Nicotinic acetylcholine receptors mediate the parasympathetic autonomic control of cardiac function. Aim of this study was the assessment of cardiac nicotinic acetylcholine receptor distribution with a novel (α₄β₂) nicotinic acetylcholine receptor PET ligand (2–deoxy–2– [¹⁸F]fluoro–D–glucose–A85380) in humans. Five healthy volunteers without cardiac disease and six patients with either Parkinson's disease or multiple system atrophy without additional overt cardiac disease were evaluated with 2–deoxy–2–[¹⁸F]fluoro–D–glucose–A85380 PET–imaging to assess the cardiac parasympathetic innervation and the putative impact of both disorders. 2–deoxy–2– [¹⁸F]fluoro–D–glucose–A85380 whole body PET–scans were performed on a Siemens PET/CT biograph^TM 75.4 min�6.7 after i.v. injection of 371.2�58.1 MBq. Average count rate density of left ventricle ROI's and a standard ROI in the right lung were measured within three consecutive slices of 10.0 mm thickness. Heart–to–lung ratios were calculated in each volunteer and patient.

Tracer uptake in the left ventricle could be measured in all of the five volunteers and the six patients. Heart–to–lung ratios in the volunteer group were not different from patients suffering from Parkinson's disease or MSA (3.2 � 0.5 vs 3.2 � 0.8 and 2.96�0.7, mean � SD), respectively.

Human cardiac nicotinic acetylcholine receptors can be visualized and measured by 2–deoxy–2– [¹⁸F]fluoro–D–glucose–A85380 PET scans both in cardiac–healthy subjects and patients suffering from Parkinson's disease or multiple system atrophy. The heart– as well as the lung–tracer uptake was almost constant throughout all subjects leading to a good targetto– background ratio. These first results suggest no impact of either PD or MSA on cardiac nicotinic acetylcholine receptors.