RT Journal Article
SR Electronic
T1 Impact of presynaptic sympathetic imbalance in long-QT syndrome by positron emission tomography
JF Heart
JO Heart
FD BMJ Publishing Group Ltd and British Cardiovascular Society
SP 332
OP 339
DO 10.1136/heartjnl-2017-311667
VO 104
IS 4
A1 Zumhagen, Sven
A1 Vrachimis, Alexis
A1 Stegger, Lars
A1 Kies, Peter
A1 Wenning, Christian
A1 Ernsting, Marko
A1 Müller, Jovanca
A1 Seebohm, Guiscard
A1 Paul, Matthias
A1 Schäfers, Klaus
A1 Stallmeyer, Birgit
A1 Schäfers, Michael
A1 Schulze-Bahr, Eric
YR 2018
UL http://heart.bmj.com/content/104/4/332.abstract
AB Objective We investigated the impact of cardiac presynaptic norepinephrine recycling in patients with long-QT syndrome (LQTS) using positron emission tomography (PET) with 11C-meta-hydroxyephedrine ([11C]mHED-PET).Methods [11C]mHED-PET was performed in 25 patients with LQTS (LQT1: n=14; LQT2: n=11) and 20 healthy controls and correlated with clinical parameters. [11C]mHED-PET images were analysed for global and regional retention indices (RI) and washout rates (WO) reflecting dynamic parameters of the tracer activity.Results Global and regional RI values were similar between patients with LQTS and controls. Although the global WO rates were similar between these groups, regional WO rates were on average higher in the lateral left ventricle (LV) wall in patients with LQTS (dose, mean ±SD; 0.08±0.14 vs 0.00%±0.09% min–1; p=0.033). In addition, patients with LQTS with a longer QTc interval showed a higher global WO rate. Clinical symptoms correlated with higher global WO rates. In the presence of normal global WO rates, asymptomatic LQTS patients showed higher global RI values.Conclusion The increased regional WO rate of [11C]mHED in the lateral LV suggests an imbalance of presynaptic catecholamine reuptake and release, resulting in a higher synaptic catecholamine concentration, in particular in LQT1 patients. This might enhance β-adrenoceptor signalling and thereby aggravate inherited ion channel dysfunction and may facilitate occurrence of ventricular tachyarrhythmias. Detection of regional differences in LV sympathetic nervous function may modify disease expression and potentially serve as a non-invasive risk marker in congenital LQTS.Trial registration number 2006-002767-41;Results.