Left Atrial Phasic Function Research Articles

Left atrial phasic function in hypertensive patients with significant aortic stenosis and preserved ejection fraction.

The purpose of this investigation was to evaluate the influence of hypertension on left atrial (LA) function in patients with moderate and severe AS. This cross-sectional study included 121 patients with moderate and severe AS and preserved left ventricular (LV) ejection fraction ( > 50%) and 79 age-matched controls who underwent a comprehensive echocardiographic examination. LA phasic function was determined by both volumetric and strain methods. Our findings showed that the LV ejection fraction was similar between hypertensive and normotensive AS patients. Maximal, minimal, and pre-A LA volume indexes gradually increased from controls to moderate-to-severe AS patients. The total, passive and active LA emptying fraction (EF) gradually decreased in the same direction. LA phasic function estimated with strain analysis showed that reservoir, conduit, and pump LA phasic functions were lower in all AS patients than in normotensive controls. However, there was no significant difference between moderate and severe AS except in LA pump function, which was lower in severe AS. Differences in LA phasic function were more prominent in volumetric than in strain analyses. Blood pressure, LV mass index, and AS severity were independent of other clinical and echocardiographic parameters associated with LA phasic function in patients with AS. In conclusion, hypertension has an additive impact on LA phasic function in patients with moderate and severe AS. Blood pressure and AS severity were independently associated with LA phasic function parameters in AS patients. Volumetric assessment of LA phasic function should not be completely replaced with strain analysis.

Phasic Left Atrial Function in Cancer Patients Before Initiation of Anti-Cancer Therapy.

We aimed to explore left atrial (LA) remodeling in the patients with solid cancer before initiation of chemo- or radiotherapy. This retrospective investigation included 92 chemo- and radiotherapy-naive cancer patients and 40 age- and gender-matched controls with a similar cardiovascular risk profile as the cancer group. All participants underwent comprehensive echocardiographic examination before the start of chemo- or radiotherapy. LA phasic function was evaluated in volumetric and strain method. Indexed minimal and pre-A LA volumes were significantly higher in the cancer patients. Total and passive LA emptying fraction (EF) were significantly lower, whereas active LAEF was significantly higher in the cancer patients. LA total longitudinal strain was significantly lower in the cancer patients. Strain rate analysis of LA phasic function showed that LA function during systole and early diastole was reduced in the cancer group, while it was increased during late diastole. These findings indicated that LA reservoir and conduit functions, assessed with LA volumetric and strain analysis, were deteriorated in the cancer group. On the other hand, LA booster pump function was elevated in the cancer group in comparison with the controls. In the whole population, cancer was associated with reduced LA total longitudinal strain independently of age, gender, BMI, LV hypertrophy, E/e’ ratio, diabetes, and hypertension. LA phasic function was impaired in the chemo- and radiotherapy-naive cancer patients in comparison with the control group. Cancer, LV hypertrophy, and hypertension were associated with reduced LA longitudinal strain independently of other important clinical parameters.

Abstract TP201: Characterizing Left Atrial Mechanics and the Associations With Stroke Severity

Introduction: The importance of left atrial (LA) function in cardioembolic stroke is increasingly recognized, but the associations between LA phasic function and ischemic stroke severity (admission NIH stroke scale (NIHSS)) is unknown. Two-dimension speckle tracking echocardiography (STE) allows an accurate, reproducible, and detailed assessment of the 3 components of the LA cycle. Methods: LA STE analysis was quantified using a post-processing wall motion tracking software according to standard definitions. Strain/strain rate curves for the 3 components of the LA cycle: 1) Reservoir (Maximum Global longitudinal strain (Smax)/strain rate (Srmax), total LA emptying fraction (tEF)) 2) Conductive (Early LA Strain rate (Sre), passive emptying fraction (pEF)) 3) Active (Late LA Strain rate (Sra), active emptying fraction (aEF)) were evaluated. The association of NIHSS (quintiles) with LA strain/strain rate was tested using ordinal logistic regression adjusted for covariates (Table 1) Results: Average participants (N=62) were middle aged, normotensive men. Incremental increases in Sre (worse LA conduction) was nonsignificantly associated with increased odds of higher NIHSS (OR 1.13 , 95%CI 0.67-1.88). Incremental increases in Sra (worse LA contraction) was associated with decreased odds of higher NIHSS that persisted after adjustment for demographics and LV function (OR 0.68, 95%CI 0.46-1.00). Better LA reservoir function (incremental Smax increases) was suggestive of decreased odds of worse stroke. Conclusions: This study suggest that odds of a more severe stroke is lower in patients with better LA reservoir function and worse LA contraction, but higher in participants with worse LA conductive function, mirroring the dynamic changes in diastolic dysfunction (impaired LA conduction, compensatory increase in contractile phase). Additional work to increase power and further characterize these associations is ongoing.

