Hypertensive patients with left ventricular hypertrophy have global left atrial dysfunction and impaired atrio-ventricular coupling

Longitudinal Evaluation of Atrial Function in Patients with Tetralogy of Fallot

Atrial function provides insight into ventricular diastolic function. Invasive assessment of left ventricular (LV) diastolic function correlates with development of sustained ventricular tachyarrhythmias in patients with repaired tetralogy of Fallot (rTOF). Non-invasive assessment of atrial function may prove key towards assessment of diastolic function. We longitudinally evaluated the progression of biatrial function in patients with rTOF, regardless of pulmonary valve replacement (PVR). Patients with rTOF who had multiple CMR were identified. CMR examinations were retrospectively reviewed. Left (LA) and right (RA) atrial size and function were measured in the two and four-chamber views and assessed over time and after PVR. Left and right atrial reservoir, conduit, pump strain and strain rates were determined using tissue tracking. Thirty-six patients with rTOF were identified (64% male), ten (28%) had PVR during the study. Median age of PVR was 16.5 years. No improvement in RA or LA function was observed after PVR. A decline in RA reservoir strain rate (p < 0.05) and RA pump strain (p < 0.05) were observed despite improvements in right ventricular systolic function (p < 0.05). In patients who had multiple CMR without PVR, RA reservoir strain rate (p < 0.05) and pump strain rate (p < 0.05) worsened over time. LA pump strain decreased over time in all patients. There is progressive decline of several RA functional parameters over time. No significant improvement in LA or RA function after PVR was observed. Additional studies are needed to understand how these changes may relate to poor outcomes and potentially better guide timing of PVR.

Impact of Type 2 Diabetes Mellitus on Left Atrioventricular Coupling and Left Atrial Deformation in Patients with Essential Hypertension: An MRI Feature Tracking Study

BACKGROUND

Hypertension (HTN) and type 2 diabetes mellitus (T2DM) are both associated with left ventricular (LV) and left atrial (LA) structural and functional abnormalities; however, the relationship between the left atrium and ventricle in this population is unclear.

PURPOSE

To identify differences between hypertensive patients with and without T2DM as the basis for further investigation the atrioventricular coupling relationship.

STUDY TYPE

Cross-sectional, retrospective study.

POPULATION

89 hypertensive patients without T2DM [HTN (T2DM-)] (age: 58.4 +/- 11.9 years, 48 male), 62 hypertensive patients with T2DM [HTN (T2DM+)] (age: 58.5 +/- 9.1 years, 32 male) and 70 matched controls (age: 55.0 +/- 9.6 years, 37 male).

FIELD STRENGTH/SEQUENCE

2D balanced steady-state free precession cine sequence at 3.0 T.

ASSESSMENT

LA reservoir, conduit, and booster strain (εs, εe, and εa) and strain rate (SRs, SRe, and SRa), LV radial, circumferential and longitudinal peak strain (PS) and peak systolic strain rate and peak diastolic strain rate (PSSR and PDSR) were derived from LA and LV cine images and compared between groups.

STATISTICAL TESTS

Chi-square or Fisher's exact test, one-way analysis of variance, analysis of covariance, Pearson's correlation, multivariable linear regression analysis, and intraclass correlation coefficient. A P value <0.05 was considered significant.

RESULTS

Compared with controls, εs, εe, SRe and PS-longitudinal, PDSR-radial, and PDSR-longitudinal were significantly lower in HTN (T2DM-) group, and they were even lower in HTN (T2DM+) group than in both controls and HTN (T2DM-) group. SRs, εa, SRa, as well as PS-radial, PS-circumferential, PSSR-radial, and PSSR-circumferential were significantly lower in HTN (T2DM+) compared with controls. Multivariable regression analyses demonstrated that: T2DM and PS-circumferential and PS-longitudinal (β = -4.026, -0.486, and -0.670, respectively) were significantly associated with εs; T2DM and PDSR-radial and PDSR-circumferential were significantly associated with εe (β = -3.406, -3.352, and -6.290, respectively); T2DM and PDSR-radial were significantly associated with SRe (β = 0.371 and 0.270, respectively); T2DM and PDSR-longitudinal were significantly associated with εa (β = -1.831 and 5.215, respectively); and PDSR-longitudinal was significantly associated with SRa (β = 1.07).

DATA CONCLUSION

In hypertensive patients, there was severer LA dysfunction in those with coexisting T2DM, which may be associated with more severe LV dysfunction and suggests adverse atrioventricular coupling.

EVIDENCE LEVEL

3.

TECHNICAL EFFICACY

Stage 3.

Sex-Related Differences of Left Atrial Strain in Patients With Hypertension Using Cardiac Magnetic Resonance Feature Tracking

PURPOSE

Previous studies demonstrated the impact of sex on left ventricular (LV) strain in patients with essential hypertension. However, little is known about the effect of sex on left atrial (LA) strain in patients with hypertension. This study aimed to explore the sex-related differences of LA strain by using cardiac magnetic resonance feature tracking in patients with hypertension and preserved LV ejection fraction.

MATERIALS AND METHODS

One hundred and fifty hypertensive patients (100 men and 50 women) and 105 age-matched and sex-matched normotensive controls (70 men and 35 women) were retrospectively enrolled and underwent cardiac magnetic resonance examination. LA strain parameters included LA reservoir strain (εs), conduit strain (εe), pump strain (εa), and their corresponding strain rate (SRs, SRe, and SRa).

RESULTS

Men had significantly higher LV mass index, lower εs and εe than women in both patients and controls (all P <0.05). LA strain and strain rate were significantly reduced in hypertensive patients compared with controls, both in men and women (all P <0.05). In men, hypertension and its interaction were associated with increased LV mass index and decreased εs and εe. In multivariable analysis, men, LV ejection fraction, and LA minimum volume index remained independent determinants of εs and εe in all hypertensive patients (all P <0.05).

CONCLUSION

LA strain was significantly impaired in hypertensive patients, and men had more impaired LA strain than women. These findings further emphasize the sex-related differences in the response of LA strain to hypertension in the early stage.

Association of diabetes and glycemic control with left atrial function: The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND AIMS

Although glycemic status is associated with impaired cardiac structure and function, less is known on left atrial (LA) function across the glycemic spectrum. We evaluated the association of diabetes and glycemic control with LA function in a community-based cohort of older adults.

