NEURONAL DYSFUNCTION IN HEART-FAILURE ASSESSED BY CARDIAC 123-IODINE METAIODOBENZYLGUANIDINE SCINTIGRAPHY

In patients with chronic heart failure, increased sympathetic activity and cardiac sympathetic neuronal dysfunction are present and have bee n related to unfavourable clinical outcome. Modification of these alte rations with the objective to improve prognosis has become an importan t aim of pharmacological therapy for these patients. A noninvasive tec hnique to assess sympathetic neuronal function at the cardiac level ma y be valuable in evaluating newly developed therapeutic strategies. 12 3-iodine metaiodobenzylguanidine can be used to visualize cardiac symp athetic nerve function and activity. Single photon emission computeriz ed tomographic is preferred to planar scintigraphy since it does not d epend on superposition of other anatomical structures and may allow as sessment of regional cardiac 123-iodine metaiodobenzylguanidine uptake . Although the quantitation of cardiac uptake in these tomographic ima ges has several limitations, the use of the left ventricular cavity as a reference, calibrated by the 123-iodine activity in a blood sample drawn at the time of acquisition, may have clinical applications, with respect to the evaluation of therapeutical intervention in patients w ith heart failure.