Left Atrial Total Emptying Fraction Research Articles

Abstract 18920: Left Atrial Function is Associated With Left Ventricular Mass in Women With Preserved Left Ventricular Ejection Fraction and Late Gadolinium Enhancement on Cardiac MRI

Introduction: Myocardial fibrosis detected by late gadolinium enhancement (LGE) on cardiac MRI may be related to conditions with increased left ventricular (LV) mass and diastolic dysfunction. Women have an increased incidence of LV diastolic dysfunction and poorer clinical outcomes compared to men. Aim: To examine gender-based associations between LV mass and left atrial total emptying fraction (LATEF), a surrogate for diastolic function, in patients with LGE on cardiac MRI. Methods: We analyzed 134 consecutive patients undergoing cardiac MRI and LGE sequences on a 1.5T GE scanner. LV mass and LV/LA volumes (indexed by BSA) were measured offline from cine SSFP images using Precession software. Presence of LGE was reported. Nonparametric analyses were performed. Results: 40 patients with more than mild mitral regurgitation, pericardial disease, or LVEF <50% were excluded. 94 patients studied (49% women) had a median age of 51 years [IQR 38-67] with no gender-based difference. Median LV mass index (LVMi) for all patients was 69.5 g/m2 [IQR 57-82] and was higher in LGE vs no-LGE patients (p<0.001) and higher in men vs women (p<0.05). Median LATEF for all patients was 0.50 [IQR 0.41-0.54] and was lower in LGE vs no-LGE patients (p<0.001) with no gender-based difference. LVMi had a strong inverse correlation with LATEF for all patients and for the LGE group (r=-0.58, p<0.001 and r=-0.51, p<0.001 respectively). LVMi had a very strong inverse correlation with LATEF (r=-0.74, p<<0.001) in women with LGE and moderate inverse correlation in women with no-LGE (r=-0.45, p=0.02). LVMi had a moderate inverse correlation with LATEF in men with LGE (r=-0.48, p. <0.01) and no correlation in men with no-LGE (Figure). Conclusions: LA function inversely correlates with indexed LV mass, most strongly in women with LV LGE. Further exploration of these parameters may allow earlier detection of LV diastolic dysfunction and improved risk stratification.

Left atrial total emptying fraction measured by cardiovascular magnetic resonance imaging predicts low-voltage areas detected during electroanatomical mapping.

Low-voltage areas (LVAs) found during left atrial (LA) electroanatomical mapping are increasingly targeted by radiofrequency catheter ablation (RFCA) on top of pulmonary vein isolation to improve arrhythmia-free survival in patients with atrial fibrillation (AF). However, pre-procedural prediction of LVAs remains challenging. The purpose of the present study was to describe the association between parameters of LA function and dimensions, respectively, derived from pre-procedural cardiovascular magnetic resonance (CMR) imaging, and the presence of LVAs on LA voltage mapping. Patients who underwent first-time RFCA for paroxysmal or persistent AF and who were in stable sinus rhythm during pre-procedural CMR imaging were included in this study. Cardiovascular magnetic resonance-derived parameters of LA function and dimensions were calculated. Low-voltage areas were defined as areas with bipolar voltage amplitudes of ≤0.5 mV on electroanatomical mapping. In total, 259 consecutive patients were included in this analysis. Low-voltage areas were found in 25 of 259 patients (9.7%). Compared with those without LVAs, patients with LVAs were significantly older, were more likely to be female, had a higher CHA2DS2-VASc score, had larger LA volumes, and had a lower LA total emptying fraction (TEF). In multivariate analysis, only LA TEF [odds ratio (OR) 0.885, 95% confidence interval (CI) 0.846-0.926, P < 0.001] and the CHA2DS2-VASc score (OR 1.507, 95% CI 1.115-2.038, P = 0.008) remained independently associated with the presence of LVAs. Left atrial TEF and the CHA2DS2-VASc score were independently associated with the presence of LVAs found during LA electroanatomical mapping. These findings may help to improve pre-procedural prediction of pro-arrhythmogenic LVAs and to improve peri-procedural patient management.

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

BackgroundCoronary 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). MethodsForty-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. ResultsCompared 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). ConclusionsImpairment 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.

A retrospective study on the clinical significance of cardiac computed tomography in heart failure patients with preserved ejection fraction.

