ABSTRACT

Cardiac neurotransmission imaging with single photon emission computed tomography allows in vivo assessment of presynaptic reuptake and storage of neurotransmitters. Cardiac 123iodine-metaiodobenzylguanidine uptake may be impaired in some patients with neurologic disorders of the central and peripheral nervous system with autonomic dysfunction. In clinical practice, it is difficult to identify the cause of a parkinsonian syndrome in many patients, in particular when symptoms have begun recently and are confined to the extrapyramidal system. During orthotopic heart transplantation, the entire recipient heart is excised except for the posterior atrial walls, to which the donor atria are anastomosed. During the process, the allograft becomes completely denervated. In patients presenting with idiopathic ventricular tachycardia and fibrillation, no structural or functional abnormalities of the myocardium can be demonstrated by conventional imaging and clinical testing. Early diagnosis and treatment are of clinical importance because ventricular fibrillation is the most common arrhythmia at the time of sudden death.