Impaired Left Atrial Mechanical Function Research Articles

Impaired left atrial mechanical functions as indicators for increased aortic root diameter in hypertensive and diabetic patients.

Previous studies have demonstrated that increased aortic root diameter (ARD) is frequently associated with increased cardiovascular (CV) events and is apredictor of stroke. Two-dimensional speckle tracking echocardiography (2D-STE) provides abetter evaluation of left atrial (LA) functions. Left atrial mechanical dispersion is auseful predictor of new-onset atrial fibrillation (AF) independent of LA enlargement and dysfunction. We aimed to investigate the relationship between ARD and LA mechanical functions. The present study included 93consecutive patients with hypertension and diabetes. The relationships between ARD and LA functions was evaluated. Study population was divided into two groups according to the mean ARD values: group1 (ARD ≤30.03 mm, n = 53) and group2 (ARD >30.03 mm, n = 40). In group2, age, LA maxvolume (vol), LA preA vol, LA min vol, LA emptying fraction, LA active ejection fraction (EF), and LA expansion index were significantly higher compared to group1. S‑LAs and SR-LAs (peak LA strain and strain rate, respectively, during ventricular systole) and S‑LAe and SR-LAe (peak early diastolic LA strain and strain rate, respectively) were significantly lower in group2 compared to group1. Age, LA max vol, LA preA vol, LA min vol, LA emptying fraction, LA active EF, LA expansion index, S‑LAs, S‑LAe, SR-LAs, and SR-LAe were significantly associated with increased ARD. In multivariate logistic regression analysis, age, LA expansion index, and SR-LAe were independent predictors for ARD. Impaired LA mechanical functions determined by speckle tracking methods are related with increased ARD independent of LV diastolic dysfunction.

Relation between Left Atrial Remodeling in Young Patients with Cryptogenic Stroke and Normal Inter-atrial Anatomy.

Background and PurposeTo investigate an association between left atrial (LA) structural and P wave dispersion (PWD) during sinus rhythm, and electrical remodeling in cryptogenic stroke (CS) patients.MethodsForty CS patients and 40 age- and sex-matched healthy controls were enrolled. P wave calculations were based on 12-lead electrocardiography (ECG) at a 50-mm/s-paper speed with an amplitude of 10 mm/mV. Difference between the maximum and minimum P wave duration was the P wave dispersion (PWD=Pmax-Pmin). LA deformation was evaluated by speckle tracking echocardiography within 3 days of the acute event.ResultsPWD was 30.1±7.0 ms and 27.4±3.5 ms in CS and control group (P=0.02), whereas LA maximum volume index [LAVImax] was 20.4±4.5 mL/m2 and 19.9±2.4 mL/m2 in CS and control group, respectively (P = 0.04). While global peak LA strain was [pLA-S] (LA reservoir function) 41.4 ± 6.3% and 44.5 ± 7.1% in CS and control group, (P = 0.04), global peak late diastolic strain rate values [pLA-SRa] (LA pump function) were 2.5 ± 0.4% and 2.9 ± 0.5% in CS and control group, respectively (P = 0.001). A mild and a strong negative correlation between global pLA-S and LAVImax (r=-0.49; P<0.01), and between PWD and global pLA-S (r = -0.52; P < 0.01), respectively, was observed in CS.ConclusionsIncreased PWD is associated with impaired LA mechanical functions and enlargement, and involved in the pathophysiology of AF or an AF-like physiology in CS.

Assessment of left atrial volume and function in patients with psoriasis by using real time three-dimensional echocardiography.

