Atrial Contractile Function Research Articles

P3392Prognostic implication of quantitative left atrial contractile function assessed by cardiac magnetic resonance imaging-feature tracking in patients with hypertrophic cardiomyopathy

P3392Prognostic implication of quantitative left atrial contractile function assessed by cardiac magnetic resonance imaging-feature tracking in patients with hypertrophic cardiomyopathy

Left atrial strain predicts hemodynamic parameters in cardiovascular patients.

We aimed to evaluate the predictive value of left atrial (LA) reservoir, conduit, and contractile function parameters as assessed by speckle tracking echocardiography (STE) for invasively measured hemodynamic parameters in a patient cohort with myocardial and valvular diseases. Sixty-nine patients undergoing invasive hemodynamic assessment were enrolled into the study. Invasive hemodynamic parameters were obtained by left and right heart catheterization. Transthoracic echocardiography assessment of LA reservoir, conduit, and contractile function was performed by STE. Forty-nine patients had sinus rhythm (SR) and 20 patients had permanent atrial fibrillation (AF). AF patients had significantly reduced LA reservoir function compared to SR patients. In patients with SR, LA reservoir, conduit, and contractile function inversely correlated with pulmonary capillary wedge pressure (PCWP), left ventricular end-diastolic pressure, and mean pulmonary artery pressure (PAP), and showed a moderate association with cardiac index. In AF patients, there were no significant correlations between LA reservoir function and invasively obtained hemodynamic parameters. In SR patients, LA contractile function with a cutoff value of 16.0% had the highest diagnostic accuracy (area under the curve, AUC: 0.895) to predict PCWP ≥18mmHg compared to the weaker diagnostic accuracy of average E/E' ratio with an AUC of 0.786 at a cutoff value of 14.3. In multivariate analysis, LA contractile function remained significantly associated with PCWP ≥18mmHg. In a cohort of patients with a broad spectrum of cardiovascular diseases LA strain shows a valuable prediction of hemodynamic parameters, specifically LV filling pressures, in the presence of SR.

Gender influence on the adaptation of atrial performance to training

Background: High-intensity training has been associated with atrial remodelling and arrhythmias in men. Our purpose was to analyse atrial performance in female endurance athletes, compared to male athletes and controls. Methods: This was a cross-sectional study. We included four groups: female athletes, females controls, male athletes and male controls. Left (LA) and right atrial (RA) volumes and function were assessed using 2D and speckle-tracking echocardiography to determine peak atrial strain-rate at atrial (SRa) and ventricular contraction (SRs), as surrogates of atrial contractile and reservoir function, respectively. ANOVA and Bonferroni’s statistical tests were used to compare variables among groups. Results: We included 82 subjects, 39 women (19 endurance athletes, 20 controls) and 43 men (22 endurance athletes, 21 controls). Mean age was similar between groups (36.6 ± 5.6 years). Athletes had larger bi-atrial volumes, compared to controls (women, LA 27.1 vs. 15.8 ml/m2, p < 0.001; RA 22.31 vs. 14.2 ml/m2, p = 0.009; men, LA: 25.0 vs. 18.5 ml/m2, p = 0.003; RA 30.8 vs. 21.9 ml/m2, p < 0.001) and lower strain-rate (women, LASRa −1.60 vs. −2.18 s−1, p < 0.001; RASRa −1.89 vs. −2.38 s−1, p = 0.009; men, LASRa −1.21 vs. −1.44 s−1, p = 1; RASRa −1.44 vs. −1.60 s−1, p = 1). However, RA indexed size was lower and bi-atrial deformation greater in female athletes, compared to male athletes. Conclusions: The atria of both male and female athletes shows specific remodelling, compared to sedentary subjects, with larger size and less deformation at rest, particularly for the RA. Despite a similar extent of remodelling, the pattern in women had greater bi-atrial myocardial deformation and smaller RA size.

