This ECG is from an adult w/ h/o of HTN, dyslipidemia, s/p PM, smoker came in due to chest pain.
Figure 1 - ECG case
The strip shows pacing at 60 with AF as intrinsic rhythm + something else.
Do you see the difference when compared side-to-side?
Figure 2 - Side-by-side comparison of the ECG case (right side of the screen) vs. old ECG (left side of the screen)
Typically in paced rhythms the morphology is that of a left bundle branch block (LBBB) but as you can see here it is not the typical LBBB morphology that is seen in V1. This makes the usual Sgarbossa criteria for AMI in LBBB a challenge.
In the GUSTO-I trial by Sgarbossa EB, et al (17 pts with PM were analyzed -
(read this article and go back to the strip)
*They found that ST-segment elevation = 5 mm was most indicative of AMI in leads that had predominantly negative QRS complexes.
*Any degree of ST-segment elevation in a lead with a predominantly positive QRS complex was a highly specific sign of AMI. (***ST-segment elevation concordant with the QRS polarity is not expected in uncomplicated ventricular pacing)
*ST-segment depression in leads V1, V2, or V3, had a specificity of 82% for acute infarction (could represent either posterior “Q wave” infarctions or "ST depression (subendocardial)” infarcts.(***V1,V2 and V3 should not be present in these leads)
For the case, LHC revealed LAD lesion and intervention was done.
Other articles (free on the web):