Evidence-Based Pharmacological Management of Atrial Fibrillation in Patients with Heart Failure

Evidence-Based Pharmacological Management of Atrial Fibrillation in Patients with Heart Failure

S114 Abstracts ABSTRACTS 285 Right Ventricular Pacing is Associated with Impaired Endothelial Function Henry M.H. Su 1,∗ , Chim C. Lang 2 , Awsan N...

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Abstracts

ABSTRACTS

285 Right Ventricular Pacing is Associated with Impaired Endothelial Function Henry M.H. Su 1,∗ , Chim C. Lang 2 , Awsan Noman 2 , Allan D. Struthers 2 , Anna Maria Choy 2 1 The

University of Melbourne, Melbourne, Australia; of Medicine and Therapeutics, Ninewells Hospital and Medical School, Dundee, United Kingdom

2 Division

Purpose: Several pacemaker and ICD trials have suggested that conventional right ventricular pacing (RVP) is associated with increased mortality and hospitalisation, especially in those with impaired cardiac function. The underlying pathophysiological effects however are not clearly understood. This study investigated the effect of RVP on: endothelial function, plasma brain natriuretic peptide (BNP) an index of ventricular wall stress and resting and exercise cardiac output. Methods: Nine patients (age = 74.1 ± 4.5, male = 5) with dual chamber pacemakers implanted for sinus node disease were studied after chronic pacing in three randomly assigned modes: dual chamber with long atrioventricular delay (DDD-L), dual chamber with short atrioventricular delay (DDD-S) and ventricular pacing (VVI). Three patients had left ventricular systolic dysfunction (ejection fraction <40%), five diastolic dysfunction and one was normal. Cardiac output was determined using inert gas rebreathing and endothelial function by reactive hyperaemia–peripheral arterial tone (RH-PAT index). BNP was analysed using immuno-fluorescence. Results: Mean %RVP (±S.D.) was 25.3 ± 33.7% in DDD-L, 85.8 ± 21.0% in DDD-S and 47.9 ± 34.1% in VVI (p = 0.001). Endothelial function decreased significantly when patients were in modes with more RVP: 1.97 ± 0.37 DDD-L versus 1.64 ± 0.19 DDD-S, 1.64 ± 0.23 VVI (p < 0.05). BNP increased nearly two-fold in VVI, 81.5 ± 115.6 pg/mL DDD-L, 93.5 ± 88.6 pg/mL DDD-S versus 163 ± 153.4 pg/mL VVI. Resting and exercise cardiac output was 3.63 ± 0.63 L/min and 4.44 ± 1.53 L/min DDDL, 3.59 ± 0.63 L/min and 4.6 ± 1.20 L/min DDD-S versus 3.59 ± 0.63 L/min and 4.60 ± 1.20 L/min VVI, respectively. Conclusion: These novel findings suggest that RVP is associated with significant deterioration of endothelial function and increased ventricular wall stress. This data may provide the pathophysiological mechanism for the worse outcomes linked with RVP. doi:10.1016/j.hlc.2007.06.290 286 Catheter Ablation of Atypical Atrial Flutter Raymond Sy 1,∗ , Mark A. McGuire 1,2 1 Royal Prince Alfred Hospital, Camperdown, Sydney, Australia; 2 Eastern Heart Clinic Randwick, Sydney, Australia

Background: Compared with typical isthmus-dependent atrial flutter, atypical atrial flutter is less common and cure rates with catheter ablation have been lower. The aim of

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the study was to assess catheter ablation of atypical atrial flutter. Methods: Electrophysiology (EP) study and catheter ablation was performed in 26 consecutive patients presenting with atypical atrial flutter (15 male) with a mean age of 52 ± 18 years. Associated heart disease included repaired congenital heart disease (10), previous ablation of atrial fibrillation (4), mitral valve surgery (4) and ischaemic heart disease (3). Results: Forty-three atypical atrial flutters were present spontaneously or were induced during EP study. Typical atrial flutter was also present in 10 patients (38%). Threedimensional mapping systems were used in 21 patients (81%). The most frequent site of the re-entrant circuit was the anterolateral wall of the right atrium (n = 26). Other sites included peri-mitral, roof of the left atrium, and around ASD patch. Successful ablation occurred at the initial procedure in 21 patients (81%). One patient underwent two procedures and another patient underwent three procedures for successful ablation. Three patients were not cured of the target arrhythmia. Complications included pericardial tamponade (n = 1), significant femoral haematoma (n = 2) and temporary AV block (n = 1). Conclusion: Using modern techniques, catheter ablation of atypical atrial flutter has a high success rate and low complication rate. Over a third of patients with atypical atrial flutter also have typical atrial flutter and catheter ablation of the cavo-tricuspid isthmus should be considered in all patients undergoing ablation of atypical flutter. doi:10.1016/j.hlc.2007.06.291 287 Evidence-Based Pharmacological Management of Atrial Fibrillation in Patients with Heart Failure Lexin Wang 1,∗ , Shane Curran 2 , Patrick Ball 1 , Michael McCready 3 , Gerard Carroll 3 1 School

of Biomedical Sciences, Charles Sturt University, Wagga Wagga Base Hospital, NSW, Australia; 2 Department of Emergency Medicine, Wagga Wagga Base Hospital, NSW, Australia; 3 Department of Medicine, Wagga Wagga Base Hospital, NSW, Australia Aims: To assess the pharmacological management of atrial fibrillation (AF) in patients admitted to a non-metropolitan teaching hospital for chronic heart failure (CHF). Methods: The medical records of 417 patients hospitalised for CHF between 2003 and 2005 were reviewed. Patients with concomitant AF were selected for analysis. Results: There were 141 patients with persistent or permanent AF as well as CHF. Before discharge, 92 (65.2%) had persisting AF and 49 (34.8%) were in sinus rhythm (Table 1). For patients with ongoing AF at discharge, the average ventricular rate was reduced from 96 ± 27 to 78 ± 19 beats/min (P < 0.01). Resting ventricular rates of ≥80 beats/min on admission and at discharge were found in 67.7% and 35.6% of the patients, respectively (P < 0.01).

