Best method in clinical practice and in research studies to determine left atrial size

Atrial Fibrillation, Atrial Myopathy, and Thromboembolism: The Additive Value of Echocardiography and Possible New Horizons for Risk Stratification

Atrial fibrillation (AF) is the most common cardiac sustained arrhythmia, and it is associated with increased stroke and dementia risk. While the established paradigm attributes these complications to blood stasis within the atria and subsequent thrombus formation with cerebral embolization, recent evidence suggests that atrial myopathy (AM) may play a key role. AM is characterized by structural and functional abnormalities of the atria, and can occur with or without AF. Moving beyond classifications based solely on episode duration, the 4S-AF characterization has offered a more comprehensive approach, incorporating patient's stroke risk, symptom severity, AF burden, and substrate assessment (including AM) for tailored treatment decisions. The "ABC" pathway emphasizes anticoagulation, symptom control, and cardiovascular risk modification and emerging evidence suggests broader benefits of early rhythm control strategies, potentially reducing stroke and dementia risk and improving clinical outcomes. However, a better integration of AM assessment into the current framework holds promise for further personalizing AF management and optimizing patient outcomes. This review explores the emerging concept of AM and its potential role as a risk factor for stroke and dementia and in AF patients' management strategies, highlighting the limitations of current risk stratification methods, like the CHA2DS2-VASc score. Echocardiography, particularly left atrial (LA) strain analysis, has shown to be a promising non-invasive tool for AM evaluation and recent studies suggest that LA strain analysis may be a more sensitive risk stratifier for thromboembolic events than AF itself, with some studies showing a stronger association between LA strain and thromboembolic events compared to traditional risk factors. Integrating it into routine clinical practice could improve patient management and targeted therapies for AF and potentially other thromboembolic events. Future studies are needed to explore the efficacy and safety of anticoagulation in AM patients with and without AF and to refine the diagnostic criteria for AM.

Ischemic stroke and the emerging role of left atrial function

INTRODUCTION

Ischemic stroke is a leading cause of morbidity and mortality worldwide. Emerging evidence suggests that left atrial (LA) dysfunction could play a role in the pathophysiology of ischemic stroke, as a possible contributor and as a predictive biomarker.

AREAS COVERED

This narrative review details the intricate relationship between LA function, atrial fibrillation (AF), and ischemic stroke. We discuss imaging techniques used to assess LA function, the mechanisms by which impaired LA function may contribute to stroke, and its potential as a prognostic marker of stroke.

EXPERT OPINION

There is a lack of evidence-based treatments of LA dysfunction in both primary and secondary stroke prevention. This is partly due to the lack of a practical clinical definition and unanswered questions concerning the clinical implications of LA dysfunction in patients without AF. Until such questions are resolved, addressing well-known cardiovascular risk factors, like hypertension and obesity, should be prioritized for preventing AF and ischemic stroke. These risk factors are closely tied to atrial remodeling, emphasizing the importance of targeting primary modifiable factors for preventing future morbidity and mortality.

Postoperative Atrial Fibrillation Prediction by Left Atrial Size in Coronary Artery Bypass Grafting and Five-Year Survival Outcome

Background: Postoperative Atrial Fibrillation (POAF) is a common complication in cardiac surgery. Despite its multifactorial origin, the left atrial (LA) size is closely linked to POAF, raising the question of a valid cut-off value and its impact on the long-term outcome. Methods: Patients without a history of AF who underwent coronary artery bypass grafting between 2014 and 2016 were selected for this retrospective study. LA size was preoperatively assessed using the left atrial anterior-posterior diameter (LAAPd). Correlation and logistic regression analyses were performed, following a receiver-operating characteristic (ROC) analysis. Propensity score matching (PSM) was applied to ensure group comparability, followed by a comparison analysis regarding the primary endpoint of POAF and the secondary endpoints of all-cause mortality and stroke during a five-year follow-up. Results: A total of 933 patients were enrolled in the study eventually revealing a significant correlation between LAAPd and POAF (cor = 0.09, p < 0.01). A cut-off point of 38.5 mm was identified, resulting in groups with 366 patients each after PSM. Overall, patients with a dilated LA presented a significantly higher rate of POAF (22.3% vs. 30.4%, p = 0.02). In a five-year follow-up, a slightly higher rate of all-cause mortality (9.8% vs. 13.7%, HR 1.4 [0.92-2.29], p = 0.10) was observed, but there was no difference in the occurrence of strokes (3.6% vs. 3.3%, p = 0.87). Conclusions: An LAAPd of >38.5 mm was found to be an independent predictor of POAF after coronary artery bypass grafting and resulted in a non-significant tendency towards a worse outcome regarding all-cause mortality in a five-year follow-up.

Left atrial volume index: A predictor of atrial fibrillation recurrence following direct current cardioversion - A systematic review and meta-analysis

This systematic review and meta-analysis was conducted to determine the clinical relevance of echocardiographically measured left atrial (LA) size to predict the recurrence of atrial fibrillation (AF) after direct current cardioversion (DCCV). A search was performed on Medline (Ovid), Embase (Elsevier), Cochrane Central Register of Controlled Trials (CENTRAL) in Cochrane Library, Wiley and Web of Science (Clarivate) to identify relevant studies. Amongst the initial 4066 citations identified, 31 fulfilled the criteria for inclusion in the data analysis incorporating 2725 patients with a mean follow-up period of 6.5 months. The weighted mean left atrial volume index (LAVI) was 40.56 ml/m2 (95 %CI:37.24-43.88) in the sinus rhythm (SR) maintenance group versus 48.69 ml/m2 (95 % CI: 44.42-52.97) in the AF recurrence group with P value of < 0.001, left atrial diameter (LAD) was 42.06 mm (95 %CI: 41.08-43.05) in the SR maintenance group versus 45.13 mm (95 %CI: 44.09-46.16) in the AF recurrence group, P value < 0.001. Effect size analysis of LAVI showed that each unit increase in LAVI resulted in an increase in the risk of AF recurrence by 6 % (95 % CI: 3 %-10 %). Age and AF duration were also statistically significant between the two groups however comorbidities, use of beta blockers or amiodarone were not significantly different. This meta-analysis shows that AF duration, LAVI, LAD and age predict the risk of recurrence of atrial fibrillation post electrical cardioversion with LAVI being the most clinically relevant echocardiographic feature.

Which left atrial volume measurement should we use in the neonatal intensive care?

BACKGROUND

Increased left atrial volume (LAV) is a marker of cardiovascular risk. Echocardiography standards to assess LAV in adults and children are the biplane area-length method (AL) and method of disks (MOD). LAV in neonatology is usually derived as M-mode ratio between the LA and the Aorta (LAAo). The aim of this study is to determine feasibility and reliability of these methods in neonatal clinical practice.

METHODS

Clinically indicated echocardiograms in neonatal intensive care patients were retrospectively analyzed. Feasibility was determined with an image quality score describing insonation angle, foreshortening and wall clarity. Reliability was determined with Bland-Altman and correlation coefficient analysis of intra- and inter-observer measurements.

