Effects of aging on left atrial reservoir, conduit, and booster pump function: a multi-institution acoustic quantification study

Risks factors of adverse clinical outcomes in asymptomatic mitral regurgitation patients with preserved ejection fraction: a systematic review and meta-analysis

INTRODUCTION AND OBJECTIVE

Indication for mitral valve (MV) surgery in asymptomatic mitral regurgitation (MR) patients with preserved ejection fraction (EF) remains unclear. This study aims to identify risk factors of adverse clinical outcomes in asymptomatic MR patients with preserved EF for early indication of MV surgery.

METHODS

3 databases were systematically searched to include studies with asymptomatic MR patients with preserved EF. Risk factors of adverse clinical outcomes (composite outcome of MACE and MV surgery indication), mortality, and left ventricular dysfunction (LVD) are pooled with a meta-analysis of random effect model.

RESULTS

A total of 39 observational studies with 9135 asymptomatic moderate to severe MR patients are included. We identified 21 statistically significant risk factors for adverse outcomes. Increased natriuretic peptide, presence of atrial fibrillation, LV GLS > 20%, LVEDD > 35 mm, LVESD > 22 mm, and LAVI > 55 ml/mm2, ERO > 55mm2, and regurgitation volume > 60 ml (HR 2.21, 2.07, 4.23, 2.98, 4.05, 1.84, 4.02, 3.30, respectively; p-value < 0.05; I2 0-87%) are associated with greater risk of adverse clinical outcome. Risk factors associated with postoperative LVD are the increase of LVEDD, LVESD, and RVSP. Risk factors associated with mortality are increasing STS score and LV GLS.

CONCLUSION

Several clinical parameters and risk factors can be used to stratify asymptomatic MR patients with preserved ejection fraction who could benefit from early indication for MV surgery.

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.

Left atrial remodeling in adolescents with obesity evaluated by speckle-tracking echocardiography

BACKGROUND AND AIMS

In adolescents with obesity, a left atrial (LA) enlargement has been reported. However, data regarding its function and its stiffness are missing. The aim of this study was to describe LA morphology and function, using speckle-tracking echocardiography (STE) and to explore their potential determinants in adolescents with obesity.

METHODS

Twenty-eight adolescent women with obesity (13.2 ± 1.4 yr) with an illness duration of 130 ± 27 months and 33 controls (14.1 ± 2.0 yr) underwent a resting echocardiography including an analysis of left ventricular (LV) and LA morphologies and strains. A fasting venous blood sample was performed to biochemical determinations including inflammation markers.

RESULTS

LA volume and stiffness index were increased in adolescents with obesity compared to controls. LA reservoir, conduit and booster pump functions were not different between groups. By stepwise forward multivariate regression analyses, systolic blood pressures, cardiac output and sedimentation rate were the independent determinants of LA volume (p < 0.0001, β-coefficient = 0.460) whereas only the body mass index was an independent determinant of LA stiffness (p = 0.003, β-coefficient = 0.413).

CONCLUSION

In adolescents with obesity, we observed a specific LA remodeling, including higher volume and lower stiffness, which could constitute early signs of an altered LV diastolic function.

Metabolic landscape in cardiac aging: insights into molecular biology and therapeutic implications

Cardiac aging is evident by a reduction in function which subsequently contributes to heart failure. The metabolic microenvironment has been identified as a hallmark of malignancy, but recent studies have shed light on its role in cardiovascular diseases (CVDs). Various metabolic pathways in cardiomyocytes and noncardiomyocytes determine cellular senescence in the aging heart. Metabolic alteration is a common process throughout cardiac degeneration. Importantly, the involvement of cellular senescence in cardiac injuries, including heart failure and myocardial ischemia and infarction, has been reported. However, metabolic complexity among human aging hearts hinders the development of strategies that targets metabolic susceptibility. Advances over the past decade have linked cellular senescence and function with their metabolic reprogramming pathway in cardiac aging, including autophagy, oxidative stress, epigenetic modifications, chronic inflammation, and myocyte systolic phenotype regulation. In addition, metabolic status is involved in crucial aspects of myocardial biology, from fibrosis to hypertrophy and chronic inflammation. However, further elucidation of the metabolism involvement in cardiac degeneration is still needed. Thus, deciphering the mechanisms underlying how metabolic reprogramming impacts cardiac aging is thought to contribute to the novel interventions to protect or even restore cardiac function in aging hearts. Here, we summarize emerging concepts about metabolic landscapes of cardiac aging, with specific focuses on why metabolic profile alters during cardiac degeneration and how we could utilize the current knowledge to improve the management of cardiac aging.

Left atrial size predicts outcome in severe but asymptomatic mitral regurgitation

Patients with severe asymptomatic primary mitral regurgitation (MR) can be safely managed with an active surveillance strategy. Left atrial (LA) size is affected by MR severity, left ventricular function and is also associated with the risk of atrial fibrillation and may be an integrative parameter for risk stratification. The present study sought to determine the predictive value of LA size in a large series of asymptomatic patients with severe MR. 280 consecutive patients (88 female, median age 58 years) with severe primary MR and no guideline-based indications for surgery were included in a follow-up program until criteria for mitral surgery were reached. Event-free survival was determined and potential predictors of outcome were assessed. Survival free of any indication for surgery was 78% at 2 years, 52% at 6 years, 35% at 10 years and 19% at 15 years, respectively. Left atrial (LA) diameter was the strongest independent echocardiographic predictor of event-free survival with incremental predictive value for the thresholds of 50, 60 and 70 mm, respectively. In a multivariable analysis that encompassed age at baseline, previous history of atrial fibrillation, left ventricular end systolic diameter), LA diameter, sPAP > 50 mmHg and year of inclusion, LA diameter was the strongest independent echocardiographic predictor of event-free survival (adjusted HR = 1.039, p < 0.001). LA size is a simple and reproducible predictor of outcome in asymptomatic severe primary MR. In particular, it may help to identify patients who may benefit from early elective valve surgery in heart valve centers of excellence.

Left Atrial Velocity Vector Imaging Can Assess Early Diastolic Dysfunction in Left Ventricular Hypertrophy and Hypertrophic Cardiomyopathy

BACKGROUND

The function of left atrium (LA) is difficult to assess because of its ventricle-dependent, dynamic movement. The aim of this study was to assess LA function using velocity vector imaging (VVI) and compare LA function in patients with hypertrophic cardiomyopathy (HCMP) and left ventricular hypertrophy (LVH) with normal controls.

METHODS

Fourteen patients with HCMP (72% male, mean age of 52.6 ± 9.8), 15 hypertensive patients with LVH (88% male, mean age of 54.0 ± 15.3), and 10 age-matched controls (83% male, mean age of 50.0 ± 4.6) were prospectively studied. Echocardiographic images of the LA were analyzed with VVI, and strain rate (SR) was compared among the 3 groups.

RESULTS

The e' velocity (7.7 ± 1.1; 5.1 ± 0.8; 4.5 ± 1.3 cm/sec, p = 0.013), E/e' (6.8 ± 1.6; 12.4 ± 3.3; 14.7 ± 4.2, p = 0.035), and late diastolic SR at mid LA (-1.65 ± 0.51; -0.97 ± 0.55; -0.82 ± 0.32, p = 0.002) were significantly different among the groups (normal; LVH; HCMP, respectively). The e' velocity, E/e', and late diastolic SR at mid LA were significantly different between normal and LVH (p = 0.001; 0.022; 0.018), whereas LA size was similar between normal and LVH (p = 0.592). The mean late diastolic peak SR of mid LA was significantly correlated with indices of diastolic function (E/e', e', and LA size).