Left atrial (LA) volume has been identified as a predictor of adverse cardiovascular outcomes, both in the general population and in selected clinical conditions. The aim of this study was to evaluate the effect of psoriasis on LA volume and mechanical function. A total of 40 consecutive normotensive psoriasis patients free of any cardiovascular disease and 39 healthy volunteers were included. All participants underwent comprehensive transthoracic echocardiographic examination. LA volume and mechanical function were evaluated using real-time three-dimensional echocardiography (RT3DE). There were no significant differences between psoriasis and control groups with regard to conventional echocardiographic parameters. Individuals with psoriasis had a higher incidence of left ventricular diastolic dysfunction (LVDD) than the controls; nine people with psoriasis (23%) and three control individuals (8%) had LVDD (p = 0.06). With regard to the parameters obtained from RT3DE, LA maximum, LA minimum, passive stroke volume, and passive emptying fraction were significantly higher; whereas LA active emptying fraction, LA total emptying fraction, LA expansion index, and active stroke volume values were significantly lower in individuals with psoriasis compared with controls. Disease duration and Psoriasis Area of Severity Index (PASI) score correlated with the majority of volume parameters. Individuals with psoriasis had higher LA phasic volumes and impaired LA mechanical function compared with healthy controls. LA volume and functional analysis with RT3DE may facilitate recognition of subtle LA dysfunction in patients with psoriasis.

Ambulatory arterial stiffness index is associated with impaired left atrial mechanical functions in hypertensive diabetic patients: A speckle tracking study.

Objective:The ambulatory arterial stiffness index has been proposed as an indicator of arterial stiffness. The aim of this study was to test the hypothesis that increased ambulatory arterial stiffness index might be related with impaired left atrial function in hypertensive diabetic patients with no previous history of cardiovascular disease.Methods:Inclusion criteria included office systolic BP> 130 mm Hg or diastolic BP> 80 mm Hg and absence of secondary causes of HT, whereas exclusion criteria LV ejection fraction <50%, history of significant coronary artery disease, chronic renal failure, atrial fibrillation/flutter, second or third-degree atrioventricular block, moderate to severe valvular heart disease, history of cerebrovascular disease, non-dipper hypertensive pattern and sleep apnea. The study was composed of 121 hypertensive diabetic patients. Twenty-four-hour ambulatory blood pressure monitoring and echocardiography were performed in each patient. The relationship between ambulatory arterial stiffness index and left atrial functions was analyzed. AASI was calculated as 1 minus the regression slope of diastolic BP plotted against systolic BP obtained through individual 24-h ABPM.Results:The univariate analysis showed that ambulatory arterial stiffness index was positively correlated with age (r=:0.287, p=:0.001), hypertension duration (r=:0.388, p<0.001), fasting plasma glucose (r=:0.224, p=:0.014), HbA1c (r=:0.206, p=:0.023), LDL cholesterol (r=:0.254, p=:0.005), and also overall pulse pressure (r=:0.195, p=:0.002), office-pulse pressure (r=:0.188, p=:0.039), carotid intima-media thickness (r=:0.198, p=:0.029), E/E’ (r=:0.248, p=:0.006), and left atrial volume index (r=:0.237, p=:0.009). Moreover, ambulatory arterial stiffness index was negatively correlated with eGFR (r=:(-) 0.242, p=:0.008), peak left atrial strain during ventricular systole [S-LAs (r=:(-) 0.654, p<0.001)], peak left atrial strain at early diastole [S-LAe (r=:(-)0.215, p=:0.018)], and peak left atrial strain rate during ventricular systole [SR-LAs (r=:(-) 0.607, p<0.001)]. The multiple linear regression analysis showed that ambulatory arterial stiffness index was independently associated with peak left atrial strain rate during ventricular systole (SR-LAs) (p<0.001).Conclusion:In hypertensive diabetic patients, increased ambulatory arterial stiffness index is associated with impaired left atrial functions, independent of left ventricular diastolic dysfunction.

Left Ventricular Diastolic Function Is Closely Associated With Mechanical Function of the Left Atrium in Patients With Paroxysmal Atrial Fibrillation