METHODS AND RESULTS

This cross-sectional analysis included 5075 participants from the Atherosclerosis Risk in Communities Study (mean age 75.5 years, 58 % women, and 20 % Black adults) with echocardiographic strain data for LA reservoir, conduit, and contractile function. Multivariable linear regression was used to assess associations of diabetes status and glycemic control with LA function. In participants without diabetes, we used ordinal linear regression to evaluate associations of fasting glucose and HbA1c with LA function. Compared to individuals with a normal fasting glucose, prevalent diabetes was associated with 0.68 % lower LA conduit function (95 % confidence interval (CI): 1.11 to -0.25) and prediabetes a 0.47 % reduction (95 % CI: 0.85 to -0.09) in fully adjusted analyses. Persons with diabetes and high HbA1c (HgbA1c ≥ 7 % vs <7 %) had 1.05 % lower LA conduit function (95 % CI: 1.63, -0.48). Among individuals without diagnosed diabetes, higher fasting glucose, but not HbA1c, was significantly associated with worse LA conduit function. No significant associations were observed for LA reservoir and contractile function.

CONCLUSIONS

A history of diabetes, prediabetes, and higher fasting glucose levels in persons without diabetes were associated with worse LA conduit function. Corroborative research is needed in prospective cohorts as well as studies that explore underlying mechanisms.

Changes of left atrial morphology and function evaluated with four-dimensional automated left atrial quantification echocardiography in patients with coronary slow flow phenomenon and preserved left ventricular ejection fraction

BACKGROUND

Coronary slow flow phenomenon (CSFP) can cause left ventricular diastolic dysfunction (LVDD). In multiple studies, the left atrial (LA) strain has been reported to be an excellent parameter for assessing LVDD. The 4-dimensional automated LA quantification (4D Auto LAQ) dedicated to the LA was recently available. Our study aimed to evaluate subclinical changes in LA morphology and function with 4D Auto LAQ in patients with CSFP and preserved left ventricular ejection fraction (LVEF).

METHODS

Forty-eight patients with CSFP confirmed with coronary angiography and 46 age and gender-matched controls with normal coronary flow were enrolled. The thrombolysis in myocardial infarction frame count (TFC) method was used to record coronary blood flow velocities for each major coronary artery. LA volume, LA longitudinal and circumferential strains during each of the three LA phases (reservoir, conduit, and contraction), LA total emptying fraction (LATEF), LA active emptying fraction (LAAEF), and LA passive emptying fraction (LAPEF) were quantified with 4D Auto LAQ analysis.

RESULTS

Compared with controls, LA longitudinal reservoir strain (LASr), LA longitudinal strain during the conduit phase (LAScd), LA contraction strain (LASct), LA conduit circumferential strain (LAScd-c), LATEF, LAPEF decreased significantly in individuals with CSFP. Of the 4D- LAQ parameters, only LASr [odds ratio (OR): 0.773, P < 0.001] and LATEF [OR: 0.762, P < 0.001] were associated with CSFP in multivariate analysis. A LASr ≤23.00% can differentiate CSFP from controls [sensitivity, 66.7%; specificity, 93.5%; area under the curve (AUC), 0.823; P < 0.001]. A LASr of ≤19.00% could predict the elevation of LV filling pressure in the CSFP cohort [sensitivity, 76.9%; specificity, 74.3%; area under the curve (AUC), 0.792; P < 0.001]. LASr was the only index to demonstrate significant changes compared to controls in single-vessel CSFP. Compared to the right coronary artery (RCA) and left circumflex (LCX), TFC of the left anterior descending (LAD) artery was the only independent variable of LASr (Standardized Coefficients: -0.386, P = 0.037).

CONCLUSIONS

Impairment of LA reservoir function reflected by changes in LASr and LATEF can be seen in patients with CSFP. LASr could predict the elevation of LV filling pressure in CSFP individuals. LASr is more sensitive than LATEF in detecting LA reservoir dysfunction in single-vessel CSFP. CSFP in LAD exerts a more prominent influence on LASr than RCA or LCX.

Left Atrial Strain and Incident Atrial Fibrillation in Older Adults

Atrial fibrillation (AF) is frequent in older adults and associated with left atrial (LA) dysfunction. LA strain (LAε) and LA strain rate (LASR) may detect subclinical LA disease. We investigated whether reduced LAε and LASR predict new-onset AF in older adults without history of AF or stroke. LAε and LASR were assessed by speckle-tracking echocardiography in 824 participants from the community-based Cardiovascular Abnormalities and Brain Lesions study. Positive longitudinal LAε and LASR during ventricular systole, LASR during early ventricular diastole, and LASR during LA contraction were measured. Cause-specific hazards regression model evaluated the association of LAε and LASR with incident AF, adjusting for pertinent covariates. The mean age was 71.1 ± 9.2 years (313 men, 511 women). During a mean follow-up of 10.9 years, new-onset AF occurred in 105 participants (12.7%). Lower LAε and LASR at baseline were observed in patients with new-onset AF (all p <0.01). In multivariable analysis, positive longitudinal LAε (adjusted hazard ratio [HR] per SD decrease 2.05, confidence interval [CI] 1.24 to 3.36) and LASR during LA contraction (HR per SD increase 2.24, CI 1.37 to 3.65) remained associated with new-onset AF, independently of LA volumes and left ventricular function. Along with positive longitudinal LAε, reduced LASR during ventricular systole predicted AF in participants with LA volume below the median value (HR 2.54, CI 1.10 to 6.09), whereas reduced LASR during LA contraction predicted AF in participants with larger LA (HR 2.35, CI 1.31 to 4.23). In conclusion, reduced positive longitudinal LAε and LASR predict new-onset AF in older adults regardless of LA size and may improve AF risk stratification.

The effects of obesity on longitudinal ventricular and atrial strain in a rural population of Spanish children and adolescents, evaluated by a new strain software

BACKGROUND AND OBJECTIVES

Research on the relationship between body mass index (BMI) and strain values in children and adolescents is limited. Our aim was to analyse the relationship between BMI and strain values of both ventricles and left atrium in children and adolescents.

METHODS

Both ventricles and left atrial strain values were compared among different BMI categories in children and adolescents from a town in the South of Spain.

RESULTS

Of the 198 subjects, aged 6-17 years, 53% were of normal weight, 26% were overweight and 21% had obesity. Lower absolute values of left ventricular global longitudinal strain (25.9 ± 2.0% vs. 26.9 ± 2.2%, p = 0.002) and right ventricular free wall longitudinal strain (29.5 ± 4.2% vs. 30.8 ± 4.5%, p = 0.04) were found in subjects with obesity and overweight versus subjects with normal weight. A lower right ventricular four-chamber longitudinal strain was also observed in males with obesity and overweight (24.8 ± 3.3% vs. 26.4 ± 3.6%, p = 0.03). Statistically significant negative correlations of BMI were found for all ventricular, but not atrial, strain values in univariate analysis. This association turned non-significant for right ventricular four-chamber longitudinal strain in multivariate analysis.

CONCLUSIONS

Utilizing this new strain software, children and adolescents with high BMI were associated with significantly lower values for left and right ventricular free wall longitudinal strain, without impact in left atrial strain.