CONCLUSIONS

The SR is a useful tool for detailed evaluation of LA function, especially early dysfunction of LA in groups with normal LA size.

Long-term prognostic value of left atrial longitudinal strain in an elderly community-based cohort

Despite the well-known importance of left atrial (LA) mechanics in diastolic function, data are scarce regarding the prognostic power of LA longitudinal strain and its potential added value in the risk stratification of an elderly population. Accordingly, our aim was to determine the long-term prognostic importance of 2D speckle-tracking echocardiography-derived peak atrial longitudinal strain (PALS) in a community-based screening sample. Three hundred and fourteen volunteers were retrospectively identified from a population-based screening program (mean age 62 ± 11 years; 58% female) with a median follow-up of 9.5 years. All subjects who participated in the screening program underwent 2D echocardiography to measure left ventricular (LV) ejection fraction (EF), global longitudinal strain (GLS), and PALS, as well as low-dose cardiac CT to determine the Agatston score. The primary endpoint was all-cause mortality. Thirty-nine subjects (12.4%) met the primary endpoint. Subjects with adverse outcomes had significantly lower LV GLS (dead vs. alive; - 19.2 ± 4.3 vs. - 20.6 ± 3.5%, p < 0.05) and PALS (32.3 ± 12.0 vs. 41.8 ± 14.2%, p < 0.001), whereas LV EF did not show a difference between the two groups (51.1 ± 7.0 vs. 52.1 ± 6.2, %, p = NS). By multivariable Cox regression analysis, PALS was found to be a significant predictor of adverse outcomes independent of LV GLS, and Agatston and Framingham scores. In subjects with PALS values below the standard cut-off of 39%, the risk of all-cause mortality was almost 2.5 times higher (hazard ratio: 2.499 [95% confidence interval: 1.334-4.682], p < 0.05). Beyond the assessment of LV EF and LV GLS, PALS offers incremental value in cardiovascular risk stratification in a community-based elderly cohort. PALS was found to be a significant and independent predictor of long-term mortality among other classical cardiovascular risk estimators.

Quantification of Left Atrial Size and Function in Cardiac MR in Correlation to Non-Gated MR and Cardiovascular Risk Factors in Subjects without Cardiovascular Disease: A Population-Based Cohort Study

Background: In magnetic resonance imaging (MRI), the comparability of gated and non-gated measurements of the left atrial (LA) area and function and their association with cardiovascular risk factors have not been firmly established. Methods: 3-Tesla MRIs were performed on 400 subjects enrolled in the KORA (Cooperative Health Research in the Augsburg Region) MRI study. The LA maximum and minimum sizes were segmented in gated CINE four-chamber sequences (LAmax and LAmin) and non-gated T1 VIBE-Dixon (NGLA). The area-based LA function was defined as LAaf = (LAmax − LAmin)/LAmax. Inter-and intra-reader reliability tests were performed (n = 31). Linear regression analyses were conducted to link LA size and function with cardiovascular risk factors. Results: Data from 378 subjects were included in the analysis (mean age: 56.3 years, 57.7 % male). The measurements were highly reproducible (all intraclass correlation coefficients ≥ 0.98). The average LAmax was 19.6 ± 4.5 cm2, LAmin 11.9 ± 3.5 cm2, NGLA 16.8 ± 4 cm2 and LAaf 40 ± 9%. In regression analysis, hypertension was significantly associated with larger gated LAmax (β = 1.30), LAmin (β = 1.07), and non-gated NGLA (β = 0.94, all p ≤ 0.037). Increasing age was inversely associated with LAaf (β = −1.93, p < 0.001). Conclusion: LA enlargement, as measured in gated and non-gated CMR is associated with hypertension, while the area-based LA function decreases with age.

Determinants of left atrioventricular coupling index: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Recent studies have described a novel left atrioventricular coupling index (LACI), which had a better prognostic value in predicting cardiovascular events than individual left atrial (LA) or left ventricular (LV) variables.

AIMS

To identify determinants of LACI and its 10-year annual change (ΔLACI), measured by cardiac magnetic resonance (CMR), and to better understand the variables governing this left atrioventricular coupling.

METHODS

In the Multi-Ethnic Study of Atherosclerosis, 2112 study participants, free from cardiovascular disease at baseline, had LACI assessed by CMR imaging at baseline (LACI_Baseline; 2000-2002) and 10 years later (2010-2012). The LACI was defined as the ratio of LA to LV end-diastolic volumes. Linear regression analyses were performed to identify independent determinants of LACI_Baseline and ΔLACI.

RESULTS

In the 2112 participants (mean age 58.8±9.1 years; 46.6% male), after adjustment for all covariates, age was independently associated with LACI_Baseline (R²=0.10, slope=0.16) and ΔLACI (R²=0.15, slope=0.008; both P<0.001). African Americans had the highest LACI_Baseline value (18.0±7.7%). Although there was no difference in LACI_Baseline between women and men (P=0.19), ΔLACI was higher in women (1.0±1.1 vs 0.8±1.1%/year; P<0.001). Diabetes and higher body mass index (BMI) were independently associated with LACI_Baseline (both P<0.001). LACI_Baseline was independently associated with LV myocardial fibrosis markers (native T1: R²=0.11, slope=0.09 [P=0.038]; extracellular volume: R²=0.08, slope=0.28 [P=0.035]) and N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) concentration (R²=0.10, slope=-1.11; P<0.001), but was not associated with interleukin 6 or high-sensitivity C-reactive protein.

CONCLUSIONS

Age, sex, ethnicity, diabetes and BMI were independent determinants of LACI. LACI was independently associated with myocardial fibrosis markers and NT-proBNP concentration.

Incremental value of left atrial booster and reservoir strain in predicting atrial fibrillation in patients with hypertrophic cardiomyopathy: a cardiovascular magnetic resonance study

BACKGROUND

Left atrial (LA) size and function are known predictors of new onset atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) patients. Components of LA deformation including reservoir, conduit, and booster function provide additional information on atrial mechanics. Whether or not LA deformation can augment our ability to predict the risk of new onset AF in HCM patients beyond standard measurements is unknown.

METHODS

We assessed LA size, function, and deformation on cardiovascular magnetic resonance (CMR) in 238 genotyped HCM patients and compared this with twenty age, sex, blood pressure and body mass index matched control subjects. We further evaluated the determinants of new onset AF in HCM patients.

RESULTS

Compared to control subjects, HCM patients had higher LA antero-posterior diameter, lower LA ejection fraction and lower LA reservoir (19.9 [17.1, 22.2], 21.6 [19.9, 22.9], P = 0.047) and conduit strain (10.6 ± 4.4, 13.7 ± 3.3, P = 0.002). LA booster strain did not differ between healthy controls and HCM patients, but HCM patients who developed new onset AF (n = 33) had lower booster strain (7.6 ± 3.3, 9.5 ± 3.0, P = 0.001) than those that did not (n = 205). In separate multivariate models, age, LA ejection fraction, and LA booster and reservoir strain were each independent determinants of AF. Age ≥ 55 years was the strongest determinant (HR 6.62, 95% CI 2.79-15.70), followed by LA booster strain ≤ 8% (HR 3.69, 95% CI 1.81-7.52) and LA reservoir strain ≤ 18% (HR 2.56, 95% CI 1.24-5.27). Conventional markers of HCM phenotypic severity, age and sudden death risk factors were associated with LA strain components.

