Marker Of Atrial Remodeling Research Articles

Atrial functional mitral regurgitation as a marker of atrial remodeling and ablation outcomes in atrial fibrillation patients

Abstract Background Atrial fibrillation (AF) triggers a cascade of atrial remodeling processes, significantly impacting atrial function and the efficacy of ablation therapies. This remodeling fosters the development of atrial cardiomyopathy and atrial dilation, which is linked to the emergence of mitral regurgitation, paving the way for the concept of atrial functional mitral regurgitation (aFMR). Our study delves into the intricate relationship between aFMR and the electrical architecture of the atrium, specifically focusing on left atrial bipolar voltage and the prevalence and extent of low-voltage areas (LVAs) in AF patients. By exploring these associations, this research aims to deepen our understanding of the interplay between the atrial substrate alterations and the development of aFMR. Methods A total of 282 patients were enrolled, who had presented for a redo PVI procedure after experiencing AF recurrence following a previous PVI. All patients received echocardiography prior to the electrophysiological procedure. All procedures were performed using 3D mapping and radiofrequency ablation. Reconnected pulmonary veins were detected in all patients and were re-isolated. The voltage of the electroanatomical points was documented on each of the atrial walls. LVAs were calculated in selected HD maps. Patients were followed-up for one year after the blanking period. Results Our cohort comprised 282 patients, predominantly male (69.4%), with a mean age of 64 years. 56% of the patients presented with persistent AF. LA area was larger in patients with aFMR ≥ 1+ as compared to aFMR < 1+ (17.0 [14.6-19.7] vs 20.6 [16.6-24.7] cm2, p<0.001). We observed significant differences in left atrial voltage and LVA extent between patients with varying degrees of aFMR (Table 1). Upon further investigation Patients with aFMR = 1+ showed significantly lower atrial voltage compared with aFMR < 1+ yet no significant increase in LVAs area. Patients with aFMR = 2 exhibited lower average voltage amplitudes in all atrial regions and larger LVA in the posterior wall, atrial roof, and septum compared to their aFMR < 1+ counterparts. Notably, the recurrence of AF was significantly higher in the AFMR ≥ 1+ (59% vs 46% p=0.027) group within one year of follow-up. aFMR was associated with AF recurrence even after adjusting for sex, age and AF types (HR:1.517, 95% CI: 1.057-2.184, p=0.025). Conclusion The presence of aFMR in AF patients may serve as a marker of progressive atrial remodeling and the onset of left atrial cardiomyopathy, characterized by reduced atrial voltage and increased LVAs. Additionally, aFMR is linked to the outcomes of PVI, suggesting that aFMR should be considered in the decision-making process for AF therapy. Further research is needed to explore the potential reversibility of these changes.Left atrial voltage and low voltage area

Identification of atrial complex electrograms by short-coupled extrastimuli in paroxysmal and persistent atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): - Health Council of the Andalusian Regional Government through the project "PI-0057-2017". - European Regional Development Fund/European Social Fund. Introduction Electrogram fractionation during atrial fibrillation (AF) and sinus rhythm have been studied as marker of atrial remodeling and potential target for ablation. Objective The aim of our study was to analyze the response to closely coupled atrial extrastimuli and try to identify areas of hidden slow conduction (HSC) that can promote reentry and AF maintenance in paroxysmal and persistent AF. Methods Twenty consecutive patients with paroxysmal AF and persistent AF (10:10) underwent first PVI procedure. During sinus rhythm triple short coupled extrastimuli was delivered. Locations showing double or highly fragmented electrograms in response to triple extrastimuli were defined as positive electrogram (HSC-EGM) (Figure 1). Increase in duration (delta) of the bipolar EGM was recorded. Two consecutive high-density maps were acquired using a multipolar catheter during AF, sinus and paced rhythms. Spatial correlation of HSC-EGM and complex atrial fractionation (CFAEs) during AF were evaluated. Results Patients with persistent AF showed a higher number and percentage of HSC-EGM than paroxysmal AF (13,9% vs 3,3%, p<0.001) (Figure 2). Delta of EGM duration was 53 ± 22 ms compared to 16 ± 14 ms in sites with a negative response (p<0.001). The number of HSC-EGM distinguished with extrastimuli was lower than that of CFAEs during AF (19 vs 56 per map, p<0.01). The reproducibility of the extension and distribution of HSC-EGM in the repeated maps was superior to that of the CFAEs. The distribution of the HSC-EGM was comparable with those found in the initial map (p=0,32), however, there were significant differences in the distribution of CFAEs between the first map and the remap (p=0.003). Conclusion HSC-EGM in response to triple extrastimuli are more frequent in persistent AF. This type of evoked response could reveal the presence of slow conduction areas and could be considered a potential target for ablation of persistent atrial fibrillation. More studies are needed to confirm this hypothesis.

