This ECG is from a 77 year old woman who was brought to the Emergency Department by EMS. She was found to be suffering from sepsis.
ECG Interpretation The ECG shows the expected sinus tachycardia at 123 beats per minute. There is significant baseline artifact, of the type usually seen with muscle tension. The artifact makes it difficult to assess P waves and PR intervals.
What we do see is RIGHT BUNDLE BRANCH BLOCK and LEFT ANTERIOR HEMIBLOCK, also called LEFT ANTERIOR FASCICULAR BLOCK. Together, these are called BIFASCICULAR BLOCK. Most people have three main fascicles in the interventricular conduction system: the right bundle branch and the two branches of the left bundle branch, the anterior-superior fascicle and the posterior-inferior fascicle. In bifascicular block, two of the three are blocked.
The ECG criteria for right bundle branch block are:
* wide QRS (> .12 seconds)
* rSR’ pattern in V1 . (the initial R wave may be hard to see, but the QRS will be predominantly upright.