Impaired Left Atrial Function in Fabry Disease: A Longitudinal Speckle-Tracking Echocardiography Study

Fabry disease (FD) is characterized by the accumulation of sphingolipids in multiple organs, including the left atrium. It is uncertain if the left atrial (LA) reservoir, conduit, and contractile functions evaluated by speckle-tracking echocardiography are affected in Fabry cardiomyopathy and whether enzyme replacement therapy can improve LA function. In this retrospective cohort study, LA strain, strain rates, and phasic LA volumes were studied in 50 patients with FD and compared with values in 50 healthy control subjects. All three LA phasic functions were altered. Peak positive strain (reservoir function) was 38.9±14.9% versus 46.5±10.9% (P=.004), and late diastolic strain (contractile function) was 12.6±5.9% versus 15.6±5.3% (P=.010). In 15 patients who started enzyme replacement therapy during the study, most of the LA parameters improved at 1-year follow-up (peak positive strain from 32.0±13.5% to 38.0±13.5%, P=.006), whereas there was a trend toward deterioration in 15 patients who never received treatment (peak positive strain from 47.3±10.8% to 41.3±9.3%, P=.058). Nine patients with FD (21%) experienced new-onset atrial fibrillation or stroke during 4-year follow-up. By univariate analysis, peak positive strain and early diastolic strain demonstrated significant associations with clinical events, surpassing conventional echocardiographic parameters and clinical characteristics. LA reservoir, conduit, and contractile functions by speckle-tracking echocardiography were all affected in FD. Enzyme replacement therapy improved LA function. LA strain parameters were associated with atrial fibrillation and stroke.

Biatrial appendages clots in a rheumatic heart disease patient – an important lesson to remember

Patients with Atrial fibrillation (AF) are quite prone to develop atrial clots due to stasis from impaired atrial contractile function. While left atrial (LA) and left atrial appendage (LAA) thrombi are quite common, right atrial (RA) and right atrial appendage (RAA) clots are uncommonly seen. Structural and functional differences between RAA and LAA have been implicated in lower prevalence of RAA clots in AF patients. We report here simultaneous LAA and RAA clots in a patient with Rheumatic heart disease, mitral stenosis and Atrial fibrillation. Though current guidelines do not make a specific mention of RAA assessment, we highlight the fact that a comprehensive echocardiographic evaluation of both atrial appendages is of paramount importance in atrial fibrillation patients especially those who are planned to undergo balloon mitral valvotomy or cardio version. Key words: Right atrial appendage, Left atrial appendage, atrial fibrillation, Mitral stenosis, clot.

Axial tubule junctions control rapid calcium signaling in atria.

The canonical atrial myocyte (AM) is characterized by sparse transverse tubule (TT) invaginations and slow intracellular Ca2+ propagation but exhibits rapid contractile activation that is susceptible to loss of function during hypertrophic remodeling. Here, we have identified a membrane structure and Ca2+-signaling complex that may enhance the speed of atrial contraction independently of phospholamban regulation. This axial couplon was observed in human and mouse atria and is composed of voluminous axial tubules (ATs) with extensive junctions to the sarcoplasmic reticulum (SR) that include ryanodine receptor 2 (RyR2) clusters. In mouse AM, AT structures triggered Ca2+ release from the SR approximately 2 times faster at the AM center than at the surface. Rapid Ca2+ release correlated with colocalization of highly phosphorylated RyR2 clusters at AT-SR junctions and earlier, more rapid shortening of central sarcomeres. In contrast, mice expressing phosphorylation-incompetent RyR2 displayed depressed AM sarcomere shortening and reduced in vivo atrial contractile function. Moreover, left atrial hypertrophy led to AT proliferation, with a marked increase in the highly phosphorylated RyR2-pS2808 cluster fraction, thereby maintaining cytosolic Ca2+ signaling despite decreases in RyR2 cluster density and RyR2 protein expression. AT couplon "super-hubs" thus underlie faster excitation-contraction coupling in health as well as hypertrophic compensatory adaptation and represent a structural and metabolic mechanism that may contribute to contractile dysfunction and arrhythmias.

