Left atrial Frank-Starling law assessed by real-time, three-dimensional echocardiographic left atrial volume changes

The hybrid (physical-computational) cardiovascular simulator to study valvular diseases

To better understand the impact of valvular heart disease (VHD) on the hemodynamics of the circulatory system, investigations can be carried out using a model of the cardiovascular system. In this study, a previously developed hybrid (hydro-numerical) simulator of the cardiovascular system (HCS) was adapted and used. In our HCS Björk-Shiley mechanical heart valves were used, playing the role of mitral and aortic ones. In order to simulate aortic stenosis (AS) and mitral regurgitation (MR), special mechanical devices have been developed and integrated with the HCS. The simulation results proved that the system works correctly. Namely, in the case of AS - the mean pulmonary arterial pressure was increased due to increased preload of the left ventricle and the decrease in right ventricular preload was caused by a decrease in systemic arterial pressure. The severity of AS was performed based on the transaortic pressure gradient as well as using the Gorlin and Aaslid equations. In the case of severe AS, when the mean gradient was above 40 mmHg, the aortic valve orifice area was 0.5 cm2, which is in line with ACC/AHA guidelines. For the case of MR - with increasing severity of MR, there was a decrease in the left ventricular pressure and an increase in left atrial pressure. Using mechanical heart valves to simulate VHD by the HCS can be a valuable tool for biomedical research, providing a safe and controlled environment to study and understand the pathophysiology of VHD.

Study the relationship between left atrial (LA) volume and left ventricular (LV) diastolic dysfunction and LV hypertrophy: Correlate LA volume with cardiovascular risk factors

Heart failure (HF) with normal ejection fraction - the isolated diastolic heart failure, depicts increasing prevalence and health care burden in recent times. Having less mortality rate compared to systolic heart failure but high morbidity, it is evolving as a major cardiac concern. With increasing clinical use of Left atrial volume (LAV) quantitation in clinical settings, LAV has emerged as an important independent predictor of cardiovascular outcome in HF with normal ejection fraction. This article is intended to review the diastolic and systolic heart failure, their association with left atrial volume, in depth study of Left atrial function dynamics with determinants of various functional and structural changes.

Comprehensive diagnostic workup in patients with suspected heart failure and preserved ejection fraction

Diagnosis of heart failure with preserved ejection fraction (HFpEF) can be challenging and it could require different tests, some of which are affected by limited availability. Nowadays, considering that new therapies are available for HFpEF and related conditions, a prompt and correct diagnosis is relevant. However, the diagnostic role of biomarker level, imaging tools, score-based algorithms and invasive evaluation, should be based on the strengths and weaknesses of each test. The aim of this review is to help the clinician in diagnosing HFpEF, overcoming the diagnostic uncertainty and disentangling among the different underlying causes, in order to properly treat this kind of patient.

Similarities and Differences between Three-Dimensional Speckle-Tracking Echocardiography-Derived Left and Right Atrial Volumes and Volume-Based Functional Properties in the Same Healthy Adults-A Detailed Analysis from the MAGYAR-Healthy Study

Background and Objectives: It would be important to know what happens to the volume and volume-based functional properties of one atrium if the size of the other atrium is larger or smaller than the average. Therefore, the present study aimed to perform three-dimensional speckle-tracking echocardiography (3DSTE)-derived quantification of left atrial (LA) and right atrial (RA) volumes and volume-based functional properties to examine these associations in healthy adults with mean and lower or higher than mean atrial volumes. Materials and Methods: The present study consisted of 179 healthy volunteers with a mean age of 32.3 ± 12.3 years (92 males). Three-dimensional speckle-tracking echocardiography-derived LA and RA volumes and volume-based functional properties were determined in all cases. Results: When different LA or RA volume groups were evaluated, both LA and RA showed the same pattern of volume changes in all phases of atrial function with higher LA or RA volumes. In case of low and mean LA volumes, RA volumes were higher compared to their LA counterpart. In case of mean and high RA volumes, RA volumes proved to be higher as well. In case of mean LA or RA volumes, differences between LA and RA stroke volumes (SVs) could not be detected, but all atrial emptying fractions (EFs) were lower for RA than for LA. Some differences were detected in counterpart LA/RA total, passive, and active atrial SVs and EFs values in the presence of lower/higher than mean LA/RA volume. Conclusions: In case of mean LA or RA volumes, RA volumes are higher compared to their LA counterpart, LA-SVs and RA-SVs are similar, but atrial EFs are lower for RA than for LA. If lower/higher than mean LA or RA volumes are present, some differences in patterns of changes in counterpart atrial volumes-SVs and EFs-could be detected.

Assessment of left atrioventricular coupling and left atrial function impairment in diabetes with and without hypertension using CMR feature tracking

PURPOSE

The study was designed to assess the effect of co-occurrence of diabetes mellitus (DM) and hypertension on the deterioration of left atrioventricular coupling index (LACI) and left atrial (LA) function in comparison to individuals suffering from DM only.

METHODS

From December 2015 to June 2022, we consecutively recruited patients with clinically diagnosed DM who underwent cardiac magnetic resonance (CMR) at our hospital. The study comprised a total of 176 patients with DM, who were divided into two groups based on their blood pressure status: 103 with hypertension (DM + HP) and 73 without hypertension (DM-HP). LA reservoir function (reservoir strain (εs), total LA ejection fraction (LAEF)), conduit function (conduit strain (εe), passive LAEF), booster-pump function (booster strain (εa) and active LAEF), LA volume index (LAVI), LV global longitudinal strain (LVGLS), and LACI were evaluated and compared between the two groups.

RESULTS

After adjusting for age, sex, body surface area (BSA), and history of current smoking, total LAEF (61.16 ± 14.04 vs. 56.05 ± 12.72, p = 0.013) and active LAEF (43.98 ± 14.33 vs. 38.72 ± 13.51, p = 0.017) were lower, while passive LAEF (33.22 ± 14.11 vs. 31.28 ± 15.01, p = 0.807) remained unchanged in the DM + HP group compared to the DM-HP group. The DM + HP group had decreased εs (41.27 ± 18.89 vs. 33.41 ± 13.94, p = 0.006), εe (23.69 ± 12.96 vs. 18.90 ± 9.90, p = 0.037), εa (17.83 ± 8.09 vs. 14.93 ± 6.63, p = 0.019), and increased LACI (17.40±10.28 vs. 22.72±15.01, p = 0.049) when compared to the DM-HP group. In patients with DM, multivariate analysis revealed significant independent associations between LV GLS and εs (β=-1.286, p < 0.001), εe (β=-0.919, p < 0.001), and εa (β=-0.324, p = 0.036). However, there was no significant association observed between LV GLS and LACI (β=-0.003, p = 0.075). Additionally, hypertension was found to independently contribute to decreased εa (β=-2.508, p = 0.027) and increased LACI in individuals with DM (β = 0.05, p = 0.011).

CONCLUSIONS

In DM patients, LV GLS showed a significant association with LA phasic strain. Hypertension was found to exacerbate the decline in LA booster strain and increase LACI in DM patients, indicating potential atrioventricular coupling index alterations.

Differences in Effects of Length-Dependent Regulation of Force and Ca2+ Transient in the Myocardial Trabeculae of the Rat Right Atrium and Ventricle

The comparative differences in the fundamental mechanisms of contractility regulation and calcium handling of atrial and ventricular myocardium remain poorly studied. An isometric force-length protocol was performed for the entire range of preloads in isolated rat right atrial (RA) and ventricular (RV) trabeculae with simultaneous measurements of force (Frank-Starling mechanism) and Ca²⁺ transients (CaT). Differences were found between length-dependent effects in RA and RV muscles: (a) the RA muscles were stiffer, faster, and presented with weaker active force than the RV muscles throughout the preload range; (b) the active/passive force-length relationships were almost linear for the RA and RV muscles; (c) the value of the relative length-dependent growth of passive/active mechanical tension did not differ between the RA and RV muscles; (d) the time-to-peak and amplitude of CaT did not differ between the RA and RV muscles; (e) the CaT decay phase was essentially monotonic and almost independent of preload in the RA muscles, but not in the RV muscles. Higher peak tension, prolonged isometric twitch, and CaT in the RV muscle may be the result of higher Ca²⁺ buffering by myofilaments. The molecular mechanisms that constitute the Frank-Starling mechanism are common in the rat RA and RV myocardium.

