ST depression refers to a finding on an electrocardiogram, wherein the
trace in the ST segment is abnormally low below the baseline
.
What does a ST segment depression on ECG signify?
ST depression in ECG at entry indicates
severe coronary lesions and large benefits of an early invasive treatment strategy
in unstable coronary artery disease; the FRISC II ECG substudy.
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 is ST depression indicative of?
ST depression in ECG at entry indicates
severe coronary lesions
and large benefits of an early invasive treatment strategy in unstable coronary artery disease.
Is ST segment depression normal?
ST segment depression of
1 mm or more
, lasting 0.08 second or more, is generally considered a positive (abnormal) response. False-negative (normal) results can occur, however, in patients with ischemic heart disease and false-positive results can occur in normal people.
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.
Is ST elevation or depression worse?
Conclusion: In patients with a first acute anterior MI treated with primary PCI, ST elevation in
inferior leads had significantly worse short-term
and long-term outcomes compared to no ST change or ST segment depression.
Is ST depression reversible?
The ECG sign of subendocardial ischemia is ST segment depression (A).
Depression is reversible if ischemia is only transient but
depression persists if ischemia is severe enough to produce infarction. T wave inversion with or without ST segment depression (B) is sometimes seen but not ST segment elevation or Q wave.
What medications cause ST depression?
Medications including
digoxin
and multiple other anti-arrhythmic drugs that affect myocyte repolarization also can cause ST segment depression.
How many boxes do I need for ST depression?
The ST segment is depressed if it lies more than 0.1 mV (
one box
; >0.2 mV in CV
6
LL and CV
6
LU) below the baseline. Depression of ST may be seen with myocardial ischemia, hypoxia, or hypocalcemia.
Which ECG leads show ST depression?
The ECG shows ST depression in
leads V1 to V4
and only minor ST elevation, not fulfilling ST elevation myocardial infarction criteria, in leads I, aVL, and V6.
What does ST depression look like on EKG?
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 is normal ST depression?
ST segment elevation or depression
up to 0.1 mV
generally is considered within normal limits.
What causes prolonged ST segment?
Persistent ST-segment–elevation may be seen in chronic transmural infarctions associated with
aneurysm formation
, early repolarization, left ventricular hypertrophy, Brugada syndrome, repolarization abnormalities in the setting of bundle-branch blocks, pancreatitis, and very large hiatal hernias.
Is ST depression normal during stress test?
Approximately 20% of healthy individuals exhibit
upsloping ST depressions during exercise stress testing. Upsloping ST depressions are thus very common during exercise and they are not typical of myocardial ischemia. If only the J point is depressed (Figure 4, left panel), then it is referred to as J point depression.