RESULTS

104 infants ranging from 23 to 39 weeks gestation were included. The feasibility of LAAo, AL and MOD was comparable (median image score 4 out of 6 points). Linear regression between AL and MOD was excellent (R2 0.99). LAAo best-fit with MOD was reached with curve-linear regression (R2 0.28) whereby a LAAo of 1.60 correlated with 1.24 ml/kg, but with a wide 95 % CI. The correlation coefficient within and between observers for LAAo, biplane AL, biplane MOD and monoplane MOD was 0.93 (0.87-0.96), 0.98 (0.96-0.99), 0.98 (0.96-0.99), 0.99 (0.97-0.99) and 0.58 (0.11-0.81), 0.75 (0.44-0.89), 0.92 (0.88-0.98), 0.96 (0.88-0.98) respectively.

CONCLUSION

All methods were equally feasible and reliable when repeated by the same observer, but LAAo reliability was poor when repeated by a different observer. Biplane MOD was the most reliable and thus recommended in neonatal practice. Monoplane MOD performed well and could be considered as alternative but might be less accurate.

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

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

Signal-to-noise of linear and volume measures of left ventricular and left atrial size

BACKGROUND

Serial echocardiographic assessments are common in clinical cardiology, e.g., for timing of intervention in mitral and aortic regurgitation. When following patients with serial echocardiograms, each new measurement is a combination of true change and confounding noise. The current investigation compares linear chamber dimensions with volume estimates of chamber size. The aim is to assess which measure is best for serial echocardiograms, when the ideal parameter will be sensitive to change in chamber size and have minimal spurious variation (noise). We present a method that disentangles true change from noise. Linear regression of chamber size against elapsed time gives a slope, being the ability of the method to detect change. Noise is the scatter of individual points away from the trendline, measured as the standard error of the slope. The higher the signal-to-noise ratio (SNR), the more reliably a parameter will distinguish true change from noise.

METHODS

LV and LA parasternal dimensions and apical biplane volumes were obtained from serial clinical echocardiogram reports. Change over time was assessed as the slope of the linear regression line, and noise was assessed as the standard error of the regression slope. Signal-to-noise ratio is the slope divided by its standard error.

RESULTS

The median number of LV studies was 5 (4-11) for LV over a mean duration of 5.9 ± 3.0 years in 561 patients (diastole) and 386 (systole). The median number of LA studies was 5 (4-11) over a mean duration of 5.3 ± 2.0 years in 137 patients. Linear estimates of LV size had better signal-to-noise than volume estimates (p < 0.001 for diastolic and p = 0.035 for systolic). For the left atrium, the difference was not significant (p = 0.214). This may be due to sample size; the effect size was similar to that for LV systolic size. All three parameters had a numerical value of signal-to-noise that favoured linear dimensions over volumes.

CONCLUSION

Linear measures of LV size have better signal-to-noise than volume measures. There was no difference in signal-to-noise between linear and volume measures of LA size, although this may be a Type II error. The use of regression lines may be better than relying on single measurements. Linear dimensions may clarify whether changes in volumes are real or spurious.

Does Speckle Tracking Transthoracic Echocardiography Indicate Subtle Changes in Left Ventricular Function in Heart Failure Patients with Reduced Ejection Fraction Treated by Sacubitril-valsartan?

Background

In heart failure patients and reduced ejection fraction (HFrEF), assessing subtle changes in left ventricle (LV) function is crucial for monitoring treatment efficacy. This study aims to determine the effect of valsartan/sacubitril on LV ejection fraction (EF) assessed by two-dimensional (2D) transthoracic echocardiography (TTE) in comparison to that assessed by 2D TTE speckle tracking in patients with HFrEF ≤35% after 6 months of treatment.

Patients and Methods

A prospective study will be conducted on 200 heart failure patients with reduced EF (HFrEF) undergoing sacubitril-valsartan treatment. Each participant underwent a comprehensive evaluation, including physical examination, history taking, serial 12-lead electrocardiogram, and 2D echo to evaluate cardiac parameters. In addition, 2D speckle tracking echocardiography (STE) assessments were conducted before and after 6 months of valsartan/sacubitril treatment.

Results

The enrolled patients had an average age of 48 years with 63% females. At the beginning of the study, 9 (4.5%) patients were classified as New York Heart Association (NYHA) FC I, 120 (60%) as NYHA FC II, 64 (32%) as NYHA FC III, and 7 (3.5%) as FC IV. Following treatment, 82 (41%) patients improved to NYHA FC I, and 118 (59%) were in NYHA FC II. Notably, 82 (41%) patients showed improved left ventricular EF (LVEF), detected either by traditional TTE or STE, whereas 118 (59%) showed no improvement in EF through traditional TTE. In addition, 74 (37%) patients demonstrated improvement detected by STE. In contrast, 44 (22%) patients demonstrated no improvement in EF detected by either TTE or STE.

Conclusion

STE was a more reliable diagnostic method for seeing early LVEF improvement in patients with HFrEF receiving valsartan/sacubitril treatment not seen by conventional TTE.

Pitfalls and Tips in the Assessment of Aortic Stenosis by Transthoracic Echocardiography

Aortic stenosis (AS) is a valvular heart disease that significantly contributes to cardiovascular morbidity and mortality worldwide. The condition is characterized by calcification and thickening of the aortic valve leaflets, resulting in a narrowed orifice and increased pressure gradient across the valve. AS typically progresses from a subclinical phase known as aortic sclerosis, where valve calcification occurs without a transvalvular gradient, to a more advanced stage marked by a triad of symptoms: heart failure, syncope, and angina. Echocardiography plays a crucial role in the diagnosis and evaluation of AS, serving as the primary non-invasive imaging modality. However, to minimize misdiagnoses, it is crucial to adhere to a standardized protocol for acquiring echocardiographic images. This is because, despite continuous advances in echocardiographic technology, diagnostic errors still occur during the evaluation of AS, particularly in classifying its severity and hemodynamic characteristics. This review focuses on providing guidance for the imager during the echocardiographic assessment of AS. Firstly, the review will report on how the echo machine should be set to improve image quality and reduce noise and artifacts. Thereafter, the review will report specific emphasis on accurate measurements of left ventricular outflow tract diameter, aortic valve morphology and movement, as well as aortic and left ventricular outflow tract velocities. By considering these key factors, clinicians can ensure consistency and accuracy in the evaluation of AS using echocardiography.

Deep learning estimation of three-dimensional left atrial shape from two-chamber and four-chamber cardiac long axis views

AIMS

Left atrial volume is commonly estimated using the bi-plane area-length method from two-chamber (2CH) and four-chamber (4CH) long axes views. However, this can be inaccurate due to a violation of geometric assumptions. We aimed to develop a deep learning neural network to infer 3D left atrial shape, volume and surface area from 2CH and 4CH views.

