A case report in Prehospital Emergency Care describes an obese (>200 kg) chest pain patient who refused to lie supine because of severe back pain. A 12 lead ECG was done with all the leads placed posteriorly, and the resultant electrocardiograph showed characteristic ST elevation in II, III and AVF with ST depression in AVL. The inferior MI was confirmed in hospital on repeat ECG, biomarker rise, and a thrombus in his right coronary artery at angiography.

Abstract A prehospital 12-lead electrocardiogram (ECG) is commonly used for patients with suspected ST-segment elevation myocardial infarction (STEMI). This case report describes how paramedics diagnosed inferior STEMI with all ECG leads positioned on a patient’s back (i.e., “all-posterior” positioning). The patient was hemodynamically stable but morbidly obese and markedly diaphoretic. Owing to severe back pain, he refused to lie in the supine position for assessment or transport. At the emergency department, a 12-lead ECG with the patient in lateral recumbency confirmed the diagnosis of inferior STEMI. This case shows that an all-posterior 12-lead ECG can be used to identify STEMI when optimal patient positioning is not possible.

Prehospital Diagnosis of ST-segment Elevation Myocardial Infarction Using an “All-Posterior” 12-Lead Electrocardiogram
Prehosp Emerg Care. 2011 Jul-Sep;15(3):410-3