CONCLUSIONS

LA strain components are impaired in HCM and, together with age, independently predicted the risk of new onset AF. Increasing age and phenotypic severity were associated with LA strain abnormalities. Our findings suggest that the routine assessment of LA strain components and consideration of age could augment LA size in predicting risk of AF, and potentially guide prophylactic anticoagulation use in HCM.

Hemodynamic function of the right ventricular-pulmonary vascular-left atrial unit: normal responses to exercise in healthy adults

With each heartbeat, the right ventricle (RV) inputs blood into the pulmonary vascular (PV) compartment, which conducts blood through the lungs at low pressure and concurrently fills the left atrium (LA) for output to the systemic circulation. This overall hemodynamic function of the integrated RV-PV-LA unit is determined by complex interactions between the components that vary over the cardiac cycle but are often assessed in terms of mean pressure and flow. Exercise challenges these hemodynamic interactions as cardiac filling increases, stroke volume augments, and cycle length decreases, with PV pressures ultimately increasing in association with cardiac output. Recent cardiopulmonary exercise hemodynamic studies have enriched the available data from healthy adults, yielded insight into the underlying mechanisms that modify the PV pressure-flow relationship, and better delineated the normal limits of healthy responses to exercise. This review will examine hemodynamic function of the RV-PV-LA unit using the two-element Windkessel model for the pulmonary circulation. It will focus on acute PV and LA responses that accommodate increased RV output during exercise, including PV recruitment and distension and LA reservoir expansion, and the integrated mean pressure-flow response to exercise in healthy adults. Finally, it will consider how these responses may be impacted by age-related remodeling and modified by sex-related cardiopulmonary differences. Studying the determinants and recognizing the normal limits of PV pressure-flow relations during exercise will improve our understanding of cardiopulmonary mechanisms that facilitate or limit exercise.

Left atrial structural and functional remodeling following balloon mitral valvuloplasty

Mitral stenosis (MS) is associated with left atrial (LA) functional and morphological changes as a result of chronic increase in LA pressure. Relieving the mitral obstruction via balloon mitral valvuloplasty (BMV) might be associated with LA structural and functional remodeling. To study alterations of LA volume and functions 1 year following successful BMV in patients with isolated rheumatic severe mitral stenosis. Thirty patients (median age 33 years, 22 women) with severe rheumatic MS were included in the study. Using biplane method, trans-thoracic 2D echocardiography was used to estimate LA volume indexed to body surface area (BSA). Maximal, minimal and pre-A left atrial volumes were measured and indexed to BSA. LA volumetric functions were then assessed and the measurements were repeated 6 months and 1 year after successful valvuloplasty. At baseline, median mitral valve area (MVA) was 0.9 (0.6-1.3) cm² measured by planimetry with a mean pressure gradient of 12.5 (8-24) mmHg. Following BMV, a significant regression of left atrial volume index was noticed at 6 months compared to baseline (51 vs. 60 ml/m², p = 0.001) with a further decrease at 1 year (48 vs. 51 ml/m², p = 0.03). At 6 months, volumetric assessment of left atrial functions showed a significant improvement in LA total emptying fraction (42% vs 30%, p = 0.001) as well as in LA passive emptying fraction (26% vs 14%, p = 0.033) and LA active emptying fraction (20% vs. 18%, p = 0.016). All these indices showed further improvement at 1 year [47% (P = 0.02), 29% (p = 0.03) and 31% (p = 0.001) respectively]. In patients with isolated rheumatic MS, mitral valvuloplasty was associated with a significant decline of LA volume accompanied by a significant improvement of its volumetric functions.

Left atrial anteroposterior diameter in dogs: reference interval, allometric scaling, and agreement with the left atrial-to-aortic root ratio

Left atrial enlargement (LAE) is a well-known negative prognostic factor in dogs with myxomatous mitral valve disease (MMVD). Left atrial-to-aortic root ratio (LA/Ao) is the most commonly used method to evaluate left atrial (LA) size in dogs, while the left atrial anteroposterior diameter (LAD) has been proposed as an additional measurement of LA size in different species. The aim of this study was to establish a normal reference range of LAD normalized to body weight (LADn) in dogs using allometric scales, and to evaluate the agreement between LADn and LA/Ao in the detection of LAE in dogs with MMVD. This was a retrospective, multicenter, observational study. We included 330 healthy dogs, 30 dogs with MMVD in ACVIM stage B1, 30 dogs in ACVIM stage B2, and 30 dogs in ACVIM stage C. The reference range for the LAD, depending on body weight, was between 16.91 mm and 49.68 mm. The reference range for the LADn in healthy dogs was between 10.49 and 15.72. LADn was significantly greater in dogs with MMVD compared to healthy dogs, and a significant difference in LADn was noted between different ACVIM stages (P<0.001). The most accurate cut-off value of LADn to differentiate between dogs in groups B2 and C was 20.3 (sensitivity, 83.3%; specificity, 83.3%). There was a misclassification rate of 37% between LADn and LA/Ao in the detection of LAE in group B1. This study provides a normal reference range for LAD in dogs, which can be used as an additional tool to assess LAE in dogs with MMVD.

Burden of premature atrial beats in middle-aged endurance athletes with and without lone atrial fibrillation versus sedentary controls

BACKGROUND

The burden of premature atrial beats (PABs) at 24-h electrocardiographic (ECG) monitoring correlates with the risk of atrial fibrillation. It is unknown whether prolonged and intense exercise increases the burden of PABs, thus contributing to the higher prevalence of atrial fibrillation observed in middle-aged athletes.

METHODS

We compared the burden of PABs at 24-h ECG monitoring off therapy in 134 healthy middle-aged (30-60-year-old) competitive athletes who had practised 9 (7-11) h of endurance sports for 8 (4-15) consecutive years, 134 age- and gender-matched healthy sedentary individuals, and 66 middle-aged patients (20 athletes and 46 non-athletes) with 'lone' paroxysmal atrial fibrillation.

RESULTS

More than 50 PABs/24 h or ≥1 run of ≥3 PABs were recorded in 23/134 (17%) healthy athletes and in 29/134 (22%) sedentary controls (p = 0.61). Healthy athletes with frequent or repetitive PABs were older (median 50 years vs. 43 years, p < 0.01) and had practised sport for a longer time (median 10 years vs. 6 years, p = 0.03). At multivariable analysis only age (odds ratio 1.11, 95% confidence interval 1.04-1.20, p < 0.01) remained an independent predictor of a higher burden of PABs. Also among patients with 'lone' paroxysmal atrial fibrillation, there was no difference in the prevalence of >50 PABs/24 h or ≥1 run of ≥3 PABs between athletes (40%) and controls (48%, p = 0.74).

CONCLUSIONS

Middle-aged endurance athletes, with or without paroxysmal atrial fibrillation, did not show a higher burden of PABs at 24-h ECG monitoring than sedentary controls. Age, but not intensity and duration of sports activity, predicted a higher burden of PABs among healthy athletes.

