ST Depression, ischemia as baseline? Ummm...

[GoNightingale, BSN, RN]

To my wonderous ICU, CCU, PCU nurses out there, has anyone ever heard of ST-depression on a tele strip to be a patient's "baseline"? I have always thought that ST depression is somewhat acute vs. chronic or "baseline". From my studies and recent inquiries, I have been and still are under the impression that ST depression, since it is a relection of myocardial ischemia, usually shows up on monitor when there is stable or unstable angina and sometimes precipitates an AMI or a NONSTEMI.

But I've never heard of ST-depression showing up throughout the course of a hospital stay as the pt's baseline and not being acted upon or at least somehow treated. But I'm a newbie at this so..........could be wrong and would love to be enlightened by voices of experience.

Thanks!:heartbeat

[PedsDrNurseTheo, ADN, BSN, MSN, DNP, RN, EMT-P, NP]

It depends. While ST-segment depression is most certainly a common sign of ischemia, it is not always definitively caused by ischemia. So the ST-depression might very well be baseline, while not a sign of an ischemic condition.

Hypokalemia, digitalis effect, left ventricular hypertrophy, bundle branch blocks or other infranodal conduction delays, and mitral valve prolapse can all be potential factors in ST changes; any two given cardiologists can often argue about any one given ECG at times. Prinz-metal angina and other vasospastic conditions can cause an acute-on-chronic ischemic change in ECG; though Prinz-metal usually causes ST elevation.

Definitive diagnostic testing is usually required to provide a cause; it's why we do enzymes and other tests as well as ECGs. Remember too that ECGs miss a rather substantial percentage of MIs - so not so much a definitive marker of ischemia/infarct, though they are useful to raise the index of suspicion.

Certainly an interesting question and one worth researching. I recommend this website among others: The University of Utah's ECG Learning Center.

[GoNightingale, BSN, RN]

It depends. While ST-segment depression is most certainly a common sign of ischemia, it is not always definitively caused by ischemia. So the ST-depression might very well be baseline, while not a sign of an ischemic condition.

Hypokalemia, digitalis effect, left ventricular hypertrophy, bundle branch blocks or other infranodal conduction delays, and mitral valve prolapse can all be potential factors in ST changes; any two given cardiologists can often argue about any one given ECG at times. Prinz-metal angina and other vasospastic conditions can cause an acute-on-chronic ischemic change in ECG; though Prinz-metal usually causes ST elevation.

Definitive diagnostic testing is usually required to provide a cause; it's why we do enzymes and other tests as well as ECGs. Remember too that ECGs miss a rather substantial percentage of MIs - so not so much a definitive marker of ischemia/infarct, though they are useful to raise the index of suspicion.

Certainly an interesting question and one worth researching. I recommend this website among others: The University of Utah's ECG Learning Center.

Wow.......! What an interesting and enlightening reply. Appreciate it lot! Definitely going to check out UofU's website.