METHODS AND RESULTS

A 3D UNet was trained and tested using 2CH and 4CH segmentations generated from 3D coronary computed tomography angiography (CCTA) segmentations (n = 1700, with 1400/100/200 cases for training/validating/testing). An independent test dataset from another institution was also evaluated, using cardiac magnetic resonance (CMR) 2CH and 4CH segmentations as input and 3D CCTA segmentations as the ground truth (n = 20). For the 200 test cases generated from CCTA, the network achieved a mean Dice score value of 93.7%, showing excellent 3D shape reconstruction from two views compared with the 3D segmentation Dice of 97.4%. The network also showed significantly lower mean absolute error values of 3.5 mL/4.9 cm2 for LA volume/surface area respectively compared to the area-length method errors of 13.0 mL/34.1 cm2 respectively (P < 0.05 for both). For the independent CMR test set, the network achieved accurate 3D shape estimation (mean Dice score value of 87.4%), and a mean absolute error values of 6.0 mL/5.7 cm2 for left atrial volume/surface area respectively, significantly less than the area-length method errors of 14.2 mL/19.3 cm2 respectively (P < 0.05 for both).

CONCLUSIONS

Compared to the bi-plane area-length method, the network showed higher accuracy and robustness for both volume and surface area.

Echo-Doppler and strain assessment of filling pressures in adults with congenitally corrected transposition and systemic right ventricles

AIMS

Systolic dysfunction of the systemic right ventricle (sRV) is common in adults with transposition of the great arteries and sRV. In acquired disease, diastology analysis for assessment of filling pressures (FP) is paramount in patient care.

METHODS AND RESULTS

Retrospective analysis of 47 adults with sRV without prior systemic tricuspid valve surgery undergoing catheterization and echocardiography within 7 days (median -2 [-1, -3]) from January 2000 to February 2021 at our institution. Median age was 48 (31, 55) years, and 16 (34.0%) patients were female. FPs were normal in 21 patients (44.7%). Left atrial size was enlarged in most patients (83.0%) with mean indexed value 58.3 ± 23.4 mL/m2. Tissue Doppler e' was not significantly different between those with high FPs vs. normal (medial 0.07 ± 0.03 vs. 0.08 ± 0.03 m/s, P = 0.63; lateral 0.08 ± 0.04 vs. 0.08 ± 0.04 m/s, P = 0.88). E velocity and subpulmonic mitral regurgitant velocity were higher in those with high FPs (0.9 ± 0.3 vs. 0.6 ± 0.2 m/s, P = 0.005; 3.8 ± 1.1 vs. 2.8 ± 0.9 m/s, P = 0.004). Left atrial reservoir strain, sRV global longitudinal strain, and subpulmonic left ventricular strain were worse in those with high FP (18.0 ± 7.6 vs. 27.9 ± 10.2%, P = 0.0009; -13.0 ± 4.4 vs. -17.9 ± 5.0%, P = 0.002; -16.8 ± 5.7 vs. -23.0 ± 3.8%, P = 0.001).

CONCLUSION

Despite the complex anatomy, FPs can be assessed non-invasively in adults with sRV without prior systemic tricuspid valve surgery. The current guideline algorithm for diastolic dysfunction in acquired heart disease has limited applicability in this population. Given the limitations of Doppler in this heterogeneous population, strain analysis can be a helpful adjunct for estimation of FPs.

Association Between Electrocardiographic Left Atrial Enlargement and Echocardiographic Left Atrial Indices Among Hypertensive Subjects in a Tertiary Hospital in South South Nigeria

INTRODUCTION

Left atrial (LA) enlargement poses a clinically significant risk of adverse cardiovascular outcomes for patients. To maximize the utility of LA size in diagnosis, its accurate measurement using electrocardiogram (ECG) and echocardiogram (ECHO) to assess LA linear diameter and LA volumes is expedient. The LA volumes correlate better than LA linear diameter with diastolic function variables. It is therefore expedient to use LA volumes routinely in assessing LA size as they may detect early and subtle changes in LA size and function.

METHODS

A descriptive cross-sectional study was conducted on 200 adult hypertensive patients attending the outpatient cardiology clinic at Delta State University Teaching Hospital, Oghara, Nigeria, irrespective of blood pressure control and duration of hypertension whether on antihypertensive medications or not. The SPSS version 22 (IBM Corp., Armonk, NY, USA) was used for data management and analysis.

RESULT

There was a significant association between electrocardiographic left atrial (ECG-LA) enlargement and echocardiographic left atrial (ECHO-LA) size (LA linear diameter and LA maximum volume) in the study. Logistic regression analysis showed a significant odds ratio for all associations. With LA linear diameter as standard for assessing LA enlargement, the ECG had a sensitivity of 19%, specificity of 92.4%, a positive predictive value of 51%, and a negative predictive value of 73% in detecting LA enlargement. Using ECHO-LA maximum volume as a standard for assessing LA enlargement, the ECG had a sensitivity of 57.3%, a specificity of 67.7%, a positive predictive value of 42.9%, and a negative predictive value of 79% in detecting LA enlargement. The LA maximum volume showed relatively higher sensitivity and negative predictive values while LA linear diameter showed relatively higher specificity and positive predictive values.

CONCLUSION

A good association exists between ECG-LA enlargement and ECHO-LA enlargement. However, in ruling out LA enlargement on ECG, it is better to use LA maximum volume as a standard rather than the LA linear diameter.

Biatrial Volumetric Assessment by Non-ECG-Gated CT Pulmonary Angiography Correlated with Transthoracic Echocardiography in Patients with Normal Diastology

Atrial size is a predictor of cardiovascular mortality. Non-ECG-gated computed tomography pulmonary angiography (CTPA) is a common test for cardiopulmonary evaluation but normative values for biatrial volumes are lacking. We derived normal CT biatrial volumes using manual and semiautomated segmentation with contemporaneous transthoracic echocardiography (TTE) to confirm normal diastology. Thirty-five consecutive cases in sinus rhythm with no history of cardio-vascular, renal, or pulmonary disease and normal diastolic function were selected. Planimetric CTPA measurements were compared to TTE volumes measured using area length method. TTE and CTPA derived normal LAVi and RAVi were 27 + 5 and 20 + 6 mL/m², and 30 + 8 and 29 + 9 mL/m², respectively. Bland-Altman analysis revealed an underestimation of biatrial volumes by TTE. TTE-CT mean biases for LAV and RAV were -5.7 + 12.0 mL and -16.2 + 14.8 mL, respectively. The CT intraclass correlation coefficients (ICC 95% CI) for LA and RA volumes were 0.99 (0.96-1.00) and 0.96 (0.76-0.99), respectively. There was excellent correlation (p &lt; 0.001) between the semiautomated and manual measurements for LA (r 0.99, 95% CI 0.98-0.99) and RA (r 0.99, 95% CI 0.99-1.00). Atrial volumetric assessment on CTPA is easy and reproducible and can provide additional metric in cardiopulmonary assessment.