Sex-specific echocardiographic reference values: the women's point of view

: Clinical presentation, diagnosis and outcomes of cardiac diseases are influenced by the activity of sex steroid hormones. These hormonal differences explain the later development of heart diseases in women in comparison with men and the different clinical picture, management and prognosis. Echocardiography is a noninvasive and easily available technique for the analysis of cardiac structure and function. The aim of the present review is to underline the most important echocardiographic differences between sexes. Several echocardiographic studies have found differences in healthy populations between women and men. Sex-specific difference of some of these parameters, such as left ventricular (LV) linear dimensions and left atrial volume, can be explained on the grounds of smaller body size of women, but other parameters (LV volumes, stroke volume and ejection fraction, right ventricular size and systolic function) are specifically lower in women, even after adjusting for body size and age. Sex-specific differences of standard Doppler and Tissue Doppler diastolic indices remain controversial, but it is likely for aging to affect LV diastolic function more in women than in men. Global longitudinal strain appears to be higher in women during the childbearing age - a finding that also highlights a possible hormonal influence in women. All these findings have practical implications, and sex-specific reference values are necessary for the majority of echocardiographic parameters in order to distinguish normalcy from disease. Careful attention on specific cut-off points in women could avoid misinterpretation, inappropriate management and delayed treatment of cardiac diseases such as valvular disease and heart failure.

In-depth echocardiographic analysis of left atrial function in healthy adults using speckle tracking echocardiography and volumetric analysis

Purpose

Left atrial (LA) dilatation is predictive for complications in a multitude of cardiac diseases; therefore, adequate assessment is essential. Technological advances have made it possible to quantify LA function with Speckle Tracking Echocardiography (STE); however, there are currently no recommendations for normal values with regard to LA function. We aimed to assess LA myocardial and volumetric function in a healthy cohort and investigate correlations with baseline characteristics.

Methods

This prospective cohort study included 147 (aged 20–72) healthy individuals and assessed LA volumetric function using maximum, minimum and pre‐a‐wave volumes and myocardial function using reservoir function using peak strain in LA relaxation (LA‐strain), conduit function using peak strain rate in early LA contraction (LA‐SRe) and pump function using peak strain rate in late LA contraction (LA‐SRa).

Results

Mean LA‐strain was 39.7 ± 6.2%, LA‐SRe −2.78 ± 0.62 s⁻¹ and LA‐SRa −2.56 ± 0.62 s⁻¹. Subjects were divided into 5 age decades (each 50% female). LA‐strain and LA‐SRe were lower in the oldest groups, whereas LA‐SRa was higher. LA‐SRa was higher in males(−2.69 ± 0.68 s⁻¹ vs −2.42 ± 0.52 s⁻¹). Age‐specific values are provided. Age proved to be an independent predictor for LA‐SRa after correction for blood pressure and heart rate. LA expansion index and passive emptying fraction decreased with age, while active emptying fraction increased with age. LA maximum volume did not increase with age.

Conclusion

This study provides normal values for the three phasic functions of the LA, assessed with STE and volumetric function. Our results suggest the need for age‐specific reference ranges, and normal values for this cohort have been calculated.

Left atrial size and function in a South Asian population and their potential influence on the risk of atrial fibrillation

BACKGROUND

South Asians have a low prevalence of atrial fibrillation (AF) compared with Caucasians despite having a higher prevalence of conventional risk factors for the arrhythmia. The reason for this disparity is uncertain but may be due to ethnic differences in atrial morphology. This study examines the association between ethnicity and left atrial (LA) size and function in South Asian and Caucasian subjects using the reference technique of cardiovascular magnetic resonance imaging (MRI).

HYPOTHESIS

South Asians have smaller LA size and therefore increased LA function.

METHODS

Retrospective case-control study of 60 South Asian and 60 Caucasian patients who had undergone a clinically indicated MRI between April 2010 and October 2017 and had been found to have a structurally normal heart. LA and left ventricular (LV) volume and function were assessed and compared between the ethnicities.

RESULTS

In comparison with Caucasians, South Asians had significantly lower minimum (27.7 ± 11.1 mL vs 34.9 ± 12.3 mL, P = 0.002) and maximum LA volumes (64.7 ± 21.1 mL vs 80.9 ± 22.5 mL, P < 0.001), lower LV end-diastolic volume (P < 0.001), lower LV stroke volume (P < 0.001), and lower LV mass (P = 0.022) and these values remained significant after correcting for body surface area. Further analysis revealed that LA volume was independently associated with South Asian ethnicity. There was no difference in LA function between the ethnic groups.

CONCLUSIONS

South Asians have reduced LA volumes and a proportionally smaller heart size in comparison to Caucasians. Smaller LA size may protect against the development of AF by reducing the risk of reentrant circuit formation and atrial fibrosis development.

The aging heart

As the elderly segment of the world population increases, it is critical to understand the changes in cardiac structure and function during the normal aging process. In this review, we outline the key molecular pathways and cellular processes that underlie the phenotypic changes in the heart and vasculature that accompany aging. Reduced autophagy, increased mitochondrial oxidative stress, telomere attrition, altered signaling in insulin-like growth factor, growth differentiation factor 11, and 5'- AMP-activated protein kinase pathways are among the key molecular mechanisms underlying cardiac aging. Aging promotes structural and functional changes in the atria, ventricles, valves, myocardium, pericardium, the cardiac conduction system, and the vasculature. We highlight the factors known to accelerate and attenuate the intrinsic aging of the heart and vessels in addition to potential preventive and therapeutic avenues. A greater understanding of the processes involved in cardiac aging may facilitate our ability to mitigate the escalating burden of CVD in older individuals and promote healthy cardiac aging.

Pulmonary vein isolation combined with spironolactone or renal sympathetic denervation in patients with chronic kidney disease, uncontrolled hypertension, paroxysmal atrial fibrillation, and a pacemaker

BACKGROUND

Atrial fibrillation (AF) commonly occurs in chronic kidney disease (CKD), occasioning adverse outcomes. Merging pulmonary vein isolation (PVI) and renal sympathetic denervation (RSD) may decrease the recurrence of AF in subjects with CKD and uncontrolled hypertension. We considered that RSD could reduce the recurrence of AF in patients with CKD by modulating sympathetic hyperactivity. We aimed to evaluate the impact of RSD or spironolactone 50 mg/day associated with PVI in reducing systolic blood pressure (BP), AF recurrence, and AF burden in patients with a history of paroxysmal AF and mild CKD.

METHODS

This was a single-center, prospective, longitudinal, randomized, double-blind study. The individuals were randomly divided into two groups (PVI + spironolactone, n = 36, and PVI + RSD, n = 33). All of them were followed for exactly 1 year to assess maintenance of sinus rhythm and to monitor the other variables.

RESULTS

Ambulatory BP measurements were reduced in both groups and at the 12th month also differed between groups. Significantly more patients in the PVI + RSD (61%) than in the PVI + spironolactone group (36%) were AF-free at the 12th month of follow-up, P = 0.0242. Toward the end of the study, the mean AF burden was lower in the PVI + RSD group as compared to PVI + spironolactone group, at the 9th month: ∆ = - 10% (P < 0.0001), and at the 12th month: ∆ = - 12% (P < 0.0001), respectively.

