Predicting myocardial viability from floor ECG following MI
February 14, 2024 by dr s venkatesan
As soon as upon a time, lengthy, way back, cardiologists was frightened about akinetic segments, scars, useless tissue, and Q waves earlier than trying revascularization by both PCI or CABG. Now, the idea of myocardial viability has turn out to be a cliché ( fairly demeaning) at the very least throughout the cath labs. At present ,we observe a self administered whip . Each post-MI affected person needs to be thought of for revascularization as a default technique no matter the extent of dysfunction or scarring .This will occur both within the IRA territory or non-IRA territory or each.
This technique is now dis-armed with contemporary proof within the type of REVIVE -BRICS trial. There might be some distinct errors in the best way many Interpreted this examine. (Learn right here about REVIVE tral Perera D, Ryan et al JAMA Cardiol. 2023)
Lets return and be taught one thing from the 12 months 1999
For these cardiologists who nonetheless suppose myocardial viability is a crucial issue earlier than revascularization, let me pull out a 30 year-old examine from the College of Aberdeen, UK, that regarded into the standard ECG to detect viability. The authors went past simply observing presence or absence of Q waves .It conveys a terrific studying level.
Modified from Al-Mohammad A, et al Coronary heart. 1999 Dec;82(6):663-7. (Ref 1) Matching means non-viable myocardium (Tissue appears akinetic or scar-like, whereas PET concurs and reveals lack of metabolic exercise. That is known as matching, and the phase is non-viable) Mismatch means viable myocardium (Tissue seem useless by akinetic Echo however metabolism intact ie a mismatch implying viability )
It’s worthy to notice, the authors regarded particularly over the segments that subtended Q waves and regarded for viability matching. It was correlated with a PET scan, the gold normal for viability testing even now.
The outcomes had been vital and insightful. What we infer from this examine is definitely a easy message. In post-MI sufferers, even with the burden of q-waves, if the return wave overshoots the baseline and inscribes some form of r-wave (Qr, QR, qR patterns), there’s a excessive chance of viable tissue when in comparison with QS wave. It’s a new lesson from a previous paper for me. , ie any R is nice whether or not it’s preceded by q or not.
It’s good to recall ,different easy clues to the presence of viable myocardial tissue, corresponding to presence of angina, M-mode wall thickening. To not neglect different modalities like, nicely preserved sub endocardial operate by speckle monitoring echo, dobutamine-stress, myocardial distinction echo, and LGE-MRI.
Last message
As on 2024, the idea of myocardial viability testing has not vanished. We should guarantee, to not move on a incorrect message to technology subsequent cardiologists, that viability exams are outdated and out of date.
Reference
#Predicting #myocardial #viability #floor #ECG
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