Comparison between blood coagulability in the intra-atrial and peripheral regions during the acute phase after rapid atrial pacing.

The changes in intra-atrial blood coagulability of acute phase after development of atrial fibrillation (AF) have not been elucidated in human. In the present study, blood coagulability were examined in the intra-atrial and peripheral regions during the acute phase after development of rapid atrial pacing (RAP) in experimentally created model dog similar to AF, using Total Thrombus-formation Analysis System (T-TAS) that is capable of comprehensively evaluating thrombogenicity in the bloodstream in the microvascular channel. According to the results, both the coagulating function evaluating time to +10 kPa (T-10) and occlusion time (OT) of the AR chip (chip for thrombus analysis mixed with coagulation and platelet) were significantly shortened in the atrial blood as early as 30 min after pacing (T-10, 150.5 +/- 40.5 s; OT, 212.4 +/- 44.3 s) compared to the pre-pacing levels (T-10, 194.5 +/- 47.5 s; OT, 259.9 +/- 49.5 s) (P<0.05). The OT of PL chip (chip for platelet thrombus analysis) was significantly shortened 30 min after pacing (231.8 +/- 57.6 s), compared to the pre-pacing level (289.5 +/- 96.0 s) (P<0.05). Meanwhile, none of T-10 and OT of AR and PL chips showed any significant changes in the peripheral blood. The study demonstrated increase of blood coagulability 30 min after development of RAP. While no significant changes were observed in the peripheral blood in the present study, the outcome suggested that the anti-thrombus treatments are better to be started early after AF even if coagulability of the peripheral blood shows no change.