Experimental studies of atrial fibrillation: a comparison of two pacing models

2008 ◽  
Vol 294 (3) ◽  
pp. H1206-H1215 ◽  
Author(s):  
Gabriel Laurent ◽  
Gordon Moe ◽  
Xudong Hu ◽  
Howard Leong-Poi ◽  
Kim A. Connelly ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Experimental Studies ◽  
Severe Heart Failure ◽  
Left Ventricular ◽  
Control Group ◽  
Type Iii Collagen ◽  
Atrial Remodeling ◽  
Venous Flow ◽  
Group 2

Rapid ventricular pacing (RVP) is a well-established animal model of atrial fibrillation (AF). However, this model is limited by a high mortality rate and severe heart failure. The purpose of our study was to assess a new canine model of inducible AF. We performed acute, short-term, simultaneous atrioventricular pacing (SAVP) and RVP (in random order) in 14 dogs for 30 s. SAVP produced more echocardiographic pulmonary venous flow reversal, a greater increase in mean pulmonary capillary wedge pressure, and a significantly greater decrease in left atrial emptying function (−84.4 ± 38.6% vs. −23.7 ± 27.1%, P < 0.05) than RVP. Thirty dogs were randomized to three, longer-term, study groups: eight dogs in the control group (no pacing), eight dogs in the RVP group (2 wk at 240 beats/min followed by 3 wk at 220 beats/min), and fourteen dogs in the SAVP group (2 wk at 220 beats/min). SAVP induced less left ventricular dysfunction but more left atrial dysfunction than RVP. SAVP dogs had similar atrial effective refractory periods as RVP dogs but more heterogeneity in conduction and more AF inducibility (83% vs. 40%, P < 0.05) and maintenance (median 1,660 vs. 710 s, P < 0.05) than RVP dogs. SAVP induced more collagen turnover and was associated with a significantly greater increase in type III collagen in the atria compared with RVP dogs (6.9 ± 1.5 vs. 4.8 ± 1.6, respectively, P < 0.05 vs. 1.1 ± 0.7 in unpaced control dogs). In conclusion, the SAVP model induced profound mechanical and substrate atrial remodeling and reproducible sustained AF. This new model is clinically relevant and may be useful for testing AF interventions.

scholarly journals Echocardiography in Patients with Atrial Fibrillation - What Should the Internist Doctor Know?

2020 ◽  
Vol 17 (4) ◽  
pp. 49-60
Author(s):  
Maria-Luiza Toplicianu-Dimitriu ◽  
Ioan Tiberiu Nanea
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Structural Changes ◽  
Excess Mortality ◽  
Ventricular Dysfunction ◽  
Imaging Technique ◽  
Left Ventricular ◽  
Clinical Impact ◽  
Atrial Remodeling ◽  
Routine Imaging

AbstractAtrial fibrillation (AF) is the most common cardiac arrhythmia, with an increasing prevalence and an enormous clinical impact due to the high stroke rate, left ventricular dysfunction and excess mortality. The occurrence and maintenance of AF is favored by both the degree of left atrial (LA) dilation and the association of fibrotic lesions of the myocardium. The LA is a marker of adverse cardiovascular events in patients with AF. Atrial remodeling can be electrical (shortening atrial refractory), structural (altering geometry and altering collagen content) and contractile (loss of contractility). Cardiac imaging plays a central role in the clinical management of this arrhythmia. Echocardiography represents the routine imaging technique used in patients with AF, with a role in detecting LA dysfunction and cardiac structural changes that predispose to this arrhythmia, also having the ability to predict the maintenance of sinus rhythm after cardioversion and after ablation.