The effect of urgent blood pressure reduction on left atrial strain in patients with hypertensive attack : Blood pressure lowering affects LA strain

BACKGROUND

Left atrial (LA) strain is a robust measure of LA function and is a useful parameter to assess left ventricular filling pressure. While initially considered as a "load-independent" parameter of LA function, later studies have found that acute changes in LA preload may affect LA reservoir and contractile strains. Acute alterations in blood pressure (BP) induces a change in left ventricular (LV) filling pressure without imposing a volume load, thus providing an opportunity to assess the effects of the change in LA afterload on LA mechanics. This study aims to understand the effect of acute BP changes on LA strain.

METHODS

A total of 40 patients admitted to the emergency department with hypertensive urgency were included. All patients underwent a comprehensive echocardiographic examination including measurement of LA reservoir, conduit and contractile strains. A repeat set of measurements were obtained after BP lowering.

RESULTS

Average drop in mean BP following intervention was 18.1 ± 5.4%. LV end-systolic and end-diastolic volumes, as well as maximum and minimum LA volumes were decreased significantly after BP reduction. The absolute increases in reservoir and contractile strains were 2.3 ± 4.7% (7.9% ± 13.8% relative to baseline) and 2.5 ± 3.3% (13.5 ± 19.0% relative to baseline), respectively, with both changes being statistically significant (p = 0.003 for reservoir and p < 0.001 for contractile strains). There were no significant changes in conduit strain after BP intervention (p = 0.79). The change in both LA reservoir and contractile strains were more evident in those with a previous diagnosis of hypertension and those with a smaller degree of change in mean BP after intervention.

CONCLUSION

In patients with an acute hypertension, lowering BP leads to an acute improvement in LA reservoir and contractile strains. Thus, acute changes in systemic BP should be considered when LA mechanics are evaluated.

Left atrial strain assessment using cardiac computed tomography in patients with hypertrophic cardiomyopathy

PURPOSE

To evaluate left atrial (LA) function in patients with hypertrophic cardiomyopathy (HCM) by LA strain assessment using cardiac computed tomography (CT-derived LA strain).

MATERIALS AND METHODS

This was a retrospective study of 34 patients with HCM and 31 non-HCM patients who underwent cardiac computed tomography (CT) using retrospective electrocardiogram-gated mode. CT images were reconstructed every 5% (0-95%) of the RR intervals. CT-derived LA strain (reservoir [LASr], conduit [LASc], and booster pump strain [LASp]) were semi-automatically analyzed using a dedicated workstation. We also measured the left atrial volume index (LAVI) and left ventricular longitudinal strain (LVLS) for the left atrial and ventricular functional parameters to assess the relationship with CT-derived LA strain.

RESULTS

CT-derived LA strain significantly correlated with LAVI: r = - 0.69, p < 0.001 for LASr; r = - 0.70, p < 0.001 for LASp; and r = - 0.35, p = 0.004 for LASc. CT-derived LA strain also significantly correlated with LVLS: r = - 0.62, p < 0.001 for LASr; r = - 0.67, p < 0.001 for LASc; and r = - 0.42, p = 0.013 for LASp. CT-derived LA strain in patients with HCM was significantly lower than that in non-HCM patients: LASr (20.8 ± 7.6 vs. 31.7 ± 6.1%, p < 0.001); LASc (7.9 ± 3.4 vs. 14.2 ± 5.3%, p < 0.001); and LASp (12.8 ± 5.7 vs. 17.6 ± 4.3%, p < 0.001). Additionally, CT-derived LA strain showed high reproducibility; inter-observer correlation coefficients were 0.94, 0.90, and 0.89 for LASr, LASc, and LASp, respectively.

CONCLUSION

CT-derived LA strain is feasible for quantitative assessment of left atrial function in patients with HCM.

Dependence of Left Ventricular Rotational Mechanics on Left Atrial Volumes in Non-Smoker Healthy Adults: Analysis Based on the Three-Dimensional Speckle-Tracking Echocardiographic MAGYAR-Healthy Study

Introduction: As has been established, the left ventricle (LV) and the left atrium (LA) form an organic unit of the left heart; however, little is known about the dependence of LV rotational parameters on LA volumes, even in healthy circumstances. Therefore, the present study aimed to assess the associations between basal and apical LV rotations and LA volumes and volume-based functional properties throughout the cardiac cycle in healthy adults by three-dimensional speckle-tracking echocardiography. Methods: The present study comprised 167 healthy adults (age: 33.4 ± 12.6 years, 77 males) with normally directed LV rotational mechanics. All subjects underwent complete two-dimensional Doppler echocardiography with three-dimensional speckle-tracking echocardiography (3DSTE)-derived data acquisition. The 3DSTE-derived LA volumes and LV rotational parameters were determined at a later date. Results: An increasing end-systolic maximum LA volume (Vmax) was associated with increasing pre-atrial-contraction early (VpreA) and minimum end-diastolic (Vmin) LA volumes, and all stroke volumes were increased as well. Systolic basal left ventricular rotation (LVrot) was highest in the case of the highest systolic Vmax and early-diastolic VpreA. Apical LVrot did not show obvious associations with any increasing LA volumes. The highest systolic basal LVrot was associated with significantly increased diastolic VpreA and Vmin. Reduced diastolic LA volumes (VpreA, Vmin) were seen in the case of increased apical LVrot. An increasing basal LVrot was associated with the tendentious lowering of the apical LVrot and the significant elevation of LV twist. Similarly, an increasing apical LVrot was associated with the tendentious lowering of basal LVrot and the significant elevation of LV twist. Conclusions: Strong associations and adaptations between 3DSTE-derived LA volumes throughout the cardiac cycle and LV rotational mechanics were evidenced, even in healthy circumstances.

Right atrial volumes and strains in healthy adults: is the Frank-Starling mechanism working?-detailed analysis from the three-dimensional speckle-tracking echocardiographic MAGYAR-Healthy Study

Background

With larger blood volume flowing into a cardiac chamber, by stretching muscle fibers, increased contraction force could be detected. This phenomenon is called Frank-Starling mechanism, allowing the output of a cardiac chamber to be synchronized without external regulation. The purpose of the present study was to investigate the Frank-Starling mechanism in the right atrium (RA) represented by its volumes, volume-based functional properties and strains respecting the cardiac cycle in healthy adults by three-dimensional (3D) speckle-tracking echocardiography (3DSTE).

Methods

The present single center retrospective cohort study comprised 179 healthy adult volunteers (mean age: 33.2±12.0 years, 92 males), in whom complete two-dimensional Doppler echocardiography with 3DSTE was performed. Subjects were divided into 3 groups according to the mean value of maximum RA volume (V_max) ± standard deviation: V_max <30 mL, 30 mL ≤ V_max <60 mL and V_max ≥60 mL.

Results

All RA volumes respecting the cardiac cycle of all subjects and calculated separately for females and males and their indexed equivalents increased with V_max. RA stroke volumes increased with V_max regardless of the phase it was measured in. While total atrial emptying fraction representing the reservoir phase remained unchanged with the increase of V_max, a significant increase in passive atrial emptying fraction representing the conduit phase could be detected, in case of V_max >60 mL (28.9%±15.1% vs. 32.5%±12.6%, P<0.05). Active atrial emptying fraction representing the booster pump function did not change with the increase of V_max. Most global and mean segmental peak RA strains did not show significant changes with increasing RA volumes except for the RA area strain, it was the largest when V_max was larger than 60 mL (64.7%±44.9% vs. 83.3%±49.4%, P<0.05). RA circumferential, longitudinal and area strains at atrial contraction decreased with increasing V_max, RA radial and 3D strains did not change significantly with increasing V_max.

Conclusions

Increasing RA volumes do not cause significant increase in RA contractility represented by strains, but reduction in strains in longitudinal and circumferential directions could be detected in end-diastolic booster pump function. In contrast to the left atrium, obvious signs of Frank-Starling mechanism could not be detected in case of the RA.

Left Ventricular, Left Atrial and Right Ventricular Strain Modifications after Maximal Exercise in Elite Ski-Mountaineering Athletes: A Feasibility Speckle Tracking Study

Eleven world elite ski-mountaineering (Ski-Mo) athletes were evaluated for pronounced echocardiographic physiological remodeling as the primary aim of our feasibility speckle tracking study. In this context, sports-related cardiac remodeling was analyzed by performing two-dimensional echocardiography, including speckle tracking analysis of the left atrium (LA), right ventricle (RV) and left ventricular (LV) global longitudinal strain (LV-GLS) at rest and post-peak performance. The feasibility echocardiographic speckle tracking analysis was performed on eleven elite Ski-Mo athletes, which were obtained in 2022 during the annual medical examination. The obtained data of the professional Ski-Mo athletes (11 athletes, age: 18-26 years) were compared for different echocardiographic parameters at rest and post-exercise. Significant differences were found for LV-GLS mean (p = 0.0036) and phasic LA conduit strain pattern at rest and post-exercise (p = 0.0033). Furthermore, negative correlation between LV mass and LV-GLS (p = 0.0195, r = -0.69) and LV mass Index and LV-GLS (p = 0.0253, r = -0.66) at rest were elucidated. This descriptive reporting provided, for the first time, a sport-specific dynamic remodeling of an entire elite national team of the Ski-Mo athlete's left heart and elucidated differences in the dynamic deformation pattern of the left heart.

