Stunned myocardium

Last revised by Bahman Rasuli on 14 Mar 2021

Citation, DOI, disclosures and article data

Citation:

Morgan M, Rasuli B, Luijkx T, et al. Stunned myocardium. Reference article, Radiopaedia.org (Accessed on 20 Apr 2024) https://doi.org/10.53347/rID-34436

DOI:

https://doi.org/10.53347/rID-34436

Permalink:

https://radiopaedia.org/articles/34436

rID:

34436

Article created:

20 Feb 2015, Matt A. Morgan ◉

Disclosures:

At the time the article was created Matt A. Morgan had no recorded disclosures.

View Matt A. Morgan's current disclosures

Last revised:

14 Mar 2021, Bahman Rasuli ◉

Disclosures:

At the time the article was last revised Bahman Rasuli had no recorded disclosures.

View Bahman Rasuli's current disclosures

Revisions:

6 times, by 5 contributors - see full revision history and disclosures

Systems:

Cardiac

Tags:

cardiac, ischemia, cardiac pet, cardiac mri, thallium, cases

Synonyms:

Myocardial stunning

Stunned myocardium refers to a situation in which an acute transient myocardial ischemic event results in a prolonged wall motion abnormality which eventually resolves.

The term is usually distinguished from "hibernating" myocardium, in which a chronic ischemic process leads to chronic left ventricular dysfunction.

The myocardium at risk of being stunned in a more typical human clinical situation is myocardium which has a low fractional flow reserve at rest. Between 40-80% stenosis, there is normal coronary blood flow, but a decrease in maximal coronary blood flow. Myocardium in this territory is at risk of being "stunned" with a maximal effort.

Some think that the difference in stunned myocardium and hibernating myocardium is one of degree rather than of kind and that the two conditions may often coexist ². In addition, some think that hibernating myocardium is a result of repeated episodes of stunning ³.

Radiographic features

Nuclear medicine

the appearance of ²⁰¹Tl stress-redistribution-reinjection SPECT and rest-redistribution SPECT, as well as ^99mTc-MIBI SPECT, are similar to hibernating myocardium
Cardiac PET appearance is similar to hibernating myocardium

Cardiac MRI

appearance is similar to hibernating myocardium
- quantitative perfusion assessment gives an indication of myocardial viability
quantitative cutoffs for appropriate wall thickness, with or without dobutamine challenge, have problematic specificity
presence of delayed enhancement / scar likely best indication that the myocardium is no longer viable in that region

Differential diagnosis

hibernating myocardium
- the two entities may exist on a spectrum and imaging findings are similar
myocardial infarction
- matched rest and stress perfusion abnormality in nuclear medicine SPECT studies
- decreased uptake in FDG-PET/CT
- wall thinning and postcontrast delayed enhancement in regions of infarct and scar on cardiac MRI