Surgical Restoration of Antero-Apical Left Ventricular Aneurysms: Cardiac Computed Tomography for Therapy Planning

Background

Surgical ventricular restoration (SVR) leads to functional improvement by volume reduction and restoration of left ventricular (LV) geometry. Our purpose was to refine the planning for SVR using cardiac computed tomography (CCT).

Methods

The possibility to anticipate the postoperative residual LV volume was assessed using CCT in 205 patients undergoing SVR combined with coronary artery bypass grafting (77%), mitral valve repair/replacement (19%) and LV thrombectomy (19%). The potential of CCT to guide the procedure was evaluated. Additionally, the predictive value of CCT characteristics on survival was addressed.

Results

30-day, 1- and 5-year survival was 92.6, 82.7, and 72.1%, respectively, with a marked reduction of NYHA class III-IV quota after surgery (95.1% vs. 20.5% in the follow-up). Both pre- and postoperative LV end-systolic volume index (LVESVI) were predictive of all defined endpoints according to the following tertiles: preoperative: <74 ml/m², 74–114 ml/m² and >114 ml/m²; postoperative: <58 ml/m², 58–82 ml/m² and >82 ml/m². On average, a 50 ml/m² increase of preoperative LVESVI was associated with a 35% higher hazard of death (p = 0.043). Aneurysms limited to seven antero-apical segments (1–7) were associated with a lower death risk (n = 60, HR 0.52, CI 0.28–0.96, p = 0.038). LVESVI predicted by CCT was found to correlate significantly with effectively achieved LVESVI (r = 0.87 and r = 0.88, respectively, p < 0.0001).

Conclusions

CCT-guided SVR can be performed with good mid-term survival and significant improvement in HF severity. CCT-based assessment of achievable postoperative LV volume helps estimate the probability of therapeutic success in individual patients.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Optimising Large Animal Models of Sustained Atrial Fibrillation: Relevance of the Critical Mass Hypothesis

BACKGROUND

Large animal models play an important role in our understanding of the pathophysiology of atrial fibrillation (AF). Our aim was to determine whether prospectively collected baseline variables could predict the development of sustained AF in sheep, thereby reducing the number of animals required in future studies. Our hypothesis was that the relationship between atrial dimensions, refractory periods and conduction velocity (otherwise known as the critical mass hypothesis) could be used for the first time to predict the development of sustained AF.

METHODS

Healthy adult Welsh mountain sheep underwent a baseline electrophysiology study followed by implantation of a neurostimulator connected via an endocardial pacing lead to the right atrial appendage. The device was programmed to deliver intermittent 50 Hz bursts of 30 s duration over an 8-week period whilst sheep were monitored for AF.

RESULTS

Eighteen sheep completed the protocol, of which 28% developed sustained AF. Logistic regression analysis showed only fibrillation number (calculated using the critical mass hypothesis as the left atrial diameter divided by the product of atrial conduction velocity and effective refractory period) was associated with an increased likelihood of developing sustained AF (Ln Odds Ratio 26.1 [95% confidence intervals 0.2-52.0] p = 0.048). A receiver-operator characteristic curve showed this could be used to predict which sheep developed sustained AF (C-statistic 0.82 [95% confidence intervals 0.59-1.04] p = 0.04).

CONCLUSION

The critical mass hypothesis can be used to predict sustained AF in a tachypaced ovine model. These findings can be used to optimise the design of future studies involving large animals.

Low-intensity pulsed ultrasound ameliorates cardiac diastolic dysfunction in mice: a possible novel therapy for heart failure with preserved left ventricular ejection fraction

AIMS

Heart failure with preserved left ventricular ejection fraction (HFpEF) is a serious health problem worldwide, as no effective therapy is yet available. We have previously demonstrated that our low-intensity pulsed ultrasound (LIPUS) therapy is effective and safe for angina and dementia. In this study, we aimed to examine whether the LIPUS therapy also ameliorates cardiac diastolic dysfunction in mice.

METHODS AND RESULTS

Twelve-week-old obese diabetic mice (db/db) and their control littermates (db/+) were treated with either the LIPUS therapy [1.875 MHz, 32 cycles, Ispta (spatial peak temporal average intensity) 117-162 mW/cm2, 0.25 W/cm2] or placebo procedure two times a week for 4 weeks. At 20-week-old, transthoracic echocardiography and invasive haemodynamic analysis showed that cardiac diastolic function parameters, such as e', E/e', end-diastolic pressure-volume relationship, Tau, and dP/dt min, were all deteriorated in placebo-treated db/db mice compared with db/+ mice, while systolic function was preserved. Importantly, these cardiac diastolic function parameters were significantly ameliorated in the LIPUS-treated db/db mice. We also measured the force (F) and intracellular Ca2+ ([Ca2+]i) in trabeculae dissected from ventricles. We found that relaxation time and [Ca2+]i decay (Tau) were prolonged during electrically stimulated twitch contractions in db/db mice, both of which were significantly ameliorated in the LIPUS-treated db/db mice, indicating that the LIPUS therapy also improves relaxation properties at tissue level. Functionally, exercise capacity was also improved in the LIPUS-treated db/db mice. Histologically, db/db mice displayed progressed cardiomyocyte hypertrophy and myocardial interstitial fibrosis, while those changes were significantly suppressed in the LIPUS-treated db/db mice. Mechanistically, western blot showed that the endothelial nitric oxide synthase (eNOS)-nitric oxide (NO)-cGMP-protein kinase G (PKG) pathway and Ca2+-handling molecules were up-regulated in the LIPUS-treated heart.

CONCLUSIONS

These results indicate that the LIPUS therapy ameliorates cardiac diastolic dysfunction in db/db mice through improvement of eNOS-NO-cGMP-PKG pathway and cardiomyocyte Ca2+-handling system, suggesting its potential usefulness for the treatment of HFpEF patients.

Effects of Sacubitril/Valsartan Treatment on Left Ventricular Myocardial Torsion Mechanics in Patients with Heart Failure Reduced Ejection Fraction 2D Speckle Tracking Echocardiography

BACKGROUND

Left ventricular ejection fraction (LVEF) is calculated from volumetric change without representing true myocardial properties. Strain echocardiography has been used to objectively measure myocardial deformation. Myocardial strain can give accurate information about intrinsic myocardial function, and it can be used to detect early-stage cardiovascular diseases, monitor myocardial changes with specific therapies, differentiate cardiomyopathies, and predict the prognosis of several cardiovascular diseases. Sacubitril/valsartan has been shown to improve mortality and reduce hospitalizations in patients with heart failure with reduced ejection fraction (HFrEF). The effect of sacubitril/valsartan angiotensin receptor neprilysin inhibitor (ARNI) on left ventricular (LV) ejection fraction (EF) and torsion dynamics in HFrEF patients has not been previously described.

