title: Patients with paroxysmal atrial fibrillation but not paroxysmal supraventricular tachycardia display evidence of platelet activation during arrhythmia.
abstract: It is well known that chronic atrial fibrillation (CAF) and paroxysmal atrial fibrillation (PAF) are associated with hypercoagulable state. However, pathological hemostatic changes during the paroxysmal supraventricular tachycardia (PSVT) have not yet been elucidated. To determine platelet activity in patients with PSVT, PAF and CAF, we examined the levels of beta-thromboglobulin (BTG) and platelet factor 4 (PF4) during tachyarrhythmia attacks. We measured the levels of BTG and PF4, as an index of platelet activation in 15 patients with PAF (9 men, mean age 45+/-11), and 14 patients with PSVT (8 men, mean age 40+/-10). Levels were compared to 22 age and sex matched healthy controls in sinus rhythm and with 25 patients with CAF (16 men, mean age 51+/-12). Blood samples were taken during arrhythmia and 24 hours after conversion to sinus rhythm. Patients taking medications or have clinical conditions that may affect the BTG and PF4 levels were excluded. In patients with PAF, BTG and PF4 levels were significantly higher than in controls (p<0.009, and p=0.002, respectively), and in patients with PSVT (p<0.004, and p=0.009, respectively), however, BTG and PF4 levels were significantly lower than CAF patients (p=0.002, and p=0.02, respectively). Moreover, BTG and PF4 levels were significantly decreased 24 hours after conversion to sinus rhythm (p<0.0001), and p=0.004, respectively). Although BTG and PF4 levels in patients with PSVT were significantly lower than in patients with PAF (p=0.04, and p=0.009, respectively) and CAF (p=0.0001, and p=0.0001, respectively), BTG and PF4 levels were similar to controls and did not change significantly after recovery to sinus rhythm (p=NS for all). These results indicate that there was no platelet activation in patients with PSVT during tachyarrhythmia but significantly increased platelet activity in PAF and CAF patients. There was a significant decrement of the platelet activity to a level of control subjects twenty-four hours after cardioversion of PAF.
authors.affiliation: Department of Cardiology, Hacettepe University, Ankara, Turkey. eatalar@hacettepe.edu.tr
authors.forename: Enver
authors.initials: E
authors.lastname: Atalar
authors.forename: Ibrahim C
authors.initials: IC
authors.lastname: Haznedaroglu
authors.forename: Tayfun
authors.initials: T
authors.lastname: Acil
authors.forename: Necla
authors.initials: N
authors.lastname: Ozer
authors.forename: Harun
authors.initials: H
authors.lastname: Kilic
authors.forename: Kenan
authors.initials: K
authors.lastname: Ovunc
authors.forename: Serdar
authors.initials: S
authors.lastname: Aksoyek
authors.forename: Nasih
authors.initials: N
authors.lastname: Nazli
authors.forename: Sirri
authors.initials: S
authors.lastname: Kes
authors.forename: Giray
authors.initials: G
authors.lastname: Kabakçi
authors.forename: Serafettin
authors.initials: S
authors.lastname: Kirazli
authors.forename: Ferhan
authors.initials: F
authors.lastname: Ozmen
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000097:blood / Q000503:physiopathology; D001281:Atrial Fibrillation / Q000097:blood / Q000503:physiopathology*; D001792:Blood Platelets / Q000378:metabolism; D004554:Electric Countershock; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation / Q000502:physiology*; D010978:Platelet Factor 4 / Q000032:analysis; D013614:Tachycardia, Paroxysmal / Q000097:blood / Q000503:physiopathology*; D013617:Tachycardia, Supraventricular / Q000097:blood / Q000503:physiopathology*; D001620:beta-Thromboglobulin / Q000032:analysis
chemical_list: D001620:beta-Thromboglobulin; D010978:Platelet Factor 4