute STEMI or NISTE. Seven readers studied electrocardiograms of consecutive patients showing STE. Patients with left bundle branch block or ventricular rhythms were excluded. Readers decided if, based on electrocardiographic results, they would have activated the pPCI protocol. If NISTE was chosen, readers selected from 12 possible explanations as to why STE was present. Of 84 patients, 40 (48%) had adjudicated STEMI. The percentage for which readers recommended pPCI varied (33% to 75%). Readers' sensitivity and specificity ranged from 55% to 83% (average 71%) and 32% to 86% (average 63%), respectively. Positive and negative predictive values ranged from 52% to 79% (average 66%) and 67% to 79% (average 71%), respectively. Broad inconsistencies existed among readers as to the chosen reasons for NISTE classification. In conclusion, we found wide variations in experienced interventional cardiologists in differentiating STEMI with a need for pPCI from NISTE. Current guidelines for acute ST-segment elevation myocardial infarction (STEMI) emphasize the need for shortening door-to-balloon times in patients presenting with symptoms suggestive of myocardial ischemia and STE1Antman E.M. Anbe D.T. Armstrong P.W. Bates E.R. Green L.A. Hand M. Hochman J.S. Krumholz H.M. Kushner F.G. Lamas G.A. Mullany C.J. Ornato J.P. Pearle D.L. Sloan M.A. Smith Jr, S.C. Alpert J.S. Anderson J.L. Faxon D.P. Fuster V. Gibbons R.J. Gregoratos G. Halperin J.L. Hiratzka L.F. Hunt S.A. Jacobs A.K. Ornato J.P. 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Yancy C.W. 2007 Focused update of the ACC/AHA 2004 guidelines for the management of patients with ST-elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.J Am Coll Cardiol. 2008; 51: 210-247Abstract Full Text Full Text PDF PubMed Scopus (783) Google Scholar, 3Kushner F.G. Hand M. Smith Jr, S.C. King III, S.B. Anderson J.L. Antman E.M. Bailey S.R. Bates E.R. Blankenship J.C. Casey Jr, D.E. Green L.A. Hochman J.S. Jacobs A.K. Krumholz H.M. Morrison D.A. Ornato J.P. Pearle D.L. Peterson E.D. Sloan M.A. Whitlow P.L. Williams D.O. 2009 Focused updates: ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction (updating the 2004 guideline and 2007 focused update) and ACC/AHA/SCAI guidelines on percutaneous coronary intervention (updating the 2005 guideline and 2007 focused update): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines.J Am Coll Cardiol. 2009; 54: 2205-2241Abstract Full Text Full Text PDF PubMed Scopus (1177) Google Scholar and encourage making triage decisions based on prehospital 12-lead electrocardiographic (ECG) transmission.2Antman E.M. Hand M. Armstrong P.W. Bates E.R. Green L.A. Halasyamani L.K. Hochman J.S. Krumholz H.M. Lamas G.A. Mullany C.J. Pearle D.L. Sloan M.A. Smith Jr., S.C. Anbe D.T. Kushner F.G. Ornato J.P. Pearle D.L. Sloan M.A. Jacobs A.K. Adams C.D. Anderson J.L. Buller C.E. Creager M.A. Ettinger S.M. Halperin J.L. Hunt S.A. Lytle B.W. Nishimura R. Page R.L. Riegel B. Tarkington L.G. Yancy C.W. 2007 Focused update of the ACC/AHA 2004 guidelines for the management of patients with ST-elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.J Am Coll Cardiol. 2008; 51: 210-247Abstract Full Text Full Text PDF PubMed Scopus (783) Google Scholar, 4Curtis J.P. Portnay E.L. Wang Y. McNamara R.L. Herrin J. Bradley E.H. Magid D.J. Blaney M.E. Canto J.G. Krumholz H.M. National Registry of Myocardial Infarction-4The pre-hospital electrocardiogram and time to reperfusion in patients with acute myocardial infarction, 2000–2002: findings from the National Registry of Myocardial Infarction-4.J Am Coll Cardiol. 2006; 47: 1544-1552Abstract Full Text Full Text PDF PubMed Scopus (181) Google Scholar, 5Garvey J.L. MacLeod B.A. Sopko G. Hand M.M. National Heart Attack Alert Program (NHAAP) Coordinating CommitteeNational Heart, Lung, and Blood Institute (NHLBI)National Institutes of HealthPre-hospital 12-lead electrocardiography programs: a call for implementation by emergency medical services systems providing advanced life support—National Heart Attack Alert Program (NHAAP) Coordinating Committee; National Heart, Lung, and Blood Institute (NHLBI); National Institutes of Health.J Am Coll Cardiol. 