What are the differences between a transmural MI and an Subendocardial MI?
Discussion. The results of this study are that subendocardial infarction is associated with a significant reduction in longitudinal S and SR, whereas radial and circumferential function are relatively preserved. In contrast, transmural infarction is associated with a reduction of both long-axis and short-axis function.
What are the ECG changes in sub endocardial MI and transmural MI?
In transmural MI, ischemia in the subendocardium spreads to the epicardium and involves full thickness of the myocardium. In the acute phase, the ECG signs are ST segment elevation. The elevated ST segment may slope upward or be horizontal or dome-shape.
What is a Subendocardial MI?
A subendocardial infarct results in necrosis exclusively inolving the innermost aspect of the myocardium. Usually a subendocardial infarct is the result of a partially occluded epicardial coronary artery (i.e. NSTEMI).
Why is ST elevation transmural?
An acute ST-elevation myocardial infarction occurs due to occlusion of one or more coronary arteries, causing transmural myocardial ischemia which in turn results in myocardial injury or necrosis.
What is the difference between ST elevation and ST depression?
According to the theory of the ischemie injury current there is a noticeable ST deviation in ECG of ischemie patient. ST depression has major role in detecting of ischemia. ST elevation is associated to special cases of ischemia or situation after myocardial infarction.
What is a non transmural infarction?
A non-transmural myocardial infarction refers to a myocardial infarction that does not involve the full thickness of the myocardium. It was one believed that the development of Q waves indicated that the infarction was “transmural,” however autopsy studies failed to confirm this.
What is transmural ischemia?
Transmural ischemia implies that the entire wall thickness – from endocardium to epicardium – is affected in the area supplied by the occluded artery. In subendocardial ischemia only the subendocardium is affected.
What is Subendocardial ischemia?
Abstract. Most forms of heart disease cause myocardial damage which often is confined to the deep (subendocardial) layer of left ventricular muscle. Much clinical and experimental evidence suggests that subendocardial muscle is prone to ischaemic damage, and a physiological mechanism for this vulnerability is described …
What is transmural injury?
The transmural cell damage gradient may be the result of transmural gradients of wall. stress and intramyocardial pressure in vivo. Therefore, it appears that factors other than blood flow. are the major determinants of ischemic cellular damage in the left ventricular wall of hearts lacking. a collateral blood supply. …
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 is the difference between transmural and subendocardial ischemia?
Transmural ischemia implies that the entire wall thickness – from endocardium to epicardium – is affected in the area supplied by the occluded artery. In subendocardial ischemia only the subendocardium is affected.
Why is the subendocardial area more prone to mi?
The Subendocardial infarcts results from locally decreased blood supply due to narrowing of the coronary arteries. The subendocardial area is more prone to MI as it is located the farthest from the heart’s blood supply.
Can a STEMI show up on ECG with a posterior MI?
Sometimes, it is obvious on the ECG when a posterior MI accompanies an inferior STEMI, but it can also occur all by itself. The ECG criteria to diagnose a posterior MI — treated like a STEMI, even though no real ST segment elevation is apparent — include: ST segment depression (not elevation) in V1 to V4. Think of things backwards.
What is the hallmark of transmural ischemia?
Although ST-segment elevations are the hallmark of transmural ischemia, they are actually preceded by hyperacute T-waves. These T-waves are symmetric, broad based and have high amplitude. They occur immediately (within seconds) following occlusion of the coronary artery.