Associations between Mitral Annular and Left Atrial Volume Changes in Healthy Adults-Detailed Analysis from the Three-Dimensional Speckle-Tracking Echocardiographic MAGYAR-Healthy Study

Background

Three-dimensional (3D) speckle-tracking echocardiography (3DSTE) is one of the newest development in non-invasive imaging offering simultaneous 3D evaluation of atria and valvular annuli. 3DSTE was used to analyze correlations between left atrial (LA) volume changes and mitral annular (MA) dimensions and functional properties in healthy adult subjects.

Methods

A total of 297 healthy subjects were enrolled in this retrospective cohort study, from which insufficient quality of images was responsible for the exclusion of 98 cases (33%). The remaining study population consisted of 199 healthy adults without valvular regurgitation/stenosis in sinus rhythm (mean age: 33.5 ± 12.7 years, 104 males, body mass index: 24.7 ± 1.2 kg/ m 2 , systolic and diastolic blood pressure: 118.2 ± 3.4 mmHg and 78.3 ± 4.5 mmHg, respectively). Two-dimensional Doppler echocardiography and 3DSTE were performed in all cases.

Results

Larger LA volumes were associated with more dilated MA dimensions with its reduced function. Elevated LA stroke volumes could be demonstrated only in systole and end-diastole, while increased LA emptying fraction was present only in end-diastole. Reduced MA fractional area change was associated with larger diastolic LA volumes, smaller early diastolic LA stroke volume, in addition all LA emptying fractions were smaller as well. Correlations could be demonstrated between LA and MA parameters.

Conclusions

3DSTE is suitable not only for chamber quantifications, but also for the assessment of valvular annular dimensions. Strong relationship exists between LA volumes and MA dimensions and functional properties.

From Left Atrial Dimension to Curved M-Mode Speckle-Tracking Images: Role of Echocardiography in Evaluating Patients with Atrial Fibrillation

Left atrial (LA) enlargement and dysfunction increase the risk of atrial fibrillation (AF). Traditional echocardiographic evaluation of the left atrium has been limited to dimensional and semi-quantification measurement of the atrial component of ventricular filling, with routine measurement of LA function not yet implemented. However, functional parameters, such as LA emptying fraction (LAEF), may be more sensitive markers for detecting AF-related changes than LA enlargement. Speckle-tracking echocardiography has proven to be a feasible and reproducible technology for the direct evaluation of LA function. The clinical application, advantages, and limitations of LA strain and strain rate need to be fully understood. Furthermore, the prognostic value and utility of this technique in making therapeutic decisions for patients with AF need further elucidation. Deep learning neural networks have been successfully adapted to specific tasks in echocardiographic image analysis, and fully automated measurements based on artificial intelligence could facilitate the clinical diagnostic use of LA speckle-tracking images for classification of AF ablation outcome. This review describes the fundamental concepts and a brief overview of the prognostic utility of LA size, LAEF, LA strain and strain rate analyses, and the clinical implications of the use of these measures.

Acute Left Atrial Response to Different Eccentric Resistance Exercise Loads in Patients with Heart Failure with Middle Range Ejection Fraction: A Pilot Study

In this study, we aimed to assess acute changes occurring on atrial function following single bouts of eccentric resistance exercise (ECC-RE) performed at two different loads. Twenty-five patients with chronic heart failure with middle range ejection fraction (HFmrEF) participated in three experimental sessions in a randomized order and on separate days: two sessions of ECC RE at 20% (ECC-20) of one-repetition maximum (1-RM) and 50% (ECC-50) 1-RM, and one session of control, without exercise. Each session lasted three minutes. Before and immediately after the sessions, patients underwent echocardiography and blood pressure and heart rate measurement. Peak atrial longitudinal strain (PALS) and peak atrial contractile strain (PACS) significantly increased after both ECC-20 (+16.3%) and ECC-50 (+18.1%) compared to control (between sessions p = 0.022). Peak atrial contractile strain (PACS) significantly increased after ECC-50 (+28.4%) compared to ECC-20 (+17.0%) and control (between sessions p = 0.034). The ratio of transmitral and annular velocities (E/E') increased significantly after ECC-20 (+10.4%) and ECC-50 (+19.0%) compared to control (between groups p = 0.003). EF, left ventricular longitudinal strain, and stroke volume did not change after ECC-RE sessions compared to control. Cardiac output increased significantly after ECC-20 and ECC-50 compared to control, (between groups p = 0.025). In conclusion, both ECC-RE sessions were well tolerated, and LA functional reserve was properly mobilized in response to ECC-RE in patients with HFmrEF. Cardiac output increased at the cost of an increased LV filling pressure, but no detrimental changes of LV function occurred.

Contractile Behavior of Right Atrial Myocardium of Healthy Rats and Rats with the Experimental Model of Pulmonary Hypertension

There is a lack of data about the contractile behavior of the right atrial myocardium in chronic pulmonary heart disease. We thoroughly characterized the contractility and Ca transient of isolated right atrial strips of healthy rats (CONT) and rats with the experimental model of monocrotaline-induced pulmonary hypertension (MCT) in steady state at different preloads (isometric force-length), during slow force response to stretch (SFR), and during post-rest potentiation after a period of absence of electrical stimulation (PRP). The preload-dependent changes in the isometric twitch and Ca transient did not differ between CONT and MCT rats while the kinetics of the twitch and Ca transient were noticeably slowed down in the MCT rats. The magnitude of SFR was significantly elevated in the MCT right atrial strips and this was accompanied by the significantly higher elevation of the Ca transient relative amplitude at the end of SFR. The slow changes in the contractility and Ca transient in the PRP protocol did not differ between CONT and MCT. In conclusion, the alterations in the contractility and Ca transient of the right atrial myocardium of monocrotaline-treated rats with pulmonary hypertension mostly concern the elevation in SFR. We hypothesize that this positive inotropic effect in the atrial myocardium may (partly) compensate the systolic deficiency of the right ventricular failing myocardium.

Correlations between left atrial volumes and strains in healthy adults: Detailed analysis from the three-dimensional speckle-tracking echocardiographic MAGYAR-Healthy Study

INTRODUCTION

Little is known about the relationship between left atrium (LA) volumes and contractility features along the cardiac cycle. The present study aimed to assess, by three-dimensional speckle-tracking echocardiography (3DSTE), correlations between LA volumes, volume-based functional properties, and strains during the cardiac cycle in healthy adults.

METHODS

We included 217 healthy adult volunteers (mean age 33.4 ± 12.7 years, 112 males) who underwent complete two-dimensional Doppler echocardiography with 3DSTE.

RESULTS

LA stroke volumes were greater in subjects with the greater maximum LA volume (V_max ) in reservoir, conduit, and booster pump phases of LA function. While LA emptying fraction in LA reservoir phase was not different between subjects depending in their V_max value, a significantly lower LA emptying fraction could be detected in LA conduit phase in subjects whose V_max was >50 mL. In booster pump function, LA emptying fraction was not significantly different whatever the V_max . Only global and mean segmental peak LA radial strain (RS) and 3D strain (3DS) and the same strains at atrial contraction appeared greater in subjects with greater V_max , whereas the other strain parameters were not different.

CONCLUSIONS

In healthy subjects, LA-RS and LA-3DS, objective features of LA contractility, are greater in subjects with greater LA volumes up to a point beyond which this association disappears.