Incremental Effect of Mitral Regurgitation on Left Atrial Dysfunction and Atrioventricular Interaction in Hypertensive Patients by MRI

BACKGROUND

Mitral regurgitation may occur when hypertension causes left ventricular (LV) and left atrial (LA) remodeling. However, its role in LA function in hypertensive patients remains unclear.

PURPOSE

To explore how mitral regurgitation affects LA function in hypertension and to investigate atrioventricular interaction in hypertensive patients with mitral regurgitation.

STUDY TYPE

Retrospective.

POPULATION

A total of 193 hypertensive cases and 64 controls.

FIELD STRENGTH/SEQUENCE

A 3.0 T/balanced steady-state free precession.

ASSESSMENT

LA volume (LAV), LA strain (reservoir, conduit, and active), LA ejection fraction, and LV strain (global peak longitudinal [GLS], circumferential [GCS], and radial strain [GRS]) were evaluated and compared among groups. Regurgitant fraction (RF) was evaluated in regurgitation patients and used to subdivide patients into mild (RF: 0%-30%), moderate (RF: 30%-50%), and severe (RF: >50%) regurgitation categories.

STATISTICAL TESTS

One-way analysis of variance, Spearman and Pearson's correlation coefficients (r), and multivariable linear regression analysis. A P value <0.05 was considered statistically significant.

RESULTS

Hypertensive patients without mitral regurgitation showed significantly impaired LA reservoir and conduit functions and significantly decreased LV GLS but preserved pump function and LAV compared to controls (P = 0.193-1.0). Hypertensive cases with mild regurgitation (N = 22) had significantly enlarged LAV and further reduced LA reservoir function, while the group with moderate regurgitation (N = 20) showed significantly reduced LA pump function, further impaired conduit function, and significantly reduced LV strain. The severe regurgitation (N = 13) group demonstrated significantly more severely impaired LA and LV functions and LAV enlargement. Multivariable linear regression showed that regurgitation degree, GRS, GCS, and GLS were independently correlated with the LA reservoir, conduit, and active strain in hypertensive patients with mitral regurgitation.

DATA CONCLUSION

Mitral regurgitation may exacerbate LA and LV impairment in hypertension. Regurgitation degree, LV GRS, GCS, and GLS were independent determinants of the LA strain in hypertensive patients with mitral regurgitation, which demonstrated atrioventricular interaction.

EVIDENCE LEVEL

4.

TECHNICAL EFFICACY

Stage 3.

Sex, gender, and subclinical hypertensiveorgan damage-heart

Hypertension-mediated organ damage (HMOD) at cardiac level include a variety of abnormal phenotypes of recognized adverse prognostic value. Although the risk of cardiac HMOD is related with the severity of BP elevation, the interaction of numerous non-hemodynamic factors plays a relevant role in this unfavorable dynamic process. In particular, sex-related differences in cardiovascular (CV) risk factors and HMOD have been increasingly described. The objective of the present review is to provide comprehensive, updated information on sex-related differences in cardiac HMOD, focusing on the most important manifestations of subclinical hypertensive heart disease such as left ventricular hypertrophy (LVH), LV systolic and diastolic dysfunction, left atrial and aortic dilatation. Current evidence, based on cross-sectional and longitudinal observational studies as well as real-world registries and randomized controlled trials, suggests that women are more at risk of developing (and maintaining) LVH, concentric remodeling and subclinical LV dysfunction, namely the morpho-functional features of heart failure with preserved ejection fraction. It should be pointed out, however, that further studies are needed to fill the gap in defining gender-based optimal therapeutic strategies in order to protect women's hearts.

The relationship between epicardial adipose tissue thickness and arrhythmias in patients with hypertension: a 3.0T cardiac magnetic resonance study

OBJECTIVES

To investigate the relationship between epicardial adipose tissue (EAT) thickness using cardiac magnetic resonance imaging (CMR) and arrhythmias in hypertensive patients.

METHODS

Fifty-four hypertensive patients with arrhythmias (HTN [arrhythmias+]), 79 hypertensive patients without arrhythmias (HTN [arrhythmias-]), and 39 normal controls were retrospectively enrolled. EAT thickness was measured on cine images. Analysis of covariance with Bonferroni's post hoc correction, Pearson or Spearman analysis, receiver operating characteristic curve, and intraclass correlation coefficient analysis were performed.

RESULTS

All hypertensive patients had impaired left ventricular (LV) and left atrial (LA) myocardial deformation, and HTN (arrhythmias+) patients displayed higher LV myocardial native T1, LA volume index, and increased EAT thickness than HTN (arrhythmias-) patients and normotensive controls. The presence of LV late gadolinium enhancement (LGE) was higher in hypertensive patients with arrhythmias than in those without arrhythmias. EAT thickness metrics significantly correlated with age, systolic blood pressure, body mass index, triglycerides and high-density lipoprotein levels, LV mass index and native T1 (all p < 0.05). EAT thickness parameters were able to differentiate hypertensive patients with arrhythmias from those without arrhythmias and normal controls, and the right ventricular free wall had the highest diagnostic performance.

CONCLUSION

An accumulation of EAT thickness could further induce cardiac remodeling, promote myocardial fibrosis, and exaggerate function in hypertensive patients with arrhythmias.

ADVANCES IN KNOWLEDGE

CMR-derived EAT thickness metrics could be a useful imaging marker for differentiating hypertensive patients with arrhythmias, which might be a potential target for the prevention of cardiac remodeling and arrhythmias.

Different phenotype of left atrial function impairment in patients with hypertrophic cardiomyopathy and hypertension: comparison of healthy controls

Background

The impairment of atrial function and atrial-ventricular coupling in diseases with left ventricular (LV) hypertrophy has been increasingly recognized. This study compares left atrium (LA) and right atrium (RA) function, as well as LA-LV coupling, in patients with hypertrophic cardiomyopathy (HCM) and hypertension (HTN) with preserved LV ejection fraction (EF), using cardiovascular magnetic resonance feature tracking (CMR-FT).

Methods

Fifty-eight HCM patients, 44 HTN patients, and 25 healthy controls were retrospectively enrolled. LA and RA functions were compared among the three groups. LA-LV correlations were evaluated in the HCM and HTN groups.

