This ECG was obtained from an elderly man who was complaining of acute-onset chest pain, radiating down his left arm.  He also complained of a cough, and had audible rhonchi.  The machine interpretation gives several possible explanations for the widespread ST elevation noted on the ECG.  The paramedics were a bit distracted by the machine's interpretation, and by the respiratory symptoms, and decided not to call a "cardiac alert" on the patient.  They did, however, quickly transport him to the closest hospital, which happened to have full-service cardiac facilities.  The patient was diagnosed with an acute M.I. and treated with angioplasty in the cath lab, with a good outcome.  Afterward, the medics felt that they "overthought" this one, and should have given more weight to the patient's symptoms.  Teach your students to evaluate their experiences with open minds and unafraid of self-criticism, so they may learn from every patient.  This patient received excellent care, and the paramedics added to their "information banks", upon which they will draw for many years to come. 

Although the angiogram results are not available to us, it is plausible that a proximal occlusion of the LCA, near the bifurcation of the LAD and the diagonal, could cause ST elevation in V3 through V6, with mild elevation in Lead II (which is oriented to the leftward portion of the inferior wall), and ST and T changes in the high lateral leads (I and aVL). 

This week's ECG of the Week is from an elderly woman who suffered an acute occlusion of the right coronary artery.  The ECG clearly shows ST elevation in leads II, III, and aVF, indicating inferior wall injury.  In this case, this ECG was obtained in the field by paramedics, and was the second ECG done on this patient. For this tracing, the paramedics obtained V3 and V4 on the right side to better view the right ventricle. V3 and V4 right clearly show ST elevation as well, indicating RVMI.  The slight coving and elevation observable in V1 is also an indication of RV involvement, and the ST depression in V2 indicates posterior wall injury.  All of this results from a proximal lesion of the RCA in this patient.  Such a lesion carries a high morbidity and mortality.

Taking the time to obtain a right ventricular lead is controversial in some settings.  Some believe the patient's hemodynamic condition should be treated, regardless of the presence or absence of ST elevation in right chest leads.  Others find it very helpful to know that the right ventricle is affected.  In this case, paramedics in this community have a protocol to avoid the use of nitroglycerine in RVMI patients, even when the BP is adequate.  So, for them, it is important to have the information gathered from V Right leads.

The rhythm here is interesting, as well, and not at all uncommon for IWMI patients.  The baseline artifact makes it a bit difficult to march out all the P waves, but it appears they are sinus P waves that are slightly irregular at a rate of 52 to 54.  The PR intervals appear to be progressively prolonging, but there is no "grouped beating" observable on this short strip.  A lack of a concurrent Lead II rhythm strip also makes it difficult to determine the rhythm, as Lead II does have very visible P waves, and would be helpful.  The regularity of the narrow complex bradycardia points to a junctional escape rhythm, which would make this a third-degree AVB at the AV node level, which is very common with IWMI.  What do you think?

This month's strip from Jason Roediger's ECG Challenge blogpost is a nice complement to the strip presented here.  His is much clearer, and has a Lead II rhythm strip.  Do you think these ECGs show the same rhythm, or two different rhythms?

For an excellent discussion of "AV Dissociation" vs. "AV Block", go to Christopher Watford's Ask the Expert post.  Thanks very much to ECG Guru Sebastian Garay for this interesting ECG.

This is a good example of acute anterior wall M.I., with ST elevation in V1 through V6, as well as in Leads I and aVL.  The extensive distribution of ST segment elevations across the anterior and high lateral walls indicates a proximal LAD artery occlusion.  In addition, this ECG shows right bundle branch block, with a QRS width of 144 ms (.14 sec.) and an rsR' pattern in V1. There is also a wide s wave in Lead I which is partly obscurred in V6 by the ST elevation.  The right axis deviation (98 degrees) suggests a left posterior fascicular block which, when coupled with the RBBB, is a bi-fascicular block.  P waves are difficult to see.  Do you think they are found at the end of the QRS complexes, representing a long first-degree AVB?  Look at leads V3 through V6 for clues.

Please feel free to add your comments below.  The more "gurus" the better.

A good ECG to teach your students that a patient facing a life-threatening emergency may have a "normal" rate and regular rhythm.  There is something in this ECG for beginners through advanced students.

A good teaching ECG, showing clearly elevated ST segments in V1 through V4.  This patient had an LAD occlusion.  In addition, he has new-onset atrial fib at a rate of about 120/min.  Atrial fib has decreased cardiac output because of the loss of P waves prior to the QRS complexes, and a resultant decreased ventricular filling pressure.  In addition, this fast rate contributes to increased myocardial oxygen demand and damage.  An early priority, along with getting this patient to PCI, is slowing the rate.