Relationship between electrical conduction and phasic left atrial function: P-wave signal-averaged electrocardiography and time-left atrial volume curve assessments using two-dimensional speckle-tracking echocardiography.

P-wave signal-averaged electrocardiography (P-SAECG) can detect imperceptible conduction abnormalities, and volume analysis using two-dimensional speckle-tracking echocardiography (2-DSTE) allows us to easily measure the phasic function of the left atrium (LA). Both conduction abnormalities and functional deformation of the LA may be linked to the clinical outcome; however, the exact relationship is unclear. The aim of this study was to investigate the relationship between the phasic function of the LA and electrical conduction using P-SAECG and 2-DSTE. The subjects were 112 male volunteers (age 46.9 ± 13.2years) with normal cardiac function who underwent P-SAECG and 2-DSTE. The filtered p-wave duration (FPD) and the root-mean-square voltage for the last 20ms (RMS20) on P-SAECG wave were measured in ms and μV, respectively. Total emptying function (EF) (reservoir function), passive EF (conduit function), and active EF (booster pump function) of the LA were calculated as percentages to evaluate phasic LA function using 2DSTE. The mean FPD was 134.3 ± 11.7ms and the mean RMS20 was 4.59 ± 2.39μV. The mean total EF was 60.5 ± 13.1%, mean passive EF was 39.4 ± 13.9%, and mean active EF was 35.1 ± 13.9%. FPD had a negative correlation with passive EF (r=-0.20, p = 0.039). FPD showed no significant relationship with total EF (r=-0.03, p = 0.78) or active EF (r = 0.13, p = 0.18). There was a significant association between RMS20 and passive EF (r = 0.19, p = 0.048); however, no there was no correlation between RMS20 and total EF (r = 0.12, p = 0.23), or between RMS20 and passive EF (r=-0.02, p = 0.86). In multivariate regression analysis, passive EF was an independent factor that influenced FPD duration. This study indicated that FPD was associated with conduit function, which includes phasic LA function. Therefore, electrical conduction of the LA and left ventricular diastolic function are closely related. In the clinical setting, when conduction abnormalities are detected, lifestyle measures or interventions can be applied to reduce cardiovascular risk.

Evaluation of Left Atrial Electromechanical Delay and Left Atrial Phasic Functions in Surgical Early Menopause Patients.

BACKGROUNDThis study evaluated the atrial electromechanical delay (AEMD) and the left atrial (LA) mechanical functions in patients with surgical early menopause.METHODSA total of 62 patients were included in the study: 33 patients with surgical early menopause and 29 age- and sex-matched healthy controls. The duration distance from the start of the P wave to the beginning of the A wave for the lateral mitral annulus, septal mitral annulus, and lateral tricuspid annulus was assessed by tissue Doppler echocardiography. The differences in these durations were used to calculate the inter- and intra-atrial mechanical delays. LA volumes were evaluated using the biplane area-length technique, and LA mechanical function values were measured.RESULTSThe baseline laboratory and clinical characteristics were similar between the two groups. Surgical early menopause patients displayed increased static atrial electromechanical connection (PA′) times for the septal mitral annulus and lateral tricuspid annulus compared to the controls. However, the lateral mitral annulus, the inter-atrial, the intra-LA, and the right atrial EMD PA′ times were not significantly altered in surgical early menopause patients compared to controls. Importantly, the LA volume index (28.1 ± 8.17 vs. 24.89 ± 7.96 mL/m2, p = 0.019), the maximal LA volume (49.6 ± 14.1 vs. 42.9 ± 16.1 mL, p = 0.004), the minimal LA volume (18.4 ± 7.0 vs. 15.2 ± 9.0 mL, p = 0.022), and the atrial precontraction LA volume (31.0 ± 10.9 vs. 24.9 ± 10.1 mL, p = 0.006) were higher in the patients with surgical early menopause compared to the controls. The LA reservoir, conduit and pumping functions and the total, passive, and active emptying volumes were all comparable between the two groups (p = 0.09; 0.06; 0.68; 0.06; 0.48; 0.07, respectively).CONCLUSIONSPatients with surgical early menopause demonstrated impaired atrial electrical delay and electromechanical functions.