Prognostic Value of Left Atrial Strain in Outpatients with De Novo Heart Failure

Left atrial (LA) dysfunction has been related to symptom onset in patients with heart failure (HF). However, the potential prognostic role of LA function has been scarcely studied in outpatients with new-onset HF symptoms. Consecutive outpatients with suspected HF onset evaluated at a one-stop clinic were screened. HF diagnosis was performed according to current guidelines. LA function was analyzed in patients in sinus rhythm by speckle-tracking echocardiography, determining LA peak strain rate after atrial contraction (LASRa) as a surrogate of atrial contractile function. Yearly prospective follow-up was conducted to report cardiovascular hospital admission or death. Patients without HF in sinus rhythm were followed as a control group. Survival curves were estimated using the Kaplan-Meier method. One hundred fifty-four outpatients were included (mean age, 74±10years; 67% women) with a median follow-up duration of 44.4months (interquartile range, 31-58months). Final diagnosis was 29.9% non-HF and 70.1% HF. More than two in five patients with HF (44.4%) had AF (n=48), and 55.6% (n=60) were in sinus rhythm. The latter were divided according to LASRa tertile: highest, -1.93±0.39sec-1; middle, -1.08±0.21sec-1; and lowest, -0.47±0.18sec-1. At the end of follow-up, patients with atrial fibrillation had a low event-free survival rate (56.3%), similar to those in the lower LASRa tertile (55.0%). The non-HF group had the best prognosis, and the higher and middle LASRa tertiles had intermediate prognoses (event-free survival, 85%, 75%, and 70%, respectively). The study of contractile LA function in outpatients with new-onset HF provides prognostic stratification. The early identification of patients at higher risk on the basis of their atrial function would allow focusing on them independently of their final diagnoses.

Acute, Exercise Dose-Dependent Impairment in Atrial Performance During an Endurance Race: 2D Ultrasound Speckle-Tracking Strain Analysis

ObjectivesThis study sought to understand and characterize the acute atrial response to endurance exercise and the influence of the amount of exercise performed. BackgroundEndurance exercise seems to be recognized as a risk factor for developing atrial arrhythmia. Atrial geometrical and functional remodeling may be the underlying substrate. MethodsEchocardiography was performed in 55 healthy adults at baseline and after a 3-stage trail race: a short race (S) (14 km), n = 17; a medium race (M) (35 km), n = 21; and a long race (L) (56 km), n = 17. Analysis consisted of standard, speckle-tracking assessment of both the left ventricle (LV) and right ventricle (RV) and both the left atrium (LA) and the right atrium (RA): a-wave strain (Sa) and strain rate (Ra) as a surrogate for atrial contractile function and s-wave strain (St) and strain rate (SR) as reservoir function. ResultsAfter the race, RA reservoir function decreased in group M (Δ% SRs: −12.5) and further in group L (Δ% SRs: −15.4), with no changes in group S. RA contractile function decreased in group L (Δ% SRa: −9.3), showed no changes in group M (Δ% SRa: +0.7), and increased in group S (Δ% SRa: +14.8). A similar trend was documented in LA reservoir and contractile function but with less pronounced changes. The decrease in RA reservoir after the race correlated with the decrease in RV global longitudinal strain (GLS) (Δ% RVGLS vs. RASt and RASRs: +0.44; p < 0.05 and +0.41, respectively; p < 0.05). ConclusionsDuring a trail-running race, an acute exercise-dose dependent impairment in atrial function was observed, mostly in the RA, which was related to RV systolic dysfunction. The impact on atrial function of long-term endurance training might lead to atrial remodeling, favoring arrhythmia development.

Left atrial active contractile function parameters assessed by cardiac MR are sensitive to myocardial iron.