This study investigated the correlation between cardiac function parameters by cardiac computed tomography (CT) and the clinical outcomes of heart failure patients with preserved ejection fraction (HFpEF) to provide experimental data for the diagnosis of HFpEF. A total of 157 HFpEF patients admitted to our hospital from January 2017 to January 2019 were retrospectively analyzed. The patients were divided into event and non-event groups according to the occurrence or absence of adverse events. Cardiac function parameters, such as the left ventricular (LV) end-diastolic volume (LVEDV) and LV end-diastolic volume index (LVEDVI), were obtained via CT scan. Also, the N-terminal-pro hormone b-type natriuretic peptide (NT-proBNP) levels in patients' serum were measured using an enzyme linked immunosorbent assay (ELISA) kit, and echocardiographic parameters such as LV posterior wall thickness (LVPWT) were also recorded. Further, Cox regression was employed to analyze factors associated with the clinical outcomes. Compared with patients in the non-event group, the left ventricular end-diastolic mass (LVM), LVEDVI, left ventricular end-systolic volume index (LVESVI), left atrial end-diastolic volume index (LAEDVI), and left atrial end-systolic volume index (LAESVI) were significantly increased, and the left ventricular total emptying fraction (LVTEF) and left atrial total emptying fraction (LATEF) were markedly decreased in the event group patients. Also, the E/e' and LAEDVI were related factors affecting the clinical outcomes of HFpEF patients. The above indicators displayed a significant predictive for the clinical outcomes of HFpEF patients. Several cardiac function measures, including LAEDVI, are factors associated with the clinical outcomes of HFpEF patients.

Left atrial phasic volumes and functions changes in asymptomatic patients with sarcoidosis: evaluation by three-dimensional echocardiography

Background Cardiac involvement is the leading cause of morbidity and death in patients with sarcoidosis. However, many patients remain asymptomatic until the late-stage. In this study, we investigated the left atrial (LA) phasic volumes and functions changes by three-dimensional (3D) echocardiography measurements in asymptomatic patients with sarcoidosis, which has good correlation with cardiac magnetic resonance imaging. Methods In this cross-sectional study, 44 asymptomatic patients with sarcoidosis and 40 age, sex and BMI-matched healthy volunteers underwent two-dimensional (2D) and 3D-echocardiograpy. Standard echocardiographic and tissue Doppler imaging parameters were obtained. LA phasic volumes were assessed by 3D-echocardiography. From the 3D-echocardiography derived values, LA active, passive, and total emptying fraction (EF) were calculated. Results All left ventricular ejection fractions (LVEF) obtained by 2D and 3D-echocardiography were normal (≥50%). While LA diameters (33.36 ± 4.23 vs. 30.57 ± 5.43) and E/e’ septal annulus ratios (10.82 ± 1.79 vs. 9.27 ± 1.81) were significantly higher, A-wave (70.80 ± 5.81 vs. 74.51 ± 5.41) and e’septal annular velocities (6.48 ± 1.58 vs. 9.03 ± 1.63) were significantly lower in the sarcoidosis group as compared with control group, respectively. While 3D-echocardiography derived LA-minimum volume indices (LAVImin) (13.89 ± 2.75 vs. 12.23 ± 1.73) were significantly higher, 3D-echocardiography derived LA active EFs (AAEF) (30.78 ± 3.52 vs. 38.52 ± 4.75) and LA total EFs (TAEF) (47.71 ± 7.47 vs. 53.32 ± 5.81) were found to be significantly lower in the sarcoidosis group as compared with control group, respectively. Conclusion LAVImin, AAEF and TAEF calculated based on LA phasic volumes obtained by 3D-echocardiography may be promising indicators of subclinical cardiac involvement in asymptomatic patients with sarcoidosis.

Comparison Between Echocardiography and Cardiac Computed Tomography in the Evaluation of Diastolic Dysfunction and Prediction of Heart Failure

