Goal of study: To identify the extent of systemic activation of the coagulation cascade and to evaluate thrombogenic effect of the radiofrequency catheter ablation. Methods and results: Markers of activation of the coagulation cascade (D-dimers [DD]), markers of activation of the fibrinolytic system (tissue plasminogen activator [t-PA] and its inhibitor [PAI-1]), and markers of endothelial damage (von Willebrand factor [vWf]) were monitored in 50 patients undergoing catheter ablation. Levels of these substances were identified in time T0 - at the beginning of the examination, T1 - after finishing diagnostic part of the electrophysiological study, T2 - after finishing all applications of radiofrequency energy, and T3 - 24 hours after T2. Levels of vWf were significantly elevated in time T1 compared to values in T0 (p < 0.001) and were further elevating after finishing the procedure in time T2 (p < 0.05). Levels of t-PA were also elevated in time T1, however after application of the radiofrequency energy, further increase in T2 was nonsignificant. Concentrations of PAI-1 were in time T2 significantly lower compared to T1 values (p < 0.001). Levels of DD were significantly elevated during entire procedure and elevated levels persisted even 24 hours later (p < 0,001). Levels of vWf a t-PA in time T2 correlated with total time of application of radiofrequency energy. Significantly higher activation of the coagulation cascade was identified, in patients undergoing isolation of pulmonary veins compared to patients undergoing catheter ablation of other arrhythmias. In the subgroup of patients treated with anticoagulation before the intervention elevation of DD levels in times T1 and T2 was lower compared to patients who did not undergo any treatment (p < 0.05). Conclusion: The radiofrequency catheter ablations activate the coagulation cascade. Moreover, application of the radio frequency energy increases systemic thrombogenic state and this effect “depends on the dose”. A risk group make patients undergoing catheter isolation of pulmonary veins.

        Key words: Catheter ablations - Complications - Coagulation system - Thrombus - Pulmonary Vein Isolation