To determine the impact of myocardial iron overload on left atrial (LA) volume and function using MR in patients with systemic iron overload. Thirty-eight patients with systemic iron overload disease and 10 controls underwent 1.5 Tesla MR performing steady state free precession short-axis cine-series of the LA. Three-dimensional-volumetry was assessed to calculate LA volumes and function. Parameters were indexed (i) to body surface area. The myocardial transverse relaxation rate R2* was determined in the ventricular septum using a multi-echo GRE sequence (breathhold; electrocardiography triggered; 12 echoes; echo time = 1.3-25.7 ms). Significantly decreased active atrial emptying fraction (AAEF) (23% [95%-range, 7-34] versus 36% [95%-range, 14-49], P = 0.009), active atrial emptying volume (AAEVi) (5.5 mL/m2 [95%-range, 2-11] versus 11.9 mL/m2 [95%-range, 3-23], P = 0.008), and active peak emptying rate (APERi) (46 mL/s/m2 [95%-range, 29-69] versus 75 mL/s/m2 [95%-range, 45-178], P < 0.001) were found for patients with myocardial iron overload (R2* > 40 s-1 ) compared with patients with normal myocardial iron levels (R2* < 40 s-1 ). Receiver operating characteristics (ROC) analysis revealed higher potential to indicate myocardial iron overload for the AAEF (area under the ROC curve [AUC] = 0.84; P < 0.0001), APERi (AUC = 0.87; P < 0.0001), and AAEVi (AUC = 0.80; P < 0.0001) compared with LA ejection fraction (LAEF) (AUC = 0.68; P = 0.02) with equal sensitivities and specificities of 82% (AAEF), 79% (APERi), 73% (AAEVi), and 57% (LAEF). MR parameters of active LA contractile function were associated with myocardial iron overload. This cross-sectional study suggests impaired active LA contractile function to be sensitive to myocardial iron toxicity. 3 J. Magn. Reson. Imaging 2017;45:535-541.

La función de la aurícula izquierda está alterada en algunos pacientes con ictus criptogénico: potenciales implicaciones en su evaluación y tratamiento

Introduction and objectivesStroke etiology remains undetermined in up to 30% of cases. Paroxysmal atrial fibrillation is found in 20% to 28% of patients with stroke initially classified as being of undetermined etiology. The aim of our study was to analyze left atrial function in ischemic stroke patients to identify patterns associated with cardioembolic etiology and to determine whether the patterns identified can be found in individuals initially classified as having a stroke of undetermined etiology. MethodsWe studied a cohort of in-hospital ischemic stroke patients referred for transthoracic echocardiography. Treating neurologists determined stroke etiology based on the TOAST classification. Left atrial contractile function was assessed using 2-dimensional echocardiography to determine their ejection fraction and speckle tracking to measure left atrial strain rate: a-wave. Left atrial function was compared between stroke etiology subgroups and healthy controls. ResultsNinety-seven patients (aged 67±15 years) with ischemic stroke (16.5% large-artery atherosclerosis, 15.5% small-vessel occlusion, 11.3% cardioembolic, 5.1% other determined etiology, 51.1% undetermined etiology) and 10 healthy volunteers (aged 63±7 years) were included. Left atrial ejection fraction was significantly decreased only in patients with stroke of cardioembolic and undetermined etiology compared with the control group (31.5±17.2%, 40.2±17.1%, and 59.1±8.4%, respectively; P=.004). The left atrial strain rate was significantly lower in patients with stroke caused by cardioembolic or undetermined etiology, or large-artery atherosclerosis compared with controls (−0.86±0.49, −1.31±0.56, −1.5±0.47, −2.37±1.18, respectively; P<.001). ConclusionsPatients with stroke of undetermined etiology with left atrial function (ejection fraction and strain) similar to that of cardioembolic stroke patients may be misclassified and could potentially benefit from prolonged electrocardiography monitoring. Left atrial function analysis (ejection fraction and strain) might help to identify potential cardioembolic sources in patients with stroke of undetermined etiology.Full English text available from:www.revespcardiol.org/en

Left Atrial Function Is Impaired in Some Patients With Stroke of Undetermined Etiology: Potential Implications for Evaluation and Therapy

