Technetium‐99m stannous pyrophosphate myocardial scintigraphy: Serial imaging to detect myocardial infarcts in patients

Typically, technetium‐99m stannous pyrophosphate ( 99m Tc‐PYP) myocardial scintigrams become abnormal within 10‐12 h following acute myocardial infarction. Ordinarily, the 99m Tc‐PYP scintigrams become increasingly abnormal between 24 and 72 h following the infarct and then become normal 6‐7 days after the event. However, occasional patients and their 99m Tc‐PYP myocardial scintigrams deviate from this expected pattern by initially developing an abnormal 99m Tc‐PYP scintigram as late as 4‐5 days following an acute myocardial infarction. Others retain “persistently abnormal” 99m Tc‐PYP myocardial scintigrams after their myocardial infarcts. The clinical importance and potential prognostic importance of these deviations from the expected patterns with 99m Tc‐PYP myocardial imaging are discussed and the need for serial myocardial imaging is emphasized.