2006; 47: 485-491Abstract Full Text Full Text PDF PubMed Scopus (81) Google Scholar However, although this approach has been shown to shorten times to the catheterization laboratory, less is known about the accuracy of such an approach. In the absence of ECG signs of left ventricular hypertrophy (LVH) or left bundle branch block, guidelines define STE as new STE at the J point in ≥2 contiguous leads with cut-off points of ≥0.2 mV in men and ≥0.15 mV in women in leads V2 and V3 or ≥0.1 mV in other leads.6Thygesen K. Alpert J.S. White H.D. Jaffe A.S. Apple F.S. Galvani M. Katus H.A. Newby L.K. Ravkilde J. Chaitman B. Clemmensen P.M. Dellborg M. Hod H. Porela P. Underwood R. Bax J.J. Beller G.A. Bonow R. Van der Wall E.E. Bassand J.P. Wijns W. Ferguson T.B. Steg P.G. Uretsky B.F. Williams D.O. Armstrong P.W. Antman E.M. Fox K.A. Hamm C.W. Ohman E.M. Simoons M.L. Poole-Wilson P.A. Gurfinkel E.P. Lopez-Sendon J.L. Pais P. Mendis S. Zhu J.R. Wallentin L.C. Fernandez-Aviles F. Fox K.M. Parkhomenko A.N. Priori S.G. Tendera M. Voipio-Pulkki L.M. Vahanian A. Camm A.J. De Caterina R. Dean V. Dickstein K. Filippatos G. Funck-Brentano C. Hellemans I. Kristensen S.D. McGregor K. Sechtem U. Silber S. Tendera M. Widimsky P. Zamorano J.L. Morais J. Brener S. Harrington R. Morrow D. Lim M. Martinez-Rios M.A. Steinhubl S. Levine G.N. Gibler W.B. Goff D. Tubaro M. Dudek D. Al-Attar N. Universal definition of myocardial infarction.Circulation. 2007; 116: 2634-2653Crossref PubMed Scopus (2201) Google Scholar However, nonischemic STE (NISTE) is found in >90% of healthy men.7Hiss R.G. Lamb L.E. Allen M.F. Electrocardiographic findings in 67,375 asymptomatic subjects X. Normal values.Am J Cardiol. 1960; 6: 200-231Abstract Full Text PDF PubMed Scopus (104) Google Scholar, 8Surawicz B. Parikh S.R. Prevalence of male and female patterns of early ventricular repolarization in the normal ECG of males and females from childhood to old age.J Am Coll Cardiol. 2002; 40: 1870-1876Abstract Full Text Full Text PDF PubMed Scopus (140) Google Scholar Up to 15% of patients presenting with chest pain have NISTE.9Brady W.J. Perron A.D. Martin M.L. Beagle C. Aufderheide T.P. Cause of ST segment abnormality in ED chest pain patients.Am J Emerg Med. 2001; 19: 25-28Abstract Full Text Full Text PDF PubMed Scopus (70) Google Scholar, 10Otto L.A. Aufderheide T.P. 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Electrocardiographic ST-segment elevation: the diagnosis of acute myocardial infarction by morphologic analysis of the ST segment.Acad Emerg Med. 2001; 8: 961-967Crossref PubMed Scopus (55) Google Scholar In the present study we assessed the ability of interventional cardiologists to differentiate between STEMI and NISTE using only electrocardiograms of consecutive patients for whom the primary percutaneous coronary intervention (pPCI) protocol had been activated by emergency department physicians. A database of a large urban medical center contained records of 240 consecutive patients for whom the pPCI protocol had been activated because of suspected acute STEMI from January 2008 through December 2008. Two readers (V.T. and H.D.H.) collected 84 electrocardiograms showing STE in ≥2 contiguous leads. Patients with left bundle branch block or ventricular rhythms including electronic ventricular pacing were excluded. We also excluded patients whose patterns of STE did not meet guideline-based criteria for acute STEMI. To confirm that ECG STE represented true acute STEMI, we performed detailed chart reviews that included final diagnoses from the in-hospital physician's progress and discharge notes and examined reports of in-hospital coronary