Introduction and objectivesStroke etiology remains undetermined in up to 30% of cases. Paroxysmal atrial fibrillation is found in 20% to 28% of patients with stroke initially classified as being of undetermined etiology. The aim of our study was to analyze left atrial function in ischemic stroke patients to identify patterns associated with cardioembolic etiology and to determine whether the patterns identified can be found in individuals initially classified as having a stroke of undetermined etiology. MethodsWe studied a cohort of in-hospital ischemic stroke patients referred for transthoracic echocardiography. Treating neurologists determined stroke etiology based on the TOAST classification. Left atrial contractile function was assessed using 2-dimensional echocardiography to determine their ejection fraction and speckle tracking to measure left atrial strain rate: a-wave. Left atrial function was compared between stroke etiology subgroups and healthy controls. ResultsNinety-seven patients (aged 67±15 years) with ischemic stroke (16.5% large-artery atherosclerosis, 15.5% small-vessel occlusion, 11.3% cardioembolic, 5.1% other determined etiology, 51.1% undetermined etiology) and 10 healthy volunteers (aged 63±7 years) were included. Left atrial ejection fraction was significantly decreased only in patients with stroke of cardioembolic and undetermined etiology compared with the control group (31.5±17.2%, 40.2±17.1%, and 59.1±8.4%, respectively; P=.004). The left atrial strain rate was significantly lower in patients with stroke caused by cardioembolic or undetermined etiology, or large-artery atherosclerosis compared with controls (−0.86±0.49, −1.31±0.56, −1.5±0.47, −2.37±1.18, respectively; P<.001). ConclusionsPatients with stroke of undetermined etiology with left atrial function (ejection fraction and strain) similar to that of cardioembolic stroke patients may be misclassified and could potentially benefit from prolonged electrocardiography monitoring. Left atrial function analysis (ejection fraction and strain) might help to identify potential cardioembolic sources in patients with stroke of undetermined etiology.

Differential atrial performance at rest and exercise in athletes: Potential trigger for developing atrial dysfunction?

Highly trained athletes show an increased risk of atrial arrhythmias. Little is known about atrial volumes and function during exercise in this population. Our aim was to analyze atrial size and contractile function during exercise. Fifty endurance athletes with 11±8h of training per week and 30 sedentary control subjects were included. Echocardiography was performed at baseline and during exercise. Left (LA) and right atrial (RA) size and function were assessed by two-dimensional echocardiography. Peak negative strain (Sa) during atrial contraction and active atrial emptying volume (AEV) were measured. Athletes and control subjects showed a significant increment of deformation and AEV of both atria with exercise (P<0.01 vs baseline for LA and RA). Among athletes, a subgroup with significant LA (n=8)/RA (n=15) dilatation (≥40mL/m2 ) showed a significantly lower increment in AEV with exercise (LA∆AEV: 1.4±1.1mL/m2 vs 2.1±0.9mL/m2 , P=0.04; RA∆AEV: 0.9±0.8mL/m2 vs 2.3±1.1mL/m2 , P<0.01) and lower increment in deformation vs other athletes (LA∆Sa: -3.2±2.9% vs -9.5±4.4%, P<0.01; RA∆Sa: -2.5±3.3% vs. -9.8±3.3%, P<0.01). During exercise, active atrial strain increases, but less in athletes compared to controls, but due to larger atrial volumes, they reached similar increases in atrial emptying volume. However, this overall lesser deformation increases from a subgroup with significant atrial dilatation showing impairment in atrial contractile reserve.

Atrial Contractile Function in Patients With Paroxysmal Atrial Fibrillation

The aim of study was to investigate atrial contractile function in patients with paroxysmal atrial fibrillation (AF) in sinus rhythm using transthoracic echocardiography. 35 patients with paroxysmal AF and arterial hypertension (mean age 62 ± 10 years, 43% males) were enrolled in the study. Control group was composed of comparable patients with arterial hypertension without heart rhythm disturbances. We found significant depression of atrial contraction function in patients with AF in sinus rhythm expressed as decrease in left atrium EF, A' velocity and VTI, and increase in A/A' ratio, whereas peak a velocity was not affected. Patients with AF has markedly depressed atrial contractile function in sinus rhythm, to improve measurements accuracy we propose to use A/A' ratio as LA contractile function marker minimally dependent from LV diastolic function.

