Tachycardia, fever to 105, and ischemic ST Elevation -- a Bridge too Far

Discussion of Figure-1: As per Dr. Smith — ECG #1 showed marked sinus tachycardia at ~140/minute — with diffuse ST segment elevation.I often find it difficult to determine the precise amount of ST elevation when the heart rate is very fast. For clarity — I ’ve added short horizontal RED lines in Figure-1 to show what I took as the “baseline” for assessing the amount of J-point ST elevation for the 2 ECGs in this figure.It may be especially difficult when there is marked tachycardia to identify the J-point that defines the number of millimeters of ST elevation. This is because of the tendency for the ST segment to be curved rather than showing a distinct J-point when the heart rate is fast. For clarity — I’ve added BLUE arrows in ECG #1 to show what I took as the J-point in various leads. I accept that others may differ with the location of my arrows. Suffice it to say that there appears to be ≥4-5 mm of ST elevation in leads V2-thru-V5, with a lesser amount of ST elevation in leads I, aVL, V1 and V6.Clinical Context is everything! Given the tachycardia + the lack of chest pain in this patient who was thought to have septicemia — I was not convinced that ECG #1 was the result of an acute cardiac event. Tachycardia may sometimes produce a surprising amount of ST elevation — that greatly decreases (or even goes away) when the heart ra...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs