The cardiac atria are chambers of active remodeling and dynamic collagen turnover during evolving heart failure

Determinants of Left Atrial Compliance in the Metabolic Syndrome: Insights from the "Linosa Study"

The association between left atrial (LA) impairment and cardiovascular diseases (CVD) and between dyslipidaemia and CVD are well known. The present study aims to investigate the relationships between metabolic factors and LA dimensions and compliance, as well as test the hypothesis that metabolic factors influence LA function independent from hemodynamic mechanisms. Arterial blood pressure (BP), waist and hip circumference, metabolic indices, and a complete echocardiographic assessment were obtained from 148 selected inhabitants (M/F 89/59; age 20−86 years) of Linosa Island, who had no history of CVD. At enrollment, 27.7% of the subjects met the criteria for metabolic syndrome (MetS) and 15.5% for arterial hypertension (HTN). LA compliance was reduced in subjects with MetS compared to those without (53 ± 27% vs. 71 ± 29%, p = 0.04) and was even lower (32 ± 17%, p = 0.01) in those with MetS and HTN. At multiple regression analysis, the presence of MetS independently determined LA maximal area (r = 0.56, p < 0.001), whereas systolic BP and the total cholesterol/HDL cholesterol ratio determined LA compliance (r = 0.41, p < 0.001). In an apparently healthy population with a high prevalence of MetS, dyslipidaemia seems to independently influence LA compliance. At a 5-year follow-up, LA compliance was reduced in both all-cause and CVD mortality groups, and markedly impaired in those who died of CVD. These findings may contribute to understanding the prognostic role of LA function in CVD and strengthen the need for early and accurate lipid control strategies.

Association between complete right bundle branch block and atrial fibrillation development

Background

Complete right bundle branch block (CRBBB) is an important predictor of atrial fibrillation (AF) recurrence after pulmonary vein isolation. However, the association between CRBBB and AF development remains unclear.

Methods

We performed a retrospective study of 2639 patients (male, n = 1549; female, n = 1090; mean age, 58 ± 13 years). CRBBB was defined as a late R (R′) wave in lead V₁ or V₂ with a slurred S wave in lead I and/or lead V₆ with a prolonged QRS duration (≥120 ms).

Results

Among the 2639 patients, CRBBB was detected in 40 patients (1.5%), and the prevalence of AF was 7.4% (196/2639). The proportion of patients with AF and CRBBB was higher than the proportion of patients with AF without CRBBB (22.5% vs. 7.2%; p = 0.001). In the forward multivariate logistic analysis, CRBBB (odds ratio [OR], 3.329; 95% confidence interval [CI], 1.350–8.211; p = 0.009), complete left bundle branch block (OR, 2.209; 95% CI, 1.238–3.940; p = 0.007), age (OR, 1.020; 95% CI, 1.005–1.035; p = 0.009), valvular heart disease (OR, 2.332; 95% CI, 1.531–3.552; p < 0.001), left atrial diameter (OR, 1.133; 95% CI, 1.104–1.163; p < 0.001), left ventricular ejection fraction (OR, 1.023; 95% CI, 1.006–1.041; p = 0.007), and class I or III anti‐arrhythmic drug use (OR, 10.534; 95% CI, 7.090–15.651; p < 0.001) were associated with AF.

Conclusion

Complete right bundle branch block was significantly associated with AF development in hospitalized patients with cardiovascular diseases.

Heart Failure and Atrial Fibrillation: Diastolic Function Differences Depending on Left Ventricle Ejection Fraction

Background: Heart failure (HF) and atrial fibrillation (AF) are prevalent cardiovascular diseases, and their association is common. Diastolic dysfunction may be present in patients with AF and all types of HF, leading to elevated intracardiac pressures. The objective of this study was to analyze diastolic dysfunction in patients with HF and AF depending on left ventricle ejection fraction (LVEF). Material and methods: This prospective study included 324 patients with chronic HF and AF (paroxysmal, persistent, or permanent) hospitalized between January 2018 and March 2021. The inclusion criteria were age older than 18 years, diagnosis of chronic HF and AF, and available echocardiographic data. The exclusion criteria were a suboptimal echocardiographic view, other cardiac rhythms than AF, congenital heart disease, or coronavirus 2 infection. Patients were divided into three subgroups according to LVEF: subgroup 1 included 203 patients with HF with reduced ejection fraction (HFrEF) and AF (62.65%), subgroup 2 included 42 patients with HF with mildly reduced ejection fraction (HFmrEF) and AF (12.96%), and subgroup 3 included 79 patients with HF with preserved ejection fraction (HFpEF) and AF (24.38%). We performed 2D transthoracic echocardiography in all patients. Statistical analysis was performed using R software. Results: The E/e' ratio (p = 0.0352, OR 1.9) and left atrial volume index (56.4 mL/m2 vs. 53.6 mL/m2) were higher in patients with HFrEF than in those with HFpEF. Conclusions: Patients with HFrEF and AF had more severe diastolic dysfunction and higher left ventricular filling pressures than those with HFpEF and AF.

The Role of the Left Atrial Strain Parameters on Grading of Aortic Regurgitation

Background:

Grading the severity of aortic regurgitation (AR) is very important for clinical follow-up. In AR, left atrial (LA) mechanics can be affected in time and LA strain variations can be illuminating for the grading of AR. The purpose of this study is to determine whether the LA strain parameters are associated with the severity of AR or not.

Methodology:

Sixty-four consecutive patients with AR were included in this study. Patients divided into three groups as mild (n: 22), moderate (n: 15), or severe (n: 27). All patients' LA strain measurements were performed and results were compared between groups.

Results:

Between the groups, LA reservoir (LA-Res) in the mild, moderate, and severe AR groups was 42.0 ± 18.0, 41.4 ± 14.8, and 29.2 ± 6.0, respectively (P: 0.002) and LA pump in the mild, moderate, and severe AR groups was 21.2 ± 8.7, 19.3 ± 7.4, and 13.1 ± 4.4, respectively (P < 0.001), different, while no difference was noticed on LA SRs, LA SRe, and LA SRa.

Conclusion:

This study showed that LA-Res and LA pump parameters of the patients with severe AR significantly decreased compared to those of the mild and moderate AR group. The grading of the LA mechanics in patients with chronic AR might provide a supplementary contribution to the present parameters in the grading of AR.