Results

LA reservoir (LA total EF, ɛs, and SRs), conduit (LA passive EF, ɛe, SRe), and booster pump (LA booster EF, ɛa, SRa) functions were significantly impaired in HCM and HTN patients compared to healthy controls (HCM vs. HTN vs. healthy controls: ɛs, 24.8 ± 9.8% vs. 31.3 ± 9.3% vs. 25.2 ± 7.2%; ɛe, 11.7 ± 6.7% vs. 16.8 ± 6.9% vs. 25.5 ± 7.5%; ɛa, 13.1 ± 5.8% vs. 14.6 ± 5.5% vs. 16.5 ± 4.5%, p < 0.05). Reservoir and conduit functions were more impaired in HCM patients compared to HTN patients (p < 0.05). LA strains demonstrated significant correlations with LV EF, LV mass index, LV MWT, global longitudinal strain parameters, and native T1 in HCM patients (p < 0.05). The only correlations in HTN were observed between LA reservoir strain (ɛs) and booster pump strain (ɛa) with LV GLS (p < 0.05). RA reservoir function (RA ɛs, SRs) and conduit function (RA ɛe, SRe) were significantly impaired in HCM and HTN patients (p < 0.05), while RA booster pump function (RA ɛa, SRa) was preserved.

Conclusions

LA functions were impaired in HCM and HTN patients with preserved LV EF, with reservoir and conduit functions more affected in HCM patients. Moreover, different LA-LV couplings were apparent in two different diseases, and abnormal LA-LV coupling was emphasized in HTN. Decreased RA reservoir and conduit strains were evident in both HCM and HTN, while booster pump strain was preserved.

Combination of cardiac color Doppler ultrasound, serum MR-ProANP and NT-ProBNP forecasted hypertensive LVH and LFH

To analyze the value of the combined test of the cardiac color Doppler ultrasound, the serum middle receptor pro-atrial natriuretic peptide (MR-ProANP) and the N-terminal pro-brain natriuretic peptide (NT-ProBNP) in forecasting the hypertensive left ventricular hypertrophy (LVH) and left heart failure (LHF). All patients were subjected to cardiac color Doppler ultrasound examination to obtain left atrium volume index (LAVI), left ventricular end-diastolic diameter (LVEDD), early-diastolic peak flow velocity (E), early-diastolic mean flow velocity (e'), early-diastolic peak flow velocity/early-diastolic mean flow velocity (E/e') and left ventricular ejection fraction (LVEF). Biomarkers were performed to obtain serum MR-ProANP and NT-ProBNP concentrations, and statistical analysis was performed. The LVEF was obviously lower than that in the control group (P<0.01). The area under the receiver operating characteristic (ROC) curve (AUC) values of LVEF, E/e', serum MR-ProANP and NT-ProBNP alone were in the range of 0.7-0.8. The AUC, sensitivity and specificity of LVEF and E/e' combined with MR-ProANP and NT-ProBNP to diagnose hypertensive LVH and LHF were 0.892, 89.14% and 78.21%, which were higher than those of single diagnosis. In the heart failure group, LVEF was negatively correlated with serum MR-ProANP and NT-ProBNP concentrations (P<0.05), and E/e' was positively correlated with serum MR-ProANP and NT-ProBNP concentrations (P<0.05). Pump function and ventricular remodeling in patients with hypertensive LVH and LHF are closely related to serum MR-ProANP and NT-ProBNP levels. Combination of the two testing can improve the prediction and diagnostic efficacy of LHF.

Association of sodium intake with adverse left atrial function and left atrioventricular coupling in Chinese

OBJECTIVES

High sodium intake is strongly associated with hypertension and obesity. This study aims to investigate the relationship between 24-h urinary sodium (a surrogate measure of sodium intake), ambulatory blood pressure parameters, left atrial function, and left atrioventricular coupling. Further, we intend to examine whether blood pressure and BMI might be mediators of the relationship between 24-h urinary sodium and subclinical cardiac function.

METHODS

Our study had 398 participants, all of whom were subjected to 24-h urine collection, 24-h ambulatory blood pressure measurement, and cardiac magnetic resonance imaging.

RESULTS

The average age of the participants was 55.70 ± 11.30 years old. The mean urinary sodium of the participants was 172.01 ± 80.24 mmol/24 h. After adjusting for age, sex, history of diabetes, smoking status, alcohol consumption, and use of diuretics, 24-h urinary sodium was correlated with multiple ambulatory blood pressure parameters, BMI, left atrial function, and the left atrioventricular coupling index (LACI) (P < 0.05). Mediation analysis showed that BMI explained 16% of the indirect effect of 24-h urinary sodium and left atrial function and 30% of the indirect effect of LACI. Independent of the mediator, 24-h urinary sodium had a significant direct effect on left atrial function and left atrioventricular coupling.

CONCLUSIONS

Higher 24-h urinary sodium was associated with a greater BMI as well as poor left atrial function and left atrioventricular coupling, and the BMI mediated the relationship between 24-h urinary sodium and subclinical left cardiac function. Furthermore, and more importantly, 24-h urinary sodium may have directly affected the left atrial function and left atrioventricular coupling independent of intermediary factors.

Quantitative Differentiation of Left Atrial Performance in Hypertrophic Cardiomyopathy: Comparison Between Nonobstruction and Occult Obstruction With 4-dimensional Volume-strain

OBJECTIVE

The objective of this study was to describe the different components of left atrial (LA) dysfunction predictors in nonobstructive and occult obstructive hypertrophy cardiomyopathy (HCM) patients especially with preserved left ventricular (LV) ejection fraction, particularly using LA 4-dimensional (D) longitudinal and circumferential strains.

METHODS

Twenty-eight nonobstructive HCM patients and 30 occult obstructive HCM patients according to LV outflow tract gradient at rest and after exercise were prospectively enrolled. 4D echocardiographic evaluation was performed in 58 HCM patients, both nonobstructive and occult obstructive, and 38 control subjects. LA reservoir, conduit, contractile functions were performed by 4D volume-strain with volumes and longitudinal, circumferential strains.

RESULTS

Optimal correlation coefficients obtained between LV 4D mass (index) and LA 4D longitudinal/circumferential strain (r=-0.860 to 0.518, all P<0.001). Both nonobstructive and occult obstructive HCM patients had increased volumes and significantly decreased longitudinal, circumferential strain values with lower reservoir, conduit, contractile functions than the controls (all P<0.001). Occult obstructive HCM patients presented incremented volumes compared with nonobstructive ones (P<0.001 to 0.003). Lower conduit function and higher contractile function indicated with lower reservoir function revealed by circumferential strain in occult obstructive HCM patients than nonobstructive ones (P<0.001 to 0.017). Interclass correlation coefficients of intraobserver and interobserver in the LV and LA 4D value evaluations were >0.75 and >0.85, respectively.

CONCLUSIONS

LA volumes were significantly increased and LA reservoir, conduit, and contractile functions were significantly impaired in HCM patients. Furthermore, different performances of LA functional analyses in nonobstruction and occult obstruction patients with 4D volume-strain echocardiography may facilitate the recognition of subtle LA dysfunctional differentiation in HCM patients.

