Posterior myocardial infarction: are we failing to diagnose this?. Issue 1 (20th October 2010)

• Record Type: Journal Article
• Authors: Khan, Jamal Nasir; Chauhan, Abhishek; Mozdiak, Ella; Khan, Jawad M; Varma, Chetan
• Is Part Of: Emergency medicine journal. Volume 29:Issue 1(2012)
• Page Start: 15
• Page End: 18
• Publication Date: 2010-10-20
• Subjects: Cardiac care -- acute myocardial infarct -- acute coronary syndrome -- thrombolysis -- ECG; Emergency medicine -- Periodicals; 616.02505
• DOI: 10.1136/emj.2010.099861
• Languages: English
• ISSNs: 1472-0205

Abstract

Abstract : Introduction: Isolated posterior ST-elevation myocardial infarction (STEMI) accounts for up to 7% of STEMIs. The diagnosis is suggested by indirect anterior-lead ECG changes. Confirmation requires presence of ST-elevation in posterior-leads (V7–V9). We investigated the ability of hospital doctors and paramedics to diagnose posterior STEMI (PMI). Methods: Doctors in the emergency department and acute medical unit at two teaching hospitals and West Midlands Ambulance Service Paramedics were asked to interpret a 12-lead ECG illustrating ST-depression and dominant R-wave in V1-V2 in the context of cardiac chest pain, and identify PMI as a potential diagnosis. Their ability to identify PMI was compared with their ability to diagnose anterolateral STEMI on a 12-lead ECG. We assessed whether doctors knew that posterior-leads were required to confirm PMI and whether doctors and nurses could position posterior-leads. Results: 44 of the 117 doctors (38%) identified PMI as a potential diagnosis. PMI was identified by 73% of registrars, 30% of senior house-officers and 18% of house-officers. 50% of doctors who identified potential PMI knew that posterior-leads were required to confirm the diagnosis. 20% of doctors correctly positioned these and 19% knew the diagnostic criteria for PMI (ST-elevation ≥1 mm in V7–V9). 13 of the 60 nurses (22%) in the emergency department and acute medical unit correctly positioned posterior-leads. Five of the 50 (10%) paramedics identified PMI as a potential diagnosis. Doctors and paramedics were significantly better at diagnosing anterolateral STEMI than PMI. Conclusions: A significant proportion of doctors and paramedics were unable to diagnose PMI. Hence, the majority of PMIs may be being missed. Routine use of posterior-leads in the standard assessment of patients with chest pain may identify up to an additional 7% of STEMIs, allowing prompt reperfusion therapy, which would reduce morbidity and mortality.