Left Atrial Remodeling Mechanisms Associated with Atrial Fibrillation

Heart disease has always been one of the important diseases that endanger health and cause death. Therefore, it is particularly important to understand left atrium reconstruction and atrial fibrillation before heart image processing. The purpose of this paper is to provide an important review of the mechanisms of left atrial remodeling (LAR) associated with atrial fibrillation (AF). LAR refers to the spectrum of pathophysiological changes in (i) atrial structure and physiological function, and (ii) electric, ionic, and molecular milieu of the LA, in response to stresses imposed by conditions such as hypertension, myocardial ischemia, autonomic denervation and congestive heart failure. The main mechanisms of LAR include electrical remodeling, structural remodeling, metabolic remodeling, autonomic remodeling, neurohormones and inflammation, and other influencing factors. LAR is not only the basic mechanism of AF and heart failure, but also the pathophysiological basis of its progression. In clinical practice, AF is the most common persistent arrhythmia, and is believed to be the result of a combination of mechanisms that have triggers and maintenance mechanisms, including spontaneous ectopic pacing and multiple wavelet reentry. While LA electrophysiological, structural, and ultra-structural changes trigger AF, in turn, AF alters the LA electrical and structural properties that promote its maintenance and recurrence. Chronic AF leads to extensive changes in atrial cellular substructures, including loss of myofibrils, accumulation of glycogen, changes in mitochondrial shape and size, fragmentation of sarcoplasmic reticulum, and dispersion of nuclear chromatin. Electrical remodeling and structural remodeling of the atria during AF, involving structural changes and functional impairment of the left atrium, can lead to serious decline in left ventricular function and severe heart failure. Therefore, LAR and AF are inter-activating phenomena, and the resulting complications can cause serious disabling and fatal events. In this paper, we present (i) the mechanisms of LAR, in the form of structural, electrical, metabolic, and neurohormonal changes, and (ii) their interactive roles in initiating and maintaining AF. These in-depth understanding of the atrial remodeling mechanisms can in turn provide useful insights into the treatment of AF and heart failure.

Clinical and cardiac structural predictors of atrial fibrillation persistence

AIMS

The persistence of atrial fibrillation (AF) has been associated with differential clinical outcomes, with studies showing that persistent and permanent AF results in increased morbidity and mortality when compared to the paroxysmal subtype. Given the established prognostic implications of AF subtype, we sought to discern the clinical and structural cardiac parameters associated with persistent/ permanent AF.

MATERIALS AND METHODS

Consecutive patients admitted to our institution between January 2013 and January 2018 with a primary diagnosis of non-valvular AF who underwent comprehensive transthoracic echocardiography were retrospectively appraised. Assessment of clinical and echocardiographic parameters was undertaken and compared according to AF subtype.

RESULTS

Of 1010 patients, 665 (mean age 66.8 ± 13.5 years, 53% men) had comprehensive transthoracic echocardiography on index admission and were included in the primary analysis. The majority of patients (n = 468; 70%) had paroxysmal AF while 197 (30%) had persistent/ permanent AF. Multivariable logistic regression analysis showed that heart failure (adjusted OR 3.135; 95% CI 2.099 to 4.682, P < .001), right atrial (RA) area ≥18 cm² (adjusted OR 2.147; 95% CI 1.413 to 3.261, P < .001) and left atrial emptying fraction (LAEF) ≤34% (adjusted OR 2.959; 95% CI 1.991 to 4.398, P < .001) were independent predictors of persistent /permanent AF.

CONCLUSIONS

The presence of heart failure, increased RA size and impaired LA function were associated with persistent/ permanent AF. These clinical and cardiac structural risk markers of AF persistence may identify a target population for early intervention to prevent adverse cardiovascular outcomes.

A combined Langendorff-injection technique for simultaneous isolation of single cardiomyocytes from atria and ventricles of the rat heart

Single cardiomyocytes are widely used for investigations of the cellular and molecular mechanisms of regulation and modulation of cardiac performance. Intact cardiomyocytes allow one to study in detail cell function avoiding the effects of extracellular matrix and neighboring cells. The most established protocols of cardiomyocyte isolation are based on the isolated heart perfusion using a Langendorff-apparatus or on intraventricular perfusion using a syringe. However, the yield of single cardiomyocytes obtained by these methods may be low due to the cell injury following non-uniform enzyme digestion of connective tissue in different heart chambers. Moreover, isolation of atrial cardiomyocytes is challenging because of their small size and complex geometric shape. Here we present a new protocol for simultaneous isolation of high quality cardiomyocytes from the atria, ventricular free walls and interventricular septum. The protocol is based on the combination of the Langendorff perfusion method with the intraventricular and intra-atrial injection technique taking into account the collagen content variation between the different heart chambers. Obtained cells demonstrate rod-shaped morphology, a clear and regular sarcomere striation pattern and rat-specific frequency-dependence of contraction and calcium transient parameters. Our protocol provides gentle cell isolation that increases the yield of single cardiomyocytes suitable for biophysical researches .

Pathophysiology of Hypertensive Heart Disease: Beyond Left Ventricular Hypertrophy

PURPOSE OF REVIEW

Given that the life expectancy and the burden of hypertension are projected to increase over the next decade, hypertensive heart disease (HHD) may be expected to play an even more central role in the pathophysiology of cardiovascular disease (CVD). A broader understanding of the features and underlying mechanisms that constitute HHD therefore is of paramount importance.

RECENT FINDINGS

HHD is a condition that arises as a result of elevated blood pressure and constitutes a key underlying mechanism for cardiovascular morbidity and mortality. Historically, studies investigating HHD have primarily focused on left ventricular (LV) hypertrophy (LVH), but it is increasingly apparent that HHD encompasses a range of target-organ damage beyond LVH, including other cardiovascular structural and functional adaptations that may occur separately or concomitantly. HHD is characterized by micro- and macroscopic myocardial alterations, structural phenotypic adaptations, and functional changes that include cardiac fibrosis, and the remodeling of the atria and ventricles and the arterial system. In this review, we summarize the structural and functional alterations in the cardiac and vascular system that constitute HHD and underscore their underlying pathophysiology.

The role of fibroblast - Cardiomyocyte interaction for atrial dysfunction in HFpEF and hypertensive heart disease

AIMS

Atrial contractile dysfunction is associated with increased mortality in heart failure (HF). We have shown previously that a metabolic syndrome-based model of HFpEF and a model of hypertensive heart disease (HHD) have impaired left atrial (LA) function in vivo (rat). In this study we postulate, that left atrial cardiomyocyte (CM) and cardiac fibroblast (CF) paracrine interaction related to the inositol 1,4,5-trisphosphate signalling cascade is pivotal for the manifestation of atrial mechanical dysfunction in HF and that quantitative atrial remodeling is highly disease-dependent.

METHODS AND RESULTS

Differential remodeling was observed in HHD and HFpEF as indicated by an increase of atrial size in vivo (HFpEF), unchanged fibrosis (HHD and HFpEF) and a decrease of CM size (HHD). Baseline contractile performance of rat CM in vitro was enhanced in HFpEF. Upon treatment with conditioned medium from their respective stretched CF (CM-SF), CM (at 21 weeks) of WT showed increased Ca²⁺ transient (CaT) amplitudes related to the paracrine activity of the inotrope endothelin (ET-1) and inositol 1,4,5-trisphosphate induced Ca²⁺ release. Concentration of ET-1 was increased in CM-SF and atrial tissue from WT as compared to HHD and HFpEF. In HHD, CM-SF had no relevant effect on CaT kinetics. However, in HFpEF, CM-SF increased diastolic Ca²⁺ and slowed Ca²⁺ removal, potentially contributing to an in-vivo decompensation. During disease progression (i.e. at 27 weeks), HFpEF displayed dysfunctional excitation-contraction-coupling (ECC) due to lower sarcoplasmic-reticulum Ca²⁺ content unrelated to CF-CM interaction or ET-1, but associated with enhanced nuclear [Ca²⁺]. In human patients, tissue ET-1 was not related to the presence of arterial hypertension or obesity.