METHODS

The study involved 73 patients with HFrEF, for all patients Full history was taken, full clinical examination was done. Baseline vital signs, ECG, NYHA classification, conventional echocardiography and STE were done at baseline study and after 6 and 11 months.Basal and apical LV short-axis images were acquired for further off-line analysis. Using commercially available two-dimensional strain software, apical, basal rotation, and LV torsion were calculated.

RESULTS

ARNI group of patients showed improvement of symptoms, LV global longitudinal strain (LVGLS)% and diastolic parameters including, E/A, E/e', TV, untwist onset and rate after 6 months of therapy in comparison to the traditionally treated patients. The improvement continued for 11 months with in additional significant improvement of systolic parameters in the form of LVGLS%, EF%, Twist, Apical and basal rotations, main dependent parameters for improvement of EF% was LVGLS% and Apical rotation.

CONCLUSION

To the best of our knowledge, this is the first study to demonstrate that therapy with sacubitril/valsartan in HFrEF patients could create a state of gradual and chronic LV deloading which cause relieving of myocardial wall tensions and decreasing the LV end diastolic pressure this state could cause cardiac reverse remodeling and reestablishment of starling forces proprieties of LV myocardium, which lead to increase of LV EF.

Validation of evaluating left ventricular diastolic function with estimated left atrial volume from anteroposterior diameter

Background

Left atrial (LA) volume (LAV) is one of the recommended key variables for evaluating left ventricular (LV) diastolic function. However, only LA anteroposterior diameter (LAAP) is available in numerous large-scale existing databases. Therefore, this study aimed to validate whether LV diastolic function could be evaluated with estimated LAV from LAAP.

Methods

A total of 552 inpatients with sinus rhythm were consecutively enrolled. LAV was measured by biplane Simpson’s disk summation method. LV diastolic function was evaluated according to the 2016 proposed recommendations. Best-fitting regression models of LAAP index (LAAPI)–LAV index (LAVI) were developed and equations with the highest F-value were chosen in the first 276 subjects (derivation set), and concordance for evaluating LV diastolic function between using estimated and observed LAVI was verified in the remaining 276 subjects (validation set).

Results

In the derivation set, the linear model has the highest F-value in all subjects and in the subjects with normal or depressed LV ejection fraction. In the validation set, using the linear equation (LAVI = 2.05 × LAAPI − 13.86), the higher area under curve and narrower range of difference were shown between estimated LAVI and observed LAVI, respectively. Further, concordance for diagnosis (overall proportion of agreement, 88.4%; κ = 0.79) and grading (overall proportion of agreement, 84.8%; κ = 0.74) of LV diastolic dysfunction was substantial between using estimated and observed LAVI.

Conclusions

LV diastolic function can be evaluated with estimated LAVI from LAAPI, which might provide a surrogate method when the direct measurement of LAV is not available.

Longitudinal changes in maternal left atrial volume index and uterine artery pulsatility indices in uncomplicated pregnancy

BACKGROUND

Data on the relationship between longitudinal changes in maternal volume-dependent echocardiographic parameters and placentation in uncomplicated pregnancy are limited.

OBJECTIVE

This study aimed to evaluate changes in volume-dependent echocardiographic parameters in uncomplicated pregnancy to test the hypothesis of the existence of an association between volume-dependent echocardiographic parameters and Doppler ultrasound parameters of fetal circulation and the uterine artery in uncomplicated pregnancy and to establish which of the volume-dependent echocardiographic parameters best depicts volume changes and correlates best with Doppler ultrasound of fetal circulation and the uterine artery in healthy pregnancy.

STUDY DESIGN

Data from 60 healthy pregnant women were analyzed. A complete echocardiographic study was performed at 11 to 13, 20 to 22, and 30 to 32 weeks' gestation: left ventricular end-diastolic volume, early diastolic peak flow velocity, late diastolic peak flow velocity, left atrial area, and left atrial volume index were assessed. Obstetrical assessment was performed including fetal growth and uterine artery pulsatility index. Fetal well-being was assessed by umbilical and middle cerebral artery blood flow. Serum pregnancy-associated plasma protein A and free β-human chorionic gonadotropin were assessed during the routine first-trimester scan (11-13 weeks' gestation).

RESULTS

Left ventricular end-diastolic volume and left atrial area increased significantly between 11 to 13 and 20 to 22 weeks' gestation but not between 20 to 22 and 30 to 32 weeks' gestation. Left atrial volume index measured at 30 to 32 weeks' gestation correlated with uterine artery pulsatility indices in 3 trimesters. Changes in the left atrial volume index between the third and first trimesters correlated significantly with the uterine artery pulsatility index measured at 20 to 22 weeks' gestation (r=-0.345; P=.020) and at 30 to 32 weeks' gestation (r=-0.452; P=.002). Changes in the left atrial volume index between the second and first trimesters significantly correlated with the uterine artery pulsatility index measured in the first trimester (r=-0.316; P=.025).

CONCLUSION

Our study showed that in an uncomplicated pregnancy, among volume-dependent echocardiographic parameters, left atrial volume index increased between both the first and second trimesters and the second and third trimesters and correlated with parameters of Doppler ultrasound of the fetal circulation and the uterine artery. Our results expand on the previous observation on the relationship between maternal cardiovascular adaptation and placentation in women with heart diseases to the population of healthy women with uncomplicated pregnancy.

Elevated Troponin T and Enlarged Left Atrium Are Associated with the Incidence of Atrial Fibrillation in Patients with CKD Stage 4-5

INTRODUCTION

Atrial fibrillation (AF) and CKD are commonly coexisting conditions. However, data on epidemiology of AF in patients with CKD stage 4-5 is scarce.

METHODS

We prospectively enrolled 210 consecutive non-dialysis patients with CKD stage 4-5 between 2013 and 2017. Follow-up data on AF incidence along with medical history, laboratory tests, and echocardiography at baseline were gathered.

RESULTS

At baseline, mean age was 62 years, estimated glomerular filtration rate 12.8 mL/min, and 73/210 (34.8%) participants were female. Altogether, 41/210 (19.5%) patients had a previous diagnosis of AF. After median follow-up of 46 [IQR 27] months, new-onset AF occurred in 33/169 (19.5%) patients (69.9 events/1,000 person-years). In the Cox proportional hazard model, age >60 years (HR 4.27, CI 95% 1.57-11.64, p < 0.01), elevated troponin T (TnT) >50 ng/L (HR 3.61, CI 95% 1.55-8.37, p < 0.01), and left atrial volume index (LAVI) >30 mL/m2 (HR 4.82, CI 95% 1.11-21.00, p = 0.04) were independently associated with the incidence of new-onset AF.

CONCLUSION

The prevalence and incidence of AF was markedly high in this prospective study on patients with CKD stage 4-5. Elevated TnT and increased LAVI were independently associated with the occurrence of new-onset AF in patients with severe CKD.

