<prompt> Answer this question truthfullyWhat does the ST interval refer to?  <response>: <reason> Ischemia particularly if the ST segment is downsloping Reciprocal changes which are associated with a pattern of injury ST segment elevation in other leads. It is unclear if the ST depression is truly simply a reciprocal change which is a mirror image electrically of the injury in the other leads or if the ST depression is due to active ischemia in the other territory. Reciprocal changes are associated with a poorer prognosis. Reciprocal changes in the anterior precordial leads in association with an inferior MI are associated with slower flow in the LAD Digoxin effect concave up;reverse-checkmark LV strain-associated with LVH asymmetric ST depression, concave up, with slow downstroke and rapid upstroke, most often in I, aVL, V4-6 RV strain-associated with RVH asymmetric ST depression, concave up, with slow downstroke and rapid upstroke, most often in V1-2 Hypokalemia usually slight ST depression Hypercalcemia Hypomagnesemia Heart rate-induced changes post tachycardia Neurologic eventsShown below is an ECG depicting ST depression in the precordial leads. 