Characterization of Cardiac Amyloidosis by Atrial Late Gadolinium Enhancement Using Contrast-Enhanced Cardiac Magnetic Resonance Imaging and Correlation With Left Atrial Conduit and Contractile Function

The diagnosis of cardiac amyloidosis (CA) often necessitates invasive myocardial biopsy. We sought to evaluate whether late gadolinium enhancement (LGE) of the atrial myocardium by cardiac magnetic resonance imaging was associated with impaired left atrial (LA) function and whether the extent of LA LGE may enhance diagnostic differentiation of CA from other cardiomyopathies. Twenty-two patients with biopsy-proven CA, 37 with systemic hypertension (SH), and 22 with nonischemic dilated cardiomyopathy (NIDC) underwent cardiac magnetic resonance imaging and echocardiographic evaluation. Patients with CA had greater minimal LA volume (57 ± 53 vs 24 ± 18 in SH and 19 ± 25% in NIDC, p= 0.003), and significantly lower total LA emptying function (19 ± 14 vs 40 ± 14 in SH and 33 ± 20% in NIDC, p= 0.0006). The mean proportion of atrial enhancement (LGELA%) was significantly greater in patients with CA than with SH and NIDC (59 ± 36% vs 7.4 ± 2.1 and 2.9 ± 9.0%, p <0.0001, respectively). There was also a strong inverse correlation between both active and total atrial emptying (r=-0.69, p= 0.001; r=-0.67, p= 0.01, respectively) with LGELA% for patients with CA. In multivariate regression analysis, LGELA% was the strongest adjusted predictor for CA diagnosis. Using receiver operating characteristic analysis, LGELA% ≥33% produced the greatest diagnostic utility for CA (sensitivity 76%, specificity 94%). Patients with CA may have extensive LGE of the LA myocardium, which is associated with marked reduction in LA emptying function. The extent of LA LGE was highly predictive for the diagnosis of CA.

Lack of Correlations between Electrophysiological and Anatomical-Mechanical Atrial Remodeling in Patients with Atrial Fibrillation

Atrial fibrillation (AF) progressively leads to electrical remodeling (ER) and anatomical-mechanical remodeling (AR), whose relationships in humans remain poorly known. ER and AR were compared in patients undergoing percutaneous radiofrequency (RF) ablation for AF. ER was defined by right and left appendage activation rates as a surrogate for atrial refractory periods. AR was approached by left atrial (LA) diameters and area and left atrial appendage (LAA) area and contractile function (mean emptying flow velocity) (LAAFV) before RF ablation. Mean duration between successive LAA contractions was considered as LAA mechanical rate. Forty-one patients (31 men, age: 64 ± 9 years) with paroxysmal (27%), persistent (61%), or long-persistent AF (12%) were prospectively included (ejection fraction: 44 ± 16%). Parameters exploring AR were highly correlated to each other: LA area (28 ± 7 cm(2) ), LAA area (5.7 ± 2.25 cm(2) ), LA transverse (49 ± 7 mm), and anteroposterior diameter (59 ± 13 mm) or LAAFV (29 ± 13 cm/s; P < 0.05 for each comparison). Parameters exploring ER were also highly correlated: right atrial appendage (RAA; 181 ± 39 ms) and LAA (176 ± 33 ms) activation rates (P < 0.0001). There was no significant correlation between any ER and AR parameter. Only LAA mechanical rate (174 ± 36 ms) was correlated to LAA or RAA activations rates (P ≤ 0.01). ER and AR are not mutually related, atrial activation rate being not correlated to LA or LAA size or function. Thus, the mechanisms leading to AF-induced atrial remodeling may differ for anatomical and electrophysiological aspects.

EComment re: Atrial apoptosis and fibrosis adversely affect atrial conduit, reservoir and contractile functions.

eComment re: Atrial apoptosis and fibrosis adversely affect atrial conduit, reservoir and contractile functions.

EReply to: atrial apoptosis and fibrosis adversely affect atrial conduit, reservoir and contractile functions.

eReply to: atrial apoptosis and fibrosis adversely affect atrial conduit, reservoir and contractile functions.

Atrial apoptosis and fibrosis adversely affect atrial conduit, reservoir and contractile functions.