CONCLUSIONS

Atrial remodeling is a complex entity that is highly disease and stage dependent. The activity of fibrosis related to paracrine interaction (e.g. ET-1) might contribute to in vitro and in vivo atrial dysfunction. However, during later stages of disease, ECC is impaired unrelated to CF.

Atrial fibrosis in non-atrial fibrillation individuals and prediction of atrial fibrillation by use of late gadolinium enhancement magnetic resonance imaging

INTRODUCTION

Besides the traditional concept of atrial fibrillation (AF) perpetuating atrial structural remodeling, there is increasing evidence that atrial fibrosis might precede AF, highlighting the need for better characterization of the fibrotic substrate. We aimed to assess atrial fibrosis by use of late gadolinium enhancement magnetic resonance imaging (LGE-MRI) in non-AF individuals and to identify predisposing risk factors. A second aim was to establish a risk score for the prevalence of AF using atrial fibrosis in addition to established clinical variables.

METHODS AND RESULTS

Non-AF individuals without structural heart disease (n = 91) and matched AF controls (n = 91) underwent MRI for assessment of LGE. According to the established UTAH classification, atrial LGE ≥20% was considered extensive. Mean left atrial (LA) fibrosis in non-AF and AF individuals were 8.8 ± 6.5% and 12.5 ± 5.8%, respectively. Body mass index (BMI) >30 kg/m ² and LA volume were predictors of atrial fibrosis. Diastolic function was not significantly different with respect to atrial fibrosis. A novel scoring system for the prevalence of AF (2 points for arterial hypertension and/or left ventricular ejection fraction <55%; 3 points for atrial fibrosis >6%) was derived demonstrating that patients in the intermediate/high-risk group had a significantly increased risk of AF.

CONCLUSION

This study reports unexpectedly high atrial fibrosis in non-AF patients without apparent heart disease, highlighting the concept that structural fibrotic alterations may precede AF onset in a significant proportion of individuals. BMI as a predictor of atrial fibrosis suggests that lifestyle and drug intervention, that is, weight reduction, could positively influence fibrosis development. The derived risk score for AF prevalence provides the basis for prospective studies on AF incidence.

Contribution of the left atrial remodeling to the elevated pulmonary capillary wedge pressure in patients with WHO Group II pulmonary hypertension

BACKGROUND

The contribution of progressive left atrial (LA) enlargement to elevated pulmonary capillary wedge pressure (PCWP) in patients with WHO Group II pulmonary hypertension (PH) has not been well studied. We hypothesized that progressive LA enlargement is associated with increased PCWP.

METHODS

A cross-sectional retrospective cohort consisted of 166 patients with HF and WHO Group II PH, confirmed by right heart catheterization (RHC). LA anteroposterior dimension and volume were measured on TTE. PCWP and other hemodynamic parameters were measured by RHC. Univariate and multivariate logistic regression models were used for analysis.

RESULTS

LA enlargement was associated with advanced age, increased BMI, and LV ejection fraction < 40%. PCWP was progressively increased in patients with dilated LA: 16.9 ± 7.4 mmHg in normal LA, 17.6 ± 7.2 mmHg in mildly dilated LA, 22.6 ± 6.3 mmHg in moderately and 22 ± 7.6 in severely dilated LA (p < 0.001). In multiple logistic regression, after adjustment for echocardiographic and clinical variables, severe LA enlargement was independently predictive of elevated PCWP (OR 3.468; 95% CI 1.046-11.504; p = 0.042). After excluding significant mitral regurgitation, progressive LA dilatation was associated with higher PCWP V-wave amplitude: from 21.3 ± 10.4 mmHg in patients with normal LA size, to 30.9 ± 11.7 mmHg in moderately dilated and 31.0 ± 11.6 mmHg in severely dilated LA (p < 0.001).

CONCLUSIONS

In patients with HF and WHO Group II PH, progressive LA enlargement was independently associated with elevated PCWP. After excluding significant mitral regurgitation, LA enlargement was also associated with increased V-wave amplitude, indicative of decreased atrial compliance.

Investigating a biomarker-driven approach to target collagen turnover in diabetic heart failure with preserved ejection fraction patients. Effect of torasemide versus furosemide on serum C-terminal propeptide of procollagen type I (DROP-PIP trial)

AIM

Heart failure with preserved ejection fraction (HFpEF) is associated with myocardial remodelling including severe pro-fibrotic changes contributing to an increase in left ventricular stiffness and diastolic dysfunction. Serum C-terminal propeptide of procollagen type I (PIP) strongly correlates with the turnover of extracellular cardiac matrix proteins and fibrosis. Torasemide, but not furosemide, was described to reduce collagen type I synthesis in clinically unstable patients with heart failure with reduced ejection fraction. We evaluated whether its effect translated to HFpEF patients with type 2 diabetes mellitus (T2DM) and abnormal basal PIP levels.

METHODS AND RESULTS

We performed a relatively small, single-centre, randomised, double-blind, two-arm parallel-group, active controlled clinical trial in 35 HFpEF patients with T2DM to determine the effects of a 9-month treatment with torasemide vs. furosemide on changes of serum PIP levels. Patients with increased PIP levels (≥110 ng/mL), or evidence of structural changes with a left atrial volume index (LAVI) >29 mL/m² and abnormal PIP levels (≥70 ng/mL), were eligible to participate. Fifteen patients were female (42%), mean age was 69 years, body mass index was 34.7 kg/m² , 83% were in New York Heart Association class II/III. Echocardiographic characteristics showed a mean left ventricular ejection fraction of >60%, a left ventricular mass index >120 g/m² , an E/e' ratio of 14, and a LAVI of 40 mL/m² with a NT-proBNP of 174 ng/L and a 6-minute walk distance of 421 m. Mean per cent change in PIP was 2.63 ± 5.68% (±SEM) in torasemide vs. 2.74 ± 6.49% in furosemide (P = 0.9898) treated patients. Torasemide was not superior to furosemide in improving functional capacity, diastolic function, quality of life, or neuroendocrine activation.

CONCLUSION

In this hypothesis-generating, mechanistic trial in stable HFpEF patients with T2DM, neither long-term administration of torasemide nor furosemide was associated with a significant effect on myocardial fibrosis, as assessed by serum PIP. Further studies are urgently needed in this field. More specific diuretic and anti-fibrotic treatment strategies in T2DM and/or HFpEF are warranted.

Left atrial changes in early stages of heart failure with preserved ejection fraction

BACKGROUND AND AIM

Increased left atrial (LA) mass was introduced as a compensatory mechanism in heart failure (HF) patients. Furthermore, atrial conduction time and LA emptying fraction is are deteriorated in HF with preserved ejection fraction (HFpEF). The aim of this study was to assess the early LA changes in HFpEF patients.

