Left atrial systolic reserve in idiopathic vs. ischaemic-dilated cardiomyopathy

Feasibility and functional correlates of left atrial volume changes during stress echocardiography in chronic coronary syndromes

An enlarged left atrial volume index (LAVI) at rest mirrors increased LA pressure and/or impairment of LA function. A cardiovascular stress may acutely modify left atrial volume (LAV) within minutes. Aim of this study was to assess the feasibility and functional correlates of LAV-stress echocardiography (SE) Out of 514 subjects referred to 10 quality-controlled labs, LAV-SE was completed in 490 (359 male, age 67 ± 12 years) with suspected or known chronic coronary syndromes (n = 462) or asymptomatic controls (n = 28). The utilized stress was exercise in 177, vasodilator in 167, dobutamine in 146. LAV was measured with the biplane disk summation method. SE was performed with the ABCDE protocol. The intra-observer and inter-observer LAV variability were 5% and 8%, respectively. ∆-LAVI changes (stress-rest) were negatively correlated with resting LAVI (r = - 0.271, p < 0.001) and heart rate reserve (r = -.239, p < 0.001). LAV-dilators were defined as those with stress-rest increase ≥ 6.8 ml/m², a cutoff derived from a calculated reference change value above the biological, analytical and observer variability of LAVI. LAV dilation occurred in 56 patients (11%), more frequently with exercise (16%) and dipyridamole (13%) compared to dobutamine (4%, p < 0.01). At multivariable logistic regression analysis, B-lines ≥ 2 (OR: 2.586, 95% CI = 1.1293-5.169, p = 0.007) and abnormal contractile reserve (OR: 2.207, 95% CI = 1.111-4.386, p = 0.024) were associated with LAV dilation. In conclusion, LAV-SE is feasible with high success rate and low variability in patients with chronic coronary syndromes. LAV dilation is more likely with reduced left ventricular contractile reserve and pulmonary congestion.

The differences in left atrial function between ischemic and idiopathic dilated cardiomyopathy patients: A two-dimensional speckle tracking imaging study

PURPOSE

To evaluate left atrial (LA) function in patients with ischemic (ICM) or idiopathic dilated (DCM) cardiomyopathy via two-dimensional speckle-tracking imaging.

METHODS

We measured the LA maximum volume, minimum volume, and volume before the atrial systole, and calculated total emptying volume, expansion index, active emptying volume, and fraction. We measured strain and strain rate during systole and late diastole using two-dimensional speckle-tracking imaging, and analyzed correlations between variables.

RESULTS

We found no significant differences in LA size, left ventricle (LV) end-diastole diameter, LV ejection fraction (EF), E/A, E/e', deceleration time of the E wave, and effective mitral regurgitant orifice area between the DCM and the ICM group. However, the LA expansion index, active EF, systolic and late diastolic strain, and strain rate were lower in the ICM group (p < 0.05). The expansion index and active EF were positively correlated with the systolic strain rate and the absolute value of the late diastolic strain rate, respectively.

CONCLUSIONS

LA basic echocardiographic variables did not reflect the differences between ICM and DCM patients, but the systolic and late diastolic strain, as well as the strain rate, were lower in DCM patients. Two-dimensional speckle-tracking imaging is a promising method to differentiate these patients. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:437-445, 2016.

Evaluation of left atrial function in patients with iron-deficiency anemia by two-dimensional speckle tracking echocardiography

Background

Iron-deficiency anemia (IDA) is a global health problem and a common medical condition that can be seen in everyday clinical practice. And two-dimensional speckle tracking echocardiography (2D-STE) has been reported very useful in evaluating left atrial (LA) function, as well as left ventricular (LV) function. The aim of our study is to evaluate the LA function in patients with IDA by 2D-STE.

Methods

65 patients with IDA were selected. This group of patients was then divided into two groups according to the degree of hemoglobin: group B (Hb > 90 g/L) and group C (Hb60 ~ 90 g/L). Another 30 healthy people were also selected as control group A. Conventional echocardiography parameters, such as left atrial diameter (LAD), peak E and A of mitralis (E, A), E/A, end-diastolic thickness of ventricular septum (IVST d), end-diastolic thickness of LV posterior wall (PWTd) and left ventricular end-diastolic dimension (LVDd) were obtained from these three groups. Left atrial minimum volume (LAVmin), left atrial pre-atrial contraction volume (LAVp) and left atrial maximum volume (LAVmax) were measured by Simpson’s rule, whereas left atrial active ejection fraction (LAAEF) and left atrial passive ejection fraction (LAPEF) were obtained from calculation. Two-dimensional images were acquired from apical four-chamber view and two-chamber view to store images for offline analysis. The global peak atrial longitudinal strain and strain rate of systolic LV (GLSs, GLSRs) as well as early and late diastolic LV strain rate (GLSRe, GLSRa) curves of LA were acquired in each LA segment from basal segment to top segment of LA by 2D-STE.

