Cardioversion and false positive technetium-99m stannous pyrophosphate myocardial scintigrams

The present studies performed in experimental animals demonstrate that electrical direct current cardioversion can produce skeletal muscle damage and increased technetium-99m stannous pyrophosphate (/sup 99m/Tc-PYP) uptake; in exerimental animals the electricity damaged skeletal muscle shows necrosis with extensive calcium deposition. In addition, the frequent administration of high energy cardioversion produces myocardial necrosis with calcium deposition, increased /sup 99m/Tc-PYP myocardial uptake and a positive /sup 99m/Tc-PYP myocardial scintigram. The data indicate that, if diagnostic /sup 99m/Tc-PYP myocardial scintigraphy is contemplated after cardioversion, paddle placement should be slightly removed from the anteroposterior projection of the heart on the external chest wall to avoid possible subsequent confusion between increased myocardial and skeletal muscle uptake of /sup 99m/Tc-PYP. If multiple high energy cardioversion episodes are necessary, myocardial necrosis resulting from electrical injury may occur and be responsible for increased myocardial uptake of /sup 99m/Tc-PYP with a resultant positive /sup 99m/Tc-PYP myocardial scintigram