Case No. 4 B: Chest Pain
A 68 year old white male presenting to EMS with chest pain and a history of HTN. No further on this case in known at this time.
This ECG demonstrates a 3:2 Wenkibach phenomenon with an initial inconsistency, possibly due to an A:V ratio shift or artifactual event. Note the subtle elevation in V6; again, a 15lead tracing would have been optimal here.
It should not be forgotten that although inferior wall STEMI typically results from RCA occlusion, it may also arise from a lesion in the Circumflex; in the latter case, the right heart is spared and RCA dependent conduction system elements remain unaffected. Dr. Smith has recently presented an example of this phenomenon as well as a review of a risk stratification ECG algorhythm recently proposed to deliniate RCA vs CLX lesions on ECG. While the case above meets several of these criteria (aVR depression and V6 eleveation), the manifest conduction system involvment all but eliminates the possibility of a CLX eitiology. I hope to post a better example of the DeVerna RCA/CLX decision tool in the near future; see Dr. Smith’s ECG site for a superior and more appropriately exemplified discussion of this new research.