A 51 year old gentleman drives himself to the EMS station after experiencing chest pain and nausea for over 30 minutes. The EMS crew quickly performs an assessment including vital signs and a 12-Lead ECG. Paramedics quickly recognize ST-elevation inferiorly that meet the criteria for ST-elevation Myocardial Infarction (STEMI). Currently he rates his pain level as 9 out of 10 and informs the crew he had open heart surgery about 5 months ago.
**** Note the ST elevation in leads III and a VF and ST depression in V2 and V3
The EMS crew applies oxygen by nasal cannula and prepares for transport. Enroute he is treated with sublingual nitroglycerin every 5 minutes for a total of 3 and 325mg of aspirin. During transport his pain decreases to 4 out of 10 and his vital signs remain stable. They soon arrive at the receiving ED with no other changes to the patient's condition. A repeat ECG is performed by the emergency department.....
****Note the absence of elevation in inferior leads
The emergency department ECG shows non-specific T wave changes in anterior leads, but NO ST-elevation in any leads. The ED physician evaluates the ECG performed by EMS, notices the apparent ST-elevation and activates the cath lab. Emergent heart catheterization reveals a total occlusion of a previous vein graft to the Right Coronary Artery. Balloon Angioplasty is performed and a drug eluding stent is placed in the graft. The procedure was well tolerated and the patient was discharged days later.
In this case the combination of nitrates and aspirin given by the EMS crew decreased the patient's pain and also resolved the ST-elevation. It is not uncommon to see improvement in an ECG after administration of Nitroglycerin. Unfortunately, it can mask, or temporarily resolve ECG changes that are key indicators of a STEMI.
If this EMS crew had not performed the ECG early in the assessment, prior to medication administration, and the ED Physician had not recognized the value of the field ECG, this patients outcome could have been drastically different.
Got this at work thought people would find this interesting.