Left atrial function in heart failure with mid-range ejection fraction differs from that of heart failure with preserved ejection fraction: a 2D speckle-tracking echocardiographic study.

Heart failure (HF) with mid-range ejection fraction (HFmrEF) shares similar diagnostic criteria to HF with preserved ejection fraction (HFpEF). Whether left atrial (LA) function differs between HFmrEF and HFpEF is unknown. We, therefore, used 2D-speckle-tracking echocardiography (2D-STE) to assess LA phasic function in patients with HFpEF and HFmrEF. Consecutive outpatients diagnosed with HF according to current European recommendations were prospectively enrolled. There were 110 HFpEF and 61 HFmrEF patients with sinus rhythm, and 37 controls matched by age. LA phasic function was analysed using 2D-STE. Peak-atrial longitudinal strain (PALS), peak-atrial contraction strain (PACS), and PALS-PACS were measured reflecting LA reservoir, pump, and conduit function, respectively. Among HF groups, most of left ventricular (LV) diastolic function measures, and LA volume were similar. Both HF groups had abnormal LA phasic function compared with controls. HFmrEF patients had worse LA phasic function than HFpEF patients even among patients with LA enlargement. Among patients with normal LA size, LA reservoir, and pump function remained worse in HFmrEF. Differences in LA phasic function between HF groups remained significant after adjustment for confounders. Global PALS and PACS were inversely correlated with brain natriuretic peptide, LA volume, E/A, E/e', pulmonary artery systolic pressure, and diastolic dysfunction grade in both HF groups. LA phasic function was worse in HFmrEF patients compared with those with HFpEF regardless of LA size, and independent of potential confounders. These differences could be attributed to intrinsic LA myocardial dysfunction perhaps in relation to altered LV function.

A16547 The Association of Central Aortic Stiffness with Left Atrial Phasic Function in Patients with Hypertension

Objectives: We aimed to explore the relationship between central aortic stiffness and LA phasic function in hypertensive (HTN) patients. Methods: 2D-speckle-tracking strain echocardiography was performed on 218 HTN (110 male, 55 ± 14 years) with preserved LV ejection fraction (EF > 50%). Phasic LA function (reservoir, conduit, contractile) was analyzed. Global longitudinal LA strain (LA LS) was measured as an average value from apical 4C and 2C views. Central hemodynamics including central pulse pressure (PP), PP amplification, augmentation index ([email protected]) and pulse wave velocity (PWV) were measured, Results: Central hemodynamic parameters showed significant correlations with global LALS ([email protected]: r = − 0.18, p = 0.03; PWV: r = − 0.25, p < 0.01) and passive LA EF, reflecting LA conduit function (AIx @75: r = − 0.29, p < 0.01: central PP: r = − 0.19, p = 0.02: PP amplification: r = 0.27, p < 0.01), while no significant correlation between peripheral PP and LA functional parameters was noted. Correlations between LA conduit function and central hemodynamic parameters were more prominent in patients without LVH than those with LVH (Figure). Multiple regression analysis showed independent correlations between LA conduit function and [email protected] 75 (p = 0.04). Conclusion: The central hemodynamic showed better correlations with LA functional parameters than peripheral hemodynamic parameters. Central aortic stiffness in patients with hypertension may contribute to impairment of LA conduit function before LV remodeling occurs

Dissecting Clinical and Metabolomics Associations of Left Atrial Phasic Function by Cardiac Magnetic Resonance Feature Tracking