Results

Compared with group A, there were no differences between group B and group A (all P > 0.05). The LAAEF and GLSRa were significantly higher in group C compared with those of group A and group B (all P < 0.01). The LAPEF, GLSs, GLSRs and GLSRe were significantly lower in group C compared with those of group A and group B (all P < 0.01).

Conclusions

2D-STE could evaluate the LA function in patients with IDA.

Effects of various cardiovascular drugs on indices obtained with two-dimensional speckle tracking echocardiography of the left atrium and time-left atrial area curve analysis in healthy dogs

OBJECTIVE

To evaluate the effects of dobutamine, esmolol, milrinone, and phenylephrine on left atrial phasic function of healthy dogs.

ANIMALS

9 healthy Beagles.

PROCEDURES

Following sedation with propofol on each of 4 experimental days, dogs were administered a constant rate infusion of dobutamine (5 μg/kg/min), esmolol (500 μg/kg/min), milrinone (25 μg/kg, IV bolus, followed by 0.5 μg/kg/min), or phenylephrine (2 μg/kg/min). There was at least a 14-day interval between experimental days. Each drug was administered to 6 dogs. Conventional and 2-D speckle tracking echocardiography were performed before (baseline) and after administration of the cardiovascular drug, and time-left atrial area curves were derived to calculate indices for left atrial reservoir, conduit, and booster pump functions (left atrial phasic function) and left ventricular contractility and lusitropy.

RESULTS

Compared with baseline values, indices for left atrial reservoir and booster pump functions and left ventricular contractility and lusitropy were significantly increased following dobutamine administration; indices for left atrial phasic function and left ventricular lusitropy were changed insignificantly, and indices for left ventricular contractility were significantly impaired following esmolol administration; indices for left atrial phasic function and left ventricular relaxation were changed insignificantly, and indices for left ventricular systolic function were significantly augmented following milrinone administration; and indices for left atrial phasic function and left ventricular lusitropy were changed insignificantly, and indices of ventricular contractility were significantly impaired following phenylephrine administration.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that, following administration of dobutamine, esmolol, milrinone, or phenylephrine to healthy dogs, left atrial phasic function indices were fairly stable and did not parallel changes in left ventricular function indices.

Left Atrial Contractility in Ischemic Heart Disease Patients with Left Ventricular Systolic Dysfunction

Background:

Left atrial (LA) active emptying plays an important role in left ventricular (LV) filling. It not only depends on LA preload but also on LA contractility. Our aim was to assess LA wall contraction velocity (LAWV) and its relation to each of LA active stroke volume index (LAASVI) and LA active emptying fraction (LAAEF) as markers of LA active emptying in patients with ischemic heart disease (IHD) and impaired LV systolic function.

Methods:

We studied 50 consecutive patients with stable IHD and LV ejection fraction <45% and 50 healthy controls. Standard echocardiography assessed: Biplane LV volumes and ejection fraction, trans-mitral Doppler E and A wave velocities and E/A ratio, indexed biplane LA volumes pre- and post-atrial contraction, LAASVI and LAAEF. LAWV was measured by tissue Doppler imaging.

Results:

Trans-mitral Doppler A velocity was lower in the study group 60.64 ± 20.6 vs 72.46 ± 17.13 cm/s (P = 0.002). Accordingly, E/A ratio was higher in the study group 1.32 ± 0.78 vs 0.92 ± 0.3 (P < 0.0001). Indexed biplane LAV-pre atrial contraction was larger in the study group 23.61 ± 3.8 vs 17.16 ± 3.57mL/m² (P < 0.0001). Indexed biplane LAV-post atrial contraction was larger in the study group 16.22 ± 4.14 vs 13.19 ± 3.56mL/m² (P=0.0002). Accordingly, biplane LAASVI was higher in the study 53 group 7.9 ± 1.26 vs 3.96 ± 0.63 mL/m² (P < 0.0001). LAAEF was larger in the study group 32.37 ± 8.89 vs 24.31 ± 7.12% (P < 0.0001). LAWV was lower in the study group 6.78 ± 0.51 vs 10.58 ± 0.67 cm/sec (P < 0.0001).