Myocardial strain in hypertension: a meta-analysis of two-dimensional speckle tracking echocardiographic studies

AIM

Available evidence on systolic dysfunction in systemic hypertension, as assessed by left ventricular (LV) mechanics, is still based on single studies. Thus, we performed a systematic meta-analysis of two-dimensional speckle-tracking studies in order to provide an updated comprehensive information on this issue.

METHODS

The PubMed, OVID-MEDLINE, and Cochrane library databases were analyzed to search English language articles published from the inception up to 31 December 2020. Studies were identified by using MeSH terms and crossing the following search items: 'myocardial strain', 'left ventricular mechanics', 'speckle tracking echocardiography', 'systolic dysfunction', 'hypertensive heart disease', 'systemic hypertension', 'essential hypertension'.

RESULTS

Data from 4276 individuals (2089 normotensive controls and 2187 mostly uncomplicated hypertensive patients) were included. Left ventricular (LV) mass index, relative wall thickness, left atrial volume index and E/e' ratio were significantly higher in hypertensive patients than in normotensive controls. LV ejection fraction did not differ in the two pooled groups (SMD -0.048 ± 0.054, 95% CI -0.20 to 0.10, P = 0.30), whereas LV global longitudinal strain (GLS) was significantly impaired in the hypertensive group (SMD: 1.07 ± 0. 15, 95% CI 0.77-1.36, P < 0.0001). Similar findings were obtained in a sub-analysis restricted to 15 studies in which mean age was similar in cases and controls (SMD 1.21 ± 0.23, 95% CI 0.76-1.67, P = 0.002).

CONCLUSION

The present meta-analysis suggests that GLS assessment unmasks systolic dysfunction undetected by conventional ejection fraction in the uncomplicated hypertension setting and that this parameter should be incorporated into routine work-up aimed to identify hypertension-mediated cardiac damage.

Early Left Ventricular Diastolic Dysfunction and Abnormal Left Ventricular-left Atrial Coupling in Asymptomatic Patients With Hypertension: A Cardiovascular Magnetic Resonance Feature Tracking Study

PURPOSE

Hypertension (HTN) patients suffer from increased risk of left ventricular (LV) diastolic dysfunction and LV hypertrophy (LVH). Evaluation of early LV diastolic function requires accurate noninvasive diagnostic tools. The aim of this study was to evaluate whether cardiovascular magnetic resonance feature-tracking (CMR-FT) could detect early LV dysfunction and evaluate LV-left atrium (LA) correlation in HTN patients.

MATERIALS AND METHODS

In all, 89 HTN patients and 38 age-matched and sex-matched controls were retrospectively enrolled and underwent CMR examination. HTN patients were divided into LVH (n=38) and non-LVH (n=51) groups. All LV deformation parameters were analyzed in radial, circumferential, and longitudinal directions, including peak strain, peak systolic strain rate and peak diastolic strain rate (PDSR), LA strain and strain rate (SR), including LA reservoir function (εs, SRs), conduit function (εe, SRe), and booster pump function (εa, SRa).

RESULTS

Compared with controls, the LV PDSR in radial, circumferential, and longitudinal directions and the LA reservoir and conduit function were significantly impaired in HTN patients regardless of LVH (all P<0.05). LV longitudinal and radial PDSR were correlated with LA reservoir and conduit function (all P<0.01). Among all LV and LA impaired deformation parameters, the longitudinal PDSR (in LV) and εe (in LA) were the most sensitive parameter for the discrimination between non-LVH and healthy volunteers, with an area under the curve of 0.70 (specificity 79%, sensitivity 55%) and 0.76 (specificity 95%, sensitivity 49%), respectively. The area under the curve reached 0.81 (specificity 82%, sensitivity 75%) combined with the longitudinal PDSR and εe.

CONCLUSION

CMR-FT could detect early LV diastolic dysfunction in HTN patients, which might be associated with LA reservoir and conduit dysfunction.

Amiodarone inhibits arrhythmias in hypertensive rats by improving myocardial biomechanical properties

The prevalence of arrhythmia in patients with hypertension has gradually attracted widespread attention. However, the relationship between hypertension and arrhythmia still lacks more attention. Herein, we explore the biomechanical mechanism of arrhythmia in hypertensive rats and the effect of amiodarone on biomechanical properties. We applied micro-mechanics and amiodarone to stimulate single ventricular myocytes to compare changes of mechanical parameters and the mechanism was investigated in biomechanics. Then we verified the expression changes of genes and long non-coding RNAs (lncRNAs) related to myocardial mechanics to explore the effect of amiodarone on biomechanical properties. The results found that the stiffness of ventricular myocytes and calcium ion levels in hypertensive rats were significantly increased and amiodarone could alleviate the intracellular calcium response and biomechanical stimulation. In addition, experiments showed spontaneously hypertensive rats were more likely to induce arrhythmia and preoperative amiodarone intervention significantly reduced the occurrence of arrhythmias. Meanwhile, high-throughput sequencing showed the genes and lncRNAs related to myocardial mechanics changed significantly in the spontaneously hypertensive rats that amiodarone was injected. These results strengthen the evidence that hypertension rats are prone to arrhythmia with abnormal myocardial biomechanical properties. Amiodarone effectively inhibit arrhythmia by improving the myocardial biomechanical properties and weakening the sensitivity of mechanical stretch stimulation.

Left atrial stiffness index as a marker of early target organ damage in hypertension

This study aimed to evaluate left atrial (LA) mechanics using two-dimensional speckle-tracking echocardiography (2DSTE) and investigate their correlations with measures of target organ damage (TOD) in hypertension. We enrolled 42 healthy controls (Group I) and 286 hypertension patients: Group II (n = 79) had an LA volume index (LAVI) <28 ml/m²; Group III (n = 92) had an LAVI ≥28 ml/m²; and Group IV (n = 115) had hypertension with left ventricular hypertrophy (LVH). We measured the following parameters: LA reservoir strain and strain rate (LA_S-S, LA_SR-S), LA conduit strain and strain rate (LA_S-E and LA_SR-E), and LA booster strain and strain rate (LA_S-A and LA_SR-A). The LA stiffness index (LASI) was defined as the ratio of early diastolic transmitral flow velocity/lateral mitral annulus myocardial velocity (E/e') to LA_S-S. We performed correlation and regression analyses of individual TOD with LA phasic functions, the LASI, and cardiovascular risk factors. Our findings showed that there was a trend toward a gradual increase in the LASI from controls to normal LA and enlarged LA patients and finally to hypertrophic LV patients. The LASI was significantly higher in Group III [0.28 (0.20, 0.38)] than in Group I [0.20 (0.16, 0.23)] and Group II [0.22 (0.18, 0.27)] and was the highest in Group IV [0.33 (0.26, 0.43)]. The LA reservoir and conduit function gradually decreased from Group I to Group IV. Multivariate regression analysis revealed that the LASI was independently correlated with individual TOD. In conclusion, abnormal LA mechanics precede LA enlargement and LVH, and an increased LASI can be used as a marker of early TOD in hypertension.