Predictors and Mechanisms of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

Atrial fibrillation (AF) in hypertrophic cardiomyopathy (HC) is associated with significant symptomatic deterioration, heart failure, and thromboembolic disease. There is a need for better mechanistic insight and improved identification of at risk patients. We used cardiovascular magnetic resonance (CMR) to assess predictors of AF in HC, in particular the role of myocardial fibrosis. Consecutive patients with HC referred for CMR 2003 to 2013 were prospectively enrolled. CMR parameters including left ventricular volumes, presence and percentage of late gadolinium enhancement in the left ventricle (%LGE) and left atrial volume index (LAVi) were measured. Overall, 377 patients were recruited (age 62 ± 14 years, 73% men). Sixty-two patients (16%) developed new-onset AF during a median follow up of 4.5 (interquartile range 2.9 to 6.0) years. Multivariable analysis revealed %LGE (hazard ratio [HR] 1.3 per 10% (confidence interval: 1.0 to 1.5; p = 0.02), LAVi (HR 1.4 per 10 mL/m²[1.2 to 1.5; p < 0.001]), age at HC diagnosis, nonsustained ventricular tachycardia and diabetes to be independent predictors of AF. We constructed a simple risk prediction score for future AF based on the multivariable model with a Harrell's C-statistic of 0.73. In conclusion, the extent of ventricular fibrosis and LA volume independently predicted AF in patients with HC. This finding suggests a mechanistic relation between fibrosis and future AF in HC. CMR with quantification of fibrosis has incremental value over LV and LA measurements in risk stratification for AF. A risk prediction score may be used to identify patients at high risk of future AF who may benefit from more intensive rhythm monitoring and a lower threshold for oral anticoagulation.

Additional roles of diastolic parameters in the diagnosis of obstructive coronary artery disease

BACKGROUND

A recent guideline emphasizes the role of four indicators, including annular e´ velocity, E/e´, left atrial (LA) size, and peak tricuspid regurgitation (TR) velocity, in the assessment of left ventricular (LV) diastolic dysfunction. This study was performed to determine the relationships among these four parameters and obstructive coronary artery disease (CAD).

METHODS

The study data were obtained from a nation-wide registry, composed of 1307 patients (age, 60.4 ± 10.8 years; 964 women) with normal LV ejection fraction (LVEF) who underwent invasive coronary angiography in the suspicion of CAD. Septal e´, E/e´, LA dimension (LAd), and TR velocity were assessed by transthoracic echocardiography.

RESULTS

Compared with patients without obstructive CAD, those with obstructive CAD showed changes in diastolic parameters indicating more progressed LV diastolic dysfunction in univariate analyses. In multiple logistic regression analysis, low septal e´ velocity (<7 cm/s) was identified as an independent risk factor associated with obstructive CAD (odd ratio, 1.91; 95% confidence interval, 1.08-3.36; P = 0.026). Receiver-operating characteristic curve analysis showed that septal e´ velocity had the most powerful value in the detection of obstructive CAD than the other three diastolic parameters (P < 0.01 for each comparison). Septal e´ velocity significantly increased diagnostic value of treadmill exercise test (TET) in the detection of obstructive CAD (P < 0.001 for integrated discrimination improvement index).

CONCLUSIONS

Among the four diastolic parameters, septal e´ velocity had the most powerful relationship with obstructive CAD in stable patients with normal LVEF. The addition of septal e´ velocity could improve the diagnostic value of TET.

Feasibility and rationale of direct current cardioversion immediately after transcatheter percutaneous edge-to-edge mitral valve repair

AIMS

Atrial fibrillation (AF) is a frequent comorbidity among patients with severe mitral regurgitation (MR). Direct current (DC) cardioversion is one of the strategies for rhythm control. However, the safety and feasibility of immediate DC cardioversion after MitraClip are not elucidated.

METHODS AND RESULTS

In this study, patients with symptomatic severe MR who underwent MitraClip were included. After fixing the MR, synchronized DC cardioversion was attempted for those with AF. A total of consecutive 60 patients, 36 subjects (60%), comorbid with AF. DC cardioversion was performed in 30 patients (mean age of 76.0 ± 9.3 years), and the successful conversion was achieved in 15 patients (50%). There was no any adverse event related to the cardioversion. Subjects with sustained conversion to SR experienced significant improvement in 6MWT (failed: 285 ± 110-308 ± 135 m, P = .278; successful: 269 ± 109 m-328 ± 78, P = .047) and reduction in NT-proBNP level (failed: 4411 ± 7401-3296 ± 4299 ng/mL, P = .217; successful: 4094 ± 2735-2353 ± 2856 ng/mL, P = .026) at 1 month.

CONCLUSIONS

Direct current cardioversion seemed to be safe and feasible immediately after the transcatheter edge-to-edge mitral valve repairs. Subjects who maintain SR experienced better functional improvement.

Three-Dimensional Echocardiography in Evaluating LA Volumes and Functions in Diabetic Normotensive Patients without Symptomatic Cardiovascular Disease

Background

Cardiovascular complications are the most serious threat to diabetic patients. Associated metabolic and microvascular changes are the main cause of cardiac function affection, and the earliest cardiac change is diastolic dysfunction. Assessment of LA function changes is a key to determine early heart damage of diabetic patients.

Objectives

To evaluate the effect of diabetes mellitus on left atrial volumes and functions by using real-time 3-dimensional echocardiography in normotensive patients free from cardiovascular disease.

Methods

The study included 110 individuals, 50 controls and 60 patients with diabetes mellitus, 30 patients with type 1 diabetes mellitus and 30 patients with type 2 diabetes mellitus. 2-dimensional echocardiography was used to assess the LA maximum volume and LA phasic volumes, and LA maximum volume indexed to body surface area were measured by 3D echocardiography. LA functions (LA total stroke volume, LA active stroke volume, and LA active emptying fraction) were obtained from RT3D volumetric analysis.

Results

The results of the analysis revealed that type 2 diabetes mellitus showed enlarged V _max, V _min, and LAVi with an increased LA total stroke volume and decreased active emptying fraction, while type 1 diabetics showed only decreased in active emptying fraction. The LA maximum volume indexed to body surface area (LAVi) was significantly higher in type 2 diabetic patients as compared to normal controls which was 23.55 ± 3.37 ml/m² versus 20.30.

Conclusion

Patients with type 2 diabetes mellitus have an increased LA volume with impaired compliance and contractility, while patients with type 1 diabetes mellitus have only impaired contractility compared to nondiabetic subjects.

Global Left Atrial Longitudinal Strain Using 3-Beat Method Improves Risk Prediction of Stroke Over Conventional Echocardiography in Atrial Fibrillation

Background:

Atrial fibrillation (AF) is associated with a risk of ischemic stroke, and functional myocardial imaging has offered novel insights on its pathophysiology and prognosis, but its use in AF-related stroke remains limited. We aimed to evaluate the feasibility of left atrial (LA) deformations and its prognostic values of ischemic stroke in a large-scale AF population.

Methods:

Peak atrial longitudinal strain (LA strain), left ventricular strain (global longitudinal strain), LA strain rate (LA SR) at reservoir (LA longitudinal systolic strain rate), and early diastolic conduit (LA longitudinal early diastolic strain rate) phases were analyzed using 2-dimensional speckle tracking echocardiography. Consecutive 3-beat averaged values of strain and SR were used. The clinical end point was ischemic stroke.