Left ventricular (LV) diastolic dysfunction may be a mechanism of left atrial (LA) electroanatomical remodeling in atrial fibrillation (AF). We evaluated the association between LV diastolic function and LA mechanical function in non-valvular paroxysmal AF (PAF). In 286 patients with PAF (males 73%, 57 ± 11 years), LA size, indexed LA volume, LV diastolic function, and LA appendage flow velocity (LAA-FV) in sinus rhythm were measured using transthoracic echocardiography, transesophageal echocardiography and cardiac computed tomography. The LA voltage map was obtained using NavX contact mapping. Patients with impaired LA mechanical function (LAA-FV <58 cm/s, n=142) showed a higher E/Em ratio (10.3 vs. 9.2, P=0.034) and lower Em velocity (6.8 vs. 7.7 cm/s, P=0.004) than those with preserved function (LAA-FV ≥ 58 cm/s, n=144). The patient population displayed weak correlations of E/Em with LAA-FV (r=-0.19, P=0.003) and LA voltage (r=-0.23, P=0.004), but more significant association of E/Em and LAA-FV (r=-0.39, P<0.001) for age ≥ 55 years and LA diameter ≥ 40 mm. E/Em was an independent predictor of LAA mechanical function (β=-0.20, P=0.013) even after age, sex, LA size and comorbidities were controlled for. In patients with non-valvular PAF, LA mechanical function is closely related to the degree of LA remodeling and LV diastolic function. Impaired LV diastolic function significantly contributes to LA electoanatomical remodeling in older patients with a larger LA.

Comparison of Left Atrial Mechanical Function in Nondipper versus Dipper Hypertensive Patients: A Speckle Tracking Study

Nondippers are known to carry a high risk of cardiovascular morbidity and mortality. The aim of this study was to investigate the effects of dipper and nondipper status of hypertension on longitudinal systolic and diastolic functions of left atrial (LA) myocardial tissue by means of two-dimensional speckle-tracking echocardiography in treated hypertensive patients. A total of 78 outpatients treated with antihypertensive drugs for at least 1 year were included in the study. The patients were classified as nondippers if their daytime ambulatory systolic and diastolic blood pressure did not decrease by at least 10% during the night. Global longitudinal LA strain/strain rate data were obtained by two-dimensional speckle imaging with automated software and compared between the groups. LA volume index, left ventricular (LV) wall thickness and mass index as well as filling pressure (E/E') were significantly higher in nondippers (all P < 0.001), whereas systolic tissue velocity (S') was significantly lower in nondippers. They also had decreased values of mean peak LA strain (dippers = 27.6 ± 5.5% vs. nondippers = 21.5 ± 4.5%, P < 0.001), strain rate during reservoir (dippers = 1.27 ± 0.4/sec vs. nondippers = 0.98 ± 0.3/sec, P = 0.001), and conduit period (dippers = 1.41 ± 0.4/sec vs. nondippers = 1.06 ± 0.3/sec, P < 0.001). Moreover, we found that LA mechanical dysfunction was closely associated with LV mass, filling pressure, and regional LV contractility. Nondipping in treated hypertensive patients was associated with an adverse cardiac remodeling and impaired LA mechanical function. Further studies are warranted to demonstrate the long-term prognostic significance of these findings.

Detection of subclinical atrial dysfunction by two-dimensional echocardiography in patients with overt hyperthyroidism

Hyperthyroidism is an important cardiovascular risk factor in the development of atrial fibrillation and heart failure. Increased atrial electromechanical intervals are used to predict atrial fibrillation, measured by tissue Doppler imaging (TDI). To evaluate atrial electromechanical delay (EMD) and left atrial (LA) mechanical function in patients with overt hyperthyroidism. Thirty-four patients with overt hyperthyroidism and 34 controls were included. A diagnosis of overt hyperthyroidism was reached with decreased serum thyroid-stimulating hormone (TSH) and increased free T4 (fT4) concentrations. Using TDI, atrial electromechanical coupling (PA) was obtained from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septum) and right ventricular tricuspid annulus (PA tricuspid). LA volumes (maximum, minimum and presystolic) were measured by the disks method in apical four-chamber view and indexed to body surface area. LA active and passive emptying volumes and fractions were calculated. LA diameter was significantly higher in hyperthyroid patients (P=0.001). LA passive emptying volume and fraction were significantly decreased in hyperthyroid patients (P=0.038 and P<0.001). LA active emptying volume and fraction were significantly increased in hyperthyroid patients (P<0.001 and P<0.001). Left and right intra-atrial (PA lateral-PA septum and PA septum-PA tricuspid) and interatrial (PA lateral-PA tricuspid) EMDs were significantly higher in hyperthyroid patients (29.2 ± 4.4 vs 18.1 ± 2.6, P<0.001; 18.7 ± 4.3 vs 10.6 ± 2.0, P<0.001; and 10.5 ± 2.9 vs 7.1 ± 1.2, P<0.001, respectively). Stepwise linear regression analysis demonstrated that fT4 and TSH concentrations were independent predictors of interatrial EMD (β=0.436, P<0.001 and β=-0.310, P=0.005, respectively). This study showed prolonged atrial electromechanical intervals and impaired LA mechanical function in patients with overt hyperthyroidism, which may be an early sign of subclinical cardiac involvement and dysrhythmias in overt hyperthyroidism.