Four-Dimensional Volume-Strain Expression in Asymptomatic Primary Hypertension Patients Presenting with Subclinical Left Atrium-Ventricle Dysfunction

OBJECTIVE

The purpose of this study was to evaluate the different components of left atrial (LA) dysfunction predictors in asymptomatic primary systemic hypertension patients with preserved left ventricular (LV) ejection fraction, particularly using LA 4-dimensional (4D) longitudinal and circumferential strain values.

METHODS AND RESULTS

Patients with no left ventricular hypertrophy (NLVH) and left ventricular hypertrophy (LVH) are all asymptomatic regarding primary blood hypertension. Thirty NLVH patients and 30 LVH patients according to LV mass index and 40 controls analyzed by 4D echocardiography were prospectively enrolled. LA volumes and longitudinal and circumferential strains were measured using 4D volume-strain echocardiography with a Vivid E95 Version 203 instrument. Correlation analysis indicated a significant relation between LV 4D mass index and LA 4D longitudinal/circumferential strain (r = -0.446 to 0.381, p = 0.000-0.042). LVH patients had a reduced LA emptying fraction compared with NLVH patients and control subjects (p < 0.01). NLVH patients had an impaired LA conduit function and increased contractile function compared with the control group (p < 0.01). LVH patients had increased LA volumes and significantly decreased reservoir, conduit and contractile functions compared with the controls (p < 0.01). LVH patients had increased LA volumes and decreased reservoir and contractile functions compared with NLVH patients (p < 0.01). The clinical utility of LA 4D volume-strain measurement was verified by receiver-operating characteristic curve analysis showing larger net benefits as evaluated with NLVH, LVH and control group comparisons. Interclass correlation coefficients of interobserver and intraobserver assessments in the LV and LA 4D value evaluations were >0.75 and >0.85, respectively.

CONCLUSIONS

LVH patients showed increased LA volumes and decreased LA emptying fractions. LA reservoir, conduit and contractile functions were significantly impaired in LVH patients. Decreased LA conduit function and increased contractile function were revealed in NLVH patients. LA volumetric and functional analyses with 4D volume-strain echocardiography may facilitate the recognition of subtle LA and LV dysfunctions in asymptomatic systemic hypertension patients.

Atrial Function and Its Role in the Non-invasive Evaluation of Diastolic Function in Congenital Heart Disease

Diastolic dysfunction has correlated with adverse outcomes in various forms of unrepaired and repaired or palliated congenital heart disease (CHD). The non-invasive assessment of diastolic function in pediatric and adult patients with CHD remains challenging. Atrial size has a pivotal role in the evaluation of diastolic function; however, a growing body of evidence supports the additional role of atrial function as a more sensitive parameter of ventricular diastolic dysfunction. While the importance of atrial function is becoming clearer in adult acquired heart disease, it remains ambiguous in those with CHD. In this review we set the stage with the current understanding of diastolic function assessment in CHD, followed by insight into atrial form and function including its non-invasive assessment, and conclude with the current knowledge of atrial function in CHD. A general pattern of decrease in reservoir and conduit function with compensatory increase followed by decompensatory decrease in contractile function seems to be the common pathway of atrial dysfunction in most forms of CHD.

Efficacy evaluation of serum galectin-3 in hypertension complicated with diastolic dysfunction

Serum galectin-3 (Gal-3) in patients with hypertension complicated with diastolic dysfunction and its predictive value for efficacy were investigated. One hundred patients with hypertension complicated with diastolic dysfunction admitted to the First Affiliated Hospital of Jiamusi University from June 2017 to December 2018 were enrolled as group A, symptomatically treated with conventional drugs. Further 80 individuals undergoing physical examination during the same period were enrolled as group B. Patients in the two groups were subjected to echocardiography to observe mitral valve early peak flow velocity (EPFV), atrial peak flow velocity (APFV), maximum flow velocity ratio of early to atrial diastole (EPFV/APFV) and peak mitral annulus velocity (E/E′). Enzyme-linked immunosorbent assay (ELISA) was used to detect serum Gal-3 concentration. According to efficacy after treatment, patients in group A were divided into the effective group (71 patients) and the invalid group (29 patients). Gal-3 concentration in group A was significantly higher than that in group B (P<0.05). After treatment, the concentration in group A was significantly lower than that before treatment (P<0.05), but significantly higher than that in group B (P<0.05). Gal-3 concentration was significantly higher in patients with cardiac function grades II, III and IV than that in patients with grade I (P<0.05). According to Spearman's test, Gal-3 concentration was positively correlated with cardiac function grading (r=0.569, P<0.001). Compared with before treatment in group A, patients after treatment had significantly higher EPFV and EPFV/APFV (P<0.05), but significantly lower APFV and E/E′ (P<0.05). Before treatment, Gal-3 concentration in the effective group was significantly lower than that in the invalid group (P<0.05). According to the receiver operating characteristic (ROC) curve, the area under curve (AUC) of Gal-3 concentration for evaluating efficacy was 0.792, the sensitivity was 73.24%, and the specificity was 79.31%. In conclusion, Gal-3 may be involved in the development and progression of hypertension complicated with diastolic dysfunction. Its concentration increases with the rise of cardiac function grading but significantly decreases after treatment. Therefore, Gal-3 concentration before treatment can be used as a potential predictor of efficacy.

Early detection of left atrial dysfunction assessed by CMR feature tracking in hypertensive patients

OBJECTIVES

To evaluate whether early left atrial (LA) dysfunction in hypertension (HTN), with or without left ventricular hypertrophy (LVH), can be detected by cardiovascular magnetic resonance feature tracking (CMR-FT).

METHODS

Seventy-three HTN patients and 29 healthy controls were retrospectively recruited. HTN patients were divided into the LVH (n = 29) and non-LVH group (n = 44). LA performance was analysed using CMR-FT in 2- and 4-chamber cine images, including LA reservoir function (total ejection fraction [EF], total strain [εs], peak positive strain rate [SRs]), conduit function (passive EF, passive strain [εe], peak early negative strain rate [SRe]) and booster pump function (booster EF, active strain [εa], late peak negative strain rate [SRa]). One-way analysis of variance with post hoc LSD tests, Spearman analysis, receiver operating characteristic curve and intra-class correlation coefficient analysis were applied for statistical analyses.

