Correlation of false negative myocardial infarct scintigraphy with postmortem studies

Area of Science:

• Cardiology
• Nuclear Medicine
• Pathology

Background:

• Myocardial infarct scintigraphy is a diagnostic tool used to assess heart attack damage.
• 99mtechnetium stannous pyrophosphate (99mTc-PYP) is a radiotracer used in myocardial scintigraphy.
• Acute transmural myocardial infarction requires accurate assessment for patient management.

Observation:

• Two patients with acute massive transmural infarct presented with negative 99mTc-PYP myocardial scintigrams.
• Both patients died shortly after scintigraphy, allowing for timely necropsy.
• Necropsy findings were correlated with the myocardial scintigram results.

Findings:

• The distribution of 99mTc-PYP in acutely infarcted myocardial tissue did not accurately reflect the scintigraphic findings in these cases.
• Negative scintigrams were observed despite significant myocardial infarction confirmed by necropsy.
• This suggests a potential for gross inaccuracy in detecting and quantifying infarct size using this method alone.

Implications:

• A single myocardial scintigram may be unreliable for determining infarct size.
• Scintigraphic findings must be correlated with electrocardiographic (ECG) and cardiac enzyme levels for accurate diagnosis.
• This highlights the importance of a multi-faceted approach in evaluating patients with suspected myocardial infarction.