Conclusion:

In patients with IHD and impaired LV systolic function, LA wall contractility is reduced. However, LAASVI and LAAEF are enhanced.

Left atrium reverse remodeling in patients with mitral valve stenosis after percutaneous valvuloplasty: a 2- and 3-dimensional echocardiographic study

INTRODUCTION AND OBJECTIVES

The left atrium is clinically relevant in patients with mitral valve stenosis. The objective of this study was to analyze the effects of percutaneous balloon valvuloplasty on left atrium volumes and the left atrium emptying fraction in symptomatic mitral valve stenosis patients using 2-dimensional and real-time 3 -dimensional transthoracic echocardiography.

METHODS

We carried out a prospective study of 28 consecutive symptomatic mitral valve stenosis patients, aged 22-72 (39 [11.5]) years, 24/28 (85.6%) women, who underwent to percutaneous balloon valvuloplasty between March 2009 and May 2011. Patients underwent 2- and 3-dimensional transthoracic and transesophageal echocardiography (atrial fibrillation) and invasive mitral valve area measurement. Echocardiographic analysis was performed before, 72 h after and 12 months after percutaneous balloon valvuloplasty. The following parameters were analyzed: a) mitral valve area (2-dimensional planimetry, pressure half-time, 3-dimensional echocardiography, invasive hemodynamic measurement); b) indexed left atrium maximum and indexed minimum volumes, and c) left atrium emptying fraction.

RESULTS

The 3-dimensional parameters of the mitral valve stenosis patients before and 72 h and 12 months after percutaneous balloon valvuloplasty were as follows: a) mitral valve area: 0.9 (0.1) cm(2); 1.8 (0.2) cm(2) (P<.001); 1.7 (0.2) cm(2) (P<.001); b) left atrium maximum volumes: 49.9 (12) mL/m(2); 42 (11.4) mL/m(2) (P<.001); 40.3 (10.2) mL/m(2) (P<.001), and c) left atrium emptying fraction: 30.1 (9.4%); 40.6 (7.4%) (P<.001); 44.1 (8%) (P<.001), respectively.

CONCLUSIONS

In symptomatic mitral valve stenosis patients who underwent percutaneous balloon valvuloplasty analysis by 2- and 3-dimensional echocardiography, improvements in left atrium reverse remodeling and left atrium emptying fraction were observed 72 h and 12 months after the procedure.

Meta-analysis of the effect of radiofrequency catheter ablation on left atrial size, volumes and function in patients with atrial fibrillation

The effects of radiofrequency catheter ablation (RFCA) on left atrial (LA) size, volumes, and function in patients with atrial fibrillation (AF) are not well understood. The aim of this study was to systematically review the effects of RFCA on LA size, volumes, and function in patients with AF. Medline, the Web of Science, the Cochrane Central Register of Controlled Trials, and the reference lists of retrieved reports were searched for relevant studies through April 2009. Studies conducted in patients with AF were included if their primary outcomes were changes in LA size or volumes and/or function before and after RFCA. Weighted mean differences for changes in LA diameter, LA maximum volume, LA minimum volume, LA ejection fraction, and LA active emptying fraction were estimated using fixed- and random-effects meta-analyses. Seventeen relevant studies (enrolling 869 patients) among 192 identified studies were included in the final analysis. Compared to preablation values, there were significant decreases in LA diameter and LA volumes at postablation follow-up. However, compared to preablation values, there were no significant differences in LA ejection fraction and LA active emptying fraction at postablation follow-up. Decreases in LA diameter and LA volumes remained significant in those without AF recurrence but not in those with AF recurrence. LA ejection fraction and LA active emptying fraction did not decrease in patients without AF recurrence, whereas they decreased in patients with AF recurrence. In conclusion, successful RFCA in patients with AF significantly decreases LA size and volumes and does not seem to adversely affect LA function.

Left atrial stiffness and its implications for cardiac function

Proper atrial function is essential for overall cardiovascular performance, mainly by its four major functions, namely, bioelectrical, hormonal, metabolic and hemodynamic. With regard to the latter, atria modulate ventricular filling by smoothing the transformation of the continuous venous return to the intermittent filling pattern of the ventricles during diastole through three main components: a phase of reservoir mainly during ventricular systole, a conduit phase during ventricular diastole and an active phase in late ventricular diastole. Although the atria assume a dynamic role in ventricular filling progression, atrial function and emptying pattern is, conversely, highly influenced by the ventricular diastolic wall stress, underlying the close connection observed between these chambers. This review focuses essentially on left atrial mechanical role, particularly on the physiological and clinical consequences of disturbed atrial compliance.