CONCLUSIONS

PVI + RSD is safe and appears to be superior to PVI + spironolactone in BP reduction, augmentation of AF event-free rate, reduction of AF burden, and improvement of renal function.

Adult echocardiographic nomograms: overview, critical review and creation of a software for automatic, fast and easy calculation of normal values

There is a crescent interest on normal adult echocardiographic values and the introduction of new deformation imaging and 3D parameters pose the issue of normative data. A multitude of nomograms has been recently published, however data are often fragmentary, difficult to find, and their strengths/limitations have been never evaluated.

AIMS

(I) to provide a review of current echocardiographic nomograms; (II) to generate a tool for easy and fast access to these data. A literature search was conducted accessing the National Library of Medicine using the keywords: 2D/3D echocardiography, strain, left/right ventricle, atrial, mitral/tricuspid valve, aorta, reference values/nomograms/normal values. Adding the following keywords, the results were further refined: range/intervals, myocardial velocity, strain rate and speckle tracking. Forty one published studies were included. Our study reveals that for several of 2D/3D parameters sufficient normative data exist, however, a few limitations still persist. For some basic parameters (i.e., mitral/tricuspid/pulmonary valves, great vessels) and for 3D valves data are scarce. There is a lack of studies evaluating ethnic differences. Data have been generally expressed as mean values normalised for gender and age instead of computing models incorporating different variables (age/gender/body sizes) to calculate z scores. To summarize results a software (Echocardio-Normal Values) who automatically calculate range of normality for a broad range of echocardiographic measurements according to age/gender/weight/height, has been generated. We provide an up-to-date and critical review of strengths/limitation of current adult echocardiographic nomograms. Furthermore we generated a software for automatic, easy and fast access to multiple echocardiographic normative data.

The effects of different physical activities on atrial fibrillation in patients with hypertension and chronic kidney disease

Background

Atrial fibrillation (AF) is highly common, and is most frequently observed in individuals with hypertension and structural cardiac disease. Sympathetic hyperactivity plays a fundamental role in the progression, maintenance and aggravation of arrhythmia. Endurance exercise training clearly lowers sympathetic activity in sympathoexcitatory disease states, and is well-tolerated by patients with chronic kidney disease (CKD).

Methods

We assessed 50 CKD patients with hypertension. Each patient provided a complete medical history and underwent a physical examination. We used an implantable cardiac monitor over a 3-year follow-up period to evaluate the effects of high-intensity interval training (HIIT) and moderate exercise (ModEx) physical activity protocols on AF occurrence, and determined the effectiveness of these protocols in improving renal function. Subjects were followed up every 6 months after the beginning of the intervention.

Results

During the 3-year follow-up, AF onset was higher in CKD patients who engaged in HIIT (72%) than in those who engaged in ModEx (24%) (hazard ratio, 3.847; 95% confidence interval, 1.694–8.740, P = 0.0013 by log-rank test). Both groups exhibited significant intra-group changes in the mean systolic 24-hour ambulatory blood pressure measurements (ABPM) between baseline and 12, 24, and 36 months. There were also significant differences in the mean systolic 24-hour ABPM between the groups at the same time points.

Conclusion

In CKD patients with hypertension, improvements in AF onset, renal function and some echocardiographic parameters were more evident in subjects who engaged in ModEx than in those who engaged in HIIT during 3 years of follow-up.

The effect of the physical activity on polymorphic premature ventricular complexes in chronic kidney disease

BACKGROUND

Polymorphic premature ventricular complexes (PVCs) are very common, appearing most frequently in patients with hypertension, obesity, sleep apnea, and structural heart disease. Sympathetic hyperactivity plays a critical role in the development, maintenance, and aggravation of ventricular arrhythmias. Endurance exercise training clearly lowers sympathetic activity in sympatho-excitatory disease states and may be tolerated by patients with chronic kidney disease (CKD).

METHODS

We assessed 40 CKD patients with hypertension with polymorphic PVCs. Patients underwent a complete medical history and physical examination. We evaluated the effectiveness of β blocker only or β blocker + exercise during 12 months of follow-up regarding the changes of the numbers of PVCs and mean heart rate (HR) by 24-hour-Holter.

RESULTS

We observed in the β blocker group a significant decrease in the number of polymorphic PVCs from baseline 36,515 ± 3,518 to 3, 6, 9 and 12 months of follow-up, 28,314 ± 2,938, 23,709 ± 1,846, 22,564 ± 1,673, and 22,725 ± 1,415, respectively (P < 0.001). In the β blocker + exercise group a significant decrease in the number of polymorphic PVCs also occurred from baseline 36,091 ± 3,327 to 3, 6, 9 and 12 months of follow-up, 29,252 ± 3,211, 20,948 ± 2,386, 14,238 ± 3,338, and 6,225 ± 2,319, respectively (P < 0.001). Comparisons between the two groups at the same time point showed differences from the sixth month onwards: the 6th (Δ = -2,761, P = 0.045), 9th (Δ = -8,325, P < 0.001) and 12th (Δ = -16,500, P < 0.001) months. There was an improvement during the 12 months of follow-up vs. baseline, after the β blocker or β blocker + exercise in mean 24-hour HR Holter monitoring, creatinine values, eGFR, and ACR.

CONCLUSION

Polymorphic PVCs may be modifiable by physical activity in CKD patients with hypertension without structural heart disease.

Left Atrial Volume Assessed by Coronary Computed Tomography in Mid Ventricular Diastasis Predicts Adverse Events

PURPOSE

Previous studies have demonstrated that left atrial (LA) volume has incremental prognostic value in predicting major adverse cardiac events (MACE). However, the predictive ability of LA volume in mid diastasis has not been investigated. We determined the incremental predictive value of LA volume indexed to body surface area (LAVi) measured in mid ventricular diastasis.

MATERIALS AND METHODS

A total of 96 patients with MACE (all-cause mortality and nonfatal myocardial infarction) were matched to 96 controls without adverse events on follow-up. Coronary computed tomographic angiography images were reconstructed at the 75% phase (mid ventricular diastasis). LA volumes were measured and indexed to the body surface area. The predictive value of LAVi was assessed using Cox proportional hazard models for the MACE.

RESULTS

LAVi was significantly larger (P<0.001) in the cases with adverse clinical outcomes (63.8±2.1 mL/m) versus the controls (50.3±1.2 mL/m). In a multivariate analysis, both significant coronary artery disease (defined as >70% stenosis in at least 1 coronary artery) and LAVi emerged as significant predictors of MACE with P-values of 0.0022 and 0.0001, respectively.

CONCLUSIONS

A significantly larger LAVi was associated with MACE. LAVi was an incremental predictor to traditional clinical variables for MACE. The assessment of LAVi may be considered during coronary computed tomographic angiography and could potentially be incorporated into risk stratification and decision-making strategies.

Decreased left atrial myocardial strain in patients with suboptimal blood pressure control

BACKGROUND

Suboptimal blood pressure (BP) control is commonly observed in patients receiving antihypertensive agents, but the relationship between uncontrolled BP and left atrial (LA) impairment remains unknown.

METHODS

This study enrolled 279 hypertensive patients who had been medicated, as well as 85 matched normal controls. The BP of systolic <140 mmHg and diastolic<90 mmHg was defined as optimal (HT1 group, n=146), otherwise as suboptimal BP control (HT2 group, n = 133). LA myocardial function was assessed by the systolic (S_Sa), early diastolic (S_Ea), and late diastolic (S_Aa) LA strains.