Results:

Among 1457 AF participants, the mean LA strain, LA longitudinal systolic strain rate, and LA longitudinal early diastolic strain rate values were 12.9±4.8%, 0.80±0.28 s − 1 , and −1.17±0.46 s − 1 , respectively. There were strong positive linear relationships of 3-beat average with index-beat analysis (R=0.94, 0.94, and 0.94 for LA strain, LA longitudinal systolic strain rate, and LA longitudinal early diastolic strain rate, respectively; all P <0.001). Multivariate Cox regression models incorporating conventional echocardiography parameters demonstrated LA strain and SRs to be independent prognosticators of ischemic stroke during a median follow-up of 37.6 months. Utilization of LA strain further provided incremental value over CHA 2 DS 2 -VASc scoring ( C statistics, 0.78–0.81; P =0.006) for ischemic stroke. Overall, the prognostic performances of LA deformations were attenuated after adding global longitudinal strains in models.

Conclusions:

LA deformations by the 3-beat method are feasible and reproducible during AF. LA strain provided additional prognostic implication over clinical information and conventional echocardiographic measures for ischemic stroke in the AF population but not incremental to global longitudinal strains.

Left atrial mass: relationship between gross anatomy and quantitative echocardiography

BACKGROUND

Left atrial (LA) enlargement is associated with increased risk of adverse cardiovascular outcomes. Unlike the left ventricular mass, LA mass has not been described. We sought to define the anatomic mass of the LA using anatomic specimens from autopsy. We hypothesized that LA mass could be estimated by echocardiography.

METHODS AND RESULTS

Using anatomic specimens of 22 subjects who died and underwent post mortem examination as well as echocardiogram, we defined normal LA mass by weighing anatomic specimens of those with normal LA volume on echocardiogram. Using 17 subjects with normal LA volume on echocardiogram, we found their LA mass on anatomic specimens to be 25.5 ± 6.3 grams (14.4 ± 3.2 g/m²). We developed an echocardiographic measure of LA mass and validated this measurement with paired LA anatomic specimens. We found the normal LA mass on echocardiogram to be 25.4 ± 6.3 g (14.4 ± 2.8 g/m²) which correlated well with anatomic specimens (β = 0.99; Confidence interval CI 0.6-1.4, P < .0001; Pearson correlation coefficient r = 0.83). Furthermore, we defined the normal LA volume to mass ratio as 1.38 ± 0.45.

CONCLUSIONS

LA mass is an additional parameter with which may contribute to the study of LA morphology.

Exploring Associations Between Cardiac Structure and Retinal Vascular Geometry

Background

Retinal arteriolar narrowing and venular widening has been widely suggested to be associated with subclinical changes in cardiac structure. The novel retinal vascular geometric indices might reflect more comprehensive information on microvasculature other than vascular caliber alone. However, the association between suboptimal retinal vascular geometry and cardiac structural alteration has not been studied.

Methods and Results

We recruited 50 participants without cardiovascular disease from the Cardiac Aging Study conducted between 2014 and 2016. We performed transthoracic echocardiography imaging to measure cardiac structure indices such as left ventricular internal diameter end diastole index, left ventricular internal diameter end systole index, left ventricular mass index, and left atrial volume index, and retinal imaging to measure retinal vascular geometric indices including branching angle, curvature tortuosity, and fractal dimension. We applied multiple linear regressions to examine associations between indices of cardiac structure and retinal vascular geometry, adjusting for age, sex, body mass index, mean blood pressure, and comorbidity. The average age of all participants was 62.54 years old and slightly more than half were male (27; 54%). Each unit increase in a set of cardiac structure indices was associated with larger retinal arteriolar branching angle (β and 95% CI: for left ventricular internal diameter end systole index, 26.93°; 6.00–47.86; for left ventricular internal diameter end diastole index, 17.86°; 1.61–34.11; for left ventricular mass index, 0.39°; 0.10–0.67; for left atrial volume index, 0.91°; 0.24–1.58).

Conclusions

Adverse retinal arteriolar geometric morphology mirrored suboptimal cardiac structural alteration.

Left atrial sphericity as a marker of atrial remodeling: Comparison of atrial fibrillation patients and controls

BACKGROUND

Left atrial (LA) sphericity has been proposed as a more sensitive marker of atrial fibrillation (AF)-associated atrial remodeling compared to traditional markers such as LA size. However, mechanisms that underlie changes in LA sphericity are not fully understood and studies investigating the predictive value of LA sphericity for AF ablation outcome have yielded conflicting results. The present study aimed to assess correlates of LA sphericity and to compare LA sphericity in subjects with and without AF.

METHODS

Measures of LA size (LA diameter, LA volume, LA volume index), LA sphericity and thoracic anteroposterior diameter (APd) at the level of the LA were determined using computed tomography (CT) imaging data in 293 AF patients (62% paroxysmal AF) and 110 controls.

RESULTS

LA diameter (40.1 ± 6.8 mm vs. 35.2 ± 5.1 mm; p < 0.001), LA volume (116.0 ± 33.0 ml vs. 80.3 ± 22.6 ml; p < 0.001) and LA volume index (56.1 ± 15.3 ml/m² vs. 41.6 ± 11.1 ml/m²; p < 0.001) were significantly larger in AF patients compared to controls, also after adjustment for covariates. LA sphericity did not differ between AF patients and controls (83.7 ± 2.9 vs. 83.9 ± 2.4; p = 0.642). Multivariable linear regression analysis demonstrated that LA diameter, LA volume, female sex, body length and thoracic APd were independently associated with LA sphericity.

CONCLUSIONS

The present study suggests that thoracic constraints rather than the presence of AF determine LA sphericity, implying LA sphericity to be unsuitable as a marker of AF-related atrial remodeling.

Prevention of sudden cardiac death in hypertrophic cardiomyopathy: Risk assessment using left atrial diameter predicted from left atrial volume

Background

Left atrial diameter (LAd) is included in the European Society for Cardiology's (ESC) risk model for assessment of sudden cardiac death (SCD) risk in hypertrophic cardiomyopathy (HCM), but the recommended measure of LA size is left atrial volume (LAv).

Hypothesis

We hypothesized that LAv could be used instead of LAd in the HCM risk‐SCD model. We aimed to determine the relation between LAd and LAv and to assess the impact of using LAv instead of LAd.

Methods

Echocardiographic measurements of anteroposterior LAd in the parasternal long‐axis window and LAv from Simpson's biplane method of disks were used. The 5‐year risk of SCD by measured LAd and by LAd predicted from LAv were estimated using the ESC risk‐SCD model.