Blanco L, Lamy J, Kachenoura N, Quesson B, Cochet H, Coronel R, Dekker LRC. A left lateral body position increases pulmonary vein stress in healthy humans

Pulmonary vein (PV) stretch is proarrhythmic for atrial fibrillation (AF). AF patients often report that a left lateral (LL) body position can trigger arrhythmia symptoms. Because the PV myocardium is thought to trigger AF, we hypothesized that the LL compared to the supine body position increases PV wall stress. Functional cardiac magnetic resonance imaging was performed in supine and LL recumbent body position in awake condition in healthy human volunteers (n = 20). Following a change from supine to LL position, the heart moved in an anterior-LL direction in the thorax. The right superior PV diameter was increased by 19% (24.6 ± 3.1 vs. 20.7 ± 3.2 mm, p = 0.009) and left atrial (LA) volume was larger by 17% (61.7[15.4] vs. 51.0[17.8] ml, p = 0.015) in LL than supine position, respectively. The passive LA conduit fraction (normalized difference between maximum and pre-contraction LA volume) increased by 25% in LL compared to supine position (19.6 ± 9.0 vs. 15.7 ± 7.6%, respectively, p = 0.016). Local wall stress in the PV regions increased in LL compared to supine position (overall mean: 1.01 ± 0.12 vs. 1.10 ± 0.10 arb. unit, LL vs. supine, position effect p = 0.041), whereas this was not the case in the LA walls (overall mean: 1.18 ± 0.31 vs. 1.21 ± 0.21 arb. unit, LL vs. supine, position effect p = 0.381). In conclusion, a left lateral body position increases PV myocardial stress during the atrial relaxation phase of healthy volunteers. These results have implications for the mechanisms of posture-triggered AF.

Left atrial strain is a predictor of left ventricular systolic and diastolic reverse remodelling in CRT candidates

AIMS

The left atrium (LA) has a pivotal role in cardiac performance and LA deformation is a well-known prognostic predictor in several clinical conditions including heart failure with reduced ejection fraction. The aim of this study is to investigate the effect of cardiac resynchronization therapy (CRT) on both LA morphology and function and to assess the impact of LA reservoir strain (LARS) on left ventricular (LV) systolic and diastolic remodelling after CRT.

METHODS AND RESULTS

Two hundred and twenty-one CRT-candidates were prospectively included in the study in four tertiary centres and underwent echocardiography before CRT-implantation and at 6-month follow-up (FU). CRT-response was defined by a 15% reduction in LV end-systolic volume. LV systolic and diastolic remodelling were defined as the percent reduction in LV end-systolic and end-diastolic volume at FU. Indexed LA volume (LAVI) and LV-global longitudinal (GLS) strain were the main parameters correlated with LARS, with LV-GLS being the strongest determinant of LARS (r = -0.59, P < 0.0001). CRT induced a significant improvement in LAVI and LARS in responders (both P < 0.0001). LARS was an independent predictor of both LV systolic and diastolic remodelling at follow-up (r = -0.14, P = 0.049 and r = -0.17, P = 0.002, respectively).

CONCLUSION

CRT induces a significant improvement in LAVI and LARS in responders. In CRT candidates, the evaluation of LARS before CRT delivery is an independent predictor of LV systolic and diastolic remodelling at FU.

Atrial fibrillation and left atrial size and function: a Mendelian randomization study

Atrial fibrillation (AF) patients have enlarged left atria (LA), but prior studies suggested enlarged atria as both cause and consequence of AF. The aim of this study is to investigate the causal association between AF and LA size and function. In the UK Biobank, all individuals with contoured cardiovascular magnetic resonance data were selected. LA maximal volume (LA max), LA minimal volume (LA min), LA stroke volume and LA ejection fraction were measured and indexed to body surface area (BSA). Two-sample Mendelian randomization analyses were performed using 84 of the known genetic variants associated with AF to assess the association with all LA size and function in individuals without prevalent AF. A total of 4274 individuals (mean age 62.0 ± 7.5 years, 53.2% women) were included. Mendelian randomization analyses estimated a causal effect between genetically determined AF and BSA-indexed LA max, LA min, and LA ejection fraction, but not between AF and LA stroke volume. Leave-one-out analyses showed that the causal associations were attenuated after exclusion of rs67249485, located near PITX2 gene. Our results suggest that AF causally increases LA size and decreases LA ejection fraction. The AF risk allele of rs67249485, located near the PITX2 gene, contributes strongly to these associations.

Alpha and beta myosin isoforms and human atrial and ventricular contraction

Human atrial and ventricular contractions have distinct mechanical characteristics including speed of contraction, volume of blood delivered and the range of pressure generated. Notably, the ventricle expresses predominantly β-cardiac myosin while the atrium expresses mostly the α-isoform. In recent years exploration of the properties of pure α- & β-myosin isoforms have been possible in solution, in isolated myocytes and myofibrils. This allows us to consider the extent to which the atrial vs ventricular mechanical characteristics are defined by the myosin isoform expressed, and how the isoform properties are matched to their physiological roles. To do this we Outline the essential feature of atrial and ventricular contraction; Explore the molecular structural and functional characteristics of the two myosin isoforms; Describe the contractile behaviour of myocytes and myofibrils expressing a single myosin isoform; Finally we outline the outstanding problems in defining the differences between the atria and ventricles. This allowed us consider what features of contraction can and cannot be ascribed to the myosin isoforms present in the atria and ventricles.

Normal reference values of left atrial volumes and volume-based functional properties using three-dimensional speckle-tracking echocardiography in healthy adults (Insights from the MAGYAR-Healthy Study)

INTRODUCTION

The present study was designed to define normal reference values of three-dimensional speckle-tracking echocardiography (3DSTE)-derived left atrial (LA) volumes, stroke volumes (SVs), and emptying fractions (EFs) with regard to the cardiac cycle.

METHODS

The present study involved 256 healthy adult subjects in sinus rhythm who underwent complete two-dimensional Doppler echocardiography and 3DSTE at the same time. However, due to inferior image quality, 87 subjects have been excluded. The remaining population sample comprised of 169 patients who gave informed consent to participate in the study.

RESULTS

While systolic maximum LA volume and early diastolic preatrial contraction LA volume did not change over age decades, late-diastolic minimum LA volume decreased and was lowest in subjects aged 40 to 49 years then increased after 50 years. Total atrial EF increased over age decades with a reduction after 50 years. Passive atrial EF showed a significant continuous increase over age decades. Active atrial EF did not change in younger ages and was the highest between ages 40 and 49 years with a significant impairment after 50 years.

CONCLUSIONS

This study shows the age- and gender-dependency of normal values of 3DSTE-derived LA volumes, stroke volumes, and emptying fractions with regard to the cardiac cycle in healthy adult subjects.

Significant functional mitral regurgitation affects left atrial function in heart failure patients: haemodynamic correlations and prognostic implications

AIMS

Functional mitral regurgitation (FMR) is a well-known pathophysiological factor in heart failure (HF) patients, and left atrial function (LAF) is a novel determinant of clinical status and outcome in this setting. However, little is known about the pathophysiological role of FMR on LAF in HFrEF patients. Aim of this study is to explore the possible interplay between the severity of FMR and LAF in heart failure with reduce ejection fraction (HFrEF) patients and their possible consequences.

METHODS AND RESULTS

We studied 97 consecutive patients with FMR classified in two groups: mild-to-moderate MR ore less (FMR group, n = 38) and moderate-to-severe or more (SFMR group, n = 59). Using the phasic method, left atrial contractile, conduit, reservoir, and total emptying function (TLAEF) were calculated to assess LAF. SFMR group showed significantly lower values of LAF compared to FMR group. LA dysfunction (LA-dys) was defined for TLAEF values below the median and groups divided in four subgroups based on its presence. Patient with LA-Dys in SFMR group showed a worse clinical status, higher incidence of right ventricular dysfunction (RV-Dys), and pulmonary hypertension (PH), and a significant worse clinical survival compared to all other groups.

CONCLUSION

In our study, the survival was significantly lower in SFMR/LA-Dys+ group. Furthermore, LA-Dys was strongly related with worse clinical status and higher incidence of PH and RV-Dys. These results suggest that in patients with SFMR and HFrEF, LA-Dys may represent both a marker of more advanced disease and a novel prognostic factor.