RESULTS

Compared with healthy controls, LA reservoir (LA total EF, εs, SRs) and conduit function (LA passive EF, εe, SRe) were significantly impaired in HTN patients with or without LVH, and these parameters significantly correlated with mitral E/A < 1 (all p < 0.05). However, LA booster pump function was relatively preserved in non-LVH patients, representing an intermediate stage between the LVH group and controls. Among LA deformation parameters, εe showed the highest diagnostic value for differentiation of HTN patients with healthy controls (AUC, 0.82; sensitivity, 80.82%; specificity, 72.41%). Observer reproducibility was good-excellent (ICC, 0.83-0.97) for all CMR-FT derived parameters.

CONCLUSIONS

CMR-FT is a promising tool for quantification of LA function. LA reservoir and conduit dysfunction might be detected early by CMR-FT in HTN patients before the presence of LVH.

KEY POINTS

• CMR-FT is a promising tool in quantifying LA function, including deformation and volumetric parameters. • LA reservoir and conduit dysfunction might be detected early by CMR-FT in HTN patients with or without LVH. • The LA booster pump function was relatively preserved in non-LVH patients.

Left Atrial Phasic Function by Cardiac Magnetic Resonance Feature Tracking Is a Strong Predictor of Incident Cardiovascular Events

BACKGROUND

The prognostic importance of left atrial (LA) dysfunction is increasingly recognized. Magnetic resonance imaging can provide excellent visualization of the LA wall. We aimed to study the association of LA dysfunction measured using feature-tracking magnetic resonance imaging with incident adverse cardiovascular events among subjects with or without heart failure (HF) at baseline.

METHODS AND RESULTS

We prospectively studied 640 adults without HF (n=419), HF with preserved ejection fraction (n=101), or HF with reduced ejection fraction (n=120). We measured phasic LA function by volumetric and feature-tracking methods to derive longitudinal strain. The composite outcome of incident HF hospitalization or death was adjudicated during a median follow-up of 37.1 months. Measures of LA phasic function were more prominently impaired in subjects with HF with reduced ejection fraction than among subjects with HF with preserved ejection fraction. In unadjusted Cox proportional hazards models, all measures of phasic LA function and volumes (maximum, minimum, and diastatic) were associated with the composite outcome. However, in analyses that adjusted for clinical risk factors, HF status, maximum LA volume, left ventricular mass, and left ventricular ejection fraction, measures of conduit and reservoir LA function, but not booster-pump function, were associated with the composite outcome. The strongest associations were observed for conduit longitudinal strain (standardized hazard ratio, 0.66; 95% CI, 0.49-0.88; P=0.004), conduit strain rate (standardized hazard ratio, 1.59; 95% CI, 1.16-2.16; P=0.0035), and reservoir strain (standardized hazard ratio, 0.68; 95% CI, 0.52-0.89; P=0.0055).

CONCLUSIONS

Phasic LA function measured using magnetic resonance imaging feature tracking is independently predictive of the risk of incident HF admission or death, even after adjusting for LA volume and left ventricular remodeling.

Effect of Obesity on Left Atrial Strain in Persons Aged 35-55 Years (The Asklepios Study)

Obesity increases the risk of heart failure and atrial fibrillation. Left atrial (LA) dysfunction is increasingly recognized as a mediator of cardiovascular disease. Early effects of obesity on LA function have not been examined in large population samples. We quantified LA strain and strain rate (SR) through speckle tracking echocardiography in 1,531 middle-aged community-based participants enrolled in the Asklepios study. We compared LA function between individuals with body mass index (BMI) < 25 kg/m² (n = 779), 25 to 29.9 kg/m² (n = 618) and ≥ 30 kg/m² (n = 134). Significant differences in reservoir longitudinal LA strain (BMI < 25 kg/m² = 35.3%, BMI 25-29.9 kg/m² = 33.1%, and BMI ≥ 30 kg/m² = 30.9%; p < 0.00001) strain rate ([SR] BMI < 25 kg/m² = 151; BMI 25 to 29.9 kg/m² = 141; and BMI ≥ 30 kg/m² = 135 %/s; p <0.00001) and expansion index (BMI < 25 kg/m² = 1.6, BMI 25 to 29.9 kg/m² = 1.4, and BMI ≥ 30 kg/m² = 1.4; p <0.00001) were seen, indicating reduced reservoir function with increasing BMI. Obesity was also associated with impaired LA conduit function, including conduit longitudinal LA strain (BMI < 25 kg/m² = 21.6%, BMI 25 to 29.9 kg/m² = 18.9%, and BMI ≥ 30 kg/m² = 16.7%; p <0.00001), SR (BMI < 25 kg/m² = -189, BMI 25 to 29.9 kg/m² = 166, and BMI ≥ 30 kg/m² = 150 %/s; p <0.0001) and passive LA emptying fraction (BMI < 25 kg/m² = 40.5, BMI 25 to 29.9 kg/m² = 36.5, and BMI ≥ 30 kg/m² = 36%, p <0.00001). These differences persisted after adjustment for age, gender and other potential confounders. In contrast to reservoir and conduit function, obesity was associated with increased booster pump function (active LA emptying fraction: BMI < 25 kg/m² = 19.4%, BMI 25 to 29.9 kg/m² = 20.5%, and BMI ≥ 30 kg/m² = 21.5%; p <0.00001). In middle-aged adults, obesity is associated with impaired reservoir and conduit LA function and higher booster function, which may be compensatory. Loss of booster LA function, either because of more advanced LA dysfunction or atrial fibrillation, may play an important role in precipitating heart failure in obese individuals.

Relationship between neutrophil/lymphocyte ratio and epicardial fat tissue thickness in patients with newly diagnosed hypertension

Objective Epicardial fat tissue thickness (EFT) and the neutrophil/lymphocyte ratio (NLR) are associated with atherosclerosis. Few studies have focused on the relationship between these parameters in patients with newly diagnosed hypertension. In this study, we examined the relationship between EFT and the NLR in patients with newly diagnosed hypertension detected by 24-hour ambulatory blood pressure monitoring (ABPM). Methods Eighty consecutive patients without chronic illness who were diagnosed with hypertension according to ABPM results and 80 otherwise healthy subjects were enrolled in the study. EFT of each participant was measured echocardiographically. The C-reactive protein (CRP) concentration and NLR were measured from venous blood samples. Results The 24-hour average systolic blood pressure was significantly higher in the hypertension group than in the control group (143±17 vs. 117±7 mmHg, respectively). There were no significant differences in age, sex, or body mass index between the two groups. EFT, the NLR, and the CRP concentration were significantly higher in the hypertension group than control group. Additionally, a significantly positive correlation between EFT and the NLR was found in both the control group and hypertension group. Conclusion A higher EFT and NLR were detected in patients with newly diagnosed hypertension than in healthy subjects.