METHODS

In 79 consecutive patients with HFpEF (age 61±8 years, NYHA class I-III, LV EF ≥45%), a complete 2-dimensional, M-mode, and Doppler echocardiographic study was performed. According to the diastolic dysfunction (DD), patients were divided into three groups: Group I-29 healthy subjects (control group); Group II-HFpEF patients with mild DD; and Group III-HFpEF patients with moderate DD.

RESULTS

The LV mass was increased (P<.05), septal s', lateral s', septal and lateral MAPSE were decreased (P<.05, for all), E/e' ratio was increased (P<.001), LA mass and minimal volume were increased (P<.001, P<.05), LA emptying fraction was decreased (P<.05), and LA dyssynchrony was deteriorated (P<.05) in patients with mild DD compared to controls. These changes were of the same nature in patients with moderate LV DD.

CONCLUSIONS

In early stage of DD, in patients with HFpEF, in addition to LV hypertrophy and compromised LV longitudinal systolic function, the LA emptying fraction is reduced, LA mass and LAV min are increased and LA dyssynchrony is significant, despite normal LA dimensions. These findings suggest early LA function deterioration irrespective of normal cavity measurements, hence a need for optimum therapy.

Effect of Cardiac Resynchronization Therapy on Left Atrial Size and Function as Expressed by Speckle Tracking 2-Dimensional Strain

Changes in left atrial (LA) strain in patients treated with cardiac resynchronization therapy (CRT) remain not entirely explored. We prospectively evaluated long-term changes in LA size and function and their relation with left ventricular (LV) reverse remodeling and noninvasive hemodynamic variables in patients treated with CRT by 2-dimensional speckle tracking echocardiography. Thirty patients (62 ± 11 years, 63% men) underwent 2-dimensional speckle tracking echocardiography before implant and after 12 months. LA area, global and regional LA strains, LV ejection fraction (LVEF) and longitudinal strain, mitral regurgitation (MR), and diastolic variables were evaluated. At 12 months, CRT responders (60%) exhibited an increase in LA strain (11.4 ± 6.5% vs 16.5 ± 7.9%, p <0.001) and a reduction in LA area (p = 0.002), which were associated with an improvement in MR, E/E' ratio, LVEF, and LV longitudinal strain. In nonresponders, a worsening in LA strain (11.4 ± 6.8% vs 8.7 ± 4.6%, p = 0.017) and LA area (p = 0.002) occurred in parallel with an increase in E/E', whereas LVEF and LV longitudinal strain were unchanged. In conclusion, over long-term follow-up, LA size and strain improved in CRT responders, while worsening in nonresponders. Changes in LV function, filling pressures, and MR seem to be related to LA reverse remodeling, giving a feedback loop.

Echocardiographic Assessment of Right Atrial Pressure in a Pediatric and Young Adult Population

Right atrial pressure (RAP) reflects right-sided cardiac hemodynamics and is useful in management of patients with cardiac and systemic disease. Studies in older adults demonstrated that inferior vena cava (IVC) diameter, IVC collapsibility index, hepatic vein systolic filling fraction (SFF), and right atrial volume (RAV) correlated with mean RAP at catheterization. This study aimed to assess the utility of echocardiographic parameters for assessment of RAP in children and young adults. Patients with pulmonary hypertension or heart transplantation undergoing right heart catheterization were recruited for this prospective observational pilot study. Transthoracic echocardiographic assessment of RAP was performed simultaneously with catheterization. For each parameter, three consecutive cardiac cycles were recorded. Long- and short-axis images of the IVC were obtained. RAV was assessed by area-length and biplane methods. IVC diameters and RAV were indexed to body surface area (BSA)(0.5) and (BSA)(1.4), respectively. Relationships between echocardiographic parameters and mean RAP were correlated using "Pearson's r." Fifty subjects aged 0.3-23 years (median 13, mean 12.3 ± 7 years) were enrolled. Mean RAP correlated modestly with RAV (r = 0.51, p < 0.001). Long-axis IVCmax (r = 0.30, p < 0.05) and tricuspid E wave velocity (r = 0.36, p < 0.01) also correlated with mean RAP. RV free wall tissue Doppler velocities, IVC collapsibility index, and hepatic vein SFF had no relation to mean RAP. In a pediatric and young adult population with pulmonary hypertension or heart transplantation, echocardiographic assessment of RAV and long-axis IVCmax provided a reasonable estimate of mean RAP. IVC collapsibility index and hepatic vein SFF demonstrated no association with mean RAP.

Left Ventricular Filling Pressure as Assessed by the E/e' Ratio Is a Determinant of Atrial Fibrillation Recurrence after Cardioversion

PURPOSE

Left ventricular (LV) filling pressure affects atrial fibrillation (AF) recurrence. We investigated the relationship between diastolic dysfunction and AF recurrence after cardioversion, and whether LV filling pressure was predictive of AF recurrence.

MATERIALS AND METHODS

Sixty-six patients (mean 58±12 years) with newly diagnosed persistent AF were retrospectively enrolled. We excluded patients with left atrial (LA) diameters larger than 50 mm, thereby isolating the effect of LV filling pressure. We evaluated the differences between the patients with (group 1) and without AF recurrence (group 2).

RESULTS

Group 1 showed increased LA volume index (LAVI) and E/e' compared to group 2 (p<0.05). During a mean follow-up period of 25±19 months, AF recurrence after cardioversion was 60.6% (40/66). The area under the receiver operating characteristics curve of E/e' for AF recurrence was 0.780 [95% confidence interval (CI): 0.657-0.903], and the optimal cut-off value of the E/e' was 9.15 with 75.0% of sensitivity and 73.1% of specificity. A Kaplan-Meier survival curve showed that the cumulative recurrence-free survival rate was significantly lower in patients with higher LV filling pressure (E/e'>9.15) compared with patients with lower LV filling pressure (E/e'≤9.15) (log rank p=0.008). Cox regression analysis revealed that E/e' [hazards ratio (HR): 1.100, 95% CI: 1.017-1.190] and LAVI (HR: 1.042, 95% CI: 1.002-1.084) were independent predictors for AF recurrence after cardioversion.

CONCLUSION

LV filling pressure predicts the risk of AF recurrence in persistent AF patients after cardioversion.

Advanced interatrial block predicts clinical recurrence of atrial fibrillation after catheter ablation

BACKGROUND

It has been demonstrated that advanced interatrial block (IAB) is associated with an increased risk of atrial fibrillation (AF); however, the impact of advanced IAB on recurrence of paroxysmal AF after catheter ablation is not clear.

METHODS

204 consecutive patients with paroxysmal AF who underwent index circumferential pulmonary vein (PV) isolation were prospectively enrolled. In all patients, a resting electrocardiogram in sinus rhythm was evaluated for the presence of advanced IAB, defined as a P-wave duration >120ms and biphasic (±) morphology in the inferior leads. Advanced IAB was detected in 20.1% of patients. AF recurrence was defined as the occurrence of confirmed atrial tachyarrhythmia lasting more than 30s beyond 3 months after the catheter ablation in the absence of any antiarrhythmic treatment.

