A weekly ECG / EKG review blog looking at some interesting ECG's from the world of Emergency Medicine.
I'm basing my interpretation solely on Dr. Henry J. L. Marriott's reclassification of A-V blocks. INTERPRETATION: Borderline sinus rhythm (rate about 99-100/min) with 2:1 Type I A-V block complicating acute inferior infarction. The following trio of findings strongly favor (about 99%) this being due to a lesion at the anatomic level of the A-V node: 1) Acute inferior infarction; 2) Somewhat prolonged P-R intervals on the conducted beats; and 3) The presence of normally narrow QRS complexes (i.e., no bundle-branch block). Conversely, 2:1 Type II A-V block usually displays a bundle-branch block and a normal P-R interval on the conducted beats.