Interatrial block and P terminal force in the general population – Longitudinal changes, risk factors and prognosis

BackgroundPartial and advanced interatrial block (IAB) and P terminal force (PTF) in lead V1 are markers of atrial remodeling and risk factors for atrial fibrillation (AF). There is a lack of information about constancy and possible factors influencing the development of these P-wave abnormalities. MethodsThe study sample consisted of 6058 Finnish participants (mean age 52.16 ± 14.60 years, 45.0% male) from the general population with an ECG taken in a health examination, and from 3224 of these participants, who had a re-examination 11 years later. Risk factors for incident partial and advanced IAB and PTF were studied using binomial logistic regression analysis, and the prognostic significance of these ECG changes for new AF was studied using time-varying Cox regression analysis. ResultsThe rate of reversal to normal of the studied ECG parameters were 47.4% for partial IAB, 40.0% for advanced IAB and 79.3% for PTF. Age, male sex, hypertension, higher BMI, higher LDL cholesterol, ECG left ventricular hypertrophy, use of beta blocker, and use of angiotensin-converting enzyme inhibitor or angiotensin II receptor antagonist were independently associated with a risk to develop incident P-wave abnormality. Partial IAB was independently associated with increased AF risk (HR 1.28 [95% CI 1.04–1.58]), as was also advanced IAB (HR 1.72 [95% CI 1.07–2.75]). ConclusionTraditional cardiovascular risk factors increase the risk of a new P-wave abnormality. Partial and advanced IAB are associated with increased AF risk. Surprisingly, P-wave abnormalities are often reversible during long-term follow-up in the general population.

Nonstenotic Carotid Plaque in Embolic Stroke of Undetermined Source: Interplay of Arterial and Atrial Disease.

Approximately one-sixth of all ischemic strokes are attributable to embolic stroke of undetermined source (ESUS). Recent analyses suggest that atrial cardiopathy and nonstenotic carotid plaque (nsCP) may represent 2 distinct underlying causes in patients with ESUS, although both diseases share common risk factors and are pathophysiologically intertwined. In this study, we, therefore, aimed to search for associations between nsCP and markers of atrial remodeling and function in patients with embolic stroke. Sixty-eight patients with ESUS or atrial fibrillation (AF)-related stroke proven by imaging who underwent comprehensive echocardiographic studies, including measurements of left atrial function and remodeling, were considered. Patients with ESUS underwent a follow-up of at least 1 year after index stroke. For 20 patients with ESUS, NT-proBNP (N-terminal pro-B-type natriuretic peptide) values were available. Presence of nsCP was evaluated considering Duplex sonography and computed tomography angiography and was further categorized in possibly or probably symptomatic nsCP. ESUS patients with nsCP tended to have higher values of septal and lateral total atrial conduction times (P=0.071 and P=0.072, respectively), left atrial volume index (P=0.077), and revealed significantly higher strain rates during early diastole (P=0.013) as well as higher NT-proBNP values (P=0.010) than ESUS patients without nsCP. Moreover, septal total atrial conduction time was significantly longer in ESUS patients with possibly symptomatic nsCP compared with those without (P=0.015). Comparison of ESUS with AF patients revealed significantly higher proportions of nsCP (P=0.010), possibly symptomatic nsCP (P=0.037), and probably symptomatic nsCP (P=0.036) in patients with atrial fibrillation-related stroke. In the regression analysis adjusted for vascular risk factors probably symptomatic nsCP remained significantly associated with AF (P=0.048, odds ratio: 4.46 [95% CI, 1.02-19.56]). Presence of nsCP is associated with AF and markers of left atrial disease in patients with embolic stroke. Therefore, a thorough evaluation regarding atrial cardiopathy and AF in patients with ESUS should not be restricted if nsCP are found, even if high-risk plaque characteristics are evident.