RESULTS

During the mean follow-up period of 13.9±6.2 months (range, 3-27 months), 62 patients (30.4%) developed recurrence of AF. The recurrence rate was higher in patients with advanced IAB than those without advanced IAB (46.3% vs. 26.4%, p=0.006). Cox regression analysis with adjustment for age, P-wave duration, CHADS2 score, and PV isolation identified advanced IAB (hazard ratio, 2.111; 95% confidence interval, 1.034-4.308; p=0.040) and left atrial diameter (hazard ratio, 1.051; 95% confidence interval, 1.004-1.100; p=0.034) as two independent predictors of recurrence of AF.

CONCLUSIONS

Patients with advanced IAB were at an increased risk of AF recurrence after catheter ablation.

Evaluating functional capacity, and mortality effects in the presence of atrial electromechanical conduction delay in patients with systolic heart failure

Objective:

Atrial functions are relatively suppressed in heart failure (HF). We aimed to investigate the associations of intra- and inter-atrial electromechanical conduction delay (EMCD) with functional class and mortality over a 12-month follow-up period.

Methods:

The prospective study included 65 patients with systolic HF and 65 healthy subjects with normal sinus rhythm. Left ventricular (LV) systolic functions and left atrial (LA) dimensions and volumes were evaluated by transthoracic echocardiography. Tissue Doppler imaging (TDI) signals at the lateral border of the mitral annulus (lateral PA’), septal mitral annulus (septal PA’), and tricuspid annulus (tricuspid PA’) were measured. Intra- and inter-atrial EMCD were calculated.

Results:

Mitral inflow velocities were studied using pulsed-wave Doppler after placing the sample volume at the leaflets’ tips. The peak early (E wave) and late (A wave) velocities were measured. The septal annular E/E’ ratio was relatively higher and lateral, septal, and right ventricular S, E’, and A’ waves were significantly lower in the HF group than in the control group (12.49±6.03 – 7.16±1.75, pE/E’ <0.0001). Intra-atrial EMCD was detected as 117.5 ms and inter-atrial EMCD as 127.5 ms in patients with prolonged atrial EMCD. A significant increase was found in prolonged intra- and inter-atrial EMCD according to functional capacity increase (p=0.012 and p=0.031, respectively). The incidence of mortality was significantly higher in patients with prolonged atrial EMCD (p=0.025), and 5 patients in the HF group died during the study over the 12-month follow-up period.

Conclusions:

In this study, we found a relationship between prolonged atrial conduction time and increased functional class and mortality in patients with systolic HF. (Anatol J Cardiol 2016; 16: 579-86)

Biomechanics of Cardiac Function

The heart pumps blood to maintain circulation and ensure the delivery of oxygenated blood to all the organs of the body. Mechanics play a critical role in governing and regulating heart function under both normal and pathological conditions. Biological processes and mechanical stress are coupled together in regulating myocyte function and extracellular matrix structure thus controlling heart function. Here, we offer a brief introduction to the biomechanics of left ventricular function and then summarize recent progress in the study of the effects of mechanical stress on ventricular wall remodeling and cardiac function as well as the effects of wall mechanical properties on cardiac function in normal and dysfunctional hearts. Various mechanical models to determine wall stress and cardiac function in normal and diseased hearts with both systolic and diastolic dysfunction are discussed. The results of these studies have enhanced our understanding of the biomechanical mechanism in the development and remodeling of normal and dysfunctional hearts. Biomechanics provide a tool to understand the mechanism of left ventricular remodeling in diastolic and systolic dysfunction and guidance in designing and developing new treatments.

Looking into a conceptual framework of ROS-miRNA-atrial fibrillation

Atrial fibrillation (AF) has been recognized as a major cause of cardiovascular-related morbidity and mortality. MicroRNAs (miRNAs) represent recent additions to the collection of biomolecules involved in arrhythmogenesis. Reactive oxygen species (ROS) have been independently linked to both AF and miRNA regulation. However, no attempts have been made to investigate the possibility of a framework composed of ROS–miRNA–AF that is related to arrhythmia development. Therefore, this review was designed as an attempt to offer a new approach to understanding AF pathogenesis. The aim of this review was to find and to summarize possible connections that exist among AF, miRNAs and ROS to understand the interactions among the molecular entities underlying arrhythmia development in the hopes of finding unappreciated mechanisms of AF. These findings may lead us to innovative therapies for AF, which can be a life-threatening heart condition. A systemic literature review indicated that miRNAs associated with AF might be regulated by ROS, suggesting the possibility that miRNAs translate cellular stressors, such as ROS, into AF pathogenesis. Further studies with a more appropriate experimental design to either prove or disprove the existence of an ROS–miRNA–AF framework are strongly encouraged.

Role of LA shape in predicting embolic cerebrovascular events in mitral stenosis: mechanistic insights from 3D echocardiography

OBJECTIVES

This study was designed to assess the role of left atrial (LA) shape in predicting embolic cerebrovascular events (ECE) in patients with mitral stenosis (MS).

BACKGROUND

Patients with rheumatic MS are at increased risk for ECE. LA remodeling in response to MS involves not only chamber dilation but also changes in the shape. We hypothesized that a more spherical LA shape may be associated with increased embolic events due to predisposition to thrombus formation or to atrial arrhythmias compared with an elliptical-shaped LA of comparable volume.

METHODS

A total of 212 patients with MS and 20 control subjects were enrolled. LA volume, LA emptying fraction, and cross-sectional area were measured by 3-dimensional (3D) transthoracic echocardiography. LA shape was expressed as the ratio of measured LA end-systolic volume to hypothetical sphere volume ([4/3π r(3)] where r was obtained from 3D cross-sectional area). The lower the LA shape index, the more spherical the shape.

RESULTS

A total of 41 patients presented with ECE at the time of enrollment or during follow-up. On multivariate analysis, LA 3D emptying fraction (adjusted odds ratio [OR]: 0.96; 95% confidence interval [CI]: 0.92 to 0.99; p = 0.028) and LA shape index (OR: 0.73; 95% CI: 0.61 to 0.87; p < 0.001) emerged as important factors associated with ECE, after adjustment for age and anticoagulation therapy. In patients in sinus rhythm, LA shape index remained associated with ECE (OR: 0.79; 95% CI: 0.67 to 0.94; p = 0.007), independent of age and LA function. An in vitro phantom atrial model demonstrated more stagnant flow profiles in spherical compared with ellipsoidal chamber.

CONCLUSIONS

In rheumatic MS patients, differential LA remodeling affects ECE risk. A more spherical LA shape was independently associated with an increased risk for ECE, adding incremental value in predicting events beyond that provided by age and LA function.