Abstracts

Table 1. Patient’s characteristics and major drug groups prescribed at discharge Ongoing AF (n = 92) Age (years) Male Amiodarone Beta-blockers Digoxin Aspirin/clopidogrel Warfarin in eligible patients

77.4 ± 9.2 53 (57.6%) 6 (6.5%) 26 (28.3%) 50 (54.3%) 39 (42.3%) 38/70 (54.3%)

Sinus rhythm (n = 49) 76.3 ± 16.2 29 (59.2%) 19 (38.8%) 19 (38.8%) 14 (28.6%) 16 (32.7%) 26/42 (61.9%)

P

NS NS <0.01 NS <0.01 NS NS

For patients with ongoing AF at discharge, the average ventricular rate was reduced from 96 ± 27 to 78 ± 19 beats/min (P < 0.01). Resting ventricular rates of ≥80 beats/min.

Conclusions: The use of rhythm or rate control drugs in this study is consistent with the current therapeutic guidelines. The target ventricular rate and antithrombotic therapy with warfarin may be improved in more than a third of the patients. doi:10.1016/j.hlc.2007.06.292 288 Complications of Permanent Pacemaker Implantation: Seven-Year Experience N. Wijesinghe ∗ , R.F. Allen, C. Sebastian, C.M. Wade, S. Heald, H.F. McAlister Department of Cardiology, Waikato Hospital, New Zealand Background: Permanent pacemakers (PPM) are frequently implanted but accurate data on implant-related complications are limited. Our aim was to ascertain the incidence of intraoperative and early postoperative complications (up to 2 months after implant) during PPM implantation at our hospital. Method: Retrospective chart review was done in all consecutive patients who had new PPM implantation at Waikato Hospital between 1 January 2000 and 31 December 2006. All procedures were performed under strict aseptic conditions and under local anaesthesia. All patients were given cephazolin 1 g intravenously prior to the procedure. Results: A total of 1060 patients had PPM implantation during this period. They included 61% men (mean age 74.1 years) and 39% women (mean age: 75.4 years). Single chamber, dual chamber and biventricular units were implanted in 47%, 52% and 1% patients, respectively. Active fixation leads were used for 58% atrial leads and 19% ventricular leads. Right atrial lead was implanted at atrial appendage (74%), atrial free wall (7%) and unspecified sites (19%). Right ventricular lead was implanted at apex (69%), right ventricular outflow tract (9%) and unspecified sites (22%). The procedure-related mortality was 0.09%. Other major complications included 0.18% cardiac arrest, 0.54% arrhythmia, 0.09% cardiac tamponade, 0.47% infection, 0.36% wound haematoma, 0.36% pneumothorax, 2.37% lead displacement (1.8% ventricular lead

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and 0.57% atrial lead) and 0.18% subclavian vein thrombosis. Overall major complication rate was 4.64% (46:1000). Conclusion: PPM implantation carries a small but definite risk of early complications. The commonest complication was lead displacement (51% of total complications). Infection rate was less than 1%. Our complication rates were comparable with published data. doi:10.1016/j.hlc.2007.06.293 Electrophysiology – Basic Science – Posters 289 Prognostic Implications of Elevated Cardiac Troponin I After Elective Coronary Artery Stent Implantation R. Yadav, T. David ∗ , P. Narayanan, S. Latouf, P. Challa, L. Jones The Townsville Hospital, Townsville, Queensland, Australia Background: The diagnostic and prognostic role of cardiac troponins in acute coronary syndromes is well established. However, there are conflicting reports on the prognostic significance of minor forms of myocardial injury following successful elective coronary stenting. Methods: Prospective clinical study of 214 consecutive patients undergoing elective stenting of de novo coronary or saphenous vein graft lesions from January 2005 to December 2005. Periprocedural myocardial injury was assessed by analysis of 12 lead ECG and cardiac troponin I (cTn I point of care test, threshold 0.1 ng/ml) before, immediately after and at 12 h following the intervention. Recurrence of angina, unstable angina and major adverse cardiac events (MACE: acute myocardial infarction, target vessel revascularisation, strokes and death) were recorded during clinical follow up at 6 weeks, 3, 6 and 12 months. Results: Post-procedural cTn I was elevated in 74 patients (Grp A) and not detected in 140 patients (Grp B). The baseline demographic and coronary angiographic profiles were similar in both groups. Follow up at 12 months was complete in 200 patients (91.3%). Grp A was associated with a higher overall incidence of cardiac events (13% vs. 5.3%, p < 0.01) chiefly attributed to coronary artery bypass surgery (CABG) (5.8% vs. 0.8%, P < 0.05). Conclusion: Following elective coronary artery stent implantation, cTn I identifies patients at risk of adverse clinical events at 12 months and in our group of patients was predominantly in the form of surgical revascularisation. doi:10.1016/j.hlc.2007.06.294

ABSTRACTS

Heart, Lung and Circulation 2007;16:S1–S201