Recent data indicate that left atrial (LA) function assessment by cardiac computed tomography (CT) is closely related to diastolic dysfunction (DD). Therefore, we aimed to perform a direct comparison between CT and echocardiography for diagnosis of advanced DD and prediction of future heart failure or cardiovascular death. We identified 340 patients who had both spiral cardiac CT and a proximate echocardiogram. LA total emptying fraction (LATEF), a measure of global LA function, was automatically calculated from CT data, as a surrogate for diastolic function and was compared with echocardiographic grades of diastolic function. The area under the receiver operating characteristic curve for LATEF to differentiate between advanced DD (grades 2 and 3) and all other grades was 0.84 (0.79 to 0.88). Over a median of 4 years, 69 events (admissions for heart failure and cardiovascular deaths) occurred. By multivariate Cox analysis, LATEF &lt;40% provided incremental prognostic information after adjustments for advanced DD by echocardiography (hazard ratio 2.15, 95% confidence interval 1.13 to 3.94). There was a significant interaction (p=0.03) between LATEF and echocardiography-based diastolic grades. Stratified analyses within the diastolic function groups revealed that LATEF &lt;40% was equivalent to echocardiography in predicting events in the subgroup with advanced DD by echocardiography (p=0.20) but was associated with a significantly higher event rates in patients with normal filling pressures (p=0.0001) or indeterminate diastolic function (p=0.04) by echocardiography. In conclusion, LA function derived from CT can accurately detect advanced DD diagnosed by echocardiography and has additive value to echocardiography-derived DD.

Left atrial function by cardiac computed tomography is a predictor of heart failure and cardiovascular death

We sought to evaluate cardiac CT angiography (CCTA)-based assessment of left atrial (LA) function as a predictor of hospitalizations for heart failure (HF) and cardiovascular (CV) mortality. LA function was evaluated using automatic derivation of LA volumes to calculate LA total emptying fraction (LATEF) in 788 consecutive patients with normal sinus rhythm who had undergone spiral CT scans. The relationship between LATEF evaluated by CCTA and the composite endpoint of admission for HF or CV mortality was analyzed using Cox models. During a median follow-up of 4 years, there were 100 events, 62 HF hospitalizations, and 38 cardiovascular deaths. Mean LATEF was 30.7±10.7% and 40.5 ± 11.2% in patients with and without events, respectively (p<0.0001). A high LATEF (upper tertile > 46%) was associated with a very low event rate (3.5% at 6 years [95% CI 1.7-7.1%]). The adjusted HR for HF or CV mortality was 4.37 (95% CI 1.99-9.60) in the lowest LATEF tertile, and 2.29 (95% CI 1.03-5.14) in the middle tertile, relative to the highest tertile. For the endpoint of HF alone, adjusted HR for the lowest LATEF tertile was 5.93 (95% CI 2.23-15.82) and for the middle tertile 2.89 (95% CI 1.06-7.86). The association of LATEF with outcome was similar for patients with both reduced and preserved left ventricular (LV) ejection fraction (Pinteraction =0.724). Reduced LATEF was associated with a high event rate, even when coupled with normal LA volume. CCTA-derived LA function is a predictor of HF hospitalization or CV death, independent of clinical risk factors, LA volume, and LV systolic function. • Left atrial function can be automatically derived from cardiac CTA scans. • Cardiac CTA-derived left atrial function is a predictor of hospitalization for heart failure and cardiovascular death. • Evaluation of left atrial function could be useful in identifying patients at risk of heart failure.

Accuracy of Diastolic Function by Cardiac Computed Tomography Relative to Echo-Doppler: Additive Clinical and Prognostic Value.

We aimed to assess the agreement between cardiac computed tomography (CT) and echo for diagnosing advanced diastolic dysfunction (DD) and to assess the prognostic value of CT-based parameters. One hundred one consecutive patients who had both CT and echo-Doppler within 1 month were included. Diastolic function was assessed by CT using a previously validated method, based on left atrial volume changes, and compared with echocardiography grades 0 to 3. Patients were followed up for a combined outcome of cardiac death and hospitalization for heart failure. By operating characteristic curve analysis, the best CT-based parameter for predicting advanced DD based on echo was left atrial total emptying fraction. Left atrial total emptying fraction <36% had sensitivity/specificity of 76%/86%. Agreement between echo and CT for detecting advanced (grades 2/3) DD was substantial (κ = 0.62, P < 0.0001). By Cox multivariate analysis, left atrial total emptying fraction was a powerful independent predictor of outcome at 3 years (hazard ratio, 8.0 [2.2-28.4]; P < 0.0001). Computed tomography-based assessment of DD has a good agreement with echo-Doppler-based results. Left atrial total emptying fraction seems to have a strong prognostic value.

Left heart function evaluation of patients with essential hypertension and paroxysmal atrial fibrillation by two-dimensional speckle tracking imaging combined with real-time three-dimensional ultrasound imaging.

