Search results
Results from the WOW.Com Content Network
In electrocardiography, the ST segment connects the QRS complex and the T wave and has a duration of 0.005 to 0.150 sec (5 to 150 ms). It starts at the J point ...
The ST segment is the plateau phase, in which the majority of the myocardial cells had gone through depolarization but not repolarization. The ST segment is the isoelectric line because there is no voltage difference across cardiac muscle cell membrane during this state. Any distortion in the shape, duration, or height of the cardiac action ...
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]
Risk factors are similar to other types of ischemic heart disease. [1] The underlying mechanism is unclear; though may involve subendocardial ischemia or collateral circulation. [1] 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]
Research in the late 2000s has linked this finding to ventricular fibrillation, particularly in those who have fainted or have a family history of sudden cardiac death. [5] [6] [7] Although there is a significant relationship between ventricular fibrillation and some early repolarization's patterns, the overall lifetime occurrence of idiopathic ventricular fibrillation is exceptionally rare. [8]
However, ST segment depression is not suggestive of ischaemic location of the heart. ST segment depression in eight or more leads, associated with ST segment elevation in aVR and V1 are associated with left main coronary artery disease or three-vessel disease (blockage of all three major branches of coronary arteries).
Different wave shapes generated by different parts of the heart's action potential The ECG complex. P=P wave, PR=PR interval, QRS=QRS complex, QT=QT interval, ST=ST segment, T=T wave Principle of ECG formation. The red lines represent the depolarization wave, not bloodflow. An electrocardiogram is a recording of the electrical activity of the ...
Duke Treadmill Score is one of the tools for predicting the risk of ischemia or infarction in the heart muscle. [1] 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)]