C-reactive Protein is Markedly Increased Following Radiofrequency Ablation of Atrial Fibrillation
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ABSTRACTS S132 Heart, Lung and Circulation Abstracts 2009;18S:S1–S286 298 C-REACTIVE PROTEIN IS MARKEDLY INCREASED FOLLOWING RADIOFREQUENCY ABLATION OF ATRIAL FIBRILLATION Scott Willoughby , Ross Roberts-Thomson, Han Sung Lim, Anisha Prabhu, Bobby John, Martin K. Stiles, Prashanthan Sanders Cardiovascular Research Centre, Department of Cardiology, Royal Adelaide Hospital and the Disciplines of Medicine and Physiology, University of Adelaide, Adelaide, Australia Introduction: It is well established that AF is associated with the risk of thromboembolic events. Furthermore, in the first two weeks following termination of AF by percu- taneous left atrial radiofrequency ablation (LARFA) this risk in dramatically increased despite continuous anti- coagulant therapy. Recent evidence also links AF to an inflammatory state. However, limit data are available for the role inflammation plays in the increased thrombotic risk following LARFA. Therefore, this study was designed to investigate the effect of LARFA on C-reactive protein levels. Methods: 21 patients (mean age 60 ± 2 years) with AF undergoing pulmonary vein isolation were studied. C- reactive protein levels were measure at 3 time points: before ablation (baseline), 24 h after ablation and 48 h after ablation. Results: Pulmonary vein isolation was accomplished in all patients. During the study no recurrence of AF was observed. C-reactive protein levels at baseline were 2.6 ± 0.5 mg/L. Following ablation C-reactive protein lev- els were markedly elevated at 24 h and 48 h (P < 0.001, Fig. 1). Conclusions: The increase in C-reactive protein levels observed within the first 2 days following LARFA suggests that the ablation procedure leads to stimulation of inflam- matory processes. Increased inflammation may promote a prothrombotic state and contribute to atrial thrombosis or thromboembolism. Fig. 1. Effect of radiofrequency ablation on C-reactive protein levels. doi:10.1016/j.hlc.2009.05.300 299 DEGREE OF ANISOTROPY DETERMINES THE STA- BILITY OF SPIRAL WAVES: IMPLICATIONS FOR MAINTENANCE OF ATRIAL FIBRILLATION P. Kuklik 1,3 , L. Szumowski 2 , J.J. ˙ Zebrowski 1 , P. Sanders 3 1 Faculty of Physics and Center of Excellence for Complex Systems Research at Warsaw University of Technology, ul. Koszykowa 75, Warsaw, Poland 2 Institute of Cardiology, Warsaw, Poland 3 Cardiovascular Research Centre, Department of Cardiology, Royal Adelaide Hospital and the Disciplines of Medicine and Physiology, University of Adelaide, Adelaide, Australia Background: Structural remodeling is an increasingly recognized condition predisposing to the development of atrial fibrillation (AF). Effect of remodeling on stability of the spiral wave has not been investigated. Methods: A modified FitzHugh–Nagumo model was used to model the conduction of activation waves. Anisotropic cell coupling was modeled by introduction of two diffusion coefficients: diffusion coefficient along the x axis (D X ) and along y axis (D Y ). Two scenarios were investi- gated: small-scale inhomogeneity introduced by addition of Gaussian noise to cells coupling and as an example of the global scale inhomogeneity, we introduced spatial variability of coupling coefficients: D X (x, y) = 2(1 −|x|/L) and D Y (x, y) = 2(1 −|y|/L) where L is the sample length. Results: Small-scale inhomogeneity of the cells coupling caused a breakup of spiral wave into several indepen- dent spiral waves or waves circulating around conduction obstacles. Number of the independent wavelets was max- imized (n = 11) for standard deviation of the noise equal to 0.07. For global scale inhomogeneity, spiral wave was attracted to its geometrical center. The assessment of the attraction strength by resonant forcing showed linear dependency between attracting force and distance from the center of the trap. Conclusions: Cell-to-cell coupling and fiber orientation, both important determinants of the degree of anisotropy, have an important role in stability of functional reen- try arrhythmias. However, its effect is ambiguous. It may either promote breakup leading to creation of additional waves, or anchor and stabilize the spiral wave. This prop- erty makes tissue structure inhomogeneity important and complex factor in AF mechanism. doi:10.1016/j.hlc.2009.05.301
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Transcript of C-reactive Protein is Markedly Increased Following Radiofrequency Ablation of Atrial Fibrillation
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S132 Heart, Lung and CirculationAbstracts 2009;18S:S1–S286
298C-REACTIVE PROTEIN IS MARKEDLY INCREASEDFOLLOWING RADIOFREQUENCY ABLATION OFATRIAL FIBRILLATION
Scott Willoughby, Ross Roberts-Thomson, Han SungLim, Anisha Prabhu, Bobby John, Martin K. Stiles,Prashanthan Sanders
Cardiovascular Research Centre, Department of Cardiology,Royal Adelaide Hospital and the Disciplines of Medicine andPhysiology, University of Adelaide, Adelaide, Australia
Introduction: It is well established that AF is associatedwith the risk of thromboembolic events. Furthermore, inthe first two weeks following termination of AF by percu-taneous left atrial radiofrequency ablation (LARFA) thisrisk in dramatically increased despite continuous anti-coagulant therapy. Recent evidence also links AF to aninflammatory state. However, limit data are available forthe role inflammation plays in the increased thromboticrisk following LARFA. Therefore, this study was designedto investigate the effect of LARFA on C-reactive proteinlevels.