P1015Left atrial sphericity as a marker of atrial remodeling: comparison of atrial fibrillation patients and controls

Abstract Background/Introduction Left atrial (LA) sphericity has been proposed as a more sensitive marker of atrial fibrillation (AF)-associated atrial remodeling compared to traditional markers such as LA size. However, mechanisms that underlie changes in LA sphericity are not fully understood and studies investigating the predictive value of LA sphericity for AF ablation outcome have yielded conflicting results. Purpose The present study aimed to assess correlates of LA sphericity and to compare LA sphericity in subjects with and without AF. Methods Measures of LA size (LA diameter, LA volume, LA volume index), LA sphericity and thoracic anteroposterior diameter (APd) at the level of the LA were determined in a total of 293 AF patients (62% paroxysmal AF) and 110 controls. Cardiac computed tomography (CT) images were analyzed offline by a reviewer blinded to clinical parameters. The AF cohort consisted of consecutive patients referred for cardiac CT imaging prior to first AF ablation procedure between January 2015 and January 2018. The control cohort consisted of subjects with no history of AF who underwent cardiac CT imaging between January 2012 and October 2014 to exclude coronary artery disease. Results LA diameter (40.1 ± 6.8 mm vs. 35.2 ± 5.1 mm; p < 0.001), LA volume (116.0 ± 33.0 ml vs. 80.3 ± 22.6 ml; p < 0.001) and LA volume index (56.1 ± 15.3 ml/m² vs. 41.6 ± 11.1 ml/m²; p < 0.001) were significantly larger in AF patients compared to controls (Figure), also after adjustment for age and sex. LA sphericity did not differ between AF patients and controls (83.7 ± 2.9 vs. 83.9 ± 2.4; p = 0.642). A moderate correlation was noted between thoracic APd and LA sphericity in both females (R = 0.521, p < 0.001) and males (R = 0.498, p < 0.001). Multivariable linear regression analysis demonstrated that LA diameter, LA volume, female sex, body length and thoracic APd were independently associated with LA sphericity. Conclusion The present study suggests that thoracic constraints rather than the presence of AF determine LA sphericity, implying LA sphericity to be unsuitable as a marker of AF-related atrial remodeling. Abstract Figure. Comparison of LA imaging characteristics

Left atrial sphericity as a marker of atrial remodeling: Comparison of atrial fibrillation patients and controls

BackgroundLeft atrial (LA) sphericity has been proposed as a more sensitive marker of atrial fibrillation (AF)-associated atrial remodeling compared to traditional markers such as LA size. However, mechanisms that underlie changes in LA sphericity are not fully understood and studies investigating the predictive value of LA sphericity for AF ablation outcome have yielded conflicting results. The present study aimed to assess correlates of LA sphericity and to compare LA sphericity in subjects with and without AF. MethodsMeasures of LA size (LA diameter, LA volume, LA volume index), LA sphericity and thoracic anteroposterior diameter (APd) at the level of the LA were determined using computed tomography (CT) imaging data in 293 AF patients (62% paroxysmal AF) and 110 controls. ResultsLA diameter (40.1 ± 6.8 mm vs. 35.2 ± 5.1 mm; p < 0.001), LA volume (116.0 ± 33.0 ml vs. 80.3 ± 22.6 ml; p < 0.001) and LA volume index (56.1 ± 15.3 ml/m2 vs. 41.6 ± 11.1 ml/m2; p < 0.001) were significantly larger in AF patients compared to controls, also after adjustment for covariates. LA sphericity did not differ between AF patients and controls (83.7 ± 2.9 vs. 83.9 ± 2.4; p = 0.642). Multivariable linear regression analysis demonstrated that LA diameter, LA volume, female sex, body length and thoracic APd were independently associated with LA sphericity. ConclusionsThe present study suggests that thoracic constraints rather than the presence of AF determine LA sphericity, implying LA sphericity to be unsuitable as a marker of AF-related atrial remodeling.

Circulating Stromelysin-1 (MMP-3): A potential predictor for atrial fibrillation in patients with mitral stenosis

