ST depression

It is often a sign of myocardial ischemia, of which coronary insufficiency is a major cause.

Also, it can be a normal variant or artifacts, such as: Other, non-ischemic, causes include: A mnemonic can be used for some causes of ST depression, namely DEPRESSED ST:[citation needed] D - Drooping valve (mitral valve prolapse) E - Enlargement of the left ventricle P - Potassium loss R - Reciprocal ST depression (e.g. inferior wall MI) E - Encephalon hemorrhage S - Subendocardial infarct S - Subendocardial ischemia E - Embolism (pulmonary) D - Dilated cardiomyopathy S - Shock T - Toxicity (digitalis/quinidine) For non-transmural ischemia (subendocardial ischemia) injured cells are closer to the inside of heart wall, resulting in a systolic injury current.

A systolic injury current results from a greater depolarization in healthier cells.

[citation needed] ST segment depression may be determined by measuring the vertical distance between the patient's trace and the isoelectric line at a location 2[4]-3 millimeters from the QRS complex.

[citation needed] In a cardiac stress test, an ST depression of at least 1 mm after adenosine administration indicates a reversible ischaemia, while an exercise stress test requires an ST depression of at least 2 mm to significantly indicate reversible ischaemia.