BackgroundThis study aims to assess the value of two-dimensional speckle tracking imaging (2D-STI) combined with real-time 3-dimensional echocardiography (RT-3DE) in evaluating left heart function in patients with combined ETH and PAF.MethodsA prospective study was designed, and the research period was from January 2017 to January 2020. A PAF observation group comprised of patients with ETH and PAF, a PAF control group of patients with ETH but without PAF, and a healthy volunteer group referred to as the healthy group, each comprised of 50 patients was established. All patients underwent routine ultrasound imaging examination using 2D-STI and RT-3DE. The interventricular septum thickness (IVST), left and right atrioventricular diameter (LAD), left ventricular posterior wall thickness (PWT), left ventricular ejection fraction (LVEF), the mean left atrium peak strain (mSs, mSe, mSa), strain rate (mSRs, mSRe, mSRa), the left ventricular mass (LVM), left ventricular mass index (LVMI), and left atrial total emptying volume (LATEV), the left atrial volume index (LAVI), left atrial total emptying fraction (LATEF), left atrium expansion index (LAEI), left atrium passive ejection fraction (LAPEF), and left atrial active ejection fraction (LAAEF) were calculated. Patients in the PAF observation group received telmisartan combined with rosuvastatin after diagnosis and 12- and 24-month-follow up visits were conducted. During these visits, 2D-STI combined with RT-3DE was used to evaluate cardiac function and each patient’s blood pressure was monitored.ResultsPatients in the PAF observation group had a significantly longer course of ETH than patients in the PAF control group (13.5±4.4 vs. 10.32±5.6, P=0.002). The comparison of routine 2D-STI and RT-3DE ultrasound indexes among the three groups also showed significant differences (P<0.01). During the 2-year follow-up period, the IVST, LAD, PWT, and LVEF of remaining patients significantly improved as treatment progressed (P<0.05). The LAVI, LATEF, and LAEI also improved significantly as the treatment progressed (P<0.05). After 12 months of treatment, the recurrence rate of atrial fibrillation was 16.33% (8/45) and after 24 months this was 34.21% (13/38).ConclusionsCardiac function could be evaluated comprehensively by 2D-STI combined with RT-3DE in patients with ETH combined with PAF at initial diagnosis and follow-up.

Fibroblast Growth Factor 23 and Long-Term Cardiac Function: The Multi-Ethnic Study of Atherosclerosis.

Although FGF23 (fibroblast growth factor 23) is associated with heart failure and atrial fibrillation, the mechanisms driving these associations are unclear. Sensitive measures of cardiovascular structure and function may provide mechanistic insight behind the associations of FGF23 with various cardiovascular diseases. In MESA (the Multi-Ethnic Study of Atherosclerosis), we evaluated the associations of baseline serum FGF23 (2000-2002) with measures of left ventricular (LV) and left atrial mechanical function on cardiac magnetic resonance at 10-year follow-up (2010-2012). Of 2276 participants with available FGF23 and cardiac magnetic resonance at 10-year follow-up, participants with higher FGF23 levels were more likely White race, taking antihypertensive medications, and had lower kidney function. After covariate adjustment, FGF23 was associated with higher LV mass (β coefficient per 1 SD higher, 1.14 [95% CI, 0.16-2.12], P=0.02), worse LV global circumferential strain (β coefficient per 1 SD higher, 0.15 [95% CI, 0.05-0.25], P=0.003), worse LV midwall circumferential strain (β coefficient per 1 SD higher, 0.20 [95% CI, 0.08-0.31], P=0.001), and lower left atrial total emptying fraction (β coefficient per 1 SD higher, -0.52 [95% CI, -1.02 to -0.02], P=0.04). These associations were consistent across racial/ethnic groups and the spectrum of glomerular filtration rates. FGF23 was not associated with the presence of myocardial scar (odds ratio per 1 SD higher, 1.12 [95% CI, 0.86-1.45], P=0.42). In a multiethnic, community-based cohort, baseline FGF23 levels were independently associated with higher LV mass, lower LV systolic function, and reduced left atrial function over long-term follow-up. These findings provide potential mechanistic insight into associations of FGF23 with incident heart failure and atrial fibrillation.

Assessment of left atrial volume and function in patients with Sjögren's syndrome using three-dimensional echocardiography.