Among community cohorts, associations between clinical and metabolite factors and complex left atrial (LA) phasic function assessed by cardiac magnetic resonance (CMR) feature tracking (FT) are unknown. Longitudinal LA strain comprising reservoir strain (εs), conduit strain (εe) and booster strain (εa) and their corresponding peak strain rates (SRs, SRe, SRa) were measured using CMR FT. Targeted mass spectrometry measured 83 circulating metabolites in serum. Sparse Principal Component Analysis was used for data reduction. Among community adults (n = 128, 41% female) (mean age: 70.5 ± 11.6 years), age was significantly associated with εs (β = −0.30, p < 0.0001), εe (β = −0.3, p < 0.0001), SRs (β = −0.02, p < 0.0001), SRe (β = 0.04, p < 0.0001) and SRe/SRa (β = −0.01, p = 0.012). In contrast, heart rate was significantly associated with εa (β = 0.1, p = 0.001) and SRa (β = −0.02, p < 0.0001). Serine was significantly associated with εs (β = 10.1, p = 0.015), SRs (β = 0.5, p = 0.033) and SRa (β = −0.9, p = 0.016). Citrulline was associated with εs (β = −4.0, p = 0.016), εa (β = −3.4, p = 0.002) and SRa (β = 0.4, p = 0.019). Valine was associated with ratio of SRe:SRa (β = −0.4, p = 0.039). Medium and long chain dicarboxyl carnitines were associated with εs (β = −0.6, p = 0.038). Phases of LA function were differentially associated with clinical and metabolite factors. Metabolite signals may be used to advance mechanistic understanding of LA disease in future studies.

Validation of a rapid semi-automated method to assess left atrial longitudinal phasic strains on cine cardiovascular magnetic resonance imaging

BackgroundAbnormal left atrial (LA) function is a marker of cardiac dysfunction and adverse cardiovascular outcome, but is difficult to assess, and hence not, routinely quantified. We aimed to determine the feasibility and effectiveness of a fast method to measure long-axis LA strain and strain rate (SR) with standard cardiovascular magnetic resonance (CMR) compared to conventional feature tracking (FT) derived longitudinal strain.MethodsWe studied 50 normal controls, 30 patients with hypertrophic cardiomyopathy, and 100 heart failure (HF) patients, including 40 with reduced ejection fraction (HFrEF), 30 mid-range ejection fraction (HFmrEF) and 30 preserved ejection fraction (HFpEF). LA longitudinal strain and SR parameters were derived by tracking the distance between the left atrioventricular junction and a user-defined point at the mid posterior LA wall on standard cine CMR two- and four-chamber views. LA performance was analyzed at three distinct cardiac phases: reservoir function (reservoir strain εs and strain rate SRs), conduit function (conduit strain εe and strain rate SRe) and booster pump function (booster strain εa and strain rate SRa).ResultsThere was good agreement between LA longitudinal strain and SR assessed using the fast and conventional FT-CMR approaches (r = 0.89 to 0.99, p < 0.001). The fast strain and SRs showed a better intra- and inter-observer reproducibility and a 55% reduction in evaluation time (85 ± 10 vs. 190 ± 12 s, p < 0.001) compared to FT-CMR. Fast LA measurements in normal controls were 35.3 ± 5.2% for εs, 18.1 ± 4.3% for εe, 17.2 ± 3.5% for εa, and 1.8 ± 0.4, − 2.0 ± 0.5, − 2.3 ± 0.6 s− 1 for the respective phasic SRs. Significantly reduced LA strains and SRs were observed in all patient groups compared to normal controls. Patients with HFpEF and HFmrEF had significantly smaller εs, SRs, εe and SRe than hypertrophic cardiomyopathy, and HFmrEF had significantly impaired LA reservoir and booster function compared to HFpEF. The fast LA strains and SRs were similar to FT-CMR for discriminating patients from controls (area under the curve (AUC) = 0.79 to 0.96 vs. 0.76 to 0.93, p = NS).ConclusionsNovel quantitative LA strain and SR derived from conventional cine CMR images are fast assessable parameters for LA phasic function analysis.

Association between left atrial phasic conduit function and early atrial fibrillation recurrence in patients undergoing electrical cardioversion

