- Email: [email protected]
Right Ventricular Pacing is Associated with Impaired Endothelial Function
S114
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
Heart, Lung and Circulation 2007;16:S1–S201
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
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
Heart, Lung and Circulation 2007;16:S1–S201
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).