Pre-Operative Left Atrial Mechanical Function Predicts Risk of Atrial Fibrillation Following Cardiac Surgery

The purpose of this study was to examine whether left atrial (LA) mechanical function, as measured by LA total emptying fraction (TEF), is a predictor for the development of post-operative atrial fibrillation (POAF) following cardiac surgery. POAF is an important and frequent complication of cardiac surgery. LA enlargement has been reported to be a risk factor for POAF, but the relationship between LA mechanical function and POAF is not well understood. We examined the relationship between pre-operative LA function and POAF in patients without a history of atrial fibrillation. A total of 101 subjects (mean age 64 ± 13 years) underwent pre-operative transthoracic echocardiograms and were followed for occurrence of POAF during the hospitalization for cardiac surgery. The left atrial maximum volume (LAVmax) and left atrial minimum volume (LAVmin) were measured and indexed to body surface area (LAVmaxI and LAVminI, respectively). LA TEF was calculated as: {[(LAVmax - LAVmin)/LAVmax] × 100%}. Univariate and multivariate analyses examined clinical and echocardiographic predictors of POAF. POAF occurred in 41% of subjects. Mean LA TEF was 49 ± 15%, mean LAVmaxI was 38 ± 15 ml/m(2), and mean LAVminI was 20 ± 13 ml/m(2). Age, LA TEF, and LAVminI were independent predictors of POAF. LA TEF was lower in patients with POAF compared with those without POAF (43 ± 15% vs. 55 ± 13%, p < 0.001), and patients with a LA TEF <50% had a high risk of POAF (odds ratio: 7.94, 95% confidence interval: 3.23 to 19.54, p < 0.001). Compared with LAVmaxI >32 ml/m(2), LA TEF <50% had higher discriminatory power for POAF, which remained significantly higher when adjusted for age (p = 0.04). LA TEF is an independent predictor of POAF and is a stronger predictor of POAF than LAVmaxI is. Impaired LA mechanical function may help to identify patients who are most likely to benefit from prophylaxis for POAF.

Impaired left atrial mechanical function after cardioversion: Relation to the duration of atrial fibrillation

Objectives. We hypothesized that the time course of the recovery of atrial systolic function may be related to the duration of atrial fibrillation before cardioversion and sought to study noninvesively the recovery of left atrial mechanical function utilizing serial transthoracic Doppler studies.Background. Recovery of atrial mechanical function may be delayed for several weeks after successful cardioversion of atrial fibrillation to sinus rhythm.Methods. After successful cardioversion, 60 patients with atrial fibrillation of brief (≤2 week, 17 patients), moderate (>2 to 6 weeks, 22 patients) or prolonged (>6 weeks, 21 patients) duration were followed up with serial transmitral pulsed Doppler echocardiography immediately (60 patients) and at 24 h (45 patients), 1 week (41 patients), 1 month (31 patients) and >3 months (30 patients) after cardioversion.Results. Atrial mechanical function is greater immediately and at 24 h and 1 week after cardioversion in patients with “brief” compared with “prolonged” atrial fibrillation. In all groups, atrial mechanical function increases over time, ultimately achieving similar levels. Full recovery of atrial mechanical function, however, is achieved within 24 h in patients with brief atrial fibrillation, within 1 week in patients with moderate-duration atrial fibrillation and within 1 month in patients with prolonged atrial fibrillation.Conclusions. Recovery of left atrial mechanical function is related to the duration of atrial fibrillation before cardioversion. These findings have important implications for assessing the early hemodynamic benefit of successful cardioversion.