Assessment of biatrial function in clinically well pediatric bicaval heart transplantation patients by three-dimensional echocardiography

Atrial size and function are closely correlated with atrial contributions to cardiovascular performance. Therefore, in this study, we aimed to assess atrial size and function in pediatric heart transplantation (HTx) patients using three-dimensional echocardiography (3DE). We enrolled 33 clinically well pediatric HTx patients and 33 healthy controls with a similar distribution of sex and age to the HTx patients. All patients underwent two-dimensional echocardiography (2DE) and 3DE. 2DE- and 3DE-derived biatrial maximal volume (Vmax), minimal volume (Vmin), ejection volume (EV), ejection fraction (EF), volume before atrial contraciton (VpreA), passive EV, passive EF, active EV and active EF were obtained in all patients. The 3D left atrail (LA) Vmax, Vmin and VpreA increased significantly in HTx patients after being indexed by BSA, while 3D LAEV and passive EV decreased significantly (P < 0.05). Moreover, the 3D LAEF, LA passive EF, and LA active EF all decreased significantly in HTx patients (P < 0.05). The 3D right atrial (RA) Vmax, Vmin, and VpreA increased significantly in HTx patients (P < 0.05), while the 3D RAEF and RA passive EF decreased significantly in HTx patients (P < 0.05). 3DE-derived LAVmax, LAVpreA, LA passive EV, LAEF, and LA passive EF were all lower than the corresponding 2D parameters. 3DE-derived RAVpreA, RA passive EV and RAEF were all lower than the corresponding 2D parameters. Atrial sizes and function assessed by 3DE- and 2DE-derived parameters, yield significantly discordant results in pediatric HTx patients. 3DE confirms significantly enlarged atrial sizes and decreased atrial functions in pediatric HTx patients.

Left ventricular response after cardiac resynchronization therapy is related to early left atrial volume reduction

BACKGROUND/AIMS

The current study aimed to elucidate a time-course change in left atrial volume after cardiac resynchronization therapy (CRT) and to verify factors associated with left atrial volume reduction (LAVR) and its prognostic implications.

METHODS

The records of 97 patients were retrospectively reviewed after CRT. Echocardiographic data were analyzed at baseline before CRT, at early follow-up (FU) (≤ 1 year, median 6 months), and at late FU (median 30 months). Left ventricular volume response (LVVR) was defined as 15% reduction in left ventricular (LV) end-systolic volume (ESV). LAVR was classified into two groups by the median value at early FU: LAVR (≥ 7.5%) and no LAVR (< 7.5%).

RESULTS

LV ESV index continuously decreased from baseline to early FU and from early FU to late FU (106.1 ± 47.4 mL/m2 vs. 87.6 ± 51.6 mL/m2 vs. 72.5 ± 57.1 mL/m2). LA volume index decreased from baseline to early FU, but there were no reductions thereafter (51.8 ± 21.9 mL/m2 vs. 45.1 ± 19.6 mL/m2 vs. 44.9 ± 23.0 mL/m2). The only echocardiographic factor associated with LAVR was change in E velocity (odds ratio [OR], 1.04; p = 0.002). Early LAVR (OR, 10.05; p = 0.002) was an independent predictor for late LVVR.

CONCLUSION

LAVR was related to reduction in E velocity, suggesting its relation with optimization of LV filling pressure. Early LAVR was a predictor for LVVR to CRT in long-term FU.

Impact of stand-alone minimally invasive radiofrequency ablation with left atrial appendectomy on left atrial function assessed by echocardiography

BACKGROUND

Stand-alone minimally invasive radiofrequency (RF) ablation with left atrial (LA) appendectomy has been an effective surgical intervention for non-paroxysmal atrial fibrillation (AF) (NPAF) in patients with a medical history of thromboembolism for secondary stroke prevention. This study sought to assess the impact of this surgery on LA function.

METHODS

A total of 37 NPAF patients with a medical history of stroke or thromboembolism were enrolled in this prospective observational study, all of whom underwent stand-alone minimally RF ablation with LA appendectomy. Echocardiography was used to evaluate LA function preoperatively and 1 week and 3 months postoperatively. All patients were divided into two groups (Group AF and Group SR) according to whether sinus rhythm (SR) was restored after the surgery.

RESULTS

The surgery had no impact on LA function in Group AF. Once NPAF patients were restored to SR, LA minimal volume (LAVmin) decreased immediately compared with pre-operation (22.98±13.76 vs. 17.68±9.52 mL; P<0.05) and consequently LA reservoir function increased, including LAEF (37.69%±12.53% vs. 46.71%±8.53%, P<0.05) and LAEI (66.54%±34.39% vs. 92.15%±31.37%, P<0.05). PA-TDI of Group SR, indicating LA electromechanical coupling, were improved at three months of follow-up because of atrial stunning after the surgery (160.55±26.19 vs. 143.82±20.923 ms, P<0.05). LA contractile function was also improved at three months of follow-up (A-TVI: 2.95±1.16 vs. 5.10±1.85 cm, P<0.05).

CONCLUSIONS

Stand-alone minimal invasive RF ablation with LA appendectomy had no impact on LA function in AF patients who could not be restored to SR. However, once AF patients were restored to SR after the surgery, LA function could recover better. Meanwhile, thromboembolic events could also be reduced after the surgery.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique Identifier: NCT02039154.

Evaluation of left atrial volume and function in patients with coronary slow flow phenomenon using real-time three-dimensional echocardiography

This study aimed to evaluate the left atrial (LA) volume and phasic functions using real-time three-dimensional echocardiography (RT3DE) in coronary slow flow phenomenon (CSFP) patients with preserved left ventricular ejection fraction (LVEF). 56 patients with CSFP (36 males, 20 females) and 48 controls with normal coronary flow (27 males, 21 females) were prospectively enrolled. Comprehensive transthoracic echocardiographic examination and RT3DE for the assessment of LA dynamics were performed in all participants. LA maximum, minimum, and pre-atrial contraction volumes (LAV-max, LAV-min, and LAV-preA) were obtained for every subject. Conventional echocardiographic parameters, except for isovolumetric relaxation time and transmitral deceleration time, did not differ in two groups. RT3DE demonstrated higher LAV-max, LAV-min, LAV-preA, indexed LAV-max (LAVi-max), LA total emptying volume, and LA active emptying volume and fraction for CSFP patients compared with controls (all P < 0.05). In addition, LA total emptying fraction and LA passive emptying fraction were found to be lower in CSFP patients than in controls (all P < 0.05). Moreover, there were positive correlations between mean thrombolysis in myocardial infarction frame count values and LAV-max, LAV-min, LAV-preA, LAVi-max, and LA total and active emptying volumes. CSFP was associated with enlarged LA volumes, impaired LA reservoir and conduit function and enhanced contractile function. Evaluation of LA dynamics using RT3DE could facilitate recognition of subtle myocardial alterations related with CSFP.

Evaluation of left atrial function in type 2 diabetes mellitus patients with nonalcoholic fatty liver disease by two-dimensional speckle tracking echocardiography

OBJECTIVE

To assess left atrial function in type 2 diabetes mellitus (T2DM) patients with nonalcoholic fatty liver disease (NAFLD) by two-dimensional speckle tracking echocardiography (2D-STE).

METHODS

We classified 97 patients with T2DM into three groups according to the results of liver ultrasonography: group A (without NAFLD), group B (mild fatty liver), and group C (moderate to severe fatty liver). Conventional echocardiography parameters included left atrial end-systolic diameter (LAD), left ventricular end-systolic and end-diastolic diameter (LVDs, LVDd), end-diastolic thickness of ventricular septumi and LV posterior wall (IVSTd, LVPWTd), peak E and A of mitralis (E, A), septal and lateral early (e') mitral annular diastolic tissue velocities, then calculated E/A and E/mean e'. We measured LV ejection fraction (LVEF) and left atrial (LA) volumes (max, min, and preatrial contraction volume) by Simpson's rule, then calculated LA passive and active ejection fraction (LAPEF, LAAEF), left atrial maximum volume index (LAVImax). The global peak longitudinal systolic strain (LASRs), early diastolic strain (LASRe), and late diastolic strain (LASRa) rates of the LA were obtained by 2D-STE.

RESULTS

No differences were found between groups A and B (all P > 0.05). In group C, LAAEF and LASRa were obviously higher, while LAPEF, LASRe, and LASRs were obviously decreased compared with those values in groups A and B (all P < 0.05). The association between the severity of NAFLD and the differences in LA strain values remained significant after adjustment for confounders.

CONCLUSION

Two-dimensional speckle tracking echocardiography can evaluate the left atrial function in T2DM patients with NAFLD.

Left atrial remodeling postseptal myectomy for severe obstructive hypertrophic cardiomyopathy: Analysis by two-dimensional speckle-tracking echocardiography

BACKGROUND

Septal myectomy relieves left ventricular outflow obstruction (LVOTO) and is associated with excellent long-term outcomes. LVOTO is associated with diastolic dysfunction and increased left atrial (LA) size. We sought to investigate the changes in LA volumes and function postmyectomy and the association between these changes with clinical outcomes postmyectomy.

METHODS

Sixty-six hypertrophic cardiomyopathy patients undergoing myectomy were retrospectively studied. Preprocedural and 6- to 18-month postmyectomy follow-up transthoracic echocardiographic images were obtained. LA volumes and strain were assessed by two-dimensional speckle-tracking echocardiography.

