Inflammation in lone atrial fibrillation: New insights by coronary sinus thermography

BackgroundIn 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.MethodsWe 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.ResultsWe 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 < 0.01), in AFN (37.13 ± 0.53 °C vs 37.34 ± 0.54 °C, p < 0.01), and in controls (37.41 ± 0.69 °C vs 37.55 ± 0.68 °C, p < 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 < 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 < 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 < 0.01, R = 0.44, p = 0.02).ConclusionsPatients 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.