Cited 9 times since 2011 (0.7 per year) source: EuropePMC European journal of nuclear medicine and molecular imaging, Volume 38, Issue 10, 21 3 2011, Pages 1899-1907 Impaired cardiac sympathetic innervation in symptomatic patients with long QT syndrome. Kies P, Paul M, Gerss J, Stegger L, Mönnig G, Schober O, Wichter T, Schäfers M, Schulze-Bahr E
Purpose
Increased sympathetic activation is a key modifier for arrhythmogenesis in patients with long QT syndrome (LQTS), a congenital channelopathy. Therefore, we investigated cardiac sympathetic function using 123I-metaiodobenzylguanidine (MIBG) single photon emission computed tomography (SPECT) in a cohort of symptomatic LQTS patients and correlated these findings with the underlying genotype.
Methods
[123I]MIBG SPECT was performed in 28 LQTS patients. Among these, 18 patients (64%) had a previous syncope and 10 patients (36%) survived sudden cardiac arrest. Patients were characterized in terms of genetic subtypes and QTc interval on surface ECGs. SPECT images were analysed for regional [123I]MIBG uptake in a 33-segment bullseye scheme and compared to those obtained from 10 age-matched healthy control subjects (43±12 years).
Results
An abnormal 123I-MIBG scan was found in 17 of 28 LQTS patients (61%) with a tracer reduction mainly located in the anteroseptal segments of the left ventricle. This finding was independent of the genetic LQTS subtype. In addition, no differences were found between LQTS patients with a QTc>500 ms vs <500 ms or those suffering from syncope vs VF (p>0.05).
Conclusion
A distinct regional pattern of impaired cardiac sympathetic function was identified in the majority of symptomatic LQTS patients. This innervation defect was independent of the underlying genotype and clinical disease expression.