Left atrial mechanics: echocardiographic assessment and clinical implications

The importance of the left atrium in cardiovascular performance has long been acknowledged. Quantitative assessment of left atrial (LA) function is laborious, requiring invasive pressure-volume loops and thus precluding its routine clinical use. In recent years, novel postprocessing imaging methodologies have emerged, providing a complementary approach for the assessment of the left atrium. Atrial strain and strain rate obtained using either Doppler tissue imaging or two-dimensional speckle-tracking echocardiography have proved to be feasible and reproducible techniques to evaluate LA mechanics. It is essential to fully understand the clinical applications, advantages, and limitations of LA strain and strain rate analysis. Furthermore, the technique's prognostic value and utility in therapeutic decisions also need further elucidation. The aim of this review is to provide a critical appraisal of LA mechanics. The authors describe the fundamental concepts and methodology of LA strain and strain rate analysis, the reference values reported with different imaging techniques, and the clinical implications.

Left atrium systolic and diastolic function assessment in hypertensive patients with preserved ejection fraction

Left atrium remodeling is a physiological response to pressure overload in hypertensive patients. The aim of this study is to determine the relationship between left atrium remodeling and left ventricle diastolic dysfunction in hypertensive patients with preserved systolic function.

MATERIALS AND METHODS

We conducted a prospective study on 96 hypertensive patients (48.75 ± 5.01 years, 50 men) and 96 healthy control subjects (48.17 ± 8.52 years, 56 men), whose data were all evaluated by echocardiography measuring left atrium volumes during the reservoir,conduit and pump phases. Standard indices reflecting left ventricular filling were also assessed.

RESULTS

Medium left atrium volume indexed for body surface was significantly higher in hypertensive patients – 30.87 (6.38) mL/m² vs.21.72 (2.52) mL/m². Indexed left atrium volume was strongly associated with left ventricle diastolic function (p <0.0001). When compared to normal subjects, patients with mild diastolic dysfunction had lower corrected passive emptying volumes ( p < 0.0001) and higher corrected active emptying volumes (p = 0.001), thus leading to similar corrected total emptying volumes ( p < 0.001). However, patients with moderate diastolic dysfunction had smaller active emptying volumes, but higher passive and total emptying volumes when compared to normal controls and patients with mild diastolic dysfunction.

CONCLUSIONS

Left atrium indexed volumes evaluation during the reservoir,conduit and pump phases proved to be essential for early diastolic dysfunction assessment in hypertensive patients.

The Challenge of Chamber Stiffness Determination in Chronic Atrial Fibrillation vs. Normal Sinus Rhythm: Echocardiographic Prediction with Simultaneous Hemodynamic Validation

Echocardiographic diastolic function (DF) assessment remains a challenge in atrial fibrillation (AF), because indexes such as E/A cannot be used and because chronic, rate controlled AF causes chamber remodeling. To determine if echocardiography can accurately characterize diastolic chamber properties we compared 15 chronic AF subjects to 15, age matched normal sinus rhythm (NSR) subjects using simultaneous echocardiography-cardiac catheterization (391 beats analyzed). Conventional DF parameters (DT, Epeak, AT, Edur, E-VTI, E/E') and validated, E-wave derived, kinematic modeling based chamber stiffness parameter (k), were compared. For validation, chamber stiffness (dP/dV) was independently determined from simultaneous, multi-beat P-V loop data. Results show that neither AT, Epeak nor E-VTI differentiated between groups. Although DT, Edur and E/E' did differentiate between groups (DTNSR vs. DTAF p < 0.001, EdurNSR vs. EdurAF p < 0.001, E/E'NSR vs. E/E'AF p < 0.05), the model derived chamber stiffness parameter k was the only parameter specific for chamber stiffness, (kNSR vs. kAF p <0.005). The invasive gold standard determined end-diastolic stiffness in NSR was indistinguishable from end-diastolic (i.e. diastatic) stiffness in AF (p = 0.84). Importantly, the analysis provided mechanistic insight by showing that diastatic stiffness in AF was significantly greater than diastatic stiffness in NSR (p < 0.05). We conclude that passive (diastatic) chamber stiffness is increased in normal LVEF chronic, rate controlled AF hearts relative to normal LVEF NSR controls and that in addition to DT, the E-wave derived, chamber stiffness specific index k, differentiates between AF vs. NSR groups, even when invasively determined end-diastolic chamber stiffness fails to do so.

Myocardial cytokine expression in dogs with systemic and naturally occurring cardiac diseases

OBJECTIVE

To compare myocardial cytokine expression in dogs with naturally occurring cardiac or systemic diseases and dogs without cardiac or systemic diseases (control dogs)

SAMPLE

Myocardial tissue samples from 7 systemic disease-affected dogs (SDDs), 7 cardiac disease-affected dogs (CDDs), and 8 control dogs.

PROCEDURES

mRNA expression of interleukin (IL)-1, IL-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, transforming growth factor (TGF)-β1, TGF-β2, TGF-β3, and growth differentiation factor-15 in myocardial tissue samples obtained from CDDs, SDDs, and control dogs were analyzed via quantitative PCR assays.

RESULTS

In control dogs, only mRNA for TNF-α, TGF-β1, and TGF-β3 was detected; concentrations were significantly higher in male than in female dogs. In SDDs and CDDs, all cytokines, growth factors, and growth differentiation factor-15 were expressed. Compared with findings in SDDs, IL-1, IL-6, IL-8, IL-10, TNF-α, and IFN-γ expression was significantly increased in CDDs; specifically, IL-1, IL-8, TNF-α, TGF-β1, and TGF-β3 expression was increased in the atria and IL-8, IL-10, TNF-α, and IFN-γ expression was increased in the ventricles of CDDs.

CONCLUSIONS AND CLINICAL RELEVANCE

Data suggested that the alterations in cytokine expression in SDDs and CDDs, compared with control dog findings, were a result of inflammatory system activation. The differences in cytokine expression in atria and ventricles between SDDs and CDDs were suggestive of different remodeling processes. A better knowledge of myocardial involvement in SDDs and of immune regulation in CDDs might beneficially affect morbidity and mortality rates and provide new treatment approaches.

Expression of matrix metalloproteinases, their inhibitors, and lysyl oxidase in myocardial samples from dogs with end-stage systemic and cardiac diseases

OBJECTIVE

To compare the degree of mRNA expression for matrix metalloproteinases (MMPs), tissue inhibitors (TIMPs), and lysyl oxidase in myocardial samples from dogs with cardiac and systemic diseases and from healthy control dogs.

SAMPLE

Myocardial samples from the atria, ventricles, and septum of 8 control dogs, 6 dogs with systemic diseases, 4 dogs with dilated cardiomyopathy (DCM), and 5 dogs with other cardiac diseases.

PROCEDURES

Degrees of mRNA expression for MMP-1, -2, -3, -9, and -13; TIMP-1, -2, -3, and -4; and lysyl oxidase were measured via quantitative real-time PCR assay. Histologic examination of the hearts was performed to identify pathological changes.

RESULTS

In myocardial samples from control dogs, only TIMP-3 and TIMP-4 mRNA expression was detected, with a significantly higher degree in male versus female dogs. In dogs with systemic and cardiac diseases, all investigated markers were expressed, with a significantly higher degree of mRNA expression than in control dogs. Furthermore, the degree of expression for MMP-2, TIMP-1, and TIMP-2 was significantly higher in dogs with DCM than in dogs with systemic diseases and cardiac diseases other than DCM. Expression was generally greater in atrial than in ventricular tissue for MMP-2, MMP-13, and lysyl oxidase in samples from dogs with atrial fibrillation.