The mitral valvular disease is strongly related to atrial fibrillation (AF). The impact of matrix metalloproteinases (MMPs) on structural atrial remodeling and sustainment of AF in patients with AF is unresolved. This study aimed to investigate serum metalloproteinases as markers of atrial remodeling in patients with mitral stenosis. Blood sample, clinical and echocardiographic parameters were evaluated in 73 patients with mitral stenosis: 37 with AF and 36 with sinus rhythm. The Plasma levels of MMP-3, MMP-2, MMP-9 and TIMP-1 were measured by ELISA sandwich assay. The concentration of MMP-3 ( P = 0.05) was significantly higher in patients with AF than in patients with sinus rhythm. After adjusting for age, gender, and treatment, the regression model indicates that the high MMP-3 appears to be a risk factor for AF (OR = 1.5, P = 0.001). ROC curve showed that plasma levels of MMP-3 can be predict atrial remodeling in patient with mitral stenosis at the cutoff value of > 9.05 ng/ml with an area under the curve (AUC = 0.618, P = 0.038). The combined analysis with the receiver-operating curve of matrix parameters shows a strong association with AF where we observed an increased area (0.706, P = 0.004). Elevated level of MMP-3 was related to the occurrence of AF. This suggests that MMP-3 could be a marker of atrial remodeling in patients with AF.

Intra- and interatrial conduction abnormalities: hemodynamic and arrhythmic significance.

Alterations of normal intra- and interatrial conduction are a common outcome of multiple cardiovascular conditions. They arise most commonly in the context of advanced age, cardiovascular risk factors, organic heart disease, atrial fibrosis, and left atrial enlargement. Interatrial block (IAB), the most frequent and extensively studied atrial conduction disorder, affects up to 20% of the general primary care population. IAB can be partial (P wave duration ≥ 120ms on any of the 12 ECG leads) or advanced (P wave ≥ 120ms and biphasic morphology (positive-negative) in inferior leads). Advanced IAB is an independent risk factor for supraventricular tachyarrhythmias and embolic stroke in a variety of clinical settings. Advanced IAB is a cause of left atrial electromechanical dysfunction and left atrioventricular dyssynchrony and has been associated with left ventricular diastolic dysfunction. P wave duration is associated with cardiovascular and all-cause mortality in the general population. Atrial conduction abnormalities should be identified as markers of atrial remodeling, prognostic indicators, and, in the case of advanced IAB, a true arrhythmologic syndrome. IAB and other P wave abnormalities should prompt the search for associated conditions, the treatment of which may partially reverse atrial remodeling or prevent it if administered upstream. Future studies will help define the role of preventive therapeutic interventions in high-risk patients, including antiarrhythmic drug therapy and oral anticoagulation. Implications for the treatment of heart failure and for pacing should also be further investigated.

Radiofrequency Ablation of Persistent Atrial Fibrillation: Diagnosis-to-Ablation Time, Markers of Pathways of Atrial Remodeling, and Outcomes.

Various ablation strategies of persistent atrial fibrillation (PersAF) have had disappointing outcomes, despite concerted clinical and research efforts, which could reflect progressive atrial fibrillation-related atrial remodeling. Two-year outcomes were assessed in 1241 consecutive patients undergoing first-time ablation of PersAF (2005-2012). The time intervals between the first diagnosis of PersAF and the ablation procedures were determined. Patients had echocardiograms and measures of B-type natriuretic peptide and C-reactive protein before the procedures. The median diagnosis-to-ablation time was 3 years (25th-75th percentiles 1-6.5). With longer diagnosis-to-ablation time (based on quartiles), there was a significant increase in recurrence rates in addition to an increase in B-type natriuretic peptide levels (P=0.01), C-reactive protein levels (P<0.0001), and left atrial size (P=0.03). The arrhythmia recurrence rates over 2 years were 33.6%, 52.6%, 57.1%, and 54.6% in the first, second, third, and fourth quartiles, respectively (P(categorical)<0.0001). In Cox Proportional Hazard analyses, B-type natriuretic peptide levels, C-reactive protein levels, and left atrial size were associated with arrhythmia recurrence. The diagnosis-to-ablation time had the strongest association with the ablation outcomes which persisted in multivariable Cox analyzes (hazard ratio for recurrence per +1Log diagnosis-to-ablation time 1.27, 95% confidence interval 1.14-1.43; P<0.0001; hazard ratio fourth versus first quartile 2.44, 95% confidence interval 1.68-3.65; P(categorical)<0.0001). In patients with PersAF undergoing ablation, the time interval between the first diagnosis of PersAF and the catheter ablation procedure had a strong association with the ablation outcomes, such as shorter diagnosis-to-ablation times were associated with better outcomes and in direct association with markers of atrial remodeling.

The Association of Serum Galectin-3 Levels with Atrial Electrical and Structural Remodeling.