angiograms and echocardiograms. We also independently confirmed that those cases diagnosed as acute STEMI demonstrated the typical increase and decrease in cardiac marker levels (e.g., cardiac troponin I and creatine kinase-MB) consistent with STEMI and that subsequent ECG tracings showed the typical evolution indicative of STEMI. Seven experienced interventional cardiologists were then asked to analyze the electrocardiograms after all identifying information was removed and to decide whether they would send these patients for pPCI based on ECG findings alone, assuming patients had appropriate corresponding symptoms. Readers were blinded to clinical information for each patient including age, ethnicity, and gender; types of symptoms; and the clinical setting in which pPCI was activated. If readers did not think ECG findings warranted pPCI protocol activation, they were asked to code the electrocardiogram as NISTE and then choose from a list of 12 possible explanations as to why STE was present. Readers were allowed to code >1 reason to explain the cause of NISTE for each case. Readers were then assessed for overall accuracy, sensitivity, specificity, and positive and negative predictive values in correctly identifying patients with adjudicated STEMI. Forty patients (48%) had adjudicated true STEMI and 44 patients (52%) had NISTE (13 of these patients [30%] had positive cardiac markers suggestive of non-STEMI). Of the 84 patients (59 men, average age 61 years, range 25 to 90), 32 patients (38%) were white, 32 (38%) African-American, 12 (14%) Hispanic, and 9 (10%) of other ethnicities. Of the presenting symptoms, 62 patients (74%) had chest pain, 10 (12%) had shortness of breath, 5 (6%) had weakness, and 7 (8%) had other symptoms. With regard to risk factors, 57 patients (68%) had a previous diagnosis of hypertension, 46 patients (55%) had dyslipidemia, 30 patients (36%) had diabetes mellitus, and 27 patients (32%) had previously established coronary artery disease. Percent electrocardiograms for which pPCI was recommended varied widely among readers (33% to 75%), with sensitivities ranging from 53% to 83% (mean 71%), specificities from 32% to 86% (mean 63%), positive predictive values from 52% to 79% (mean 66%), and negative predictive values from 67% to 79% (mean 71%; Figure 1) . Even when readers chose NISTE as the diagnosis, the cause varied (Table 1). LVH, which is commonly found in our patient population, was thought to be the cause of NISTE by the individual readers in 6% to 31% of patients. Readers chose the option of old MI/aneurysm in 10% to 26% of cases. Interestingly, STEMI with spontaneous reperfusion as an indication not to activate the catheterization laboratory for possible pPCI was the least frequent choice (0% to 5%) in all patients with suspected NISTE.Table 1Possible causes of nonischemic ST-segment elevationReader1234567Left ventricular hypertrophy21% (9)20% (4)31% (8)6% (3)14% (7)27% (9)10% (4)Conduction defect17% (7)30% (6)4% (1)13% (7)12% (6)6% (2)3% (1)Early repolarization19% (8)10% (2)4% (1)4% (2)18% (9)3% (1)8% (3)Normal variant (mainly ST-segment elevation in leads V1–V3)12% (5)10% (2)15% (4)2% (1)0%12% (4)13% (5)No reciprocal changes00027% (14)0015% (6)Concave ST-segment elevation010% (2)02% (1)20% (10)6% (2)8% (3)Old myocardial infarction/aneurysm21% (9)10% (2)19% (5)13% (7)24% (12)12% (4)26% (10)Spontaneous reperfusion05% (1)02% (1)03% (1)0Pericarditis10% (4)015% (4)4% (2)6% (3)18% (6)10% (4)Brugada syndrome0002% (1)2% (1)03% (1)No ST-segment elevation05% (1)12% (3)25% (13)6% (3)12% (4)5% (2)Other0002% (1)10% (5)05% (2)Total42202653563341 Open table in a new tab We show that although 74% of patients presented with the classic symptom of chest pain, 32% had known coronary artery disease, only 48% had true STEMI. We found wide variance in the overall sensitivity and specificity of our readers in distinguishing between STEMI and NISTE. Our results