CONCLUSIONS AND CLINICAL RELEVANCE

Degrees of myocardial MMP, TIMP, and lysyl oxidase mRNA expression were higher in dogs with cardiac and systemic diseases than in healthy dogs, suggesting that expression of these markers is a nonspecific consequence of end-stage diseases. Selective differences in the expression of some markers may reflect specific pathogenic mechanisms and may play a role in disease progression, morbidity and mortality rates, and treatment response.

Management of arrhythmias in the perioperative setting

Perioperative arrhythmias are a common complication of surgery, with incidence ranging from 4% to 20% for noncardiothoracic procedures, depending on the type of surgery performed. The immediate postoperative period is a dynamic time and is associated with many conditions conducive to the development of postoperative arrhythmias. The presence of postoperative atrial fibrillation is associated with increased morbidity, ICU stay, length of hospitalization, and hospital costs. The associated burdens are expected to rise in the future, given that the population undergoing cardiac surgery is getting older and sicker. Thousands of patients undergo major surgery each year and a major complication of these procedures is the occurrence of perioperative arrhythmia. It is imperative for clinicians to be up-to-date on current management of these arrhythmias.

Role of Left Ventricular Diastolic Dysfunction in Predicting Atrial Fibrillation Recurrence after Successful Electrical Cardioversion

The role of left ventricular (LV) diastolic dysfunction in predicting atrial fibrillation (AF) recurrence after successful electrical cardioversion is largely unknown. Studies suggest that there may be a link between abnormal LV compliance and the initial development, and recurrence of AF after electrical cardioversion. Although direct-current cardioversion (DCCV) is a well-established and highly effective method to convert AF to sinus rhythm, it offers little else beyond immediate rate control because it does not address the underlying cause of AF. Preservation of sinus rhythm after successful cardioversion still remains a challenge for clinicians. Despite the use of antiarrhythmic drugs and serial cardioversions, the rate of AF recurrence remains high in the first year. Current evidence suggests that diastolic dysfunction, which is associated with atrial volume and pressure overload, may be a mechanism underlying the perpetuating cycle of AF recurrence following successful electrical cardioversion. Diastolic dysfunction is considered to be a defect in the ability of the myofibrils, which have shortened against a load in systole to eject blood into the high-pressure aorta, to rapidly or completely return to their resting length. Consequently, LV filling is impaired and the non-compliant left ventricle is unable to fill at low pressures. As a result, left atrial and pulmonary vein pressure rises, and electrical and structural remodeling of the atrial myocardium ensues, creating a vulnerable substrate for AF. In this article, we review the current evidence highlighting the association of LV diastolic dysfunction with AF recurrence after successful electrical cardioversion and provide an approach to the management of LV diastolic dysfunction to prevent AF recurrence.

The Role of Atrial Structural Remodeling in Atrial Fibrillation Ablation:An Imaging Point of View for Predicting Recurrence

Atrial fibrillation (AF) is the most common arrhythmia and is associated with a significant morbidity and mortality. Invasive catheter ablation of AF has emerged as an effective therapy for patients with symptomatic AF. Atrial remodeling, particularly structural remodeling, is important not only for AF persistence but also for AF recurrence after ablation. Atrial dilation and fibrosis are two of the core processes involved in atrial structural remodeling. Increased automaticity and triggered activity occur in atrial structural remodeling, which may cause difficulty in maintaining sinus rhythm after ablation. Furthermore, an enlarged left atrium (LA) may increase the difficulty in achieving catheter stability and thereby require more energy to complete AF ablation. AF causes similar remodeling in both the left and right atria (RA), and myocardial changes in both atria influence AF recurrence. A non-invasive assessment of fibrotic structural remodeling helps predict the outcome of AF ablation. A varie ty of cardiac imaging modalities, such as two- or three-dimensional echocardiography or multi-detector row computed tomography, have been used to estimate the magnitude of atrial structural remodeling by measuring atrial volume or LA function. Furthermore, delayed enhanced cardiac magnetic resonance imaging has been used to detect not only atrial fibrosis but also the effect of the ablation point. Thus, atrial remodeling, particularly structural remodeling, plays an important role in AF recurrence. These non-invasive imaging modalities are significant tools for estimating atrial enlargement to improve patient selection for AF ablation at the point of paroxysmal AF, and for estimating atrial fibrosis to select the AF treatment including ablation strategy at the point of development to persistent or permanent AF.

How should we measure left atrium size and function?

Echocardiographic assessment of left atrial size from M-mode or 2D echocardiography measurements has been used in clinical and research studies for years, but its accuracy is now questioned. New techniques, such as 3D and tissue Doppler imaging, assessing velocities, strain and strain rate, provide improved prognostic value in a wide range of diseases. 2D strain imaging using speckle tracking on B-mode images may yield even better, angle-independent, results than tissue Doppler imaging-derived strain echocardiography. Finally, velocity vector imaging is a novel image analysis technique that may be used to quantify left atrial volume.

Increased blood mRNA expression of inflammatory and anti-fibrotic markers in dogs with congestive heart failure

Inflammation and extracellular matrix (ECM) remodeling contribute to the development of congestive heart failure (CHF), but the pathogenesis is still incompletely understood. Therefore, whole blood samples from eight dogs without cardiac disease and eight dogs with CHF were investigated for mRNA expression of IL1β, IL2, IL4, IL6, IL8, IL10, TNFα, IFNγ, TGFβ1-3, MMP1, -2, -3, -9 and TIMP1-4 using quantitative PCR. Dogs with CHF had significantly higher IL1β (P=0.015), IL2 (P=0.043), MMP1 (P=0.031), TIMP3 (P=0.012) and lower TNFα (P<0.001), TGFβ3 (P=0.006), TIMP1 (P=0.015) and TIMP2 (P=0.011) mRNA levels. Increased pro-inflammatory IL1β and anti-fibrotic MMP1 and reduced pro-fibrotic TGFβ and TIMP1 and TIMP2 in dogs with CHF suggest progressive left ventricular remodeling. The reduction of TNFα and increase of immunomodulatory IL2 and TIMP3 might suggest control of the inflammatory response. A better understanding of inflammation and ECM remodeling in cardiac diseases may lead to novel treatment approaches.

Metabolic syndrome in an Hispanic population–cardiovascular complications

The metabolic syndrome (MetS) is presently one of the main medical problems in developing countries. This syndrome was studied in Puerto Rico at the Cardiovascular Center of Puerto Rico and the Caribbean with emphasis on understanding the cardiovascular complications.

The medical records of patients admitted between 1999 to 2005 were evaluated for three or more MetS diagnostic criteria.

One hundred and seventy-three patients met the consensus criteria of metabolic syndrome (MetS). The mean age of those diagnosed with MetS was 60 years of age. Fifty-seven percent were males and 42 percent females. The mean body mass was 30 kg/m. The ejection fraction was found to be subnormal ( 49±8%) and the end systolic dimension of the left atrium was increased ( 45±10 mm) in comparison to a group of diabetic patients without MetS used for comparison. The incidence of atrial fibrillation was found to be 16% higher in the MetS group than in the comparison group.

