This ECG is from a 65-year-old woman who presented to the Emergency Department with a complaint of chest pain. We have no other clinical information.
There are several subtle, but real, abnormalities on the ECG that should be evaluated in conjuction with her clinical situation. This is a good ECG to discuss with your more advanced students who have mastered recognition of blatant ST elevation M.I. (STEMI). But, let’s start with what is NORMAL here.
NORMAL FEATURES The normal findings are: normal sinus rhythm at about 68 bpm. The rhythm is regular without ectopy. The intervals are within normal limits. The frontal plane axis is normal. The T waves are all upright.
ABNORMAL FEATURES There is subtle ST segment elevation in Leads V1 through V3, and in I and aVL. The shape of the ST segments is concave upward, or normal. In a young, asymptomatic patient, we probably would not be at all concerned about this amount of ST elevation. However, this is an older patient with chest pain. In the chest leads, the R wave progression is interrupted, as the QRS goes abruptly from negative to positive in Lead V3. This could be due to loss of r waves ( pathological Q waves forming) in V1 and V2 lead placement, or something else.
In addition, the inferior leads (II, III, and aVF) show ST flattening, with ST depression in Lead III. Probably the best way to approach such subtle changes in a symptomatic patient is to repeat the ECG frequently while initiating evaluation and treatment of the chest pain. Often, ST segments will change rapidly during an ischemic episode. Lead aVL appears to have a pathological Q wave, but that lead sometimes has a septal q wave, which is normal. Having a prior ECG for comparison is also very helpful for differentiating acute changes.
TEACHING OPPORTUNITIES This tracing can help you teach students that not all cardiac patients will present with flagrant STEMIs, and we much learn to see subtle abnormalities and consider them in light of clinical features – history, symptoms, labs, and ECG changes.