confirm that even in patients with corresponding symptoms of STEMI and for whom the pPCI protocol was activated, it remains difficult for experienced interventional cardiologists to determine by ECG criteria alone if patients have true STEMI or if they have NISTE. In a previous study using electrocardiograms of consecutive patients showing STE that were not necessarily recorded in the acute setting, we found a similarly wide discrepancy in the range of sensitivity in experienced electrocardiographers.14Jayroe J.B. Spodick D.H. Nikus K. Madias J. Fiol M. De Luna A.B. Goldwasser D. Clemmensen P. Fu Y. Gorgels A.P. Sclarovsky S. Kligfield P.D. Wagner G.S. Maynard C. Birnbaum Y. Differentiating ST elevation myocardial infarction and nonischemic causes of ST elevation by analyzing the presenting electrocardiogram.Am J Cardiol. 2009; 103: 301-306Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar Figure 2, Figure 3 depict 4 representative cases. Figure 2 shows a patient with adjudicated anterior STEMI; however, only 3 readers chose STEMI, whereas the other 4 decided that the patient had NISTE; all marked the option "old MI/aneurysm without acute changes" and 1 added the option "lack of reciprocal changes." Figure 2 also shows a patient with NISTE. Four readers thought that the patient had STEMI. Of the 3 readers who marked "NISTE," 2 chose "early repolarization pattern" as the cause and the other chose "STE secondary to LVH." Figure 3 shows a patient with adjudicated STEMI, but only 1 reader thought as such. Two readers chose early repolarization pattern, 3 chose "pericarditis" (with 1 reader adding "concave STE"), and 1 made a diagnosis of NISTE because there were no reciprocal changes. The second electrocardiogram in Figure 3 shows NISTE. One reader thought that the patient had STEMI. Three readers decided that the patient had STE secondary to LVH, 2 readers chose old MI/aneurysm without acute changes, and 1 decided that the patient had NISTE because the STE was concave (Figure 2, Figure 3, Table 1). Indeed, this patient has LVH criteria but STE secondary to LVH is typically seen in leads V1 to V3 and not in the inferior leads. Moreover, this patient had narrow but deep q waves in the inferior leads that 2 readers thought were representative of an old MI or aneurysm. However, echocardiogram revealed LVH without any regional wall motion abnormalities.Figure 3(a) A 55-year-old woman had chest pressure for 45 minutes. Electrocardiogram showed mild ST-segment elevation in the inferior leads and leads V5 to V6. Coronary angiogram showed no significant narrowing. Laboratory values showed a positive result for cardiac troponin, her creatine kinase-MB level was 48.5 ng/ml, and there was a typical increase and decrease in cardiac marker levels. Transthoracic echocardiogram showed hypokinesis of the distal inferolateral segment with preserved left ventricular systolic function (ejection fraction 55% to 60%). It was determined this patient had a ST-segment elevation myocardial infarction. (b) A 52-year-old man with a history of uncontrolled hypertension and heavy alcohol consumption presented with chest discomfort and shortness of breath. Electrocardiogram showed left ventricular hypertrophy with ST-segment elevation in the inferior leads and leads V1 to V4 and ST-segment depression in leads I and aVL. There was no previous electrocardiogram on record for comparison. The interventional cardiologist deactivated the primary percutaneous coronary intervention protocol after seeing the patient at bedside. Cardiac markers were negative. There were no dynamic electrocardiographic changes and transthoracic echocardiogram showed mild left ventricular hypertrophy with preserved left ventricular systolic function and no regional wall motion abnormalities. Coronary angiogram on day 3 showed no significant lesions. Therefore, it was determined this patient had nonischemic ST-segment elevation.