Methods: 21 patients (mean age 60 ± 2 years) with AFundergoing pulmonary vein isolation were studied. C-reactive protein levels were measure at 3 time points:before ablation (baseline), 24 h after ablation and 48 h afterablation.
Results: Pulmonary vein isolation was accomplishedin all patients. During the study no recurrence of AFwas observed. C-reactive protein levels at baseline were2.6 ± 0.5 mg/L. Following ablation C-reactive protein lev-els were markedly elevated at 24 h and 48 h (P < 0.001,Fig. 1).
Conclusions: The increase in C-reactive protein levelsobserved within the first 2 days following LARFA suggeststhat the ablation procedure leads to stimulation of inflam-matory processes. Increased inflammation may promotea prothrombotic state and contribute to atrial thrombosisor thromboembolism.
Fig. 1. Effect of radiofrequency ablation on C-reactive protein levels.
doi:10.1016/j.hlc.2009.05.300
299DEGREE OF ANISOTROPY DETERMINES THE STA-BILITY OF SPIRAL WAVES: IMPLICATIONS FORMAINTENANCE OF ATRIAL FIBRILLATION
P. Kuklik 1,3, L. Szumowski 2, J.J. Zebrowski 1, P. Sanders 3
1 Faculty of Physics and Center of Excellence for ComplexSystems Research at Warsaw University of Technology, ul.Koszykowa 75, Warsaw, Poland2 Institute of Cardiology, Warsaw, Poland3 Cardiovascular Research Centre, Department of Cardiology,Royal Adelaide Hospital and the Disciplines of Medicine andPhysiology, University of Adelaide, Adelaide, Australia
Background: Structural remodeling is an increasinglyrecognized condition predisposing to the development ofatrial fibrillation (AF). Effect of remodeling on stability ofthe spiral wave has not been investigated.
Methods: A modified FitzHugh–Nagumo model wasused to model the conduction of activation waves.Anisotropic cell coupling was modeled by introduction oftwo diffusion coefficients: diffusion coefficient along the xaxis (DX) and along y axis (DY). Two scenarios were investi-gated: small-scale inhomogeneity introduced by additionof Gaussian noise to cells coupling and as an exampleof the global scale inhomogeneity, we introduced spatialvariability of coupling coefficients: DX(x, y) = 2(1 − |x|/L)and DY(x, y) = 2(1 − |y|/L) where L is the sample length.
Results: Small-scale inhomogeneity of the cells couplingcaused a breakup of spiral wave into several indepen-dent spiral waves or waves circulating around conductionobstacles. Number of the independent wavelets was max-imized (n = 11) for standard deviation of the noise equalto 0.07. For global scale inhomogeneity, spiral wave wasattracted to its geometrical center. The assessment ofthe attraction strength by resonant forcing showed lineardependency between attracting force and distance fromthe center of the trap.
Conclusions: Cell-to-cell coupling and fiber orientation,both important determinants of the degree of anisotropy,have an important role in stability of functional reen-try arrhythmias. However, its effect is ambiguous. It mayeither promote breakup leading to creation of additionalwaves, or anchor and stabilize the spiral wave. This prop-erty makes tissue structure inhomogeneity important andcomplex factor in AF mechanism.
doi:10.1016/j.hlc.2009.05.301