RESULTS

Both the HT1 group and HT2 group had higher BP reading, thicker interventricular septum, larger LA volume index, and enhanced active atrial emptying fraction than the control group (all <0.05). When compared with normal subjects, hypertensive patients displayed obvious reduction in the S_Sa (50.0 ± 10.9 vs. 35.9 ± 8.0%), S_Ea (30.1 ± 7.7 vs. 18.5 ± 7.1%) and S_Aa (19.9 ± 6.4 vs. 17.8 ± 4.2%) (all p < 0.001). In addition to a further impaired S_Ea found in the HT2 group than in the HT1 group (17.2 ± 5.3 vs. 19.8 ± 8.3%, p = 0.002), the treated BP of >140/90 mmHg appeared an independent risk factor associated with the abnormal S_Ea (odds ratio, 2.957; interval of confidence, 1.614-5.415; p = 0.001).

CONCLUSIONS

Suboptimal BP control status in hypertensive patients is related to a further reduction of LA myocardial function assessed by the novel 2DSTI free strain, and suboptimal BP might be regarded as a composite risk factor and therefore a simplified treatment target. However, the prognostic value of LA free strain in patients with inability to achieve the BP target needs to be evaluated in future prospective studies.

Impact of Left Ventricular Diastolic Property on Left Atrial Function from Simultaneous Left Atrial and Ventricular Three-Dimensional Echocardiographic Volume Measurement

Simultaneous left atrial (LA) and left ventricular (LV) 3-dimensional (3D) echocardiographic volume measurements enable the quantifying of precise LA function, by virtue of their independence on any geometric assumption and capability of measurement for net LA conduit volume. We sought to elucidate the impact of conventional Doppler LV diastolic property on LA volume and function derived from this method. Our study subjects consisted of 381 patients who underwent 3D echocardiography. From LA time-volume curve, maximum and minimum volume index (VI) and VI before atrial contraction (LAVIpre-c) were determined; subsequently, active emptying volume was calculated as LAVIpre-c - minimum LAVI. From LA and LV volume measurement, conduit volume was calculated as LV stroke VI - (maximum LAVI - minimum LAVI). LA volume increased depending on the severity of diastolic dysfunction. Compared with patients with normal diastolic function, LA booster pump function, as the contribution of active emptying volume to LV filling, was higher in those with mild diastolic dysfunction. Additionally, it gradually decreased as diastolic dysfunction was advanced from mild to moderate and moderate to severe degree (23.2 ± 15.5%, 29.5 ± 15.1%, 25.1 ± 16.2%, 14.9 ± 14.1%, respectively; p <0.001). Contrarily, conduit contribution was significantly higher in patients with severe diastolic dysfunction than in those with mild diastolic dysfunction; furthermore, conduit function tended to increase, reciprocally to booster pump function, as diastolic dysfunction grade was advanced (39.1 ± 28.8%, 36.8 ± 26.2%, 42.7 ± 25.6%, 52.9 ± 26.2%, respectively; p = 0.034). In conclusion, simultaneous LA and LV volumetric analyses through 3D echocardiography clearly demonstrate the characteristic LA functional alterations following LA dilation caused by LV diastolic dysfunction.

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.

Two-dimensional Speckle Tracking Echocardiography and Three-dimensional Echocardiography Characterization of Left Atrial Giant Myxoma

Myxomas are the most common cancerous nonneoplasms among the rare heart's tumors. Usually, they are located in the left atrium (LA). They are more frequent in women than in men and ranged in age from 30 to 50 years. Rarely, myxoma is completely asymptomatic and in that case represents a fortuitous discovery. However, usually, it is characterized by several symptoms as fatigue, dyspnea, chest pain, dizziness, cough, and sometimes, by sudden death. We refer on a case of LA myxoma found in a woman without symptoms but having a systolic precordial murmur. Two-dimensional echocardiography (2-DE) shown an unknown giant LA myxoma, almost completely occupying the atrial cavity. 2-D left atrial longitudinal speckle tracking echocardiography first allowed to note the changes in the percentage of "reservoir," "conduit," and "booster pump" phases of the left atrial function respect to normal subjects, revealing LA dysfunction. Three-dimensional echocardiography (3-DE) shown left atrial mass and its attachment to the atrial septum better than 2-DE. Furthermore, 3-DE allowed to define the shape of LA myxoma and its 3-D, irregular contour.

The Association of Functional Capacity With Right Atrial Deformation in Patients With Pulmonary Arterial Hypertension: A Study With Two-Dimensional Speckle Tracking

BACKGROUND

The purpose of this study was to assess right atrial (RA) myocardial mechanics in pulmonary hypertension (PH) patients using two-dimensional speckle tracking (2D-STE), and define the relationship between RA function and exercise capacity in PH patients.

METHODS

Thirty-eight consecutive PH patients were studied and compared with a control group of 25 healthy volunteers. Peak atrial longitudinal strain (PALS), RA strain rate were measured in all subjects. PALS values were obtained by averaging all segments (global PALS), and by averaging segments measured in the four-chamber view.

RESULTS

Right atrial PALS was significantly lower in PH patients than in controls, and gradually reduced with the development of cardiac insufficiency. A significantly positive correlation between global PALS and 6-minute walk distance (6MWD) was found (p=0.003). Furthermore, global PALS demonstrated the highest diagnostic accuracy (AUC of 0.979) and excellent sensitivity and specificity of 86.8% and 84%, respectively, to predict functional status using a cut-off value less than 38.08%.

CONCLUSIONS

Right atrial deformation is significantly damaged in PH patients. Right atrial reservoir function can be estimated using 2D-STE, which gradually decreases in PH patients with different World Health Organization-functional class (WHO-FC). Right atrial PALS is a valuable factor for predicting the functional status and exercise capacity in PH patients.

Effects of age on left atrial volume and strain parameters using echocardiography in a normal black population

OBJECTIVE

Normal cut-off values for left atrial (LA) size and function may be altered by aging and ethnic differences. No age-related reference values for LA volumetric measurements or LA strain exist in Africans. We aimed to establish normal age-appropriate values of LA size and function in black Africans. Additionally, we studied the correlation between age, LA strain and volumetric parameters.

METHODS

In this prospective, cross-sectional study of 120 individuals (mean age 38.7 ± 12.8 years, 50% men), subjects were classified into four age groups: 18-29, 30-39, 40-49 and 50-70 years. LA volumes were measured by biplane Simpson's method, and Philips QLAB 9 (Amsterdam, The Netherlands) speckle-tracking software was used to measure LA peak strain in the reservoir (Ɛ_R) and contractile phase (Ɛ_CT).

RESULTS

No significant differences in the maximum and minimum LAVi were noted among the four age categories (P = 0.1, P = 0.2). LA volumetric function assessment showed no difference in reservoir function between age groups (P > 0.05), conduit function decreased with advancing age (r = -0.3, P < 0.001) and booster function displayed a significant increase with age (LA active emptying volume index, P = 0.001). There was a significant decrease in LA Ɛ_R (P < 0.0001) in the older age groups, whereas Ɛ_CT remained unchanged (P = 0.27).

CONCLUSION

Age-related changes in LA reservoir, conduit and contractile function in black Africans are similar to those observed in other populations, as was the trend of declining Ɛ_R with advancing age. The preservation of Ɛ_CT with increasing age requires further analysis.