BackgroundDiastolic dysfunction promotes atrial fibrillation (AF) inducing left atrial (LA) remodeling, with chamber dilation and fibrosis. Predominance of LA phasic conduit (LAC) function should reflect not only chamber alterations but also underlying left ventricular (LV) filling impairment. Thus, LAC was tested as possible predictor of early AF relapse after electrical cardioversion (EC).Methods96 consecutive patients, who underwent EC for persistent non-valvular AF, were prospectively enrolled. Immediately after successful EC (3 h ± 15 min), an echocardiographic apical four-chamber view was acquired with transmitral velocities, annular tissue Doppler and simultaneous LV and LA three-dimensional full-volume datasets. Then, from LA–LV volumetric curves we computed LAC as: [(LV maximum − LV minimum) − (LA maximum − LA minimum) volume], expressed as % LV stroke volume. LA pump, immediately post-EC, was assumed and verified as being negligible. Sinus rhythm persistence at 1 month was checked with ECG-Holter monitoring.ResultsAt 1 month 62 patients were in sinus rhythm and 34 in AF. AF patients presented pre-EC higher E/é values (p = 0.012), no major LA volume differences (p = NS), but a stiffer LV cavity (p = 0.012) for a comparable LV capacitance (p = 0.461). Conduit contributed more (p < 0.001) to LV stroke volume in AF subpopulation. Multiple regression revealed LAC as the most significant AF predictor (p = 0.013), even after correction for biometric characteristics and pharmacotherapy (p = 0.008).ConclusionOur data suggest that LAC larger contribution to LV filling soon after EC reflects LA–LV stiffening, which skews atrioventricular interaction leading to AF perpetuation and makes conduit dominance a powerful predictor of early AF recurrence.

Left atrial phasic function and heart rate variability in patients with systemic sclerosis: A new part of the old puzzle.

We aimed to research left atrial (LA) phasic function and heart rate variability (HRV), as well as their relationship, in subjects with uncomplicated systemic sclerosis (SSc). The investigation involved 44 SSc patients and 33 age-matched healthy controls. All participants underwent clinical examination, serological tests, 24-hours Holter monitoring, and echocardiographic examination including strain analysis. Maximum, minimum, and pre-A LA volumes and volume indices were higher in the SSc patients than in the controls. The total emptying fraction, the parameter of the LA reservoir function, as well as passive LA emptying fraction, which represents the LA conduit function, were significantly lower in the SSc patients compared to the controls. Active LA emptying fraction, the parameter of the LA booster pump function, was significantly higher in the SSc participants. There was no difference in LA reservoir function between the diffuse and the limited SSc form. LA conduit function was significantly decreased, whereas LA booster pump function was compensatory increased in the diffuse SSc form compared to the limited SSc form. Similar results were obtained by LA strain analysis. HRV indices were significantly decreased in the SSc patients. Modified Rodnan skin score, the parameter of skin involvement in SSc, and HRV indices correlated well with LA phasic function in SSc. Left atrial (LA) phasic function, assessed by both volumetric and strain method, as well as cardiac autonomic nervous function is significantly deteriorated in SSc patients. Skin score and HRV indices correlate with LA phasic function parameters.

P2420The effect of obesity on left atrial volume and phasic functions assessed by real-time three-dimensional echocardiography

P2420The effect of obesity on left atrial volume and phasic functions assessed by real-time three-dimensional echocardiography

Left Atrial Phasic Function and Its Association With Atrial Fibrillation in Patients After Transcatheter Aortic Valve Implantation

BackgroundLeft atrial (LA) size is a marker of prognosis in severe aortic stenosis (AS). The aims of this retrospective study were to assess the impact of transcatheter aortic valve implantation (TAVI) on the recovery of LA phasic function and to assess the relationship between LA function and new-onset atrial fibrillation (NAF) after TAVI. MethodsIn this retrospective cohort study, LA function was measured using biplane volumes and 2-dimensional (2D) speckle tracking echocardiography (STE) in 52 patients (median age, 81 years) with severe AS before TAVI and at midterm follow-up. Twenty healthy individuals ≥ 75 years were used as controls. ResultsBefore TAVI, the 3 phasic volumetric emptying fractions and all STE-derived parameters of LA function were significantly reduced. At 5 ± 3 months after TAVI, there was an improvement in LA reservoir and contractile function. However, LA phasic volumes and emptying fractions showed minimal changes. Fourteen patients had NAF in the early postprocedural period after TAVI. These patients experienced longer hospitalization (11 days vs 6 days; P = 0.002). By bivariable logistic regression analysis, the use of a transapical approach and the LA early diastolic strain rate (SR) before TAVI were significantly associated with NAF immediately after TAVI. ConclusionsSevere AS is associated with LA dysfunction. Intrinsic LA compliance and LA contractile properties by STE improved at midterm follow-up after TAVI. Preprocedural LA early diastolic SR may predict the development of NAF after TAVI pending confirmation by larger prospective evaluations.

Left atrial phasic function and heart rate variability in asymptomatic diabetic patients.