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Electrocardiograms recorded in the field by emergency medical service teams can be interpreted at the site or electronically transmitted for interpretation at specialized centers, local emergency departments, experienced electrocardiographers, or on-call interventional cardiologists. It should be noted that in the United States, when prehospital electrocardiograms are transmitted, patients' names and other identifying details must be omitted to comply with Health Insurance Portability and Accountability Act (HIPPA) regulations. Therefore, even if previous electrocardiograms exist in hospital medical records, readers would have no access to these. This is not the case in other countries, where the reader may have access to an electronic archive of electrocardiograms. Systems have been developed in which the interpreting physician communicates with the patient and the emergency medical service team by mobile telephone in addition to reading the transmitted electrocardiogram.15Sørensen J.T. Terkelsen C.J. Nørgaard B.L. Trautner S. Hansen T.M. Bøtker H.E. Lassen J.F. Andersen H.R. Urban and rural implementation of pre-hospital diagnosis and direct referral for primary percutaneous coronary intervention in patients with acute ST-elevation myocardial infarction.Eur Heart J. 2011; 32: 430-436Crossref PubMed Scopus (151) Google Scholar It has not yet been determined if this approach improves the accuracy of pPCI activation compared to blind ECG interpretation. The reported percent false activation of pPCI protocols varies from 5% to 25%.16Larson D.M. Menssen K.M. Sharkey S.W. Duval S. Schwartz R.S. Harris J. Meland J.T. Unger B.T. Henry T.D. "False-positive" cardiac catheterization laboratory activation among patients with suspected ST-segment elevation myocardial infarction.JAMA. 2007; 298: 2754-2760Crossref PubMed Scopus (246) Google Scholar, 17Kontos M.C. Kurz M.C. Roberts C.S. Joyner S.E. Kreisa L. Ornato J.P. Vetrovec G.W. 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The alternative of using automated ECG interpretive algorithms to speed decision making has been investigated20Brown J.P. Mahmud E. Dunford J.V. Ben-Yehuda O. Effect of prehospital 12-lead electrocardiogram on activation of the cardiac catheterization laboratory and door-to-balloon time in ST-segment elevation acute myocardial infarction.Am J Cardiol. 2008; 101: 158-161Abstract Full Text Full Text PDF PubMed Scopus (140) Google Scholar, 24Clark E.N. Sejersten M. Clemmensen P. Macfarlane P.W. Automated electrocardiogram interpretation programs versus cardiologists' triage decision making based on teletransmitted data in patients with suspected acute coronary syndrome.Am J Cardiol. 2010; 106: 1696-1702Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar; however, they showed lower sensitivity. Clark et al24Clark E.N. Sejersten M. Clemmensen P. Macfarlane P.W. Automated electrocardiogram interpretation programs versus cardiologists' triage decision making based on teletransmitted data in patients with suspected acute coronary syndrome.Am J Cardiol. 2010; 106: 1696-1702Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar showed that despite increased specificity in 1 of 2 computer algorithms compared to that of cardiologists, the cardiologists had improved sensitivity (78% for the 2 algorithms vs 85% for the cardiologists).24Clark E.N. Sejersten M. Clemmensen P. Macfarlane P.W. Automated electrocardiogram interpretation programs versus cardiologists' triage decision making based on teletransmitted data in patients with suspected acute coronary syndrome.Am J Cardiol. 