Characterization of left and right atrial function in healthy volunteers by cardiovascular magnetic resonance

BACKGROUND

Left and right atrial function show a different pattern in advanced age in order to maintain adequate ventricular filling. It has been shown that left atrial (LA) function has a prognostic value in a number of heart conditions. Cardiovascular magnetic resonance (CMR) provides high quality images of the left and right atria using high temporal resolution steady state free precession (SSFP) cine sequences. We used SSFP cines to characterize atrial function in healthy, normotensive, volunteers.

METHODS

We measured maximum, preatrial contraction and minimum left and right atrial volumes in 120 healthy subjects after careful exclusion of cardiovascular abnormality (60 men, 60 women; 20 subjects per age decile from 20 to 80 years). Data were generated from 3-dimensional modeling, including tracking of the atrioventricular ring motion and time-volume curves analysis. With those measurements, all the usual parameters for left and right atrial function were calculated.

RESULTS

Gender had significant influence on some parameters of left and right atrial conduit and booster pump function. Age significantly influenced the majority of parameters of both left and right atrial function, with typically lower reservoir and conduit functions and higher booster pump function, both in males and females belonging to older age groups. CMR normal ranges were modelled for clinical use with normalization, where appropriate, for body surface area and gender, displaying parameters with respect to age.

CONCLUSIONS

CMR normal reference ranges for components of left and right atrial function are provided for males and females for a wide age range.

The addition of renal sympathetic denervation to pulmonary vein isolation reduces recurrence of paroxysmal atrial fibrillation in chronic kidney disease patients

BACKGROUND

Atrial fibrillation (AF) frequently complicates chronic kidney disease (CKD). AF treatment is challenging and requires complete pulmonary vein isolation (PVI). Recently, renal sympathetic denervation (RSD) has been reported to reduce AF recurrence when performed alongside PVI.

METHODS

A prospective therapeutic study of patients with controlled hypertension and paroxysmal AF was undertaken. Renal function was evaluated using estimated glomerular filtration rate. Outcomes for patients with normal renal function who underwent PVI (n = 101) were compared with those for CKD patients who underwent either PVI alone (n = 96) or PVI + RSD (n = 39). The primary endpoint was recurrence of AF recorded by 24-h Holter monitoring.

RESULTS

During the 22.4 ± 12.1 months following intervention, the incidence of AF recurrence was higher in CKD patients treated with PVI alone (61.5 %) than in CKD patients treated with PVI + RSD (38.5 %; HR 1.86, 95 % CI 1.14-3.03, P = 0.0251) or patients without CKD subjected to PVI (35.6 %; hazard ratio (HR) 2.27, 95 % confidence interval (CI) 1.51-3.42, P < 0.0001). In particular, the addition of RSD to PVI significantly reduced AF recurrence in CKD stage 4, but not stage 2 or 3, patients. Ambulatory blood pressure and mean heart rate were not different between groups or time points. No complications of either procedure were observed.

CONCLUSIONS

PVI + RSD is a safe treatment that is superior to PVI alone for treatment of paroxysmal AF in CKD patients.

Predictors of incipient dysfunction of all cardiac chambers after treatment of metastatic renal cell carcinoma by tyrosine kinase inhibitors

PURPOSE

We aimed to explore the hypothesis that early subclinical cardiac chamber dysfunction secondary to tyrosine kinase inhibitors (TKIs) in patients with metastatic renal cell carcinoma could be signaled by abnormal cardiac mechanics demonstrated by velocity vector imaging.

METHODS

Echocardiographic images were acquired from the apical views in 23 metastatic renal cell carcinoma patients. All patients had baseline and at least a 3-month follow-up echocardiogram after receiving TKI therapy. Subendocardial borders of all the cardiac chambers were traced to obtain volumetric and deformation indices.

RESULTS

Mean age was 67 ± 9 years with 92% men. The right ventricle peak systolic global longitudinal strain (GLɛ) and strain rate were significantly lower after TKIs (-23.49 ± 5.1 versus -19.81 ± 5.5, p = 0.002 and -1.52 ± 0.52 versus -1.24 ± 0.35 p = 0.02, respectively). LV GLɛ was not statistically different. Volumetric and deformation indices showed a minimal decrease of the right atrium reservoir and conduit functions, and no significant changes of left atrial function.

CONCLUSIONS

The right heart exhibited greater strain changes than the left heart after TKI treatment. The implications of these findings and their potential significance warrant further work.

The mitral annular displacement by two-dimensional speckle tracking: a new tool in evaluating the left atrial function

BACKGROUND

The methods used to characterize the volume change and the deformation of the left atrium are highly dependent on technical factors and difficult to use in a clinical environment. The aim of this study was to demonstrate that mitral annular displacement by speckle tracking can be an alternative method to studying the longitudinal left atrial function.

METHODS

Ninety study participants (54% men), with a mean age of 53(±15) years, underwent a complete echocardiographic examination, comprising two-dimensional, three-dimensional and tissue Doppler imaging (TDI). They were divided into normal individuals (35) and patients having an abnormal echocardiography (55).

RESULTS

There was a very strong correlation between three-dimensional volumetric function and mitral annular displacement, both for the reservoir (r = 0.78; P < 0.0001) and contractile (r = 0.76; P < 0.0001) functions. The correlation with the longitudinal strain displayed an r = 0.87, P > 0.0001 for the reservoir and r = 0.81, P < 0.0001 for the contractile function. The systolic speed in pulsed TDI and the systolic displacement had an r = 0.83, P < 0.0001. Mitral annular displacement was a very good discriminator for normal versus abnormal participants [area under the curve (AUC) for reservoir = 0.872 and for contractile = 0.843; P < 0.0001], performing less well than three-dimensional (AUC reservoir = 0.892 and contractile = 0.915; P < 0.0001) or deformation (AUC = 0.921 and 0.903 respectively; P < 0.0001), but better than pulsed TDI (AUC = 0.807; P < 0.0001). The percentage error was ±15% for interobserver and ±12% for intraobserver variability. The time taken for displacement analysis was 9 ± 3 s for an experienced cardiologist and 12 ± 4 s for a beginner.

CONCLUSION

Mitral annular displacement by speckle tracking is a reliable and fast method to evaluate left atrial function. Given the strength of the correlations with strain parameters, it could be used as a surrogate measure of the deformation of left atrium.

Study on Left Atrial Dimension and Function After Modified Endoscopic Procedure for Atrial Fibrillation at Two Years' Follow-Up

BACKGROUND

Modified endoscopic procedures for atrial fibrillation (AF) have a greater success rate because of the increased number of linear lesions. Concerns have been raised about the impact of ablation scars on the left atrium. This study aimed to examine the impact of ablation on left atrial dimension and systolic function after modified endoscopic procedures with echocardiographic measurement.

METHODS

Of 107 patients undergoing modified endoscopic ablation, 58 had paroxysmal AF and 49 had persistent or long-standing AF. The procedure was performed on the beating heart through three ports on the left chest wall. Three circular and two linear lesions were made on the left atrium. The left atrial appendage was excised by stapler. Echocardiography was performed preoperatively and at the 2-year follow-up.