Abstract 14614: The Automatically Assessed P-wave Notch Predicts Cardiovascular Events in Patients With Cardiovascular Risks: The Japan Morning Surge Home Blood Pressure (J-HOP) Study

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Tomoyuki Kabutoya ◽  
Satoshi Hoshide ◽  
Kazuomi Kario
Keyword(s):  
Left Atrial ◽  
Cardiovascular Events ◽  
Left Ventricular ◽  
Hazard Ratio ◽  
P Wave ◽  
Control Group ◽  
Atrial Remodeling ◽  
Wave Group ◽  
Left Atrial Diameter ◽  
Wave Characteristics

Background: The notched P-wave characteristics is associated with atrial remodeling. However, the relationship between notched P-wave characteristics and long-term cardiovascular events remains unclear. Hypothesis: We hypothesized that the notched P-wave would be associated with cardiovascular events. Methods: We enrolled 810 subjects from the J-HOP Study who had ≥1 of four cardiovascular risk factors. Twelve-lead electrocardiography was conducted, and the peak-to-peak distance in the M-shape was calculated automatically using a 12-lead ECG Analysis system (Fukuda Denshi, Tokyo). We compared two definitions: P waves were defined as "notched" if the peak-to-peak distance in the M-shape was ≥20 msec or ≥40 msec in lead II. The primary endpoints were fatal/nonfatal cardiovascular events: myocardial infarction, stroke, hospitalization for heart failure, and aortic dissection. We assessed the left atrial diameter and left ventricular mass index (LVMI) by echocardiography. Results: The mean follow-up period was 101±34 months, and 85 cardiovascular events occurred. When we defined a notched P wave as ≥20msec in the M shape (n=92), a notched P wave was a significant predictor of cardiovascular events after adjustment for age, gender, and comorbidity (hazard ratio 1.80, 95%CI: 1.06-3.05). When we defined a notched P wave as ≥40msec in the M shape (n=25), the hazard ratio of cardiovascular events in the notched P-wave group was significantly borderline after adjustment for covariates (hazard ratio 2.23, 95%CI: 0.90-5.56). The left atrial diameter and LVMI in the patients in the notched P-wave group (≥20 msec in the M shape) were significantly higher than those in the control group (left atrial dia. 38.8±5.9 vs. 36.8±5.0 mm, p=0.001; LVMI 103.9±27.7 vs. 96.3±25.7 g/m 2 , p=0.010). Conclusion: The automatically assessed notched P wave was associated with cardiovascular events, left atrial enlargement and left ventricular hypertrophy.

P3767Progressive left atrial remodeling associates with cholesterol efflux capacity of HDL in atrial fibrillation patients

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Takano ◽  
H Iwata ◽  
K Miyosawa ◽  
T Funamizu ◽  
H Hayashi ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Left Atrial ◽  
Cholesterol Efflux ◽  
Control Group ◽  
Atrial Remodeling ◽  
Inverse Association ◽  
Structural Remodeling ◽  
Cholesterol Efflux Capacity ◽  
Hdl Function

Abstract Background The clinical significance of high-density lipoprotein (HDL) function, represented by cholesterol efflux capacity (CEC), in addition to serum HDL cholesterol (HDL-C) levels, has been recognized in the pathogenesis and prognosis in patients with atherosclerotic cardiovascular diseases. However, the roles of HDL in the development and the progression of atrial fibrillation (AF), has been rarely evaluated. In this study, we thus hypothesized that the compromised HDL function may be associated with the progression of pathological structural remodeling in left atrium (LA). Objective We explored the association between CEC of HDL and the left atrial dimension (LAD), a maker of structural remodeling in the LA, in patients with AF and control. Methods This is a single center case-control study including consecutive 260 AF patients (AF group) and 34 paroxysmal supraventricular tachycardia (PSVT) patients (PSVT group, served as a control group), who underwent catheter ablation from July 2017 to December 2018. Blood samples were collected before catheter ablation procedure. CEC of HDL was measured by using ex vivo radiotracer system that involved incubation of [3H] cholesterol-loaded J774.1 murine macrophage-like cells with apoB-depleted serum. Results Serum HDL-C level was lower in AF group compared to those of PSVT group (55.3±15.3mg/dl vs 61.7±13.3mg/dl: p=0.024). As a marker of HDL function, CEC of HDL was significantly lower in patients with AF group compared to those in PSVT patients (4.74±0.84% vs 5.20±0.99%: p=0.005, Fig 1). In all patients including both groups, CEC of HDL was inversely correlated with LAD (r=−0.25; p<0.001, Fig 2), indicating the inverse association between HDL function and the progression of structural remodeling in AF. Moreover, multivariate logistic regression analysis adjusted by age, gender, body mass index, ejection fraction, and HDL-C demonstrated that increase in CEC of HDL was associated with the lower risk to be highest quartiles of LAD (>42mm), even adjusted by serum HDL-C levels (odds ratio of 1-SD elevation in CEC of HDL for LAD>42mm: 0.63; 95% confidence interval: 0.40–0.97, p=0.037), which implicated the link between HDL function and progression of left atrial structural remodeling. Conclusion Findings in this study may suggest that compromised HDL functionality is associated with the pathogenesis of left atrial structural remodeling in AF patients.

