What is ST segment resolution?
In most studies, resolution of the sum of ST-segment elevation (sum STR) after reperfusion therapy either by fibrinolysis or primary percutaneous coronary intervention (PCI) is used to predict infarct size, left ventricular function, epicardial vessel patency, and mortality.
What segment is St?
The ST segment is an interval between ventricular depolarization and ventricular repolarization. It is identified as the end of the QRS complex to the beginning of the T wave. The end of the T wave to the beginning of the P wave is described as the TP segment, which is the zero potential or isoelectric point.
Why are ST segments so important?
The ST segment is the most important portion of the QRS complex for evaluating ischemia (Box 9-11). The origin of this segment, at the J point, is easy to locate. Its end, which is generally accepted as the beginning of any change of slope of the T wave, is more difficult to determine.
What is ST segment compared to?
In most of individuals without prior cardiac disease, the ST segment is at the level of the preceding P-R segment and/or the following T-P segment (so called isoelectric). Deviation of the ST-segment (elevation or depression compared to the isoelectric line) can be a sign of ischemia of the heart muscle.
What is the meaning of thrombolytic?
Listen to pronunciation. (throm-BOL-ih-sis) The process of breaking up a thrombus (blood clot) that is blocking blood flow. The blood clot may be dissolved using drugs delivered through a catheter (tube) into the clot.
What is successful thrombolysis?
Successful clinical reperfusion (SCR) was defined as the presence of at least two of the following criteria at 2 hours after thrombolytic treatment: (1) significant relief of pain (a 5-point reduction on a 1 to 10 subjective scale), (2) > or =50% reduction of sum of ST segment elevation, and (3) abrupt initial increase …
Why is the ST segment isoelectric?
These minimal voltage gradients are similar to those found in the period between the end of ventricular repolarization and the beginning of the next cycle of ventricular depolarization. This near absence of voltage gradient is responsible for the normal isoelectric or practically flat ST segment on the ECG.
Why does the ST segment elevation?
ST segment elevation occurs because when the ventricle is at rest and therefore repolarized, the depolarized ischemic region generates electrical currents that are traveling away from the recording electrode; therefore, the baseline voltage prior to the QRS complex is depressed (red line before R wave).
What happens during the ST segment?
ST segment corresponds to a period of ventrical systolic depolarization, when the cardiac muscle is contracted. Subsequent relaxation occurs during the diastolic repolarization phase.
Why is the ST segment elevated?
What are examples of thrombolytics?
The most commonly used clot-busting drugs — also known as thrombolytic agents — include:
- Eminase (anistreplase)
- Retavase (reteplase)
- Streptase (streptokinase, kabikinase)
- t-PA (class of drugs that includes Activase)
- TNKase (tenecteplase)
- Abbokinase, Kinlytic (rokinase)
What is ST segment elevation and ST segment deviation?
The ST segment may be displaced upwards (ST segment elevation) or downwards (ST segment depression). The term ST segment deviation refers to elevation and depression of the ST segment. The magnitude of ST segment deviation is measured as the height difference (in millimeters) between the J point and the PR segment.
What is ST segment resolution on ECG?
ST-Segment Resolution. ST-segment resolution (STR) represents the simplest clinical evidence of effective myocardial reperfusion and lack of STR is suggestive of the occurrence of no reflow (NR) [2]. In clinical practice, STR can be assessed by either continuous monitoring or static ECG recordings.
What is the normal ST segment length?
The typical ST segment duration is usually around 0.08 sec (80 ms). It should be essentially level with the PR and TP segments. The ST segment represents the isoelectric period when the ventricles are in between depolarization and repolarization. The normal ST segment has a slight upward concavity.
What does a flat ST segment Mean?
The ST segment represents the isoelectric period when the ventricles are in between depolarization and repolarization. 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.