RESULTS

Left atrial volumes, that is, indexed maximal, minimal, and pre-A volumes reduced postmyectomy, yet remained increased compared to controls (105.6 ± 34.5 mL vs 84.9 ± 26.7 mL, 45.2 ± 25.7 mL vs 35.4 ± 22.6 mL, 70.1 ± 31.4 mL vs 35.4 ± 22.6 mL, respectively, P < 0.05). The total emptying index did not improve postmyectomy and remained lower than controls (58.6 ± 12.4 vs 59.9 ± 12.8, P = NS) whereas atrial contraction improved, yet did not normalize (active emptying index 36.1 ± 14.9 vs 41.1 ± 16.2, P < 0.05). The conduit volume remained reduced postmyectomy (18.6 ± 13.3 mL vs 16.6 ± 15.1 mL, P = NS). LA strain also did not improve postmyectomy (26.8 ± 7.3 vs 28.5 ± 8.8, P = NS). A multivariable logistic regression identified preprocedural E/e' ratio and indexed maximal LA volume, as independent predictors for LA volume reduction ≥20% postmyectomy. During a mean follow-up of 4.9 ± 2.3 years postmyectomy, 24.2% of the patients developed atrial fibrillation and <5% of patients were severely symptomatic. We found no associations between LA volumes/function and atrial fibrillation or symptoms postmyectomy.

CONCLUSION

Postmyectomy LA volumes decreased, and the contractile function improved. There was no association between LA volumes/function and clinical outcomes postmyectomy. Notably, the LA remained enlarged (though to a lesser degree) with reduced strain and emptying fraction, suggesting possible atrial myopathy.

Amaze: a double-blind, multicentre randomised controlled trial to investigate the clinical effectiveness and cost-effectiveness of adding an ablation device-based maze procedure as an adjunct to routine cardiac surgery for patients with pre-existing atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) can be treated using a maze procedure during planned cardiac surgery, but the effect on clinical patient outcomes, and the cost-effectiveness compared with surgery alone, are uncertain.

OBJECTIVES

To determine whether or not the maze procedure is safe, improves clinical and patient outcomes and is cost-effective for the NHS in patients with AF.

DESIGN

Multicentre, Phase III, pragmatic, double-blind, parallel-arm randomised controlled trial. Patients were randomised on a 1 : 1 basis using random permuted blocks, stratified for surgeon and planned procedure.

SETTING

Eleven acute NHS specialist cardiac surgical centres.

PARTICIPANTS

Patients aged ≥ 18 years, scheduled for elective or in-house urgent cardiac surgery, with a documented history (> 3 months) of AF.

INTERVENTIONS

Routine cardiac surgery with or without an adjunct maze procedure administered by an AF ablation device.

MAIN OUTCOME MEASURES

The primary outcomes were return to sinus rhythm (SR) at 12 months and quality-adjusted life-years (QALYs) over 2 years after randomisation. Secondary outcomes included return to SR at 2 years, overall and stroke-free survival, drug use, quality of life (QoL), cost-effectiveness and safety.

RESULTS

Between 25 February 2009 and 6 March 2014, 352 patients were randomised to the control (n = 176) or experimental (n = 176) arms. The odds ratio (OR) for return to SR at 12 months was 2.06 [95% confidence interval (CI) 1.20 to 3.54; p = 0.0091]. The mean difference (95% CI) in QALYs at 2 years between the two trial arms (maze/control) was -0.025 (95% CI 0.129 to 0.078; p = 0.6319). The OR for SR at 2 years was 3.24 (95% CI 1.76 to 5.96). The number of patients requiring anticoagulant drug use was significantly lower in the maze arm from 6 months after the procedure. There were no significant differences between the two arms in operative or overall survival, stroke-free survival, need for cardioversion or permanent pacemaker implants, New York Heart Association Functional Classification (for heart failure), EuroQol-5 Dimensions, three-level version score and Short Form questionnaire-36 items score at any time point. Sixty per cent of patients in each trial arm had a serious adverse event (p = 1.000); most events were mild, but 71 patients (42.5%) in the maze arm and 84 patients (45.5%) in the control arm had moderately severe events; 31 patients (18.6%) in the maze arm and 38 patients (20.5%) in the control arm had severe events. The mean additional cost of the maze procedure was £3533 (95% CI £1321 to £5746); the mean difference in QALYs was -0.022 (95% CI -0.1231 to 0.0791). The maze procedure was not cost-effective at £30,000 per QALY over 2 years in any analysis. In a small substudy, the active left atrial ejection fraction was smaller than that of the control patients (mean difference of -8.03, 95% CI -12.43 to -3.62), but within the predefined clinically equivalent range.

LIMITATIONS

Low recruitment, early release of trial summaries and intermittent resource-use collection may have introduced bias and imprecise estimates.

CONCLUSIONS

Ablation can be practised safely in routine NHS cardiac surgical settings and increases return to SR rates, but not survival or QoL up to 2 years after surgery. Lower anticoagulant drug use and recovery of left atrial function support anticoagulant drug withdrawal provided that good atrial function is confirmed.

FURTHER WORK

Continued follow-up and long-term clinical effectiveness and cost-effectiveness analysis. Comparison of ablation methods.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN82731440.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 19. See the NIHR Journals Library website for further project information.

Left Atrial Size and Function in Patients With Congenital Aortic Valve Stenosis

Little information exists on left atrial (LA) function in healthy children and in patients with congenital aortic valve stenosis (AS). We sought to determine whether patients with significant congenital AS have detectable abnormalities in LA size and function compared with matched normal controls. Retrospective chart review and analysis of 2-dimensional echocardiographic images for phasic left atrial volumes (LAVs) and longitudinal LA strain by speckle tracking in children ≥1 years of age with ≥ moderate isolated congenital AS. LAVs and LA strain in AS cases were compared with age, gender, and body surface area-matched controls (healthy children with a normal echocardiogram). Between June 2004 and October 2012, there were 36 eligible AS cases [age 13 (range 3 to 27) years; 30 males] with a median maximal Doppler gradient of 63 (range 43 to 94) mm Hg. No significant interobserver and intraobserver differences were noted in the analyses of normal subjects. Significantly higher phasic body surface area-adjusted LAVs [preatrial contraction: p = 0.01; minimal: p = 0.04] and higher LA contractile function parameters [indexed active LA stroke volume: p = 0.03; peak negative strain p = 0.04] were noted in AS cases compared with matched controls. In conclusion, compared with normal, children with congenital AS have higher preatrial contraction and minimal phasic LA volumes and higher LA contractile function.

Association of Left Atrial Function Index with Atrial Fibrillation and Cardiovascular Disease: The Framingham Offspring Study

BACKGROUND

Left atrial (LA) size, a marker of atrial structural remodeling, is associated with increased risk for atrial fibrillation (AF) and cardiovascular disease (CVD). LA function may also relate to AF and CVD, irrespective of LA structure. We tested the hypothesis that LA function index (LAFI), an echocardiographic index of LA structure and function, may better characterize adverse LA remodeling and predict incident AF and CVD than existing measures.

METHODS AND RESULTS

In 1786 Framingham Offspring Study eighth examination participants (mean age, 66±9 years; 53% women), we related LA diameter and LAFI (derived from the LA emptying fraction, left ventricular outflow tract velocity time integral, and indexed maximal LA volume) to incidence of AF and CVD on follow-up. Over a median follow-up of 8.3 years (range, 7.5-9.1 years), 145 participants developed AF and 139 developed CVD. Mean LAFI was 34.5±12.7. In adjusted Cox regression models, lower LAFI was associated with higher risk of incident AF (hazard ratio=3.83, 95% confidence interval=2.23-6.59, lowest [Q1] compared with highest [Q4] LAFI quartile) and over 2-fold higher risk of incident CVD (hazard ratio=2.20, 95% confidence interval=1.32-3.68, Q1 versus Q4). Addition of LAFI, indexed maximum LA volume, or LA diameter to prediction models for AF or CVD did not significantly improve model discrimination for either outcome.

CONCLUSIONS

In our prospective investigation of a moderate-sized community-based sample, LAFI, a composite measure of LA size and function, was associated with incident AF and CVD. Addition of LAFI to the risk prediction models for AF or CVD, however, did not significantly improve their performance.

Left ventricular function in relation to chronic residential air pollution in a general population

Background

In view of the increasing heart failure epidemic and awareness of the adverse impact of environmental pollution on human health, we investigated the association of left ventricular structure and function with air pollutants in a general population.