We used real time, three-dimensional transthoracic echocardiography (3DTTE) to evaluate left atrial (LA) volume and mechanical function in patients with primary Sjögren's syndrome (SS). We prospectively included 42 consecutive patients with primary SS and 42 controls who were similar in terms of basal characteristics. 3DTTE was used to assess LA function. Maximum LA volume, minimum LA volume, pre-atrial contraction LA volume, LA Active Stroke Volume (ASV), LA Total Stroke Volume (TSV), maximal left atrial volume index (LAVImax), Left atrial pre-contraction volume index, and Left atrial minimum volume index, ASV index, and TSV index were significantly higher in the SS group, and the LA Total Emptying Fraction, LA Expansion Index, and LA Passive Emptying Fraction were significantly lower. Although the active emptying fraction was higher in the SS group, the difference was not statistically significant. LAVImax was positive correlated with disease duration (r=.753). Left atrial function is impaired in SS patients and serves as an early marker of subclinical cardiac involvement.

Magnitude and Time Course of Left Atrial Remodeling Changes in Patients Undergoing Chronic Left Ventricular Assist Device Support

Although left ventricular (LV) reverse remodeling has been described in patients with left ventricular assist devices (LVADs), little is known about left atrial (LA) structural and functional changes. Echocardiographic parameters were obtained at pre-LVAD implant and following 1, 3, and 6 months of LVAD support. Favorable LV structural and functional response following LVAD support (i.e. Responders) was defined using previously published criteria. Structural and functional indices specific to LA such as LA volume index (LAVI) and LA total emptying fraction (LATEF) were compared in eighteen Responders versus twenty Non-Responders. Statistical comparison of quantitative data was performed using 2-tailed Wilcoxon signed-rank test for paired samples and categorical data were compared using Fisher's exact test. The magnitude and time course of functional changes as reflected by the LVEF and LATEF in Responders and Non-Responders are depicted in Figure 1A and 1B. LA remodeling structural changes over time in Responders and Non-Responders are depicted in Figure 1C. Patients experiencing post-LVAD favorable LV functional response had significantly better LA remodeling structural and functional indices before LVAD implantation and further improved those early after the initiation of LV mechanical support. LA reverse remodeling studies with longer follow-up and correlation with post LVAD-weaning patient outcomes are warranted.

Acute Impact of Balloon Mitral Valvotomy on Left Atrial Functions in Mitral Stenosis

Background: Rheumatic mitral stenosis (MS) is associated with progressive impairment of left atrial (LA) mechanical functions. This study was conducted to assess the acute impact of Balloon Mitral Valvotomy (BMV) on these functions. Methods: This single centre observational study included 25 patients with severe MS (aged 34.1 ± 7.1 years, with mean mitral valve area of 0.74 ± 0.13 cm²), in sinus rhythm, who underwent successful BMV at our hospital. Phasic LA volumes (Vmax: maximal LA volume, Vmin: minimal LA volume, and Vp: LA volume at the onset of P-wave) were measured by modified Simpson’s method. Parameters of LA reservoir function i.e. LA total emptying fraction (LATEF) and LA expansion index (LAEI); conduit function i.e. LA passive emptying fraction (LAPEF); and pump function i.e. LA active emptying fraction (LAAEF) were calculated from these volumes. All these parameters were evaluated before and 24-48 hours after BMV. Results: Successful BMV led to significant reduction in Vmax (p < 0.001), Vmin (p < 0.001), and Vp (p < 0.001). There was a significant increase in LATEF (p= 0.001) and LAEI (p= 0.002). LAPEF increased insignificantly (p= 0.057), while there was no significant change in LAAEF (p =0.127) after BMV. Conclusion: Successful BMV leads to early improvement in left atrial reservoir and conduit functions, without significantly affecting left atrial pump function. Whether these acute changes translate into long term left atrial reverse remodelling and clinical benefits thereof needs to be established by further studies.