Left atrial (LA) interstitial fibrosis is known to have a role in the initiation and maintenance of atrial fibrillation (AF). The role of galectin-3 in the pathogenesis of cardiac fibrosis has been demonstrated in previous studies. We aimed to determine whether serum galectin-3 level is associated with markers of atrial remodeling, including the extent of LA fibrosis detected by delayed enhancement magnetic resonance imaging (DE-MRI) and atrial electromechanical delay (AEMD) in paroxysmal AF patients with preserved left ventricular (LV) functions. Thirty-three patients (58 [28-74] years, 51.5% male) with paroxysmal AF who underwent DE-MRI prior to cryoballoon-based AF ablation were included in the study. Serum galectin-3 levels were measured with ELISA. LA volume index (B ± SE: 0.424 ± 0.504, 95% CI: 0.560-2.627, P = 0.004) and serum galectin-3 levels (B ± SE: 0.549 ± 7.745, 95% CI: 16.874-47.550, P < 0.001) were found to be independently correlated with extent of LA fibrosis detected with DE-MRI in paroxysmal AF patients with preserved LV function. Correlation analysis between AEMD parameters and baseline characteristics showed that galectin-3 was significantly correlated with intra-left (ρ = 0.432, P = 0.012) and inter-AEMD (ρ = 0.395, P = 0.023). Duration of AF, LAD, and extent of LA fibrosis were also found to be significantly correlated with AEMD parameters. This is a hypothesis-generating study pointing out that serum galectin-3 level is significantly associated with atrial remodeling in paroxysmal AF patients with preserved LV function. Further studies are necessary to provide exact pathophysiological mechanisms.

MMP-9 in atrial remodeling in patients with atrial fibrillation

IntroductionAtrial fibrillation (AF) is the most common arrhythmia and is associated with significant morbidity and mortality. The impact of matrix metalloproteinases (MMPs) on structural atrial remodeling and sustainment of AF in patients with persistent and permanent AF is unresolved. ObjectivesThe aim was to evaluate MMP-9 and its tissue inhibitor-1 (TIMP-1) as markers of atrial remodeling in patients with persistent AF (PAF) who underwent electrical cardioversion (ECV) and in patients with permanent AF (continuous AF, CAF). Patients and methodsPlasma levels of MMP-9 and TIMP-1, clinical findings, and echocardiographic parameters were evaluated in 39 patients with AF and in 14 controls with sinus rhythm. ResultsThe concentrations of MMP-9 were significantly higher in patients with PAF and CAF compared to controls. There was a significant increase of MMP-9 after ECV in the persistent AF group. The values of TIMP-1 were not significantly different between the groups. In patients with AF, MMP-9 levels were positively related to posterior wall thickness of the LV (r=0.356, P=0.049) and body mass index (r=0.367, P=0.046). ConclusionElevated levels of MMP-9 were related to the occurrence and maintenance of AF. This suggests that MMP-9 can be a marker of atrial remodeling in patients with AF. Regulation of the extracellular collagen matrix might be a potential therapeutic target in AF.

Left atrial spherical shape change in atrial fibrillation

Background Atrial fibrillation (AF) is associated with increase in size of the left atrium (LA). Recent studies have shown that LA shape may be an earlier and independent marker of atrial remodeling in AF. However, previous studies have been limited to qualitative assessments of shape and parameters that do not fully characterize shape. In this study, we use an entropy-driven particle-based shape modeling technique to investigate the relationship between shape and volume of the LA in AF.

Prolonged P-wave duration is associated with atrial fibrillation recurrence after successful pulmonary vein isolation for paroxysmal atrial fibrillation

Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) is successful in ∼70-80% after repeated procedures. This suggests a subgroup of PAF patients where electrical abnormalities outside the pulmonary veins are important. Prolonged P-wave duration (PWD), a marker of atrial remodelling, may identify this subgroup. This study's aim was to assess the association of PWD on standard 12 lead ECG with AF recurrence post PVI. Retrospectively, ECGs were blindly analysed on PVI patients from August 2007-August 2011; patients with persistent AF, mitral valve disease, undergoing redo procedures or no sinus rhythm (SR) ECG within 1year of PVI were excluded. ECGs were directly uploaded at 300dpi, amplified ×10, and then PWD measured in all leads. Prolonged PWD was as priori defined as maximum PWD ≥ 140ms. The selective cohort consisted of 100 patients out of a total of 170 PVI: age 58 ± 11years, 72% male, LVEF 62 ± 9%, 18% ischaemic heart disease and 13% diabetic. Thirty-five had prolonged PWD, which was associated with greater AF recurrence rates compared to those without prolonged PWD (63 vs. 38%, p < 0.05). Similarly, AF recurrence was associated with greater maximum PWD (139 ± 17 vs. 129 ± 14, p < 0.01), P-wave dispersion (58 ± 21 vs. 49 ± 15, p < 0.01), left atrium (LA) dimension (41 ± 6 vs. 38 ± 5, p < 0.05) and LA volumes (40 ± 14 vs. 34 ± 11, p < 0.05) compared to those who remained in SR. None of these variables were independent predictors of AF recurrence by multivariate analysis. The presence of pre-existent prolonged PWD is associated with a higher risk of AF recurrence post PVI for paroxysmal AF.

