The image illustrates the electrophysiological basis for ST-segment shifts observed in an ECG)l during myocardial ischemia, specifically in transmural, epicardial, and endocardial injuries.
https://t.co/Y6SUigP3QG
Understanding ST Changes in Ischemia
ST shifts on ECG aren't random
they reflect the direction of the injury current.
In subendocardial ischemia (A), injury currents are directed inward toward the ventricular cavity. Surface ECG leads record this as ST depression (e.g., in exertional angina or positive stress tests).
In transmural (epicardial) ischemia (B), the current moves outward toward the chest wall resulting in ST elevation, classic for acute MI or Prinzmetal angina.
Knowing the vector direction helps decode the ECG and the depth of myocardial injury.
Ref: Braunwald’s Heart Disease, 12th Ed
There is some debate regarding the utility of an acute abdo film but in some parts of the world is still a widely used tool
Abdominal X-Ray anatomy and review areas