We evaluated left atrial (LA) phasic function and heart rate variability (HRV) in asymptomatic diabetic patients, and the relationship between HRV indices and LA phasic function assessed by volumes and speckle tracking imaging. This cross-sectional study included 55 asymptomatic patients with type 2 diabetes and 50 healthy controls without cardiovascular risk factors. All study subjects underwent laboratory analyses, complete two-dimensional echocardiography examination (2DE) and 24-h Holter monitoring. Maximum, minimum LA and pre-A LA volumes and volume indexes are significantly higher in diabetic patients. Total and passive LA emptying fractions (EF), representing the LA reservoir and conduit function, are significantly lower in diabetic subjects. Active LA EF, the parameter of the LA booster pump function, is compensatory increased in diabetic patients. Similar results were obtained by 2DE strain analysis. Cardiac autonomic function, assessed by HRV, is significantly deteriorated in diabetic patients. Time and frequency-domain HRV measures are significantly lower in diabetic subjects than in controls. HbA1c, LV mass index and HRV are associated with total LA EF and longitudinal LA strain independently of age, body mass index and LV diastolic function in the whole study population. LA phasic function and cardiac autonomic nervous system assessed by HRV are impacted by diabetes. HbA1c and HRV are independently associated with LA reservoir function evaluated by volumetric and strain methods in the whole study population. This study emphasizes the importance of determination of LA function and HRV as important markers of preclinical cardiac damage and autonomic function impairment in diabetic patients.

Impaired Left Atrial Function in Fabry Disease: A Longitudinal Speckle-Tracking Echocardiography Study

Fabry disease (FD) is characterized by the accumulation of sphingolipids in multiple organs, including the left atrium. It is uncertain if the left atrial (LA) reservoir, conduit, and contractile functions evaluated by speckle-tracking echocardiography are affected in Fabry cardiomyopathy and whether enzyme replacement therapy can improve LA function. In this retrospective cohort study, LA strain, strain rates, and phasic LA volumes were studied in 50 patients with FD and compared with values in 50 healthy control subjects. All three LA phasic functions were altered. Peak positive strain (reservoir function) was 38.9±14.9% versus 46.5±10.9% (P=.004), and late diastolic strain (contractile function) was 12.6±5.9% versus 15.6±5.3% (P=.010). In 15 patients who started enzyme replacement therapy during the study, most of the LA parameters improved at 1-year follow-up (peak positive strain from 32.0±13.5% to 38.0±13.5%, P=.006), whereas there was a trend toward deterioration in 15 patients who never received treatment (peak positive strain from 47.3±10.8% to 41.3±9.3%, P=.058). Nine patients with FD (21%) experienced new-onset atrial fibrillation or stroke during 4-year follow-up. By univariate analysis, peak positive strain and early diastolic strain demonstrated significant associations with clinical events, surpassing conventional echocardiographic parameters and clinical characteristics. LA reservoir, conduit, and contractile functions by speckle-tracking echocardiography were all affected in FD. Enzyme replacement therapy improved LA function. LA strain parameters were associated with atrial fibrillation and stroke.

Correction: Effects of experimental cardiac volume loading on left atrial phasic function in healthy dogs.

Correction: Effects of experimental cardiac volume loading on left atrial phasic function in healthy dogs.

Effects of experimental cardiac volume loading on left atrial phasic function in healthy dogs.

OBJECTIVE To elucidate the relationship between acute volume overload and left atrial phasic function in healthy dogs. ANIMALS 6 healthy Beagles. PROCEDURES Dogs were anesthetized. A Swan-Ganz catheter was placed to measure mean pulmonary capillary wedge pressure (PCWP). Cardiac preload was increased by IV infusion with lactated Ringer solution at 150 mL/kg/h for 90 minutes. Transthoracic echocardiography was performed before (baseline) and at 15, 30, 45, 60, 75, and 90 minutes after volume loading began. At each echocardiographic assessment point, apical 4-chamber images were recorded and analyzed to derive time-left atrial area curves. Left atrial total (for reservoir function), passive (for conduit function), and active (for booster-pump function) fractional area changes were calculated from the curves. RESULTS Volume overload resulted in a significant increase from baseline in PCWP from 15 to 90 minutes after volume loading began. All fractional area changes at 15 to 90 minutes were significantly increased from baseline. In multiple regression analysis, quadratic regression models were better fitted to the relationships between PCWP and each of the total and active fractional area changes than were linear regression models. A linear regression model was better fitted to the relationship between PCWP and passive fractional area change. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that left atrial phasic function assessed on the basis of left atrial phasic areas was enhanced during experimental cardiac volume loading in healthy dogs. The effect of volume load should be considered when evaluating left atrial phasic function by indices derived from left atrial phasic sizes.

