A Fascinating Demonstration of ST/S Ratio in LBBB and Resolving LAD Ischemia

This case was contributed by one of my talented colleagues, Johanna Moore, MD.  She is our research director and is doing some great research on cardiac arrest.  Check out her research on Head-up CPR!There is more interesting stuff on Head up CPR here.  And here.CaseA patient with a history of CABG in 1998, with subsequent ischemic cardiomyopathy, called his clinic to report he had a few minutes of burning chest and epigastric pain, associated with walking, that was now gone.  They told him to call 911.  Medics arrived and recorded this ECG (pain free) about 15 minutes after the resolution of chest discomfort:Left Bundle Branch Block, but with both S-waves and T-waves cut off due to high voltage. You can see quite a bit of discordant ST depression in V5 and V6, but not out of proportionThe paramedics were worried by his ECG and had a physician check the patient and ECG at the door.The patient arrived and was free of discomfort. After briefly reviewing the patient's previous ECG, the physicians decided to expedite the patient's care by placing him in a critical care area despite the patient's well appearance.   This first ED ECG was recorded at 15 minutes after the previous prehospital ECG and 30 minutes after resolution of discomfort. There is LBBB with 7.5 mm of STE in lead V2 (the lead with the highest ST/S ratio)The S-wave is 43 mm.  The ratio is 7.5/43 = 0.174.This is below the Modified Sgarbossa cutoff of 0.25In Sm...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs