Advanced ECG Interpretations

  Notes on a Randomly-Selected ECG Jerry W. Jones, MD FACEP FAAEM Figure 1 What is the rhythm on this ECG? Don’t be too quick to respond because I just asked you a trick question! Which rhythm are we discussing – the atrial rhythm or the ventricular rhythm ? Although this looks like a “single” ECG, it is really two ECGs – an atrial ECG and a ventricular ECG – one superimposed upon the other. Let’s begin with the atrial rhythm. Do you see any P waves? I don’t. That – by definition – is either atrial fibrillation , sinus arrest or third degree SA block . Now let’s consider the ventricular rhythm. It appears irregular . It is always best to assume that a ventricular rhythm that is based on an ectopic junctional or ventricular escape pacemaker will be very regular – even though it may be very slow. That isn’t always the case, but it will be about 99% of the time in my experience. OK… let’s put these two observations together: if the atrial rhythm (or lack of an atrial ...

  Are you treating myocardial infarctions? Why? That's DEAD tissue! You should be treating myocardial ischemia! What's the difference between ST elevation and ST depression? Does ST depression ALWAYS represent a subendocardial ischemia? Does  ST elevation ALWAYS  represent an acute transmural ischemia? Which blood test do you use to confirm an acute transmural ischemia...         ...troponins, or a CK-MB? If you base you diagnosis of an acute transmural ischemia on the presence of ST elevation according to the STEMI protocol, then you are basing your diagnosis on a CK-MB, because that's the test that was used to "prove" that the ST deviation was or was not a STEMI! The STEMI protocol was based on just ONE article that used CK-MB assays as proof of acute transmural ischemia. Is there a problem with that? Well, no... if you don't mind missing about 25% of acute transmural ischemias that should have gone directly to the cath lab but instead were...

                   A Closer Look at Right Bundle Branch Block (RBBB) Jerry W. Jones, MD FACEP FAAEM I once wrote an article about “rabbit ears” and RBBB and posted it on my blog ( https://medicusofhouston.com/dr-joness-ecg-blog/) . To this date it has been the most read article I have produced. So, let’s take a closer look at RBBB.  The  right bundle branch courses down the wall of the interventricular septum on the right ventricular side. Its course is superficial at some points, so it is very susceptible to injury by central venous lines or stretching (dilatation) of the right ventricle. The diagram on the left shows both bundle branches (right – yellow, left – red). With the right bundle branch blocked up high (dotted line), the atrial impulse travels down the left bundle branch into the anterior and posterior fascicles. The left ventricle is depolarized normally and at its usual speed. The first portion of the left vent...