Abstract 3068: Intra-left Ventricular Contractile Dyssynchrony As An Independent Determinant Of Left Atrial Remodeling In Patients With Atrial Fibrillation Managed by Catheter-based Circumferential Pulmonary Venous Isolation

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
FU-CHUN CHIU ◽  
Yi-Chih Wang ◽  
Chih-Chieh Yu ◽  
Ling-Ping Lai ◽  
Juey-Jen Hwang ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Heart Disease ◽  
Catheter Ablation ◽  
Sinus Rhythm ◽  
Left Atrial ◽  
Left Ventricular ◽  
Filling Pressure ◽  
Doppler Imaging ◽  
Atrial Remodeling ◽  
Independent Determinant

BACKGROUND. Enlarged left atrial volume (LAV), resulting from multifactorial pathogenesis, carries a poorer prognosis to patients with atrial fibrillation (AF) even under well rhythm control. We hypothesized that the preexistence of intra-left ventricular (LV) contractile dyssynchrony impaired diastolic filling, which contribute to atrial remodeling in AF patients. METHODS. We investigated 40 patients (34 men and 6 women, mean age 60 ± 10 years) with paroxysmal or persistent AF who were converted mainly by catheter ablation-based circumferential pulmonary venous isolation and then pharmacologically maintained in sinus rhythm. Exclusion criteria included significant (>moderate) valvular heart disease, LV ejection fraction <55 %, or ischemic heart disease confirmed by positive stress tests or coronary angiography. The LAV was measured by 2D echocardiography [π×D1×D2×D3/6 from parasternal long-axis view (D1) and apical four-chamber view (D2 & D3)]. The peak myocardial systolic velocity (S M ) and the time to peak S M (T S ) of the 6-basal and 6-mid LV segments were measured by tissue Doppler imaging (TDI). RESULTS. With similar AF duration before conversion, patients with LAV >40ml (n = 16) had similar baseline characteristics, cardiovascular medications, QRS width, and LV chamber sizes as those with LAV <40ml (n = 24). However, TDI showed the mean S M was borderline lower (6.3 ± 1.2 vs. 7.1 ± 1.2 cm/s, p < 0.05), and the maximal intersegmental difference in T S (77 ± 43 vs. 40 ± 22 ms, p < 0.003) was greater in patients with larger LAV. The intersegmental difference in T S correlated positively with LAV (r = 0.41, p < 0.009), and LV filling pressure estimated by early transmitral flow velocity/annular diastolic velocity was significantly higher (12.3 ± 7.8 vs. 8.7 ± 2.2, p < 0.045) in patients with intersegmental difference in T S >65 ms. After adjusting for age, gender, and the diastolic parameters, intersegmental difference in T S >65ms emerged as an independent determinant of larger LAV in multivariate logistic analysis (OR=17; 95% CI=2–166, p < 0.016). CONCLUSIONS. Intraventricular dyssynchrony, which accompanied with elevated LV filling pressure, contributed independently to LA remodeling in AF patients converted into sinus rhythm by catheter ablation.

scholarly journals Atrial fibrillation in severe aortic valve stenosis — Association with left ventricular left atrial remodeling

2014 ◽  
Vol 4 ◽  
pp. 102-107 ◽  
Author(s):  
Jordi S. Dahl ◽  
Axel Brandes ◽  
Lars Videbæk ◽  
Mikael K. Poulsen ◽  
Rasmus Carter-Storch ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Aortic Valve ◽  
Aortic Valve Stenosis ◽  
Left Atrial ◽  
Left Ventricular ◽  
Atrial Remodeling ◽  
Left Atrial Remodeling

scholarly journals High level of growth differentiation factor 15 and lower left ventricular ejection fraction as predictors of left atrial thrombosis in patients with nonvalvular atrial fibrillation

