Inflammation in lone atrial fibrillation: New insights by coronary sinus thermography Konstantinos Toutouzas ⁎ , Maria Drakopoulou, Polychronis Dilaveris, Sophia Vaina, Kostas Gatzoulis, John Karabelas, Maria Riga, Elli Stefanadi, Andreas Synetos, Konstantinos Vlasis, Christodoulos Stefanadis First Department of Cardiology, Hippokration Hospital, Athens Medical School, Athens, Greece Received 12 November 2007; received in revised form 10 January 2008; accepted 14 February 2008 Available online 10 December 2008 Abstract Background: In the clinical setting there are conflicting results regarding the role of inflammatory activation in atrial fibrillation (AF). Coronary sinus (CS) thermography assesses myocardial heat production and is correlated with inflammatory states. We investigated in patients with AF whether 1) there is increased CS blood temperature and 2) the correlation of heat production with systemic inflammation. Methods: We included patients with AF and subjects with sinus rhythm. C-reactive protein (CRP) levels were measured in all patients. CS and right atrium (RA) blood temperature measurements were performed by a dedicated 7F thermography catheter. ΔT was calculated by subtracting RA from CS blood temperature. Results: We included 47 patients with AF and 23 subjects with sinus rhythm. We stratified patients with AF into two groups: normotensive (AFN) and hypertensive (AFH). ΔT was lower in the RA compared with the CS in AFH (37.27 ± 0.52 °C vs 37.47 ± 0.54 °C, p b 0.01), in AFN (37.13± 0.53 °C vs 37.34 ± 0.54 °C, p b 0.01), and in controls (37.41 ± 0.69 °C vs 37.55 ± 0.68 °C, p b 0.01). ΔΤ was greater in AFH, and AFN compared to controls (0.20 ± 0.07 °C, 0.20 ± 0.08 °C, vs 0.14 ± 0.06 °C, p b 0.01). ΔT was similar between AFH and AFN (p = 0.95). CRP was higher in AFH and AFN compared to controls (1.72 ±0.85 mg/Dl, 1.69±0.94 mg/dL, 0.98±0.71 mg/dL, p b 0.01). CRP was similar between AFH and AFN (p =0.87). A correlation between CRP with ΔT was observed in AFH and AFN (R = 0.58, p b 0.01, R = 0.44, p = 0.02). Conclusions: Patients with AF have increased myocardial heat production, which is correlated to the systemic inflammation. CS blood temperature measurement may provide significant information for the pathogenesis of AF. © 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Atrial fibrillation; Coronary sinus thermography; Inflammation; Heat production 1. Introduction Atrial fibrillation (AF) with an approximate overall prevalence of 0.9% is the most common sustained arrhythmia in clinical practice [1,2]. Recently, evidence has emerged implicating inflammation as a possible contributing factor to the initiation or maintenance AF [3,4]. Animal studies and histological evidence from human atria clearly demonstrated that in patients with AF an increased inflammatory activation is observed [5–9]. In the clinical setting there are conflicting results regarding the correlation of inflammatory markers in the peripheral blood with AF. The increased C-reactive protein (CRP) and interleukin-6 levels in subjects with AF, and the time course of postoperative AF suggested a role of inflammatory activation in the onset of AF [10]. Furthermore, the levels of interleukin-6 in patients with AF were an independent predictor of stroke or death, suggesting that inflammation in AF may predict a poor prognosis [11,12]. International Journal of Cardiology 134 (2009) 345 – 350 www.elsevier.com/locate/ijcard ⁎ Corresponding author. 24 Karaoli and Dimitriou, Holargos, Athens 15562, Greece. Tel.: +30 210 6510860; fax: +30 210 7784590. E-mail address: ktoutouz@otenet.gr (K. Toutouzas). 0167-5273/$ - see front matter © 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2008.02.028