Left Atrial Active Emptying Research Articles

Evaluation of left ventricular function with left atrio-ventricular longitudinal strain in patients with lymphoma underwent anthracycline therapy

Objective: To analyze the value of 3-dimensional speckle tracking echocardiograghy (3D-STE) derived strain parameters on the detection of subclinical myocardial deformation alterations in patients with lymphoma treated with anthracycline agents. Methods: This study was a retrospective study. A total of 37 patients with newly diagnosed diffuse large B cell non-Hodgkin lymphoma between December 2012 and December 2014 in Cancer Center, Fudan university were included. 3D-STE strain measurements were performed at baseline (T0),after the completion of two therapy circles (T1) and at the end of anthracycline regimen chemotherapy (Te). Echocardiography images were analyzed on the TTA workstation, and the indexes included left atrial minimum volume (LAVmin), left atrial emptying index (LAEF), left atrial active emptying index (LAAEF), as well as the left ventricular global longitudinal strain (LVGLS), left ventricular global circumferential strain (LVGCS), left atrial global longitudinal strain (LAGLS). The overall left atrioventricular longitudinal strain (LAVGLS) was calculated, which was the sum of the absolute values of LVGLS and LAGLS. The changes of left ventricular strain indexes measured by 3D-STE at different time points of patients were evaluated. Results: Thirty-seven patients with DLBCL, aged (48.3±12.1)years, including 23 males (63.9%), were enrolled. Compared with baseline, LVGLS (T1: (-18.63±4.73)% vs. (-22.13±4.40)%, P=0.001; Te:(-18.26±4.64)% vs. (-22.13±4.40)%, P<0.001), LAGLS (T1: (20.41±5.56)% vs. (23.98±5.59)%, P=0.003; Te: (17.60±3.96)% vs. (23.98±5.59)%, P<0.001) and LAVGLS (T1: (39.05±7.60)% vs. (46.11±7.77)%, P<0.001; Te: (40.34±8.55)% vs. (46.11±7.77)%, P<0.001) were all deteriorated at the T1 and Te. While LVGCS ((-21.98±5.82)% vs. (-26.15±7.51)%, P=0.010), LAVmin ((23.93±7.29)ml vs. (20.33±7.03)ml, P=0.029), LAEF ((28.94±11.16)% vs. (35.79±11.12)%, P=0.002) and LAAEF ((11.93±10.00)% vs. (18.10±9.96)%, P=0.013) were decreased only until Te. Conclusions: 3D-STE strain measurements could detect early myocaridial function alteration in patients receiving anthracycline regimen chemotherapy, thus may provide a novel approach to monitor anthracycline caused myocardial toxicity.

Interatrial Electromechanical Conduction Delay by ECG P-Wave and Echocardiographic Tissue Doppler Imaging for Diabetics Attending Merjan Teaching Hospital, A Comparison Study

Objectives: The objective was to study the atrial electromechanical P-wave electrocardiography (ECG)gated measurement of conduction times by tissue Doppler echocardiography (TDI) and left atrialmechanical function and volumes, the non-invasive predictors of atrial fibrillation, in diabetics. Methods:The study conducted by analytic case-control study and included 100 adult patients (63 men, 37 women;mean age 50.49 ±8.1 years), diagnosed with diabetes mellitus according to the criteria of the DiabetesAssociation of America, and 100 adults healthy (50 men; 50 women; average age 49.25 ±9.8 years) ascontrol. Tissue Doppler imaging (TDI) and conventional echocardiography study was done. Assessment ofelectromechanical delay was done with the onset of the surface ECG P-wave to the systolic a?-wave onset onTDI of the AV valve annulus of the septum, left and right ones. Using the disk method, the left atrial volumeswere assessed. The mechanical function and volumes of the left atrium were computed. Results: The E/Aand e?/a? mitral ratio was assessed by the left and septal annuli were the mean difference significantly lessin diabetics than in controls (P=0.031) and (P=0.034 correspondingly. The electromechanical inter-atrialand intra-atrial delay were significantly greater within the diabetics, contrasted to controls (P&lt;0.001) and(P=0.003) correspondingly. Volumes of active left atrial emptying (LAAEV) and the ratio of active leftatrial ejection (LAAEF) were significantly higher in diabetics in comparison with controls (P =0.002) and(P&lt;0.001) correspondingly. Both were significantly correlated to E/A and e?/a?. Conclusions: In diabetics,conduction times of the atrium by TDI and the dispersion of the P-wave by surface ECG were longer.Furthermore, the mechanical functions and volumes of the left atrium were affected by altering diastolicfunction in diabetics.

Impact of different dipping patterns on left atrial function in hypertension.

We aimed to investigate left atrial phasic function in the recently diagnosed hypertensive patients and determine association between circadian blood pressure (BP) patterns and left atrial function. The present study involved 256 untreated hypertensive patients who underwent 24-h ambulatory BP monitoring and comprehensive echocardiographic examination. All patients were divided into four groups according to the percentage of nocturnal BP drop (dippers, extreme dippers, nondippers and reverse dippers). There was no significant difference in daytime BPs between the observed groups, whereas night-time BPs significantly and gradually increased from extreme dippers and dippers, across nondippers, to reverse dippers. Total, passive and active left atrial emptying fractions that correspond with left atrial reservoir, conduit and contractile function were lower in nondippers and reverse dippers than in dippers and extreme dippers. Reservoir and contractile left atrial strains were lower in reverse dippers than in dippers and extreme dippers, whereas conduit left atrial strain was lower in reverse dippers in comparison with extreme dippers. Nondipping and reverse dipping BP patterns were, independently of age, sex, nocturnal BPs, left ventricular mass index, E/e', associated with reduced reservoir function. Nevertheless, only reverse dipping profile was independently of other circadian BP profiles, nocturnal BP, demographic and echocardiographic parameters related with reduced conduit and contractile functions. Nondipping and reverse dipping BP patterns were related with impaired left atrial phasic function. However, reverse pattern was the only circadian profile that was independently of other clinical parameters, including night-time BP, associated with decreased reservoir, conduit and contractile function.

P4351Validation by cardiac catheterization of noninvasive evaluation of left ventricular chamber and myocardial stiffness as a diastolic function using speckle tracking echocardiography

Abstract Background Left ventricular (LV) diastolic function is mainly composed of LV relaxation and LV stiffness. We reported that pulmonary capillary wedge pressure (ePCWP) and LV relaxation assessed by Tau (eTau) are noninvasively evaluated by speckle tracking echocardiography (STE). The minimum LV diastolic pressure (mLVP) was reported to have a strong correlation with Tau. Therefore, LV chamber stiffness (c-stiffness) may be assessed with the use of two LV diastolic pressure-volume coordinates: the mLVP and volume and the end-diastolic pressure (EDP) and volume. Purpose We sought to noninvasively assess LV stiffness using STE and validate the value by cardiac catheterization. Methods Echocardiography and catheterization were performed in 124 patients (age 72±8) (70 angina pectoris, 20 prior myocardial infarction, 19 hypertensive heart disease, 11 congestive heart failure and 4 paroxysmal atrial fibrillation). The ePCWP (mmHg) is noninvasively obtained as 10.8 − 12.4 × Log (left atrial active emptying function/minimum volume) and the eTau (ms) is obtained as isovolumic relaxation time/(ln 0.9 × systolic blood pressure − ln ePCWP) as previously reported. The mLVP (e-mLVP) was estimate using Tau. The estimated EDP (e-EDP) was calculated as 12.3 − 10.1 × Log (left atrial active emptying function / minimum volume). LV c-stiffness (mmHg/ml) was calculated as LV pressure change (from mLVP to EDP) obtained by catheterization divided by LV volume change during diastole which equals to stroke volume by echocardiography. Estimated c-stiffness (e-c-stiffness) was noninvasively obtained using e-mLVP and e-EDP. Furthermore, LV myocardial stiffness (m-stiffness) was calculated by LVED stress / LV longitudinal strain by STE, where LV stress (kdynes/cm2) was calculated as 0.334 × pressure × dimension / [thickness (1 + thickness/dimension)]. The estimated m-stiffness (e-m-stiffness) was calculated using e-EDP. Results The eTau and e-EDP estimated by STE had a good correlation with Tau and EDP invasively obtained by catheterization (r=0.75 and 0.63, respectively, both p&lt;0.001). There was a good correlation between Tau and mLVP (Tau = 2.06 mLVP + 33.7, r=0.70). The estimated LVED stress had good correlation with ED stress obtained by catheterization (r=0.77, p&lt;0.001). The e-c-stiffness and e-m-stiffness had a good correlation with those obtained by catheterization (e-c-stiffness; 0.116±0.07 and c-stiffness; 0.115±0.06, r=0.603, e-m-stiffness; 0.81±0.41 and m-stiffness; 0.85±0.45, r=0.89, respectively). Bland-Altman analysis revealed a good agreement between e-c-stiffness and c-stiffness, and between e-m-stiffness and m-stiffness without fixed and proportional bias. Conclusion This study demonstrated that LV stiffness may be noninvasively assessed by STE with reasonable accuracy and may have utility and value in the routine clinical practice for the diagnosis and treatment in patients with diastolic dysfunction.

Does High-Intensity Endurance Training Increase the Risk of Atrial Fibrillation? A Longitudinal Study of Left Atrial Structure and Function.

Exercise mitigates many cardiovascular risk factors associated with atrial fibrillation. Endurance training has been associated with atrial structural changes which can increase the risk for atrial fibrillation. The dose of exercise training required for these changes is uncertain. We sought to evaluate the impact of exercise on left atrial (LA) mechanical and electrical function in healthy, sedentary, middle-aged adults. Sixty-one adults (52±5 years) were randomized to either 10 months of high-intensity exercise training or yoga. At baseline and post-training, all participants underwent maximal exercise stress testing to assess cardiorespiratory fitness, P-wave signal-averaged electrocardiography for filtered P-wave duration and atrial late potentials (root mean square voltage of the last 20 ms), and echocardiography for LA volume, left ventricular end-diastolic volume, and mitral inflow for assessment of LA active emptying. Post-training data were compared with 14 healthy age-matched Masters athletes. LA volume, Vo2 max, and left ventricular end-diastolic volume increased in the exercise group (15%, 17%, and 16%, respectively) with no change in control (P<0.0001). LA active emptying decreased post-exercise versus controls (5%; P=0.03). No significant changes in filtered P-wave duration or root mean square voltage of the last 20 ms occurred after exercise training. LA and left ventricular volumes remained below Masters athletes. The athletes had longer filtered P-wave duration but no difference in the frequency of atrial arrhythmia. Changes in LA structure, LA mechanical function, and left ventricular remodeling occurred after 10 months of exercise but without significant change in atrial electrical activity. A longer duration of training may be required to induce electrical changes thought to cause atrial fibrillation in middle-aged endurance athletes. URL: https://www.clinicaltrials.gov. Unique Identifier: NCT02039154.

Left ventricular diastolic function is strongly correlated with active emptying of the left atrium: a novel analysis using three-dimensional echocardiography.

BackgroundIncreased left atrial (LA) dimensions are known to be a risk factor in predicting cardiovascular events and mortality and to be one key diagnostic tool to assess diastolic dysfunction. Currently, LA measurements are usually conducted using 2D-echocardiography, although there are well-known limitations. Real-time 3D-echocardiography is able to overcome these limitations, furthermore being a valid measurement tool compared to reference standards (e.g. cardiac magnetic resonance imaging).We investigated LA function and volume and their association to left ventricular (LV) diastolic function, using newly designed and validated software for 3D-echocardiographic analysis. This software is the first to allow for a sophisticated analysis of both passive and active LA emptying.MethodsWe analyzed 2D- and 3D-echocardiographic measurements of LA volume and function in 56 subjects and compared the results between patients with normal LV diastolic function (NDF) (n = 30, 52 ± 15 years, BMI 24.7 ± 2.6 kg/m2) and patients in which diastolic dysfunction (DDF) was suspected (n = 26, 65 ± 9 years, BMI 26.7 ± 3.7 kg/m2).ResultsVolumes during LA active emptying were significantly smaller in DDF compared to NDF (active atrial stroke volume (ASV): 3.0 (0.1–4.5) vs. 5.5 (2.7–7.8) ml, p = 0.005; True-EF: 7.3(0.1–11.5) vs. 16.2 (8.1–25.4) %, p = 0.002). Furthermore, ASV showed a stronger association to E/e’mean than all other measured LA volumes (β = − 0.35, p = 0.008). Neither total stroke LA volume, nor maximum or minimum LA volume differed significantly between the groups.ConclusionsDiastolic LV dysfunction results in a reduction in active LA emptying, which is more strongly associated with LV filling pressure than other previously investigated LA parameters.

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.

Abstract 11979: Noninvasive Evaluation of the Feature of Hypertensive Heart Failure using One-beat Real-time Three-dimensional Speckle Tracking Echocardiography With High Volume Rates

Background: Left ventricular (LV) properties in hypertension (HTN) could be deteriorated by pressure overload that causes LV hypertrophy (LVH) resulting in hypertensive heart failure (HHF). However, transition from HTN to HHF and the feature of HHF have not been noninvasively examined. Methods: We examined 31 controls (age 69±9), 47 HTN without LVH: LVH (-) (age 70±9), 47 HTN with LVH: LVH (+) (age 69±6) and 37 HHF patients (age 71±11) by 3-dimensional speckle tracking echocardiography with volume rate of 70-80vps (3D-STE). LV contractility and relaxation were assessed by radial strain rate (SR) at systole (SR-S) and isovolumic relaxation (SR-IVR). LV torsion was measured by 3D-STE. Pulmonary capillary wedge pressure (PCWP) was calculated as 10.8 - 12.4 x log (left atrial active emptying function / left atrial minimum volume index) as we reported. Tau was estimated as isovolumic relaxation time / (ln 0.9 x systolic blood pressure - ln PCWP). LV stress was calculated as LV radius x pressure / thickness. LV stiffness was estimated as diastolic stress / strain. Results: LV SR-S and SR-IVR in HHF decreased (SR-S; control: 2.5±0.8, LVH (-): 2.6±0.6, LVH (+): 2.5±0.7, HHF: 1.9±0.4* s-1. SR-IVR; -0.8±0.5, -0.7±0.4, -0.7±0.4*, -0.5±0.4* s-1, *p&lt;0.05 vs control). LV ejection fraction (EF) in HHF decreased (66±9, 69±6, 67±11, 51±14* %) associated with reduced torsion (1.4±0.2, 1.4±0.3, 1.5±0.3, 1.2±0.2* °/cm) and increased systolic stress. Tau was prolonged even in LVH (-) (29±12, 41±14*, 47±14*, 65±19*, msec). LV stiffness increased in LVH (+) and HHF (0.5±0.2, 0.6±0.4, 0.6±0.3*, 1.5±1.2*) associated with elevated PCWP (7±2, 8±4, 9±4*, 15±5* mmHg) and diastolic stress (16±5, 19±12, 21±12, 32±13* dynes/cm2). On multivariate logistic analysis, ePCWP was the parameter that showed the strongest independent factor associated with HHF. Using 11mmHg as a cutoff value, sensitivity and specificity to predict HHF in the HTN group was 83 and 81%. Conclusion: Noninvasive 3D-STE examination revealed that LV contractility and relaxation were decreased in HHF and that HHF had more reduced EF, prolonged Tau and increased stiffness associated with reduced torsion, increased systolic and diastolic stress and PCWP. PCWP was an independent determinant of HHF in echo parameters.

Left atrial phasic function interacts to support left ventricular filling during exercise in healthy athletes.

We studied the contribution of phasic left atrial (LA) function to left ventricular (LV) filling during exercise. We hypothesized that reduced LV filling time at moderate-intensity exercise limits LA passive emptying and increases LA active emptying. Twenty endurance-trained males (55 ± 6 yr) were studied at rest and during light- (∼100 beats/min) and moderate-intensity (∼130 beats/min) exercise. Two-dimensional and Doppler echocardiography were used to assess phasic volumes and diastolic function. LV end-diastolic volume increased from rest to light exercise (54 ± 6 to 58 ± 5 ml/m(2), P < 0.01) and from light to moderate exercise (58 ± 5 to 62 ± 6 ml/m(2), P < 0.01). LA maximal volume increased from rest to light exercise (26 ± 4 to 30 ± 5 ml/m(2), P < 0.01) related to atrioventricular plane displacement (r = 0.55, P < 0.005), without further change at moderate exercise. LA passive emptying increased at light exercise (9 ± 2 to 13 ± 3 ml/m(2), P < 0.01) and then returned to baseline at moderate exercise, whereas LA active emptying increased appreciably only at moderate exercise (6 ± 2 to 14 ± 3 ml/m(2), P < 0.01). Thus, the total atrial emptying volume did not increase beyond light exercise, and the increase in LV filling at moderate exercise could be attributed primarily to an increase in the conduit flow volume (19 ± 3 to 25 ± 5 ml/m(2), P < 0.01). LA filling increases during exercise in relation to augmented LV longitudinal contraction. Conduit flow increases progressively with exercise in athletes, although this is driven by LV properties rather than intrinsic LA function. The pump function of the LA augments only at moderate exercise due to a reduced diastolic filling time and the Frank-Starling mechanism.

Left Atrial Passive Emptying Function Is Preserved in Patients with Permanent Atrial Fibrillation - A 320-Slice Multidetector Computed Tomography Study

Objective: Left atrial (LA) mechanical function is thought to be virtually inexistent in patients with permanent atrial fibrillation (AF). Due to recent advances in multidetector computed tomography (MDCT) technology, it is now possible to acquire images of the entire heart in a single heartbeat. The objective of this study was to compare individual components of LA function assessed by MDCT in patients with permanent AF and patients in sinus rhythm (SR). Methods: 320-slice MDCT was performed in 30 patients with permanent AF. Measurements of LA volumes during the cardiac cycle were compared to 30 patients in SR, who were matched with respect to age, sex, left ventricular ejection fraction and body surface area. Results: LA volumes were significantly larger in patients with AF than SR patients at all times during the cardiac cycle (LA maximal volume; 82 vs. 55 ml/m², p < 0.0001, LA minimal volume; 71 vs. 30 ml/m², p < 0.0001). However, except for the absence of active LA emptying, the overall trend of the LA time-volume curve was similar in patients with AF and SR. Conclusion: Compared to SR patients, patients with permanent AF have significantly increased LA volumes throughout the cardiac cycle. Yet, a residual hemodynamic role of LA function may be maintained during permanent AF.

Left Atrial Function in Cats with Left‐Sided Cardiac Disease and Pleural Effusion or Pulmonary Edema

Congestive heart failure (CHF) in cats with left-sided heart disease is sometimes manifest as pleural effusion, in other cases as pulmonary edema. Those cats with pleural effusion have more severe left atrial (LA) dysfunction than cats with pulmonary edema. 30 healthy cats, 22 cats with pleural effusion, and 12 cats with pulmonary edema. All cats were client owned. Retrospective study. Measurements of LA size and function were made using commercial software on archived echocardiograms. Cases were identified through searches of medical records and of archived echocardiograms for cats with these conditions. There was no difference (P = .3) in LA size between cats with pleural effusion and cats with pulmonary edema. Cats with pleural effusion had poorer (P = .04) LA active emptying and increased (P = .006) right ventricular (RV) diameter when compared with cats with pulmonary edema and healthy cats. Cats that exhibited LA active emptying of <7.9%, total emptying of <13.6% (diameter) or <19.4% (area), or RV diameter of >3.6 mm were significantly (P < .001) more likely to manifest pleural effusion. Poorer LA function and increased RV dimensions are associated with pleural effusion in cats with left-sided heart disease.

Evaluation of different magnetic resonance imaging techniques for the assessment of active left atrial emptying

There is currently no agreement on the best method of assessing active left atrial (LA) emptying. This study evaluated the relative merits of cine- and velocity encoded (VENC) magnetic resonance imaging (MRI) for the assessment of active LA emptying. Total LA emptying volume (TLAEV) and active LA stroke volume (ALASV) were assessed in 107 consecutive patients using cine-MRI and transmitral flow measurements by VENC-MRI. The fraction of active LA emptying (ALAEF) was calculated as the ratio of ALASV to TLAEV. LA and left ventricular (LV) output were calculated by multiplying TLAEV and LV stroke volume by heart rate, respectively. Intra- and inter-observer variances were significantly larger for cine-MRI than for VENC-MRI measurements of ALASV (24.7 mL(2) vs. 3.7 mL(2) and 57.7 mL(2) vs. 4.2 mL(2); P < 0.0001). Biplane cine-MRI underestimated TLAEV (mean difference -57 ± 32 %; P < 0.0001) and ALASV (mean difference -24 ± 51 %; P < 0.0001) but overestimated ALAEF (mean difference 31 ± 54 %, P < 0.0001) compared with VENC-MRI. There was significantly better agreement between LV output and LA output measured by VENC-MRI compared with LA output measured by cine-MRI (mean difference 0.30 ± 1.12 L/min vs. -2.05 ± 1.44 L/min; P < 0.0001). VENC-MRI is the more appropriate method of assessing active LA emptying and its use should be favoured.

SHA 103. Value of left atrial function in predicting effort capacity in patients with left ventricular systolic dysfunction

Introduction: Left atrial (LA) function shares in left ventricular diastolic filling and, therefore, cardiac output during rest and exercise. However, there is scanty data about the relation between LA function and exercise performance in left ventricular systolic dysfunction patients (LVSD). Methods and results: This was a prospective, cross sectional study conducted on 25 patients with LVSD (EF < 40%) in sinus rhythm. LA volumes were measured using monoplane Simpson’s method. The measured LA volumes were the largest LA volume (Vmax), the smallest LA volume (Vmin), and the LA volume measured at the peak of P wave (Vp) of simultaneous ECG. Then, LA total emptying (Vmax Vmin), passive emptying (Vmax Vp) and active emptying (Vp Vmin) volumes were calculated. Then LA total emptying fraction (Vmax Vmin/Vmax), passive emptying fraction (Vmax Vp/Vmax), active emptying fraction (Vp Vmin/ Vp) were calculated. Patients were exercised using modified Bruce protocol, to determine their exercise capacity. The selected patient subdivided into two groups: group 1 with functional capacity <7 metabolic equivalent (METS) [17 patients] and group 2 with functional capacity P7 METS [8 patients]. There was a significant difference between the two groups regarding LA total emptying fraction (P 0.0006), LA active emptying fraction (P 0.045) and LA passive emptying fraction (P 0.004). Conclusion: Left atrial emptying fraction which can be easily obtained by routine echocardiography, is useful as a predictor of exercise capacity in LVSD patients.

Active left atrial emptying: assessment by cine and velocity encoded magnetic resonance imaging

Growing attention has been recently paid to the assessment of active LA emptying in patients after ablation of atrial fibrillation. Measurements of active LA emptying are typically performed by echocardiography in clinical routine. However, little is known about the role of cardiac MRI for this purpose. The present study evaluated the relative merits of biplane long-axis cine- and VENC-MRI for the assessment of active LA emptying.

The Responsibility of Left Atrial Size and Wall Contraction Velocity to Left Atrial Active Emptying in Relation to the Mitral Flow Velocity Pattern

The aim of this study was to investigate the role and limitations of left atrial (LA) preload or contractility as determinants of active LA emptying in patients with heart failure. In 56 healthy individuals (controls) and 30 patients with heart failure, the LA volume before atrial contraction (LAV(pre) I), the LA volume reduction (LASVI) and LA wall contraction velocity (LAWV) during atrial contraction, and the transmitral peak flow velocities during early diastole (E) and atrial contraction (A) were determined using two-dimensional pulsed Doppler or tissue Doppler echocardiography. LAV(pre) I and LASVI were positively correlated in patients whose A/E ratio was ≥1 (r = 0.58) and negatively correlated in those whose A/E ratio was <1 (r =-0.63). LAWV was significantly lower in those with heart failure than in the controls 2.2 (1.2) cm/sec, versus 3.3 (0.8) cm/sec; mean (standard deviation) and negatively correlated with left ventricular end-diastolic pressure (r =-0.37). LAWV and LASVI were significantly correlated (r = 0.71). This correlation was stronger in the patients whose A/E ratio was <1 than in those whose A/E ratio was ≥1. Multivariate regression analysis showed that LAWV was the only factor affecting LASVI. In patients with heart failure and an A/E ratio of <1, the contribution of LA dilatation to active LA emptying may be limited, and LAWV may be the most important determinant of active LA emptying, even if this velocity is decreased because of elevated left ventricular diastolic pressure.

Determinants of Enhanced Left Atrial Active Emptying with Aging: Left Atrial Preload, Contractility or Both?

Senile persons have reduced left ventricular (LV) relaxation and increased late diastolic filling. However, the determinant factor of the enhanced active emptying of the left atrium has not been well established. Subjects were 62 healthy individuals with a mean age of 58+/-19 (21-85) years. The biplane modified Simpson's rule was applied to measure left atrial (LA) volume at pre-atrial contraction (LAVpre) as an index of LA preload and LA volume change during atrial contraction (LASV) as an index of active LA emptying. These values were divided by the body surface area and represented as LAVpreI and LASVI, respectively. Postero-basal (dorsal cranial) left atrial wall velocity (LAWV) during atrial contraction as an index of LA contractility was measured in the apical three-chamber view by two-dimensional tissue Doppler echocardiography. Age significantly correlated with mitral flow velocity (TMA), velocity-time integral during atrial contraction (TMAVTI) and LASVI (r= 0.63, p<0.001 and r=0.71, p<0.001, r=0.21, p=0.049, respectively). LAVpreI was significantly correlated with age (r=0.44, p<0.001), LASVI (r=0.71, p<0.001), TMA (r=0.31, p=0.008) and TMAVTI (r=0.40, p<0.001). LAWV remained unchanged with aging and had no correlation with TMA, TMAVTI or LASVI. The enlargement of the LA in senile persons may be a major determinant of enhanced active LA emptying and the increased LA contractility may be less contributory.

The role of short- and long-axis function in determining late diastolic left ventricular filling in patients with hypertension: Assessment by pulsed Doppler tissue imaging

Left ventricular (LV) wall motion velocity during atrial systole is mediated by both transmitral flow and LV myocardial compliance at end-diastole. LV wall distensibility along the long- and short-axis during atrial systole and late diastolic LV filling may vary according to the remodeling of LV morphology. We measured LV wall motion velocities along the long and short axes using pulsed Doppler tissue imaging in 127 patients with hypertension to evaluate the relationship between the hemodynamic changes and LV morphology and to determine the role of both long- and short-axis function in late diastolic LV filling. Participants were classified into 3 groups according to LV dimension and end-diastolic wall thickness determined by M-mode echocardiography: group A (n = 62) without LV dilation or hypertrophy, group B (n = 55) with LV hypertrophy, and group C (n = 10) with LV dilation and systolic dysfunction. The time constant of the LV pressure decay during isovolumic diastole and the LV end-diastolic pressure were longest and greatest, respectively, in group C, compared with groups B and A. There were no significant differences in active left atrial emptying volume during atrial contraction determined by computerized echocardiographic 3-dimensional reconstruction among patient and control groups. The peak atrial systolic motion velocity of the LV posterior wall along the long axis was significantly lower in groups B and C, particularly in the latter group, than in group A. The peak atrial systolic motion velocity of the LV posterior wall along the short axis was greatest in group B and was lowest in group C compared with the other groups, respectively. The peak atrial systolic motion velocity of the LV posterior wall was greater along the long axis than the short axis in group A, but was less than the short axis in group B. In conclusion, the long- and short-axis function of the LV wall during atrial systole varies in patients with hypertension according to the severity of hemodynamic and morphologic abnormalities. The degree of LV wall expansion along the short axis is an important factor resulting from the atrial kick, and a determinant of its effectiveness. (J Am Soc Echocardiogr 2002;15:1211-7.)

Relationship between atrial function, left ventricular isovolumic relaxation time, and early filling in dual chamber-paced patients

This investigation was performed to study atrial systolic function in response to modification of atrioventricular delay in a sample of 36 patients with a DDD pacemaker implanted for complete atrioventricular block. The relation between atrial systolic performance and diastolic-related parameters was also evaluated. Isovolumic relaxation time, early diastolic peak velocity, late (atrial) diastolic peak velocity, atrial filling fraction, and atrial ejection force were recorded at a pacing rate of 70 impulses/min and at atrioventricular delay of 200, 150, and 100 msec. Our data showed that the progressive shortening of atrioventricular delay induced a gradual increase in early peak velocity (median value 46 to 53 to 61.5 cm/sec, respectively, at 200, 150, and 100 msec intervals) and a gradual decrease in isovolumic relaxation time (median 92.6 to 81.5 to 69.7 msec at 200, 150, and 100 msec, respectively), atrial peak velocity (59 to 52 to 44.5 cm/sec at 200, 150, and 100 msec, respectively), atrial filling fraction (50.5% to 40% to 23.5% at 200, 150, and 100 msec, respectively), and atrial ejection force (17.2 to 14.7 to 8.5 kilodynes at 200, 150, and 100 msec, respectively). For every atrioventricular delay value detected, we found a significant correlation between isovolumic relaxation time and early peak velocity with atrial filling fraction and atrial ejection force. In addition, atrial ejection force was related directly to atrial filling fraction at studied atrioventricular delays. The two indexes of atrial systolic performance showed a parallel decrease by shortening the atrioventricular delay, and they can quantify atrial systolic performance equally in sequentially paced patients. Furthermore, our results are in accordance with the hypothesis that the interaction between the effectiveness of active left atrial emptying and isovolumetric relaxation time may play an important role in maintaining an ideal ventricular filling despite changes in atrial systolic function. (J Am Soc Echocardiogr 1997;10:300-9.)

Left atrial mechanical function in the healthy elderly: New insights from a combined assessment of changes in atrial volume and transmitral flow velocity

To assess left atrial mechanical function in the elderly, 35 old (age > 70 years) and 18 sex-matched young (age < 50 years) healthy subjects were studied. Transmitral flow velocities were recorded with pulsed Doppler echocardiography. Left atrial volumes were measured echocardiographically at mitral valve opening (maximal) and closure (minimal) and at onset of atrial systole (P wave of the electrocardiogram) according to the biplane area-length method. Left atrial passive emptying was assessed with the passive emptying volume (maximal-volume at onset of atrial systole) and fraction (passive emptying volume/maximal). Left atrial active emptying was assessed with the active emptying volume (volume at onset of atrial systole-minimal) and fraction (active emptying volume/volume at onset of atrial systole) and with left atrial ejection force = 0.5.blood density.volume at onset of atrial systole.active emptying fraction.(A velocity)2/A integral. Left atrial volumes were greater in old compared with young subjects (maximal: 31 +/- 10 cm3/m2 vs 24 +/- 8 cm3/m2, p = 0.02; at onset of atrial systole: 23 +/- 8 cm3/m2 vs 15 +/- 5 cm3/m2, p = 0.0002; minimal: 13 +/- 5 cm3/m2 vs 9 +/- 4 cm3/m2, p = 0.001). Passive emptying volume and fraction were lower (7.8 +/- 1.7 cm3/m2 vs 9.2 +/- 3.2 cm3/m2 [p = 0.04] and 26.4% +/- 9.8% vs 37.9% +/- 11.2% [p = 0.003], respectively), whereas atrial ejection force and active emptying volume were greater in old compared with young subjects (6.8 +/- 3.3 kdynes/m2 vs 4.2 +/- 2.8 kdynes/m2 [p = 0.007] and 9.2 +/- 4.1 cm3/m2 vs 5.7 +/- 2.9 cm3/m2 [p = 0.002], respectively). The active emptying fraction was similar in the two groups (39.7% +/- 11% vs 38.4% +/- 13%; difference not significant). Thus advanced age is associated with depressed left atrial passive emptying function and increased left atrial volume. Left atrial dilation contributes to an increase in atrial ejection force and the amount of blood ejected during left atrial systole and may represent an important compensatory mechanism in this age population.