Chronic atrial volume overload and atrial fibrillation (AF) induce structural changes within atrial myocardium. The aim of this study was to evaluate the effect of adverse cellular remodelling on echocardiographic strain rate (SR) deformation indices of atrial contractile, conduit and reservoir functions. Forty-four consecutive patients with organic mitral regurgitation were analysed. Twenty-eight patients had long-standing persistent AF (AF group), while 16 were in normal sinus rhythm (NSR group). Left atrial (LA) samples were harvested from all the patients for histological analysis. Postoperative echocardiographic data acquisition was performed exclusively during organized atrial electrical activity in order to assess the contractile reserve of patients from both groups. Fibrotic atria had inferior conduit (SR-E: r = -0.36, P = 0.017), reservoir (SR-S: r = -0.31, P = 0.041) and contractile functions (SR-A: r = -0.33, P = 0.027). Analogously, atria with greater apoptotic burdens showed a negative correlation with multiple indices of left atrial functions (SR-E: r = -0.38, P = 0.010; SR-S: r = -0.33, P = 0.028; SR-A: r = -0.28, P = 0.067). The efficiency of atrial contractility was significantly reduced among AF-group patients after conversion to sinus rhythm, when compared with patients in the NSR group (LA active emptying fraction: 20 ± 12 vs 30 ± 10%, P = 0.004; SR-A: 1.1 ± 1.0 vs 2.8 ± 1.9 s(-1), P < 0.001). Superior strain-rate indices of atrial conduit and reservoir functions were noted in the NSR group (SR-E: 3.5 ± 2.3 vs 1.3 ± 1.0 s(-1), P < 0.001; LA expansion index: 86 ± 31 vs 60 ± 42%, P = 0.004). Fibrosis was evident in 7.2 [3.3;9.4]% of the LA tissue sample in the AF group, while it accounted for 3.4 [1.2;8.1]% of atrial tissue in the NSR group (P = 0.054). Apoptosis was documented in 13 (46%) patients in the AF group, whereas none of the patients in the NSR group exhibited signs of programmed cell death (P = 0.001). Myocyte degeneration was more prevalent in the AF group (odds ratio: 7.0, 95% confidence interval: 1.3-36.7, P = 0.021). Age showed a positive correlation with worsening degrees of atrial fibrosis and apoptosis (r = 0.41, P = 0.006; r = 0.49, P = 0.001, respectively). Multiple regression analysis identified SR-S (β = -1.263, P = 0.036) and age (β = 0.144, P = 0.057) as independent predictors of fibrosis. Independent determinants of apoptosis were preoperative AF (β = 4.539, P = 0.007), age (β = 0.188, P = 0.009) and SR-S (β = -1.780, P = 0.002). Atria exhibiting greater fibrotic and apoptotic burdens had impaired conduit, reservoir and contractile function, as evaluated by deformation imaging. Among patients with chronic LA volume overload, exposure to long-standing persistent AF induced more pronounced degrees of adverse atrial cellular remodelling. Strain-rate descriptors of atrial reservoir function harboured potential to predict atrial fibrosis and apoptosis.

Assessment of left atrial function by volumetric indices and tissue Doppler imaging in ischaemic and idiopathic dilated cardiomyopathy