Clinical and Echocardiographic Correlates of Left Atrial Function Index: The Framingham Offspring Study

BACKGROUND

Left atrial (LA) remodeling is a predictor of cardiovascular disease (CVD). We performed measurement of the LA function index (LAFI), a composite measure of LA structure and function, in a community-based cohort and here report the distribution and cross-sectional correlates of LAFI.

METHODS

In 1,719 Framingham Offspring Study participants (54% women, mean age 66 ± 9 years), we derived LAFI from the LA emptying fraction, left ventricular (LV) outflow tract velocity time integral, and indexed maximal LA volume. We used multivariable linear regression to assess the clinical and echocardiographic correlates of LAFI adjusting for age, sex, anthropometric measurements, and CVD risk factors.

RESULTS

The average LAFI was 35.2 ± 12.1. Overall, LAFI declined with advancing age (β = -0.27, P < .001). LAFI was significantly higher (37.5 ± 11.6) in a subgroup of participants free of CVD and CVD risk factors compared with those with either of these conditions (34.5 ± 12.2). In multivariable models, LAFI was inversely related to antihypertensive use (β = -1.26, P = .038), prevalent atrial fibrillation (β = -4.46, P = .001), heart failure (β = -5.86, P = .008), and coronary artery disease (β = -2.01, P = .046). In models adjusting for echocardiographic variables, LAFI was directly related to LV ejection fraction (β = 14.84, P < .001) and inversely related to LV volume (β = -7.03, P < .001).

CONCLUSIONS

LAFI was inversely associated with antihypertensive use and prevalent CVD and was related to established echocardiographic traits of LV remodeling. Our results offer normative ranges for LAFI in a white community-based sample and suggest that LAFI represents a marker of pathological atrial remodeling.

Late Systolic Myocardial Loading Is Associated With Left Atrial Dysfunction in Hypertension

BACKGROUND

Late systolic load has been shown to cause diastolic dysfunction in animal models. Although the systolic loading sequence of the ventricular myocardium likely affects its coupling with the left atrium (LA), this issue has not been investigated in humans. We aimed to assess the relationship between the myocardial loading sequence and LA function in human hypertension.

METHODS AND RESULTS

We studied 260 subjects with hypertension and 19 normotensive age- and sex-matched controls. Time-resolved central pressure and left ventricular geometry were measured with carotid tonometry and cardiac magnetic resonance imaging, respectively, for computation of time-resolved ejection-phase myocardial wall stress (MWS). The ratio of late/early ejection-phase MWS time integrals was computed as an index of late systolic myocardial load. Atrial mechanics were measured with cine-steady-state free-precession magnetic resonance imaging using feature-tracking algorithms. Compared with normotensive controls, hypertensive participants demonstrated increased late/early ejection-phase MWS and reduced LA function. Greater levels of late/early ejection-phase MWS were associated with reduced LA conduit, reservoir, and booster pump LA function. In models that included early and late ejection-phase MWS as independent correlates of LA function, late systolic MWS was associated with lower, whereas early systolic MWS was associated with greater LA function, indicating an effect of the relative loading sequence (late versus early MWS) on LA function. These relationships persisted after adjustment for multiple potential confounders.

CONCLUSIONS

A myocardial loading sequence characterized by prominent late systolic MWS was independently associated with atrial dysfunction. In the context of available experimental data, our findings support the deleterious effects of late systolic loading on ventricular-atrial coupling.

Association of the Active and Passive Components of Left Atrial Deformation with Left Ventricular Function

BACKGROUND

Left atrial (LA) strain imaging enables the quantitative assessment of LA function. The clinical relevance of these measurements is dependent on the provision of information incremental to the left ventricular (LV) evaluation. The aim of this study was to test the hypothesis that LA pump function but not reservoir function is independent of measurement of LV mechanics.

METHODS

Echocardiography was undertaken in a community-based study of 576 participants ≥65 years of age with one or more risk factors (e.g., hypertension, diabetes mellitus, obesity). Strain analysis was conducted using a dedicated software package, using R-R gating. LV function was classified as normal in the presence of global longitudinal strain (GLS) (≤-18%) or global circumferential strain (GCS) (≤-22%). The associations between GLS or GCS and LA reservoir, conduit, and pump strain were assessed using univariate and multivariate linear regression.

RESULTS

Patients (mean age 71 ± 5 years, 54% women) with reduced GLS had higher blood pressure and rates of diabetes and obesity (P < .05). LA reservoir strain and conduit strain were lower in the group with impaired GLS (38.2 ± 7.3% vs 39.9 ± 6.4% [P = .004] and 18.7 ± 5.7% vs 20.5 ± 5.1% [P < .001], respectively), but there was no difference in LA pump strain (19.5 ± 5.5% vs 19.3 ± 4.6%, P = .72). GLS was independently associated with LA reservoir and conduit strain (P < .05) but not independently associated with LA pump strain (P = .91). Reduced GCS was associated with a larger body mass index, male sex, and diabetes (P < .05). There were no differences in LA reservoir, conduit, and pump strain in patients with normal and abnormal GCS (P > .05).

CONCLUSIONS

The application of LA strain is specific to the component measured. LA pump strain is independent of LV mechanics.

Beta-Blocker Use Is Associated With Impaired Left Atrial Function in Hypertension

Background

Impaired left atrial (LA) mechanical function is present in hypertension and likely contributes to various complications, including atrial arrhythmias, stroke, and heart failure. Various antihypertensive drug classes exert differential effects on central hemodynamics and left ventricular function. However, little is known about their effects on LA function.

Methods and Results

We studied 212 subjects with hypertension and without heart failure or atrial fibrillation. LA strain was measured from cine steady‐state free‐precession cardiac MRI images using feature‐tracking algorithms. In multivariable models adjusted for age, sex, race, body mass index, blood pressure, diabetes mellitus, LA volume, left ventricular mass, and left ventricular ejection fraction, beta‐blocker use was associated with a lower total longitudinal strain (standardized β=−0.21; P=0.008), and lower LA expansion index (standardized β=−0.30; P<0.001), indicating impaired LA reservoir function. Beta‐blocker use was also associated with a lower positive strain (standardized β=−0.19; P=0.012) and early diastolic strain rate (standardized β=0.15; P=0.039), indicating impaired LA conduit function. Finally, beta‐blocker use was associated with a lower (less negative) late‐diastolic strain (standardized β=0.15; P=0.049), strain rate (standardized β=0.18; P=0.019), and a lower active LA emptying fraction (standardized β=−0.27; P<0.001), indicating impaired booster pump function. Use of other antihypertensive agents was not associated with LA function.

Conclusions

Beta‐blocker use is significantly associated with impaired LA function in hypertension. This association could underlie the increased risk of atrial fibrillation and stroke seen with the use of beta‐blockers (as opposed to other antihypertensive agents) demonstrated in recent trials.