Masked Hypertension and Left Atrial Dysfunction: A Hidden Association.

Masked hypertension (MH) is a clinical condition that indicates normal values of clinic blood pressure (BP) but elevated 24-hour BP. The purpose of this study was to investigate the relationship between MH and left atrial (LA) phasic function evaluated by both the volumetric and speckle tracking method. This cross-sectional study included 49 normotensive individuals, 50 patients with MH, and 70 untreated sustained hypertensive patients adjusted by age and sex. MH was diagnosed if clinic BP was normal and 24-hour BP was increased. LA reservoir function was lower in patients with MH and those with sustained hypertension compared with the normotensive group. LA conduit function gradually decreased, while LA booster pump function progressively increased, from normotension to sustained hypertension. Similar results were obtained by two-dimensional echocardiographic strain analysis. Independently of main clinic and echocardiographic characteristics, 24-hour systolic BP was associated with LA passive ejection fraction, LA total longitudinal strain, LA positive longitudinal strain, and LA stiffness index. In conclusion, MH is associated with impairment of LA phasic function and stiffness, and 24-hour systolic BP increment was closely related with LA remodeling.

The influence of white-coat hypertension on left atrial phasic function

We aimed to investigate the association between white-coat hypertension (WCH) and left atrial (LA) phasic function assessed by the volumetric and speckle tracking method. This cross-sectional study included 52 normotensive individuals, 49 subjects with WCH and 56 untreated hypertensive patients who underwent a 24-h ambulatory BP monitoring and complete two-dimensional echocardiographic examination (2DE). WCH was diagnosed if clinic blood pressure (BP) was elevated and 24-h BP was normal. We obtained that maximum, minimum LA and pre-A LAV volumes and volume indexes gradually and significantly increased from the normotensive subjects, throughout the white-coat hypertensive individuals to the hypertensive patients. Passive LA emptying fraction (EF), representing the LA conduit function, gradually reduced from normotensive to hypertensive subjects. Active LA EF and the parameter of the LA booster pump function increased in the same direction. Similar results were obtained by 2DE strain analysis. The LA stiffness index gradually increased from normotensive controls, throughout white-coat hypertensive subjects to hypertensive patients. Clinic systolic BP was associated with LA passive EF (β= −0.283, p = 0.001), LA active EF (β = 0.342, p < 0.001), LA total longitudinal strain (β= −0.356, p < 0.001), LA positive longitudinal strain (β= −0.264, p = 0.009) and LA stiffness index (β = 0.398, p < 0.001) without regard to age, BMI, left ventricular structure and diastolic function in the whole study population. In the conclusion, WCH significantly impacts LA phasic function and stiffness. Clinic systolic BP was associated with functional and mechanical LA remodeling in the whole study population.

Left atrial deformation and phasic function determined by 2-dimensional speckle tracking echocardiography in healthy dogs

IntroductionFeasibility, intra- and inter-observer variability of measuring left atrial (LA) longitudinal strain and strain rate (SR) variables using speckle tracking echocardiography (STE) have not been reported in the dog. Reference intervals for these variables which can be useful to estimate LA function have been provided. AnimalsForty-eight healthy adult dogs. Materials and methodsLeft atrial longitudinal deformation was evaluated in each dog by STE, and different combinations of STE variables were used to describe the 3 phases (reservoir, conduit and booster pump phase) of the LA function. ResultsLeft atrial STE was possible in 40/48 dogs (83%). Strain and SR curves in healthy dogs were characterized, and reference intervals for several strain and SR variables are provided. Intra- and inter-observer variability, expressed as percent difference between observations or observers, was 3.58%–10.8% for indices of the LA reservoir function, 10.48%–15.82% for indices of the LA conduit function and 14.1%–34% for indices of the LA contractile function. Strain rate in early diastole and strain rate at atrial contraction variables were correlated significantly with age. No other relationships (body weight, heart rate or LA size) with any STE variables could be identified. ConclusionSpeckle tracking echocardiography provides quantitative measurements of LA longitudinal deformation and can be used to assess LA phasic function in healthy dogs. Further studies of these variables in dogs with cardiac diseases are needed to determine the clinical applicability and utility.