Predictors of Future Atrial Fibrillation Development in Patients with Hypertrophic Cardiomyopathy: A Prospective Follow‐Up Study

We evaluated whether left atrial (LA) phasic functions, P-wave dispersion (PWD), and plasma NT-proBNP levels could predict future development of atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM). Seventy patients with HCM were evaluated. The LA phasic functions including the LA total emptying volume (LATEV), LA total emptying fraction (LATEF), LA active emptying volume (LAAEV), LA active emptying fraction (LAAEF), LA passive emptying volume (LAPEV), and LA passive emptying fraction (LAPEF) were evaluated. P-wave dispersion was calculated. Plasma NT-proBNP levels were measured on the same day with echocardiographic study. Patients were followed up 53.09 ± 1.87 months. Patients who developed AF (n = 18) had significantly higher PWD values, NT-proBNP levels, LAVI, E/E' av, and resting LVOT gradients and significantly lower LATEF and LAAEF. In multivariate analysis, LATEF (P = 0.002), LAAEF (P = 0.007), logNT-proBNP level (P = 0.022), and PWD (P = 0.018) were associated with AF development. The results of receiver operating characteristic analysis revealed that a LATEF cutoff value 49% with 72% sensitivity and 81% specificity, a LAAEF cutoff value of 36% with 72% sensitivity and 71% specificity, and an NT-proBNP cutoff value of 720 pg/mL predicted future AF development with 72% sensitivity and 60% specificity. A PWD cutoff value of 47.5 msecond predicted future AF development with 78% sensitivity and 72% specificity. In patients with HCM, LA phasic functions, PWD, and NT-proBNP levels predict future development of AF. Assessment of LA phasic functions during routine echocardiographic evaluation and measuring NT-proBNP levels and PWD values of patients with HCM during daily practice may provide important data in predicting those at high risk of AF occurrence.

13. Immediate Effect of percutaneous transvenous mitral commissurotomy on atrial electromechanical delay and left atrial mechanical functions in patients with rheumatic mitral stenosis

Rheumatic mitral stenosis (MS) is associated with prolonged inter and intra-atrial electromechanical delays and impaired left atrial (LA) mechanical functions, which are considered to be markers of atrial fibrillation (AF) risk. This study was conducted to assess the immediate effect of successful percutaneous transvenous mitral commissurotomy (PTMC) on these parameters. This observational study included 25 patients with symptomatic, severe MS (aged 34.1 ± 7.1 years, with mean mitral valve area (MVA) of 0.74 ± 0.13 cm2), in normal sinus rhythm, who underwent successful PTMC at our hospital. Inter-atrial (AEMD), left intra-atrial (L-IAEMD) and right intra-atrial (R-IAEMD) electromechanical delays were measured on tissue Doppler imaging. Phasic LA volumes (Vmax: maximal LA volume, Vmin: minimal LA volume and Vp: LA volume at P-wave onset) were measured by modified Simpson’s method. Parameters of LA reservoir function i.e. LA total emptying fraction (LATEF) and LA expansion index (LAEI); conduit function i.e. LA passive emptying fraction (LAPEF); and pump function i.e. LA active emptying fraction (LAAEF) were calculated from the phasic LA volumes. PTMC was performed using the standard Inoue Balloon technique. All these parameters were evaluated and compared before and 24–48 h after PTMC. Successful PTMC led to significant reduction in AEMD (p < 0.001), L-IAEMD (p < 0.001), R-IAEMD (p < 0.001), Vmax (p < 0.001), Vmin (p < 0.001) and Vp (p < 0.001). There were significant increments in LATEF (p = 0.001), LAEI (p = 0.002) and LAPEF (p = 0.05), while there was no significant change in LAAEF (p = 0.127) after PTMC. Successful PTMC has a favorable early impact on left atrial mechanical functions and other novel parameters of atrial electromechanical remodeling in MS patients. Large scale prospective studies are required to confirm whether improvement in these markers translates into reduced long term AF risk in these patients.

Relationships between P wave dispersion, atrial electromechanical delay, left atrial remodeling, and NT-proBNP levels, in patients with hypertrophic cardiomyopathy