Left atrial (LA) contractility plays an important role in maintenance of cardiac output in patients with left ventricular systolic dysfunction. Although left atrial contractile dysfunction has been reported in dilated cardiomyopathy of ischemic and non-ischemic etiology, the mechanism of LA dysfunction and the pathophysiologic determinants of left atrial size and function have not been adequately investigated in these patients. The aim of this study was to evaluate LA size and contractile function in patients with dilated cardiomyopathy of ischemic and idiopathic etiology and to explore the mechanism and determinants of LA dilation and contractile dysfunction in these patients. 35 patients with ischemic dilated cardiomyopathy, 15 patients with idiopathic dilated cardiomyopathy and 30 control subjects were studied with transthoracic conventional echocardiography, tissue Doppler imaging (TDI) and coronary angiography (CA). Left ventricular (LV) size, systolic and diastolic functions as well as mitral regurgitation (MR) were evaluated. Left atrial volume at mitral valve opening (Vmax), onset of atrial systole, determined by onset of the P wave of the electrocardiogram (Vp) and mitral valve closure (Vmin) was determined with two-dimensional echocardiography. The left atrial contractile function was assessed by means of active emptying fraction (ACTEF = {Vp − Vmin}/Vp%) and TDI for assessment of late diastolic velocity of the mitral annulus and left atrial free wall. Left atrial Vmax was greater while ACTEF and left atrial wall velocity were lower in cardiomyopathy patients compared with the control subjects (79 ± 32 vs. 59 ± 18; P < 0.05, 27.6 ± 13 vs. 42 ± 15; P < 0.05 and 10.2 ± 4.7 vs. 16.2 ± 5.4; P < 0.05, respectively). Vmax , ACTEF and left atrial wall velocity were similarly affected in both types of cardiomyopathy, ischaemic and idiopathic, under the same loading conditions (74 ± 24 vs. 91 ± 46; P > 0.05, 29 ± 12 vs. 27 ± 13; P > 0.05 and 10 ± 5 vs. 11 ± 4; P > 0.05, respectively). The determinants of ACTEF were left atrial volume, left ventricular ejection fraction (EF), E/e’ and MR severity. Left atrial enlargement and contractile dysfunction are common in patients of dilated cardiomyopathy regardless of its aetiology, with the same degree of contractile dysfunction in both ischemic and idiopathic cardiomyopathies under similar loading conditions. This dysfunction is related to worse LV systolic and diastolic function, more severe mitral regurgitation and larger LA volume rather than to the aetiology of cardiomyopathy.

Assessment of left atrial function by volumetric indices and tissue Doppler imaging in ischaemic and idiopathic dilated cardiomyopathy

Left atrial (LA) contractility plays an important role in maintenance of cardiac output in patients with left ventricular systolic dysfunction. Although left atrial contractile dysfunction has been reported in dilated cardiomyopathy of ischemic and non-ischemic etiology, the mechanism of LA dysfunction and the pathophysiologic determinants of left atrial size and function have not been adequately investigated in these patients. The aim of this study was to evaluate LA size and contractile function in patients with dilated cardiomyopathy of ischemic and idiopathic etiology and to explore the mechanism and determinants of LA dilation and contractile dysfunction in these patients. 35 patients with ischemic dilated cardiomyopathy, 15 patients with idiopathic dilated cardiomyopathy and 30 control subjects were studied with transthoracic conventional echocardiography, tissue Doppler imaging (TDI) and coronary angiography (CA). Left ventricular (LV) size, systolic and diastolic functions as well as mitral regurgitation (MR) were evaluated. Left atrial volume at mitral valve opening (Vmax), onset of atrial systole, determined by onset of the P wave of the electrocardiogram (Vp) and mitral valve closure (Vmin) was determined with two-dimensional echocardiography. The left atrial contractile function was assessed by means of active emptying fraction (ACTEF = {Vp − Vmin}/Vp%) and TDI for assessment of late diastolic velocity of the mitral annulus and left atrial free wall. Left atrial Vmax was greater while ACTEF and left atrial wall velocity were lower in cardiomyopathy patients compared with the control subjects (79 ± 32 vs. 59 ± 18; P < 0.05, 27.6 ± 13 vs. 42 ± 15; P < 0.05 and 10.2 ± 4.7 vs. 16.2 ± 5.4; P < 0.05, respectively). Vmax , ACTEF and left atrial wall velocity were similarly affected in both types of cardiomyopathy, ischaemic and idiopathic, under the same loading conditions (74 ± 24 vs. 91 ± 46; P > 0.05, 29 ± 12 vs. 27 ± 13; P > 0.05 and 10 ± 5 vs. 11 ± 4; P > 0.05, respectively). The determinants of ACTEF were left atrial volume, left ventricular ejection fraction (EF), E/e’ and MR severity. Left atrial enlargement and contractile dysfunction are common in patients of dilated cardiomyopathy regardless of its aetiology, with the same degree of contractile dysfunction in both ischemic and idiopathic cardiomyopathies under similar loading conditions. This dysfunction is related to worse LV systolic and diastolic function, more severe mitral regurgitation and larger LA volume rather than to the aetiology of cardiomyopathy.