Left atrium regional voltage analysis in sinus rhythm in patients undergoing atrial fibrillation ablation

Background: The analysis of the amplitude of the electrograms (EGM) obtained during electroanatomic mapping of the atria during atrial fibrillation (AF) ablation could identify low voltage areas (LVA) as a marker of atrial remodelling and predict a worse outcome in the follow-up. Aims: To evaluate the presence of LVA in sinus rhythm (SR) in the patients with paroxysmal and persistent AF undergoing ablation and to correlate it with the specific clinical features and the recurrence rate in the follow-up of this population. Method: We evaluated the voltages of the EGM obtained during electroanatomic mapping of 43 patients undergoing AF ablation (age: 54±11 years; 79% men; 35% persistent AF; mean AF duration: 52±41 months; LA diameter: 44 mms (33-54), by analysing 29 segments of the left atrium (LA) corresponding to 5 anatomical regions (posterior and anterior walls, septum, roof and bottom) and 12 segments of the right atrium (RA) in sinus rhythm before AF ablation. The patients in AF at the beginning of the procedure were cardioverted before EGM acquisition. Only the points showing an adequate catheter-tissue contact were taken into account. The points with EGM voltage amplitude ≤ 0.5 mV were defined as LVA. Pulmonary veins isolation was the endpoint of the procedure in all cases. Additional ablation lines were performed in the roof and mitral isthmus in patients with persistent AF. Results: We did not find any LVA in patients with paroxysmal AF. LVA were present in 7 (47%) of the patients with persistent AF, located in the posterior (7 cases) and anterior walls (1 case), septum (2 cases) and roof (3 cases) of the LA. We did not find any LVA in the RA in any patient. The presence of LVA was not related to the coexistence of hypertension, older age, lower LA appendix velocity or AF duration. On the other hand, patients with LVA showed a larger echocardiographic LA diameter that patients without LVA (52 mms versus 43 mms; p=0.03). At a mean follow-up of 16±10 months, the patients with persistent AF and LVA showed a significant higher AF recurrence rate that patients with persistent AF without LVA (86% versus 25%; p=0.02). Conclusions: The presence of LVA in patients with persistent AF undergoing ablation procedures is frequent. LVA are mainly located in the posterior wall of the LA and their presence is related to a higher recurrence rate in this population in the follow-up. The echocardiographic LA diameter can be an accurate clinical predictor of the presence of LVA.

GEOMETRICAL REVERSE REMODELING OF LEFT ATRIUM AFTER ATRIAL FIBRILLATION ABLATION

Background: Pulmonary vein isolation (PVI) induces left atrial (LA) volume reduction, so-called reverse remodelling (RR). However, the related changes in LA geometry have not yet been evaluated. LA sphericity is a marker of atrial remodelling in patients with atrial ibrillation (AF) and is a powerful predictor of PVI success. The aim of the study was to evaluate the effect of PVI on LA sphericity and describe the spherical RR process.

