title: Chronic threshold testing of implantable cardioverter defibrillators does not increase coagulation activity or platelet activation.
abstract: It is unknown if the brief periods of circulatory statis occurring with induction of VF during DFT testing in patients with an ICD activate blood coagulation processes. To address this question, coagulation activity and platelet activation were measured in peripheral venous blood samples obtained from 12 patients undergoing DFT testing under general anesthesia, 3 (n = 11) or 6 months (n = 1) after ICD implantation for recurrent ventricular arrhythmias. Five patients were anticoagulated with warfarin and two to six episodes of VF (median five) were induced per patient. Blood samples were drawn at baseline, after each DFT test and on the following morning. Coagulation activity was assessed by measuring prothrombin fragment 1 + 2 (F1 + 2) (a marker of thrombin generation), soluble fibrin (a marker of fibrin production), and D-dimer (a breakdown product of cross-linked fibrin). Platelet activation was evaluated by measuring the expression P-selectin on the platelet surface using flow cytometry. No significant changes in F1 + 2, soluble fibrin, D-dimer, or P-selectin expression occurred during DFT testing, or between baseline and morning after samples. Moreover, results were unaffected by warfarin. These findings suggest that chronic threshold testing of implantable cardioverter defibrillators is not associated with activation of blood coagulation processes.
authors.affiliation: Center for Heart and Chest Research, Department of Medicine, Monash University, Monash Medical Center, Clayton, Victoria, Australia. joe.smolich@med.monash.edu.au
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Smolich
authors.forename: Lynette A
authors.initials: LA
authors.lastname: Yates
authors.forename: Erica
authors.initials: E
authors.lastname: Malan
authors.forename: T Eng
authors.initials: TE
authors.lastname: Gan
authors.forename: Richard W
authors.initials: RW
authors.lastname: Harper
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Alison
authors.forename: Roger E
authors.initials: RE
authors.lastname: Peverill
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects / Q000502:physiology*; D017147:Defibrillators, Implantable; D006801:Humans; D008875:Middle Aged; D015539:Platelet Activation / Q000187:drug effects / Q000502:physiology*; D014859:Warfarin / Q000494:pharmacology
chemical_list: D000925:Anticoagulants; D014859:Warfarin