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
A.V Belokurova ◽  
T.P Gizatulina ◽  
N.Y.U Khorkova ◽  
L.U Martyanova ◽  
T.I Petelina ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Ejection Fraction ◽  
Left Atrial ◽  
Roc Analysis ◽  
Left Ventricular ◽  
Growth Differentiation Factor 15 ◽  
Differentiation Factor ◽  
Group 2 ◽  
High Level ◽  
Group 1

Abstract Background The presence of left atrial/left atrial appendage (LA/LAA) thrombus is used as a surrogate marker of potential stroke in patients (pts) with atrial fibrillation (AF). Purpose To assess the role of growth differentiation factor 15 (GDF-15) level, clinical and echocardiographic (EchoCG) data as predictors of LA/LAA thrombus in pts with nonvalvular AF. Methods Out of 158 pts with nonvalvular AF admitted to Cardiology Center for radiofrequency ablation or elective cardioversion in 2019–2020 2 groups were formed according to transesophageal EchoCG results: group 1 included pts without LA/LAA thrombus (n=102, mean age 59.5±6.0 years) and group 2 (n=42, mean age 60.9±8.8 years) – pts with LA/LAA thrombus. Arterial hypertension was found in 93 pts of group 1 (91%) and in 40 pts of group 2 (95%, p=0.42), coronary artery disease - in 53 pts (52%) and 29 pts (69%), respectively (p=0.06). Both groups did not differ in frequency and spectrum of oral anticoagulants administration. General clinical assessment, EchoCG, and laboratory tests were performed, including GDF-15 (pg/ml) levels using Human GDF-15/MIC-1 ELISA kit and NT-proBNP (pg/ml) in blood. Results Pts with LA/LAA thrombus more often had persistent AF, while paroxysmal AF was more common in pts without thrombus. There was a tendency to more significant congestive heart failure in group 2. Mean CHA2DS2-VASc score was higher in pts with LA/LAA thrombus, also there was a tendency to a larger proportion of pts with scores ≥3. According to EchoCG data, sizes and volumes of both atria, right ventricle, end-systolic volume, left ventricular (LV) size, pulmonary artery systolic pressure and LV mass index were higher in group 2; LV ejection fraction (LVEF) was normal in both groups, but it was significantly lower in pts with LA/LAA thrombus: 59.1±5.1 and 64.0±7.3, respectively (p&lt;0.001). GDF-15 and NT-proBNP levels were significantly higher in group 2 compared to group 1: p=0.00025 and p=0.ehab724.048801 respectively. According to ROC analysis cut-off were set at level &gt;935.0 pg/ml for GDF-15 (AUC=0.705, 95% CI 0.609–0.800, p&lt;0.001) and &gt;143 pg/ml for NT-proBNP (AUC=0.759, 95% CI 0.670–0.849, p&lt;0.001). Multivariate logistic regression revealed the following variables as independent predictors of LAAT: GDF-15 &gt;935.0 pg/ml (OR=4.132, 95% CI 1.305–13.084) and LVEF (OR=0.859, 95% CI 0.776–0.951). According to ROC analysis, the model had a good quality: AUC=0.776 (p&lt;0.001), sensitivity was 78.3%., specificity - 78.3%. Conclusion High level of GDF-15 (&gt;935.0 pg/ml) along with lower LVEF are independent predictors of LA/LAA thrombus in pts with nonvalvular AF. FUNDunding Acknowledgement Type of funding sources: None.