We evaluated the associations among the well-known atrial fibrillation (AF) predictors including P-wave dispersion (PWD), intra- and inter-atrial electromechanical dyssynchrony (EMD), left atrial (LA) phasic functions, and plasma N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) levels, in patients with hypertrophic cardiomyopathy (HCM). Seventy patients with HCM and age and sex matched 70 subjects were enrolled. PWD, LA total emptying fraction (LATEFr), active emptying fraction (LAAEFr), passive emptying fraction (LAPEFr), expansion index (LAEI) intra- and inter-atrial EMD were calculated. Levels of NT-proBNP of all subjects were determined. Higher PWD (p = 0.006), significantly decreased LAEI (p < 0.001), LATEFr, and LAPEFr (both p values < 0.001) values and significantly increased inter-atrial (p < 0.001), LA (p = 0.001), and right atrial dyssynchrony (p < 0.001) were observed in the HCM group compared to controls. PWD was negatively correlated with LAEI (r = -0.236, p = 0.005) and LATEFr (r = -0.242, p = 0.04), however not with LAPEFr (p = 0.7), or LAAEFr (p = 0.3). Except for the LA lateral wall PA' (r = 0.283, p = 0.02), PWD was not correlated with any atrial EMD parameter. Inter-atrial dyssynchrony was related to LAEI (r = -0.272, p = 0.001), LATEFr (r = -0.256, p = 0.03), and LAPEFr (r = -0.332, p = 0.006), but not, however, to LAAEFr (p = 0.4). The plasma NT-proBNP levels of patients were not correlated with either PWD (p = 0.927) or inter-atrial dyssynchrony (p = 0.102). PWD and inter-atrial dysynchrony seem to independently promote AF, although both are associated with LA reservoir function in HCM populations. The NT-proBNP level is not associated with these two AF predictors in patients with HCM. NT-proBNP seems to be a poor marker of atrial electrical remodeling in HCM patients.

Early- and mid-term effects of percutaneous mitral balloon valvuloplasty on left atrial mechanical functions in mitral stenosis.

The aim of the study was to evaluate left atrial (LA) mechanical functions in MS before and after percutaneous mitral balloon valvuloplasty (PMBV) and to follow it up in short- and mid-term. We carried out a prospective study of 49 patients with critical mitral stenosis (MS) who had normal sinus rhythm. LA mechanical functions were evaluated before and 24-48 h, 3 months, and 1 year after PMBV, which included LA passive emptying volume (LAPEV), LA active emptying volume (LAAEV), LA total emptying volume (LATEV), LA passive emptying fraction (LAPEF), LA active emptying fraction (LAAEF), LA total emptying fraction (LATEF), and conduit volume. The transthoracic echocardiography parameters of the MS patients before and 24-48 h, 3 months, and 1 year after PMBV were as follows: (a) mitral valve area 1.1 cm² (0.9-1.6); 2.2 cm² (1.8-2.8) (p<0.001); 2.2 cm² (1.7-2.9) (NS); 2.1 cm² (1.8-2.7) (p<0.001); (b) LAPEV 13 ml/m² (9-27); 11 ml/m² (8-19) (p<0.001); 10 ml/m² (7-19) (p<0.001); 10 ml/m² (6-18) (p<0.001); (c) LATEV 26 ml/m² (19-50); 21 ml/m² (16-40) (p<0.001); 20 ml/m² (15-36) (p<0.001); 19 ml/m² (15-34) (p<0.001); (d) Conduit volume 30 ml/m² (22-44); 33 ml/m² (26-46) (p<0.001); 34 ml/m² (30-42) (p<0.001); 36 ml/m² (31-42) (p<0.001), respectively. However, LAAEV, LAPEF, LAAEF, and LATEF were not altered after PMBV. The findings of this study demonstrated an improvement of LA mechanical functions, which continued to improve for 1 year, after successful treatment of MS by PMBV.

Relationship of CHA2DS2-VASc and CHADS2 Score to Left Atrial Remodeling Detected by Velocity Vector Imaging in Patients with Atrial Fibrillation

BackgroundThe CHADS2/CHA2DS2-VASc scores are used to predict thrombo-embolic/stroke in patients with nonvalvular atrial fibrillation (AF). Nevertheless, limited data are available regarding the association between these risk stratification for stroke and left atrial (LA) remodeling status of AF patients. The purpose of this study was to explore the association between these scores and LA remodeling status assessed quantificationally by echocardiography in AF patients.MethodsOne hundred AF patients were divided into 3 groups based on the CHA2DS2-VASc/CHADS2 score: the score of 0 (low stroke risk), the score of 1 (moderate stroke risk) and the score of ≥2 (high stroke risk). All patients were performed through conventional and velocity vector imaging echocardiography. Echocardiographic parameters: maximum LA volume index (LAVImax), LA total emptying fraction (LAEFt) and LA mean strain were obtained to assess quantificationally LA remodeling status.ResultsOn categorizing with CHA2DS2-VASc, the score of 1 group showed augment in LAVImax and attenuation in LA mean strain derived from VVI, compared with the score of 0 group (LAVImax: 40.27±21.91 vs. 26.79±7.87, p=0.002; LA mean strain: 15.18±6.36 vs. 22±8.54, p=0.001). On categorizing with the CHADS2 score, similar trends were seen between the score of ≥2 and 1 groups (LAVImax: 43.72±13.77 vs. 31.41±9.50, p<0.001; LA mean strain: 11.01±5.31 vs. 18.63±7.00, p<0.001). With multivariate logistic regression, LAVImax (odds ratio: 0.92 , 95% C=I: 0.85 to 0.98, p= 0.01) and LA mean strain reflecting LA remodeling (odds ratio: 1.10, 95% CI: 1.02 to 1.19, p=0.01) were strongly predictive of the CHA2DS2-VASc score of 0.ConclusionsThe superiority of the CHADS2 score may lay in identifying LA remodeling of AF patients with high stroke risk. Whereas, the CHA2DS2-VASc score was better than the CHADS2 score at identifying LA remodeling of AF patients presenting low stroke risk.

Aging reduces left atrial performance during adrenergic stress in middle aged and older patients

During adrenergic stress, the influence of age on left atrial (LA) function is unknown. We hypothesized that aging decreases LA total emptying fraction (LAEF) during maximal adrenergic stress. The aim of the study was to determine the influence of aging on LA function during adrenergic stress in middle aged and older patients. We enrolled 167 middle aged and elderly participants, and measured LA and left ventricular (LV) volumes using a multi-slice three-dimensional cine white blood cardiovascular magnetic resonance (CMR) technique before and during intravenous dobutamine infused to achieve 80% of the maximum heart rate response for age. Paired sample t-test was used to detect differences in LA and LV volumes between baseline and peak dose stage of dobutamine stress CMR, and multivariable linear regression was used to identify predictors of LA function. Participants averaged 68 ± 8 years in age, 53% were men, 25% exhibited coronary artery disease, 35% had diabetes, 9% had a remote history of atrial fibrillation, 90% had hypertension, and 11% had inducible LV wall motion abnormalities indicative of ischemia during dobutamine CMR. Increasing age correlated with LA volumes (maximal and minimal) and inversely correlated with LAEF at rest and after peak adrenergic stress. Age was an independent predictor of LAEF during adrenergic stress, even after accounting for gender, LV volumes, and other co-morbidities including inducible ischemia. Age is associated with a decrease in LA function during adrenergic stress even after adjusting for co-morbidities associated with cardiovascular disease and LV function.

Pre-Operative Left Atrial Mechanical Function Predicts Risk of Atrial Fibrillation Following Cardiac Surgery

The purpose of this study was to examine whether left atrial (LA) mechanical function, as measured by LA total emptying fraction (TEF), is a predictor for the development of post-operative atrial fibrillation (POAF) following cardiac surgery. POAF is an important and frequent complication of cardiac surgery. LA enlargement has been reported to be a risk factor for POAF, but the relationship between LA mechanical function and POAF is not well understood. We examined the relationship between pre-operative LA function and POAF in patients without a history of atrial fibrillation. A total of 101 subjects (mean age 64 ± 13 years) underwent pre-operative transthoracic echocardiograms and were followed for occurrence of POAF during the hospitalization for cardiac surgery. The left atrial maximum volume (LAVmax) and left atrial minimum volume (LAVmin) were measured and indexed to body surface area (LAVmaxI and LAVminI, respectively). LA TEF was calculated as: {[(LAVmax - LAVmin)/LAVmax] × 100%}. Univariate and multivariate analyses examined clinical and echocardiographic predictors of POAF. POAF occurred in 41% of subjects. Mean LA TEF was 49 ± 15%, mean LAVmaxI was 38 ± 15 ml/m(2), and mean LAVminI was 20 ± 13 ml/m(2). Age, LA TEF, and LAVminI were independent predictors of POAF. LA TEF was lower in patients with POAF compared with those without POAF (43 ± 15% vs. 55 ± 13%, p < 0.001), and patients with a LA TEF <50% had a high risk of POAF (odds ratio: 7.94, 95% confidence interval: 3.23 to 19.54, p < 0.001). Compared with LAVmaxI >32 ml/m(2), LA TEF <50% had higher discriminatory power for POAF, which remained significantly higher when adjusted for age (p = 0.04). LA TEF is an independent predictor of POAF and is a stronger predictor of POAF than LAVmaxI is. Impaired LA mechanical function may help to identify patients who are most likely to benefit from prophylaxis for POAF.