RESULTS

Most patients (86.9%) patients were in sinus rhythm (SR) postoperatively. Fourteen patients (5 with paroxysmal AF and 9 with persistent/long-standing AF) failed to maintain SR. Echocardiographic data indicated that the left atrial diameter decreased only in the patients with postoperative SR but continued to increase in patients with fail SR maintenance. Left atrial function was also improved after the procedure, especially in patients with preoperative nonparoxysmal AF or with postoperative SR maintenance. Furthermore, left atrial function in patients who failed to restore SR was not worsened even with left atrial appendage excision.

CONCLUSIONS

Modified endoscopic procedure for AF improved post-procedural left atrial function of patients with SR maintenance. The left atrial function of patients with failed SR maintenance was also not worsened after left atrial appendage excision.

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

The rapid technological developments of the past decade and the changes in echocardiographic practice brought about by these developments have resulted in the need for updated recommendations to the previously published guidelines for cardiac chamber quantification, which was the goal of the joint writing group assembled by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. This document provides updated normal values for all four cardiac chambers, including three-dimensional echocardiography and myocardial deformation, when possible, on the basis of considerably larger numbers of normal subjects, compiled from multiple databases. In addition, this document attempts to eliminate several minor discrepancies that existed between previously published guidelines.

Making better scar: Emerging approaches for modifying mechanical and electrical properties following infarction and ablation

Following myocardial infarction (MI), damaged myocytes are replaced by collagenous scar tissue, which serves an important mechanical function - maintaining integrity of the heart wall against enormous mechanical forces - but also disrupts electrical function as structural and electrical remodeling in the infarct and borderzone predispose to re-entry and ventricular tachycardia. Novel emerging regenerative approaches aim to replace this scar tissue with viable myocytes. Yet an alternative strategy of therapeutically modifying selected scar properties may also prove important, and in some cases may offer similar benefits with lower risk or regulatory complexity. Here, we review potential goals for such modifications as well as recent proof-of-concept studies employing specific modifications, including gene therapy to locally increase conduction velocity or prolong the refractory period in and around the infarct scar, and modification of scar anisotropy to improve regional mechanics and pump function. Another advantage of scar modification techniques is that they have applications well beyond MI. In particular, ablation treats electrical abnormalities of the heart by intentionally generating scar to block aberrant conduction pathways. Yet in diseases such as atrial fibrillation (AF) where ablation can be extensive, treating the electrical disorder can significantly impair mechanical function. Creating smaller, denser scars that more effectively block conduction, and choosing the location of those lesions by balancing their electrical and mechanical impacts, could significantly improve outcomes for AF patients. We review some recent advances in this area, including the use of computational models to predict the mechanical effects of specific lesion sets and gene therapy for functional ablation. Overall, emerging techniques for modifying scar properties represents a potentially important set of tools for improving patient outcomes across a range of heart diseases, whether used in place of or as an adjunct to regenerative approaches.

Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging

The rapid technological developments of the past decade and the changes in echocardiographic practice brought about by these developments have resulted in the need for updated recommendations to the previously published guidelines for cardiac chamber quantification, which was the goal of the joint writing group assembled by the American Society of Echocardiography and the European Association of Cardiovascular Imaging. This document provides updated normal values for all four cardiac chambers, including three-dimensional echocardiography and myocardial deformation, when possible, on the basis of considerably larger numbers of normal subjects, compiled from multiple databases. In addition, this document attempts to eliminate several minor discrepancies that existed between previously published guidelines.

The impact of 6 weeks of atrial fibrillation on left atrial and ventricular structure and function

OBJECTIVE

The impact of prolonged episodes of atrial fibrillation on atrial and ventricular function has been incompletely characterized. The purpose of this study was to investigate the influence of atrial fibrillation on left atrial and ventricular function in a rapid paced porcine model of atrial fibrillation.

METHODS

A control group of pigs (group 1, n = 8) underwent left atrial and left ventricular conductance catheter studies and fibrosis analysis. A second group (group 2, n = 8) received a baseline cardiac magnetic resonance imaging to characterize left atrial and left ventricular function. The atria were rapidly paced into atrial fibrillation for 6 weeks followed by cardioversion and cardiac magnetic resonance imaging.

RESULTS

After 6 weeks of atrial fibrillation, left atrial contractility defined by atrial end-systolic pressure-volume relationship slope was significantly lower in group 2 than in group 1 (1.1 ± 0.5 vs 1.7 ± 1.0; P = .041), whereas compliance from the end-diastolic pressure-volume relationship was unchanged (1.5 ± 0.9 vs 1.6 ± 1.3; P = .733). Compared with baseline, atrial fibrillation resulted in a significantly higher contribution of left atrial reservoir volume to stroke volume (32% vs 17%; P = .005) and lower left atrial booster pump volume contribution to stroke volume (19% vs 28%; P = .029). Atrial fibrillation also significantly increased maximum left atrial volume (206 ± 41 mL vs 90 ± 21 mL; P < .001). Left atrial fibrosis in group 2 was significantly higher than in group 1. Atrial fibrillation decreased left ventricular ejection fraction (29% ± 9% vs 58 ± 8%; P < .001), but left ventricular stroke volume was unchanged.

CONCLUSIONS

In a chronic model of atrial fibrillation, the left atrium demonstrated significant structural remodeling and decreased contractility. These data suggest that early intervention in patients with persistent atrial fibrillation might mitigate against adverse atrial and ventricular structural remodeling.

Left Ventricular Diastolic Dysfunction Assessment with Dual-Source CT

Purpose

To assess the impact of left ventricular (LV) diastolic dysfunction on left atrial (LA) phasic volume and function using dual-source CT (DSCT) and to find a viable alternative prognostic parameter of CT for LV diastolic dysfunction through quantitative evaluation of LA phasic volume and function in patients with LV diastolic dysfunction.

Materials and Methods

Seventy-seven patients were examined using DSCT and Doppler echocardiography on the same day. Reservoir, conduit, and contractile function of LA were evaluated by measuring LA volume (LAV) during different cardiac phases and all parameters were normalized to body surface area (BSA). Patients were divided into four groups (normal, impaired relaxation, pseudonormal, and restrictive LV diastolic filling) according to echocardiographic findings. The LA phasic volume and function in different stages of LV diastolic function was compared using one-way ANOVA analysis. The correlations between indexed volume of LA (LAVi) and diastolic function in different stages of LV were evaluated using Spearman correlation analysis.

Results

LA ejection fraction (LAEF), LA contraction, reservoir, and conduit function in patients in impaired relaxation group were not different from those in the normal group, but they were lower in patients in the pseudonormal and restrictive LV diastolic dysfunction groups (P < 0.05). For LA conduit function, there were no significant differences between the patients in the pseudonormal group and restrictive filling group (P = 0.195). There was a strong correlation between the indexed maximal left atrial volume (LAVmax, r = 0.85, P < 0.001), minimal left atrial volume (LAVmin, r = 0.91, P < 0.001), left atrial volume at the onset of P wave (LAVp, r = 0.84, P < 0.001), and different stages of LV diastolic function. The LAVi increased as the severity of LV diastolic dysfunction increased.

Conclusions

LA remodeling takes place in patients with LV diastolic dysfunction. At the same time, LA phasic volume and function parameters evaluated by DSCT indicated the severity of the LV diastolic dysfunction. Quantitative analysis of LA phasic volume and function parameters using DSCT could be a viable alternative prognostic parameter of LV diastolic function.

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.