Abstract 17226: Increased Risk of Heart Failure Associated With Left Atrial Remodeling Without Known Atrial Fibrillation

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Jodi Edwards ◽  
Jiming Fang ◽  
Jeff S Healey ◽  
Kathy Yip ◽  
Lisa Mielniczuk ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Left Atrial ◽  
Left Ventricular ◽  
Administrative Databases ◽  
Risk Scores ◽  
Atrial Remodeling ◽  
Left Atrial Remodeling ◽  
Lv Dysfunction ◽  
Increased Risk

Background: Atrial fibrillation (AF) significantly increases risk for heart failure (HF) and independently increases mortality and adverse in-hospital outcomes in HF patients. Validated clinical risk scores (ARC2H) can predict HF in patients with AF, but are limited in application as AF is frequently clinically silent or undetected. However, AF may be preceded by significant preclinical remodeling (left atrial enlargement (LAE) or excessive atrial ectopy (EAE)). Whether LAE and EAE are associated with HF prior to AF is unclear. Method(s): We analyzed consecutive adults >65 years with outpatient echocardiography or Holter at 11 Ontario community cardiology clinics (2010-2017). Exclusions were history of AF, anticoagulation, pacemaker/ICD/ILR, and prosthetic valve. Using linked administrative databases, we assessed 5-year rates of HF (primary) and incident AF and death (secondary) associated with LAE and EAE and among subgroups (M vs. F; <75 vs. >75; CHADS-VASC 0-2 vs. 3-6). Competing risks cox proportional hazards estimated adjusted hazard of HF for severe LAE: >47mm (M);>52mm (F)) or increased APBs/hour (EAE: >30) or both LAE and EAE, adjusting for age, vascular comorbidities and left ventricular (LV) dysfunction. Results: In 28,261 adults (mean 73+/-6 years), direct age-adjusted survival was reduced for those with severe LAE and EAE. 5-year rates of HF were increased for severe (8.8%) vs. moderate (3.5%) and mild (1.4%) LAE and for those with excessive (3.8%) vs. normal (2.5%) ectopy. For both LAE and EAE, those >75 and with a CHADS score 3-6 showed marked increases in HF at 5 years compared to <75 (LAE: 10.6% vs. 7.9%; EAE: 4.3% vs. 1.9%) and CHADS score 0-2 (LAE:21.4% vs. 6.6%; EAE: 8.9% vs. 2.4%). Severe LAE increased hazard of HF 2-fold (HR=2.07; p<.0001), and incident AF over 3-fold (HR= 3.43; p<.0001) and EAE increased hazard of HF (HR=1.31; p<.0001) and incident AF (HR=1.13; p<.0001). Those with both LAE and EAE showed an over 3-fold increased hazard of HF (HR=3.28; p<.0014). Conclusions: Severe LAE and EAE without known AF are associated with increased risk of HF and AF after adjusting for LV dysfunction, particularly for those >75 and with high vascular burden. These data have implications for risk stratification, AF screening, and trials for HF prevention in individuals with left atrial remodeling.

scholarly journals Left atrial remodeling in heart failure: coexistence and additive prognostic power of atrial dilation and dysfunction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Rossi ◽  
E Carluccio ◽  
M Cameli ◽  
R Inciardi ◽  
G.E Mandoli ◽  
...  
Keyword(s):  
Heart Failure ◽  
Left Atrium ◽  
Left Atrial ◽  
Strain Analysis ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Atrial Remodeling ◽  
Ventricular Ejection Fraction ◽  
Functional Changes ◽  
Group 2

Abstract Background Heart failure (HF) is associated with volumetric and functional changes of left atrium (LA). Purpose It is still unclear whether the two atrial abnormalities necessarily coexist and if they have additive prognostic implications. Methods 690 patients with HF due to reduced left ventricular ejection fraction (EF) formed the study population. Each patients underwent comprehensive echocardiographic evaluation; atrial function was assessed by means of strain analysis during reservoir (PALS). End-point of the study was overall survival free of hospitalization. Results Patients were divided in 4 groups according to left atrial size (34 ml/mq) and function (PALS 20%). 64 patients (10%) were characterized by completely normal left atrium (group 1), 150 (25%) by dilated LA by normal PALS (group 2), 130 (20%) by normal LA volume but abnormal PALS (group 3) and 200 patients with dilated LA and decreased PALS (group 4). Clinical and echocardiographic characteristics of the groups are presented in the table. Decreased PALS was associated with worse survival both in patients with normal and abnormal LA volume (p&lt;0.0001 for each group). Conclusions Increased volume and decreased function of LA frequently but not necessarily coexist. LA functional impairment affects prognosis independently of LA volume. Funding Acknowledgement Type of funding source: None

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