2010; 106: 1696-1702Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar It has been proposed that the rate of inappropriate catheterization laboratory activation should be <5%.18Rokos I.C. French W.J. Mattu A. Nichol G. Farkouh M.E. Reiffel J. Stone G.W. Appropriate cardiac cath lab activation: optimizing electrocardiogram interpretation and clinical decision-making for acute ST-elevation myocardial infarction.Am Heart J. 2010; 160: 995-1003Abstract Full Text Full Text PDF PubMed Scopus (113) Google Scholar, 26Rokos I.C. Larson D.M. Henry T.D. Koenig W.J. Eckstein M. French W.J. Granger C.B. Roe M.T. Rationale for establishing regional ST-elevation myocardial infarction receiving center (SRC) networks.Am Heart J. 2006; 152: 661-667Abstract Full Text Full Text PDF PubMed Scopus (105) Google Scholar It is assumed that cardiologists—especially interventional cardiologists—would be more accurate than paramedics or emergency department physicians in differentiating STEMI from NISTE. Rokos et al18Rokos I.C. French W.J. Mattu A. Nichol G. Farkouh M.E. Reiffel J. Stone G.W. Appropriate cardiac cath lab activation: optimizing electrocardiogram interpretation and clinical decision-making for acute ST-elevation myocardial infarction.Am Heart J. 2010; 160: 995-1003Abstract Full Text Full Text PDF PubMed Scopus (113) Google Scholar suggested that the classification of appropriate versus inappropriate activation of the pPCI protocol is strongly dependent on the interventional cardiologist, and when the pPCI protocol is deactivated by an interventional cardiologist and no angiography is performed, the case can be classified as inappropriate activation.18Rokos I.C. French W.J. Mattu A. Nichol G. Farkouh M.E. Reiffel J. Stone G.W. Appropriate cardiac cath lab activation: optimizing electrocardiogram interpretation and clinical decision-making for acute ST-elevation myocardial infarction.Am Heart J. 2010; 160: 995-1003Abstract Full Text Full Text PDF PubMed Scopus (113) Google Scholar However, it would be incorrect to assume that the interventional cardiologist is always right because, as results of the present study show, the accuracy of off-line reading by experienced interventional cardiologists is far from perfect. As the population ages and the prevalence of baseline ECG abnormalities increases, diagnosing STEMI in the presence of baseline STE caused by LVH, repolarization abnormalities, or long-term infarction or aneurysm will become only more challenging.14Jayroe J.B. Spodick D.H. Nikus K. Madias J. Fiol M. De Luna A.B. Goldwasser D. Clemmensen P. Fu Y. Gorgels A.P. Sclarovsky S. Kligfield P.D. Wagner G.S. Maynard C. Birnbaum Y. Differentiating ST elevation myocardial infarction and nonischemic causes of ST elevation by analyzing the presenting electrocardiogram.Am J Cardiol. 2009; 103: 301-306Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar, 24Clark E.N. Sejersten M. Clemmensen P. Macfarlane P.W. Automated electrocardiogram interpretation programs versus cardiologists' triage decision making based on teletransmitted data in patients with suspected acute coronary syndrome.Am J Cardiol. 2010; 106: 1696-1702Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar As a result, if a wireless triage method were to be implemented, it could further increase false activations of the pPCI protocol when patients present with symptoms compatible with STEMI unless easy access to a patient's previous electrocardiograms is enabled. Results of our study confirm that a diagnosis of STEMI from the electrocardiogram alone can be challenging in a population with a high prevalence of abnormal baseline electrocardiograms. Thus, from a cost–benefit and clinical outcomes standpoint, there could be significant problems if wireless ECG transmission programs without access to previous electrocardiograms and/or communication with a patient were the only approach implemented. To our knowledge, there has been no study that proves this strategy alone would lead to improved clinical outcomes in patients who present with chest pain. We thank Chrissie Chambers, MA, ELS for editorial assistance in the preparation of this report.
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