medicmommyof2 Posted January 19, 2012 Share Posted January 19, 2012 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 VIEW LARGER 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 VIEW LARGER 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. 2 Link to comment Share on other sites More sharing options...
systemet Posted January 19, 2012 Share Posted January 19, 2012 This is a great case study, thanks for posting. A couple of things to note here for anyone new to 12-lead: * ST depression in V1-V3 (and possibly V4) is probably due to posterior wall MI, as part of the RVI. But the ST depression in I and aVL is likely reciprocal changes from the infarct. * Note how the axis changes from the first ECG (+44 degrees), to the second ECG (-24 degrees). This is likely due to a loss of functional myocardium in the RV, resulting in a predominance of LV forces. Importantly, this isn't an LAHB. * Note the Q wave in lead III in the post-ECG. [Also, it seems like there is a small amount of persistent ST elevation in III, aVF.] ------------------------------ Other thoughts: * These guys were very lucky not to sewer the patients pressure with the nitrates. Fluid would have been a better option here. * While the 12-lead was extremely useful to the ED physician for cathlab activation, imagine how much more useful it might have been if the team were able to fax ahead, and get the cathlab notified. Or even bypass the ER straight into a cathlab suite with some LMWH and plavix on the way. There is more than enough evidence to support this practice, it's life-saving, and just requires the conjoint of (i) an EMS system management that's doing it's job, (ii) a medical director who's doing his/her job, (iii) a little amount of buy-in from cardiology, which really amounts to them just doing their job, too. 1 Link to comment Share on other sites More sharing options...
scott33 Posted January 20, 2012 Share Posted January 20, 2012 The posterior wall MI is obvious here - the inferior wall, less so Link to comment Share on other sites More sharing options...
systemet Posted January 20, 2012 Share Posted January 20, 2012 The posterior wall MI is obvious here - the inferior wall, less so I agree that it's subtle in the inferior leads, but there is some concavity (coving?) to the ST segments / T wave. Link to comment Share on other sites More sharing options...
spenac Posted January 20, 2012 Share Posted January 20, 2012 (edited) MM2 you hit on a vital point, that of the ER doctor actually accepting the EMS EKG. The doctors that know me know that if I tell them there is an issue they listen. Occasionally though we get a renta doc covering and we show up and they ignore what we tell them they ignore our EKG. Thankfully more and more doctors are beginning to understand that EMS is more than a taxi service. Did you do a modified 12 lead? V4R, V8, V9. Edited January 20, 2012 by spenac Link to comment Share on other sites More sharing options...
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