Methods

In 671 randomly recruited Flemish (51.7% women; mean age, 50.4 years) we echocardiographically assessed left ventricular systolic strain and strain rate and the early and late peak velocities of transmitral blood flow and mitral annular movement (2005−2009). Using subject-level data, left ventricular function was cross-sectionally correlated with residential long-term exposure to air pollutants, including black carbon, PM2.5, PM10 (particulate matter) and nitrogen dioxide (NO2), while accounting for clustering by residential address and confounders.

Results

Annual exposures to black carbon, PM2.5, PM10 and NO2 averaged 1.19, 13.0, 17.7, and 16.8 µg/m³. Systolic left ventricular function was worse (p ≤ 0.027) with higher black carbon, PM2.5, PM10 and NO2 with association sizes per interquartile interval increment ranging from −0.339 to −0.458% for longitudinal strain and from −0.033 to −0.049 s⁻¹ for longitudinal strain rate. Mitral E and a′ peak velocities were lower (p ≤ 0.021) with higher black carbon, PM2.5 and PM10 with association sizes ranging from −1.727 to −1.947 cm/s and from −0.175 to −0.235 cm/s, respectively. In the geographic analysis, the systolic longitudinal strain sided with gradients in air pollution. The path analysis identified systemic inflammation as a possible mediator of associations with black carbon.

Conclusions

Long-term low-level air pollution is associated with subclinical impairment of left ventricular performance and might be a risk factor for heart failure.

Effect of ablation pattern on mechanical function in the atrium

BACKGROUND

Atrial fibrillation (AF) is often treated with catheter ablation, which induces scar formation to isolate misfiring electrical signals in the left atrium. Successful ablation restores sinus rhythm at the cost of replacing viable myocardium with scar. The impact of ablation scar on mechanical function of the left atrium is poorly understood.

OBJECTIVE

We used a computational model to simulate various ablation patterns and determine their effect on atrial global and regional mechanical function.

METHODS

A coupled finite-element and hemodynamic circuit model of the left atrium that represents the regional and global mechanics in paroxysmal AF patients was modified to simulate different ablation patterns: step-wise pulmonary vein isolation (PVI), wide area circumferential ablation (WACA), and a posterior ablation developed by nContact, Inc (Morrisville, NC, USA). Atrial pressure-volume relationships and regional wall motion were compared among the models.

RESULTS

Ablation increased passive stiffness and decreased active work performed by the atrium. Active emptying volume decreased with increasing scar by up to 44% (11 mL) at a scar volume of 31%. At matched scar volumes, WACA decreased active emptying more severely than PVI and nContact. Similarly, wall motion was depressed most in the WACA model because WACA involved portions of the lateral wall with higher baseline motion.

CONCLUSION

Simulated ablation depressed atrial mechanical function to an extent that depended on both scar volume and location, primarily through reducing active emptying. Placing ablation scar in regions with high baseline motion resulted in greater depression of active function, while ablation of the posterior wall was less disruptive.

Delayed and decreased LV untwist and unstrain rate in mutation carriers for hypertrophic cardiomyopathy

Background

The echocardiographic focus to detect abnormalities in genetically hypertrophic cardiomyopathy (HCM) affected subjects without left ventricular (LV) hypertrophy (G+/LVH-) has been on diastolic abnormalities in transmitral flow and longitudinal myocardial function with tissue Doppler imaging. The aim of this study was to assess diastolic LV unstrain and untwist.

Methods and results

Forty-one consecutive genotyped family members of HCM patients (mean age 37 ± 11 years, 16 men) and 41 age- and gender-matched healthy volunteers underwent speckle-tracking echocardiography to measure untwist and unstrain. No significant differences between G+/LVH- and control subjects were seen in maximal systolic twist and global longitudinal strain. In diastole, the early peak untwist rate was significantly lower in G+/LVH- subjects compared with control subjects (62 ± 19°s - 1 vs. 76 ± 30°s - 1, P <0.05), whereas the late peak untwist rate tended to be higher. Untwist from maximal twist until the first 20% of diastole was delayed in G+/LVH- subjects (39.3 ± 12.9% vs. 51.3 ± 15.6%, P <0.005). Late diastolic unstrain rate was significantly higher in G+/LVH- subjects in the inferoseptal wall (111 ± 33 s - 1 vs. 94 ± 32 s - 1, P = 0.024), the inferolateral wall (105 ± 42 vs. 75 ± 35 s - 1, P = 0.007) and the anteroseptal wall (97 ± 26 vs. 80 ± 23 s - 1, P = 0.010). Unstrain from maximal twist until the first 20% of diastole was delayed in G+/LVH- subjects in the inferoseptal (18.9 ± 14.0% vs. 30.1 ± 17.7%, P = 0.005), inferolateral (27.1 ± 16.3% vs. 39.2 ± 18.0%, P = 0.015) and anteroseptal (19.1 ± 14.7% vs. 35.8 ± 18.5%, P = 0.0003) segments.

Conclusions

In mutation carriers, for HCM LV, untwist and unstrain are delayed and untwist rate and unstrain rate are decreased.

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.

Complex evaluation of left atrial dysfunction in patients with type 1 diabetes mellitus by three-dimensional speckle tracking echocardiography: results from the MAGYAR-Path Study

OBJECTIVE

Changes in left atrial (LA) function can be observed in type 1 diabetes mellitus (T1DM). Three-dimensional (3-D) speckle tracking echocardiography (STE) seems to be a promising tool for volumetric and functional evaluation of LA. The objective of the present study was to compare 3DSTE-derived LA volumetric and strain parameters between T1DM patients and matched healthy controls.

METHODS

This prospective study consists of 17 subcutaneous insulin pump-treated non-obese patients with T1DM (mean age: 33.5±8.2 years, 8 males). To exclude possible cardiovascular disease, patients with complaints of chest pain, dyspnea, or signs of cerebrovascular disease or peripheral artery disease were not included. Their results were compared with 20 age-matched and gender-matched healthy controls (mean age: 36.9±11.0 years, 9 males). Independent sample Student t-test and Fisher's exact test were used for comparisons. Bland-Altman method was used for evaluating intraobserver and interobserver correlations.

RESULTS

Anemia and impaired renal function were not confirmed in T1DM patients. Calculated LA maximum and minimum volumes and LA volume before atrial contraction were significantly increased in T1DM patients. Total atrial stroke volume was increased (23.6±6.9 mL vs. 19.6±4.6 mL, p=0.04), whereas mean segmental circumferential peak strain was decreased (28.9%±11.4% vs. 37.3%±12.5%, p=0.04). Segmental basal longitudinal and area strains were increased, whereas segmental superior circumferential and area strains and midatrial 3-D strain were decreased in T1DM.

CONCLUSION

Both 3DSTE-derived volumetric and strain analysis confirmed alterations in LA function, suggesting early LA remodeling in patients with T1DM.

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

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

Left Atrial Intrinsic Strain Rate Correcting for Pulmonary Wedge Pressure Is Accurate in Estimating Pulmonary Vascular Resistance in Breathless Patients

OBJECTIVES

We hypothesized that left atrial deformation during atrial systole (LASRa) correlates with pulmonary capillary wedge pressure (PCWP), thus enabling echo-derived pulmonary vascular resistance (PVR) estimation in a wide range of different subsets of patients.

BACKGROUND

Various etiologies of pulmonary hypertension (PH) have different mechanisms and treatments for breathlessness. Irrespective of the location of the underlying pulmonary vascular pathology, pre- or postcapillary, the resulting PH is fairly easy to assess by Doppler echocardiography, but PVR remains a challenge.

METHODS

We prospectively included 46 patients (mean age 61 ± 13 years) in sinus rhythm, who underwent right heart catheterization because of dyspnea. According to the NICE guidelines classification, 22 belonged to group 1 pulmonary artery hypertension (PAH), 19 belonged to group 2 congestive heart failure (CHF), 1 belonged to group 4 chronic thromboembolic pulmonary hypertension (CTEPH), and 4 had normal hemodynamics. Simultaneous Doppler echocardiography using spectral, tissue Doppler, and speckle tracking echocardiography techniques for assessing LA structure and function was performed.

RESULTS

PCWPrhc correlated with LASRa (r(2) = 0.65, P < 0.001). PCWPecho was calculated using the equation (PCWPecho = 26.12 - 11.09 × LASRa), and the resulting PVR echo strongly correlated with the respective catheter-based measurements PVRrhc (r(2) = 0.69. P < 0.001) with a sensitivity of 85% and specificity of 74% identifying a PVR ≥ 3 WU.

