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S122 Abstracts Heart, Lung and Circulation2008;17S:S1–S209

Early PV conduction recovery was present in 43 PVs (43%).There was no significant difference in the rate of recov-ery between the left and right PVs (33% vs. 53%; p = 0.08),or between the superior and inferior veins (35% vs. 53%;p = 0.08). The RIPV had the highest rate of recurrence(57%); this was the first PV isolated in 50% of cases. Therewas no relationship between the order in which the PVswere isolated and the likelihood of recovery (p = 0.9). Of thePVs showing conduction recovery 14% did so in 30 min,44% by 60 min and 84% by 90 min.Conclusions: Early PV recovery occurs frequently after PVisolation. These data suggests that re-evaluation of PV con-duction before completing ablation could be important inpreventing post-ablation arrhythmias.

doi:10.1016/j.hlc.2008.05.291

291Device therapy with Implantable Cardioverter Defibril-lators (ICDs) and Cardiac Resynchronization Therapy(CRT) in Heart Failure: Does Clinical Practice Match theCurrent Guidelines?

Brendan Bell ∗, Russell Denman

The Prince Charles Hospital, Cardiology Department, Brisbane,QLD, Australia

Introduction: ICDs and CRT reduce mortality and morbid-

292Platelet Reactivity in Patients with Atrial Fibrillation:Intracardiac verses Peripheral Measurements

Scott Willoughby ∗, Ross Roberts-Thomson, LorraineMackenzie, Dennis Lau, Christopher Wong, AnthonyBrooks, Bobby John, Martin Stiles, Hany Dimitri, GlennYoung, Prashanthan Sanders

Cardiovascular Research Centre, Adelaide, South Australia,Australia

Introduction: Atrial fibrillation (AF) is associated withincreased risk of thrombus formation primarily in the leftatria (LA). However, the mechanisms underlying this phe-nomenon are unknown. Although, previous studies havedemonstrated elevated levels of coagulation and plateletactivation when measured in peripheral blood samples,little is know about platelet function within the atrium.We therefore examined if sampling from different sites(femoral vein, right atria and left atria) affects plateletreactivity.Methods: Nineteen consecutive patients (13 males: 60 ± 2[S.E.M.] years) with paroxysmal AF undergoing ablationwere studied. All patients ceased warfarin 7 days andenoxaparin 12 h prior to the procedure. Anticoagulatedblood samples were obtained at the start of the pro-cedure immediately after transseptal puncture from thefemoral vein (FV), the left atria (LA) and the right atria

ity in patients with heart failure. The incidence of deviceindication is uncertain and it is hypothesised that it farexceeds the number implanted. This study examines theproportion of patients admitted with heart failure whoqualify for device therapy and the clinical implementationof guidelines in this population.Methods: Patients admitted with heart failure over a 12month period (n = 445) were retrospectively assessed forage, gender, aetiology of heart failure, NYHA class, ejec-tion fraction, QRS width, all cause mortality, admittingunit and device implantation.Results: Preliminary findings (n = 115) were average age61 years, males 70 (61%), females 45 (39%) with NHYAclass III symptoms. Aetiology of heart failure was ischemia54 (47%), valvular 31 (27%) and dilated cardiomyopathy18 (15%). Average ejection fraction was 41% with wideQRS in 47 (41%). ACE inhibitors were used in 88 (77%)and beta-blockers in 76 (66%) patients. Only 29/55 (53%)patients fulfilling criteria for an ICD had one implanted.Excluding patients who declined an ICD or with signif-icant co-morbidities, patients admitted to a heart failureunit (HFU) had 23/25 (92%) referral rate for an ICD ver-sus 6/16 (38%) for patients admitted under general units(p < 0.001). Referral rates for CRT were 12/17 (71%) in HFUand 3/11 (27%) in general units (p = 0.01). Mortality duringfollow-up was 17%.Conclusions: There exists a gap between guidelines andclinical practice for device therapy in heart failure espe-cially in general units.

doi:10.1016/j.hlc.2008.05.292

(RA), prior to the administration of heparin. Unstimulatedblood samples were incubated with the platelet specificantibody against P-selectin (CD62P) or control and anal-ysed by whole blood flow cytometry. Blood samples hadevaluation of platelet aggregation utilizing ADP (2.5 and5 �M)-induced whole blood impedance aggregometry.Results: In patents with AF P-selectin levels were signifi-cantly elevated in the left atria (ANOVA, p = 0.01; Dunn’spost-test left atria [10.2 ± 2.4%] vs. right atria [8.6 ± 2.3%]p < 0.05). Similarly platelet aggregation was significantlyelevated in the left atria at ADP 2.5 �M (ANOVA, p < 0.01;Dunn’s post-test left atria [5.2 ± 0.6 �] vs. femoral vein[4.3 ± 0.6 �] p < 0.05) and ADP 5 �M (ANOVA, p < 0.03;Dunn’s post-test left atria [7.2 ± 0.5 �] vs. femoral vein[6.3 ± 0.7 �] p < 0.05).Conclusions: Patients with AF have increased left atrialplatelet P-selectin expression and platelet aggregationcompared to the right atria or femoral vein, respec-tively. This data suggests that previous studies which onlyexamined peripheral platelet reactivity may have underes-timated the contribution of platelets to the thrombogenicrisk in AF.

doi:10.1016/j.hlc.2008.05.293