Search results
Results from the WOW.Com Content Network
ST segment depression and T-wave changes may be seen in patients with unstable angina; Depressed but upsloping ST segment generally rules out ischemia as a cause. Also, it can be a normal variant or artifacts, such as: Pseudo-ST-depression, which is a wandering baseline due to poor skin contact of the electrode [3]
Illustration of ST segment elevation and depression The normal ST segment has a slight upward concavity. Flat, downsloping, or depressed ST segments may indicate coronary ischemia. ST elevation may indicate transmural myocardial infarction. An elevation of >1mm and longer than 80 milliseconds following the J-point.
Diagnosis is based on an ECG showing ST-segment depression at the J-point of 1 to 3 mm in leads V1 to V6, with tall and symmetrical T waves. [1] The ST-segment is upsloping and there is also often ST-segment elevation of 0.5 to 2 mm in lead aVR. [1] [2] The QRS complex is either normal or slightly wide. [1]
An upsloping, convex ST segment is highly predictive of a myocardial infarction (Pardee sign) while a concave ST elevation is less suggestive and can be found in other non-ischaemic causes. [1] Following infarction, ventricular aneurysm can develop, which leads to persistent ST elevation, loss of S wave, and T wave inversion.
The calculation is done based on the information obtained from an exercise test by this formula: [citation needed] [exercise duration by Bruce protocol] - [ 5 × (maximal ST elevation or depression)] - [4 × (treadmill angina index)] In which, the exercise duration is written in "minutes" and the ST changes in "millimetres". [1]
The Harvard step test, in scientific literature sometimes referred to as the Brouha Test, is a type of cardiac stress test for detecting and diagnosing cardiovascular disease. It is also a good measurement of fitness and a person's ability to recover after a strenuous exercise by checking the recovery rate.
Their task, which they named the Trier social stress test, consistently produced very large physiological effects in the majority of their participants, thus overcoming the limitations of earlier research. They first reported on the test in 1993, in the journal Neuropsychobiology. [1] The TSST is widely used as a stress paradigm in stress research.
The main strength of the tail suspension test is its predictive validity– performance on the test can be altered by drugs that improve depressive symptoms in people. Specifically, if antidepressant agents are administered before the test, the animal will struggle for a longer period of time than if not and exhibit more escape behaviors. [1]