CONCLUSIONS

Left atrial strain rate during atrial systole correlates closely with pulmonary capillary wedge pressure and consequently the calculated pulmonary vascular resistance, irrespective of the etiology of PH.

The effects of ivabradine on left atrial electromechanical function in patients with systolic heart failure

AIM

Heart rate (HR) reduction with ivabradine improves left ventricle filling by the prolongation of the diastolic time and increases stroke volume. But, it remains unclear what ivabradine's effect is on atrial conduction time and atrial mechanical functions. The aim of our study was to evaluate in stable outpatients with systolic heart failure (HF) the 3 months effect of ivabradine on atrial conduction time and mechanical functions.

METHOD

We evaluated prospectively 43 (31 males, 12 females) patients with HF. Before and after treatment, all patients were evaluated by transthoracic M mode, two dimensional (2D), pulsed-wave (PW), continuous wave (CW), color flow and tissue Doppler imaging (TDI), and LA volumes were obtained apical four-chamber views by a disc's method. LA maximum volume (Vmax) at the end-systolic phase, LA minimum volume (Vmin) at the end-diastolic phase, and LA volume before atrial systole (Vp) were evaluated. The LA function parameters were calculated as follows: LA passive emptying volume = Vmax - Vp; LA passive emptying fraction = [(Vmax - Vp)/Vmax] × 100%, LA active emptying volume = Vp - Vmin; LA active emptying fraction = [(Vp - Vmin)/Vp] × 100%.

RESULTS

Thirty men and 13 women with mean ± SD age of 63.9 ± 10.1 years were included in this study. Resting heart rate was significantly reduced after ivabradine treatment. There were no significantly difference in LVEF, and E/A before and after ivabradine treatment. LA diameter and Vmin were similar before and after ivabradine treatment (p = 0.793 and p = 0.284). However, Vmax and Vp were significantly decreased after ivabradine treatment (p = 0.040 and p = 0.012). Moreover, LA active emptying volume and LA active emptying fraction were significantly decreased after ivabradine treatment (p = 0.030 and p = 0.008). The PA lateral, septal, and tricuspid durations were significantly reduced after ivabradine treatment (p < 0.001, p < 0.001, and p = 0.002, respectively). Interatrial electromechanical delay and right intra-atrial electromechanical delay were significantly decreased after ivabradine treatment (33.7 ± 12.7 vs 26.2 ± 10.1, p = 0.001; and 14.1 ± 6.1 vs 9.2 ± 6.8, p < 0.001).

CONCLUSIONS

The present study demonstrated that adding ivabradine to the standard therapy reduced HR and improves significantly LA electrical and mechanical functions in systolic HF patients.

Evaluation of left atrial function by speckle tracking echocardiography in patients with systemic lupus erythematosus

Left atrial (LA) function plays a key role in maintaining optimal cardiac output. Left ventricular diastolic dysfunction (LVDD) has been reported in systemic lupus erythematosus (SLE), but whether LA functional abnormalities also occur in patients with SLE is unknown. Toward this aim we evaluated left atrial function and volume by strain and strain rate derived from speckle tracking echocardiography (STE) and their associations with LVDD. Sixty SLE patients were compared with age- and gender-matched normal controls. The LA strain (S) and strain rate (SR) during systole, early diastole and late diastole (SRs, SRe and SRa, respectively) were measured by STE. The LA volume index (LAVI), traditional parameters of LA and left ventricular diastolic function also were analysed. Global strain and positive SRe were significantly reduced in the SLE group compared with the control group (26.2% ± 9.5% vs 32.5% ± 9.8% and −2.4 ± 1.0 s−1 vs −3.1 ± 1.2 s−1, both p < 0.05). The SRs in the SLE and control groups were not significantly different (2.1 ± 0.7 s−1 vs 2.4 ± 0.8 s−1, p = 0.2). The positive SRa was increased in the SLE group compared with the control group (−2.1 ± 0.8 s−1 vs −1.6 ± 0.5 s−1, p < 0.05) and the LAVI was larger in the SLE group than in the control group (32.4 ± 8.0 vs 25.8 ± 7.1 ml/m2, p < 0.001). Patients with SLE exhibiting varying grades of LVDD displayed significant differences in LA parameters, including LAVI, SRs, SRe and SRa (all p < 0.05). Multivariate linear analysis additionally revealed that SLICC/ACR damage index (SDI) was independently and inversely associated with global strain, SRs and positive SRe. LA functions were changed in SLE patients, demonstrating impairment in conduit function, decrease in storage function and increase in pump function. Meanwhile, the magnitude of this impairment was predictively associated with the severity of LVDD. The results from this study demonstrate that STE is capable of detecting various aspects of LA functional impairment during SLE progression, and should be further explored as a diagnostic tool for improving the outcomes of SLE patients.

Evaluation of left atrial volume and function in systemic sclerosis patients using speckle tracking and real-time three-dimensional echocardiography

Objective:

The aim of the present study was to evaluate left atrial (LA) volume and functions using real-time three-dimensional echocardiography (RT3DE) and speckle tracking in systemic sclerosis (SSc) patients.

Methods:

The study was designed as a cross-sectional observational study. We studied 41 consecutive SSc patients (38 females, mean age: 49.5±11.6 years) and 38 healthy controls (35 females, mean age: 48.5±10.8 years). Patients with evidence or history of cardiovascular disease and patients with risk factors as hypertension, diabetes and chronic renal failure were excluded from the study. All study subjects underwent standard echocardiography; LA speckle tracking and RT3DE was performed to assess LA volume and phasic functions. Differences between numeric variables were tested using the independent sample Student’s t-test or Mann-Whitney U test, where appropriate.

Results:

There were no significant differences between SSC patients and controls regarding left ventricular (LV) systolic functions and two-dimensional (2-D) atrial diameters. Presence of LV diastolic dysfunction (LVDD) was evaluated and graded according to recommendations of the American Society of Echocardiography. Accordingly, LVDD was observed to be significantly more frequent in SSc patients; 16 SSc patients (39%) and 5 controls (12.8%) were observed to have LVDD (p=0.007). With regard to results obtained from RT3DE, LA maximum, minimum, and before atrial contraction volumes were significantly higher (40.5±14.6 vs. 32.6±8.9, 15.5±8.4 vs. 9.9±3.5 and 28.7±11.7 vs. 21.4±7.0 mL respectively, p<0.05 for all), whereas LA active emptying fraction, LA total emptying fraction, LA expansion index, and passive emptying fraction values were significantly (47.1±12.0 vs. 52.9±10.1%, 62.8±10.5 vs. 69.5±6.7%, 187.5±76.0 vs. 246.6±96.0, 29.6±9.3 vs. 34.4±11.0% respectively, p<0.05 for all) in SSc patients than in controls. In addition, regarding results obtained from speckle tracking echocardiography, atrial peak-systolic longitudinal strain (e), early negative strain rate (SR), late negative SR, and peak positive SR values were observed to be significantly lower in SSc patients.

Conclusion:

LA volumes were significantly increased, and LA reservoir, conduit, and contractile functions were significantly impaired in SSc patients compared with controls. LA volume and functional analyses with RT3DE and speckle tracking may facilitate the recognition of subtle LA dysfunction in SSc patients.

Reversible Changes of Left Atrial Function during Pregnancy Assessed by Two-Dimensional Speckle Tracking Echocardiography

BACKGROUND

Left ventricular diastolic function is impaired during pregnancy. However, changes in left atrial (LA) function remain unclear. We aimed to evaluate changes in LA function during pregnancy using two-dimensional speckle tracking echocardiography (2DSTE).

METHODS AND RESULTS

50 pregnant and 50 healthy nulliparous (control group) women were enrolled in this study. All pregnant women were followed up postpartum in sixth-month. The LA maximum volume, LA minimal volume and LA preatrial contraction volume were obtained using biplane modified Simpson's method. LA filling volume, LA expansion index, LA ejection fraction, passive volume, passive emptying index, active volume, and active emptying index were calculated. LA longitudinal systolic strain (SS), systolic strain rate (s-SR), early diastolic strain rate (e-SR), and late diastolic strain rate (a-SR) were obtained by 2DSTE. Compared to the control group, the reservoir function was increased in pregnant patients (P<0.05); conduit function was decreased in pregnant patients (P<0.05); booster pump function was increased in pregnant patients (P<0.05). There was no statistically significant difference between the control group and postpartum group.

CONCLUSIONS

LA reservoir and booster pump function were increased, while conduit function was decreased during pregnancy using 2DSTE. The changes were reversible. 2DSTE can easily assess LA function during pregnancy with good repeatability.