Evaluation of sympathetic re-innervation in heterotopic cardiac transplants by iodine-123-metaiodobenzylguanidine (I-123-MIBG) imaging.

Scintigraphy using iodine-123-metaiodobenzylguanidine (I-123-MIBG) has been used to demonstrate that >50% of orthotopically transplanted hearts undergo partial cardiac sympathetic re-innervation and that this occurs no earlier than 1 year post-transplant. This study used planar and singe-photon emission computed tomography (SPECT) I-123 MIBG scintigraphy to show that cardiac re-innervation was not detectable in any of the 8 patients studied 1.1 to 6.3 years post-heterotopic transplantation. Thus, potential for cardiac re-innervation varies according to the type of procedure performed.