Tc-99m pyrophosphate uptake in small areas of myocardial injury produced by radiofrequency catheter ablation of arrhythmias

Radiofrequency produces small circumscribed areas of myocardial damage and is now used most commonly for ablation of arrhythmias. The proper position of a catheter can be determined easily by fluoroscopy. However, the degree of tissue destruction cannot be assessed by electronic or radiographic techniques. Seventeen patients with arrhythmia were studied 2 days after radiofrequency catheter ablation of arrhythmias by Tc-99m pyrophosphate scintigraphy. In 14 of the 17 patients (82.4%), myocardial lesions produced by radiofrequency ablation were successfully demonstrated by SPECT imaging, whereas none showed positive uptake on planar images. Two cases are illustrated.