The number of cases of metabolic syndrome recorded within the Hispanic population of Puerto Rico showed a higher incidence of atrial fibrillation without ventricular tachycardia. This is thought to be as a result of the abnormal left ventricular and atrial function.

Recent clinical and experimental advances in atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia in clinical settings (Fuster et al., 2001), and it is often associated with congestive heart diseases (Issac et al., 2007). Many studies in both laboratory and clinical settings have sought to analyze the mechanisms of AF, develop treatments based on these mechanisms, and examine atrial remodeling in chronic AF. The aim of this paper is to analyze recent findings regarding the atrial remodeling that occurs in AF. In particular, we will describe the electrical and structural changes that involve atrial myocytes and the extracellular matrix. We will also describe the general classification and basic pathophysiology of AF and its surgical treatments.

Association between left and right atrial remodeling with atrial fibrillation recurrence after pulmonary vein catheter ablation in patients with paroxysmal atrial fibrillation: a pilot study

BACKGROUND

Left atrial (LA) remodeling is a factor in atrial fibrillation (AF) recurrence after pulmonary vein catheter ablation (CA), but right atrium (RA) remodeling has not been investigated for possible associations to AF recurrence.

METHODS AND RESULTS

Using 64-slice multidetector computed tomography, RA and LA volumes were measured 3-dimensionally before CA in 65 patients with initially proven idiopathic paroxysmal AF (mean age, 60±10 years, 81.5% men). The CA procedure was guided by CARTO Merge atrial electroanatomic mapping. Sixteen patients (24.6%) had AF recurrence within the 6-month period after the CA. The recurrence was associated with a large RA volume [odds ratio, 1.04; 95% confidence interval (CI), 1.02 to 1.07, P<0.0001], a large LA volume with 1.04 [95% CI, 1.01 to 1.06, P=0.002], and low LA mean voltage with 1.03 [95% CI, 1.01 to 1.05, P=0.002]. After adjustment for potential confounding variables, RA and LA volumes remained predictive of AF recurrence. Large atrial volumes (mL) (RA ≥87 or LA ≥99) predicted AF recurrence (sensitivity of RA volume: 81.3% in 13 of 16 patients with AF recurrence; specificity: 75.5% in 37 of 49 patients without AF recurrence; sensitivity of LA volume: 81.3% in 13 of 16 patients with AF recurrence; specificity: 69.4% in 34 of 49 patients without AF recurrence), and the combined estimate of both atrial volumes was incremental and additive prognostic power (sensitivity: 75% in 12 of 16 patients with AF recurrence; specificity: 93.9% in 46 of 49 patients without AF recurrence).

CONCLUSIONS

Both LA and RA remodeling are equally associated with post-CA AF recurrence.

Association of decreased left atrial strain and strain rate with stroke in chronic atrial fibrillation

BACKGROUND

The objective of this study was to investigate myocardial deformation of the left atrium (LA) assessed by two-dimensional speckle tracking echocardiography in patients with permanent atrial fibrillation (AF) and its value for risk stratification for stroke.

METHODS

We recruited 66 consecutive patients with permanent AF who were referred to our echocardiography laboratory for evaluation. These patients were divided into two groups according to the presence of previous stroke or not.

RESULTS

Peak positive longitudinal strain (LASp) during atrial filling, peak strain rate in the reservoir phase of LA (LASRr), and peak strain rate in the conduit phase (LASRc) were identified from LA strain and strain rate curves. The ratio of peak early filling velocity (E) of mitral inflow to early diastolic annulus velocity (E') of the medial annulus (E/E') was calculated. LASp (10.44% ± 4.2% vs. 15.69% ± 5.1%, P < .001), LASRr (1.09 ± 0.27 1/s vs. 1.37 ± 0.32 1/s, P = .001), and LASRc (-1.28 ± 0.38 1/s vs. -1.62 ± 0.43 1/s, P = .002) were significantly lower in patients with AF with stroke than those without stroke. By multivariate analysis controlling for age, LA volume index, and left ventricular ejection fraction, LASp (OR 0.787, 95% CI, 0.639-0.968, P = .023) and LASRr (OR 0.019, 95% CI, 0.001-0.585, P = .023) were independently associated with stroke but not LASRc, E', and E/E' ratio.

CONCLUSION

Decreased LASp and LASRr were independently associated with stroke in patients with permanent AF.

The right heart and pulmonary circulation (III). The pulmonary circulation in heart failure

Pulmonary hypertension due to left heart disease is a pathophysiological and hemodynamic state which is present in a wide range of clinical conditions that affect left heart structures. Although the pulmonary circulation has traditionally received little attention, it is reasonable to say that today it is a fundamental part of cardiological evaluation. In patients with heart failure, the most important clinical factors are the presence of pulmonary hypertension and right ventricular function. These factors are also essential for determining prognosis and must be taken into account when making some of the most important therapeutic decisions. The pathophysiological process starts passively but later transforms into a reactive process. This latter process, in turn, has one component that can be reversed with vasodilators and another component that is fixed, in which the underlying mechanism is congestive vasculopathy (i.e. essentially medial hypertrophy and pulmonary arterial intimal fibrosis). Currently no specific therapy is available for this type of pulmonary hypertension and treatment is the same as for heart failure itself. The drugs that have been shown to be effective in pulmonary arterial hypertension have generally had a neutral effect in clinical trials. Nevertheless, we are involved in the clinical development of a number of groups of pharmacological compounds that will enable us to make progress in the near future.

Independent relationship of left atrial size and mortality in patients with heart failure: an individual patient meta-analysis of longitudinal data (MeRGE Heart Failure)

AIMS

Left atrial (LA) size is considered a marker of poor prognosis in heart failure (HF) patients. Prior studies have recruited relatively few subjects limiting their power to adequately analyse the interaction between LA size, left ventricular (LV) systolic and diastolic function, and prognosis.

METHOD AND RESULTS

The MeRGE collaboration combines prospective data from 18 studies in HF patients. In this analysis of data from 1157 patients, the primary endpoint was death or hospitalization for worsening HF. In multivariate analysis (Cox proportion hazard model), LA area was associated with prognosis (HR 1.03 per cm(2), 95% CI 1.02, 1.05; P < 0.0001) independently of age, NYHA class, LV ejection fraction, and restrictive filling pattern (RFP). When LA area was used as a categorical variable, the HR associated with larger LA area (above median) was 1.4 (95% CI 1.13, 1.74) and when LA area index was used, the HR was 2.36 (95% CI 1.80, 3.08). When the patients with and without RFP were divided on the basis of either LA area or LA area index, significantly higher event rates were observed in those with larger LA area.

CONCLUSION

Left atrial area is a powerful predictor of outcome among HF patients with predominantly impaired systolic function, and is independent of, and provides additional prognostic information beyond LV systolic and diastolic function.