THE RELATIONSHIP BETWEEN THE LEFT ATRIAL VOLUME AND P WAVE DISPERSION IN HYPERTENSIVE PATIENTS: PP.26.65

Purpose: A maximum P wave duration (Pmax) of > 110 msec and a P wave dispersion (PWD) > 40 msec are accepted indicators of a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse, respectively. The left atrial (LA) volume is considered to be a marker of atrial remodeling. We aimed to investigate the relationship between LA volume and Pmax or PWD in patients with hypertension. Methods: We included 52 hypertensive patients in sinus rhythm. We recorded for each patient a 12-lead electrocardiogram with a paper speed of 50 mm/s and an amplification of 20 mm/mV. P wave dispersion (PWD) was defined as the difference between the duration of the widest (Pmax) and the narrowest (Pmin) P wave, measured on all leads of the 12-lead electrocardiogram. Measurements were made by a single investigator, in a blinded fashion, using a computerized program; the onset and offset points of the P wave were marked manually. The study population was classified into four groups, according to the Pmax (>/= 110 ms or < 110 ms), and the PWD (>/= 40 ms or < 40 ms). The left atrial volume (LAV) was measured by transthoracic echocardiography. Results: There were significant differences in the ejection fraction, diastolic function, and LAV between patients with a Pmax >/= 110 ms or a PWD >/= 40 ms and those with a Pmax < 110 ms or a PWD < 40 ms. The LAV was independently associated with a disturbance in interatrial conduction and an inhomogeneous propagation of the sinus impulse. The LAV can be used to identify patients with a disturbance in the propagation of the sinus impulse, which are at risk for atrial fibrillation. Conclusion: The maximum duration of the P wave and the P wave dispersion on standard 12-lead electrocardiograms are associated with the LA volume in hypertensive patients.

Signal-averaged P wave duration and the long-term risk of permanent atrial fibrillation

Objective. To assess the long-term risk of developing permanent AF in relation to the signal-averaged P wave duration (SAPWD) and clinical and echocardiographic characteristics. Design. In an observational study design we studied 131 patients with earlier ECG-documented AF and successfully restored sinus rhythm attending a long-term, follow-up visit at hospital or at home. Established permanent AF was examined in relation to primary clinical, echocardiographic, and electrophysiological parameters. Results. Only prolonged SAPWD (p =0.006) was associated with an increased risk of development of permanent AF. The risk of permanent AF after 3 years follow-up was 0.72 with an SAPWD equal to 180 ms versus 0.39 with a normal SAPWD (130 ms). We found no prognostic effect of age, gender, dilated left atrium, long duration of AF history, or long duration of the most recent episode of AF. Co-existing hypertension reduced the risk of permanent AF; this could be explained by concomitant treatment with angiotensin-converting-enzyme-inhibitors. Conclusion. Prolonged SAPWD (a marker of atrial remodelling) appears to be a risk factor for long-term development of permanent AF.

B-type natriuretic peptide predicts recurrence of atrial fibrillation after pulmonary vein antral isolation

Background: Recurrence of atrial fibrillation (AF) occurs in up to 25% of patients after pulmonary vein antral isolation (PVAI). Recently, B-type natriuretic peptide (BNP) and C-reactive protein (CRP) have been associated with AF. We aimed to test the hypothesis that elevated preablation BNP or CRP levels can predict the recurrence of AF post-PVAI. Methods: BNP and CRP levels were prospectively drawn on all patients before ablation on the day of the scheduled procedure. Follow-up was performed by weekly transtelephonic transmissions, even if asymptomatic, for 3 months and scheduled Holter monitoring at follow-up. Uniand multivariate analyses were performed on demographic, clinical and echo data, CRP and BNP to determine predictors of AF recurrence. For regression analysis log BNP and log CRP were used because these values were skewed. Results: Between 3/03 and 1/04, 521 patients underwent PVAI. After 280 136 days of follow-up 20% of patients (102/521) had recurrence of AF, defined as recurrence after 8 weeks post PVAI. There was no difference in gender distribution (25% vs 30% females), hypertension, LV function (55.8 8% vs 55.6 6%), left ventricular hypertrophy (LVH), left atrial size, history of coronary artery disease (CAD), beta-blocker or pre-procedural antiarrhythmic drug use between the patients who developed recurrence of AF and those who did not. Pre-op plasma BNP and CRP levels were higher in the recurrence group (median 87pg/ml vs 58 pg/ml, Inter Quartile Range, IQR, [44,195] vs [25,114], p 0.005 for BNP and 2.6 mg/l vs 2.1mg/l, IQR [1.15,5.5] vs [1.02,4.4] for CRP). In regression analysis that included age, gender, hypertension, LV function, LVH, left atrial size, CAD, drug use, CRP and BNP levels, only BNP predicted recurrence of AF (Odds Ratio 3.2, 95% CI: 1.7-6.0, p 0.001). Conclusion: Pre-ablation plasma BNP level is an independent predictor of AF recurrence after PVAI. CRP levels were not predictive of recurrence. BNP may be a more sensitive marker of atrial remodeling than CRP, atrial size or LV function. AB8-3