What is pathological ST depression?
ST depression occurs when the J point is displaced below baseline. Just like ST elevation, not all ST depression represents myocardial ischemia or an emergent condition. There are multiple conditions associated with ST depression. Some of these include hypokalemia, cardiac ischemia, and medications such as digitalis.
What is inferior ST abnormality?
An inferior wall MI — also known as IWMI, or inferior MI, or inferior ST segment elevation MI, or inferior STEMI — occurs when inferior myocardial tissue supplied by the right coronary artery, or RCA, is injured due to thrombosis of that vessel.
Can stress cause ST depression?
An ischemic zone of 50% transmural extent covering the entire left ventricular subendocardium caused an ST-depression pattern similar to that observed during stress test. Conclusion: In contrast to regional subendocardial ischemia, global subendocardial ischemia can explain ST depression in our model.
When is St depression normal?
ST segment depression is measured in the J point. The reference point is, as usual, the PR segment. ST segment depression less than 0.5 mm is accepted in all leads. ST segment depression 0.5 mm or more is considered pathological.
What does ST depression mean on a stress test?
Objective: The electrocardiogram (ECG) obtained during stress testing often shows a typical pattern of primary ST depression. A similar pattern can occur in unstable angina. Current textbooks consider ST depression as a direct result of partial occlusion of a coronary artery.
Why does ST depression occur?
ST segment depression occurs because when the ventricle is at rest and therefore repolarized, the depolarized ischemic subendocardium generates electrical currents that are recorded by an overlying electrode.
What does ST depression look like on ECG?
The ECG is characterized by deep and persistent, concave-upward ST-segment depression in multiple limb and chest leads. ECG changes are stable over time and accentuated during exercise.
What causes ST depression on an ECG?
The ST Segment represents the interval between ventricular depolarization and repolarization. The most important cause of ST segment abnormality (elevation or depression) is myocardial ischaemia or infarction.