Advanced ECG Interpretations

  Analyzing an Acute MI “Jones’s Rule” and Primary Repolarization Changes Jerry W. Jones, MD FACEP FAAEM Figure 1 This is another 12-lead ECG randomly selected from my collection. There is a bit of baseline wander, but that’s life! It was recorded on a 68 y/o Hispanic female in the emergency department who was complaining of chest pain. There is no other information about her. First, the absolute basics. We can see by the upright P waves in leads I and II that sinus rhythm is present. The pos/neg biphasic P wave in Lead V1 is also supportive of sinus rhythm. The P wave in Lead V2 is basically isoelectric – but that’s OK, as long as it isn’t inverted or biphasic. There is 1:1 sinoatrial conduction and the P-R intervals are normal and remain the same. The rate is quite variable and may represent a sinus arrhythmia. Also, as we will see in a moment, there is also a good reason for increased parasympathetic influence on the rate. No apparent lethal dysrhythmias and no blocks are not...

                   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...