Results

In 205 HCM patients (age 56 ± 14 years, 62% male), the relation between LAd and LAv was linear. Median 5‐year risk of SCD was 2.4% (interquartile range [IQR]: 1.6; 3.8) using measured LAd and 2.4% (IQR: 1.6; 3.7) using predicted LAd. The correlation between the SCD risk assessed by measured vs predicted LAd was excellent (r² = 0.96). Use of predicted LAd resulted in four patients (2%) being recategorized between the moderate and high‐risk categories.

Conclusions

The relation between LAd and LAv was linear with good agreement. On a population level, the correlation between the risk of SCD using measured LAd or LAd predicted from LAv was excellent. On a patient level, using LAd predicted from LAv resulted in the vast majority remaining in the same risk category; however, for a minority of patients, it changed the recommendation.

Left atrial cross-sectional area is a novel measure of atrial shape associated with cardioembolic strokes

OBJECTIVE

Cardioembolic (CE) stroke carries significant morbidity and mortality. Left atrial (LA) size has been associated with CE risk. We hypothesised that differential LA remodelling impacts on pathophysiological mechanism of major CE strokes.

METHODS

A cohort of consecutive patients hospitalised with ischaemic stroke, classified into CE versus non-CE strokes using the Causative Classification System for Ischaemic Stroke were enrolled. LA shape and remodelling was characterised by assessing differences in maximal LA cross-sectional area (LA-CSA) in a cohort of 40 prospectively recruited patients with ischaemic stroke using three-dimensional (3D) echocardiography. Flow velocity profiles were measured in spherical versus ellipsoidal in vitro models to determine if LA shape influences flow dynamics. Two-dimensional (2D) LA-CSA was subsequently derived from standard echocardiographic views and compared with 3D LA-CSA.

RESULTS

A total of 1023 patients with ischaemic stroke were included, 230 (22.5%) of them were classified as major CE. The mean age was 68±16 years, and 464 (45%) were women. The 2D calculated LA-CSA correlated strongly with the LA-CSA measured by 3D in both end-systole and end-diastole. In vitro flow models showed shape-related differences in mid-level flow velocity profiles. Increased LA-CSA was associated with major CE stroke (adjusted relative risk 1.10, 95% CI 1.04 to 1.16; p<0.001), independent of age, gender, atrial fibrillation, left ventricular ejection fraction and CHA₂DS₂-VASc score. Specifically, the inclusion of LA-CSA in a model with traditional risk factors for CE stroke resulted in significant improvement in model performance with the net reclassification improvement of 0.346 (95% CI 0.189 to 0.501; p=0.00001) and the integrated discrimination improvement of 0.013 (95% CI 0.003 to 0.024; p=0.0119).

CONCLUSIONS

LA-CSA is a marker of adverse LA shape associated with CE stroke, reflecting importance of differential LA remodelling, not simply LA size, in the mechanism of CE risk.

Echocardiographic Evaluation of Left Atrial Function to Discriminate Non-Valvular Atrial Fibrillation Development in Patients with Apical Hypertrophic Cardiomyopathy

BACKGROUND

Data is limited on baseline left atrial (LA) myocardial mechanics between apical hypertrophic cardiomyopathy (ApHCM) patients who develop non-valvular atrial fibrillation (NVAF) during follow-up and those who do not.

METHODS

This retrospective study investigated the clinical outcomes of consecutive patients newly diagnosed with ApHCM between August 2011 and July 2014 who were followed-up for at least 3 years. The patients underwent 12-lead surface electrocardiography and/or 24-hour Holter electrocardiography at least once a year. The patients were divided into two groups, namely those who did or did not exhibit NVAF during follow-up, respectively. The baseline clinical and echocardiographic data of the two groups were compared.

RESULTS

Twenty patients were studied, five of whom were lost to follow-up. Of the remaining 15 ApHCM patients, seven developed NVAF. No differences were observed in the clinical characteristics of the two groups. However, for the echocardiographic data, the NVAF development group exhibited a larger LA volume and impaired LA reservoir, conduit and booster functions. The NVAF development group also showed lower peak LA strain and stiffer left atrium. The LA volume, function, global strain and stiffness were all statistically associated with NVAF development. Among these parameters, a LA conduit function of ≤ 24.9% was found to be the best parameter to discriminate NVAF development.

CONCLUSIONS

The baseline LA function was impaired in the ApHCM patients who subsequently developed NVAF during follow-up. A LA conduit function of ≤ 24.9% was strongly associated with NVAF development.

Glycemic control is associated with atrial structural remodeling in patients with type 2 diabetes

Background

Diabetes mellitus (DM) has been demonstrated to be a strong risk factor for development and perpetuation of atrial fibrillation (AF). However, how DM and glycemic control affect the pathogenesis of AF has not been sufficiently investigated, especially for the atrial structural remodeling.

Methods

A total of 86 patients undergoing coronary artery bypass graft surgery were enrolled in this study, with atrium sample collected in the operation. The patients were divided into the DM group (n = 40) and the control group (n = 46) accordingly. Demographics, clinical data were collected and compared. Echocardiography, Masson staining and Western blotting were conducted to evaluate atrial structural remodeling.

Results

There was no significant difference between the two groups in baseline characteristics (all P > 0.05). Fast blood glucose and HbA1c of DM group were significantly higher than the control group (P < 0.001). Echocardiography results demonstrated that the left atrium diameter (LAD) and left atrium volume index (LAVI) of DM group was significantly higher than the control group (P < 0.001). Masson staining showed that the collagen volume fraction (CVF), a quantitative indicator of fibrosis, was significantly higher in DM patients (P = 0.03). Western blot results indicated that the Collagen I of DM group was more expressed in the DM group than the control group (P < 0.001). Univariate linear regression revealed that the HbA1c level was significantly associated with both LAD (Y = 1.139X + 25.575, P < 0.001, R² = 0.291) and CVF (Y = 0.444X + 29.648, P = 0.009, R² = 0.078).

Conclusions

DM was associated with atrial structural remodeling, including atrium enlargement and atrial fibrosis, which might be attributed to poor glycemic control.

Usefulness of Left Atrial Volume as an Independent Predictor of Development of Heart Failure in Patients With Atrial Fibrillation

Left atrial (LA) volume is known as a robust predictor of heart failure (HF) development in patients with sinus rhythm. However, among patients with atrial fibrillation (AF), the utility of LA volume for prediction of HF development has not been determined. The objective of this study was to investigate the utility of LA volume for prediction of HF development in patients with AF. Among adult patients who were referred for transthoracic echocardiography, those with AF at the baseline echocardiography were included and prospectively followed up to new-onset HF events. Patients who had significant valvular heart disease, congenital heart disease, or reduced left ventricular (LV) ejection fraction were excluded. Cox-proportional hazards models were used to assess the risk of HF development. Of a total of 562 patients, 422 (mean age 69.6 ± 9.7 years, 66.1% men) met study criteria, and 52 (12.3%) developed HF during a mean follow-up of 55 ± 43 months. Patients with HF events had larger indexed LA volume, compared with those without HF events (69 ± 46 vs 50 ± 23 ml/m², p <0.0001). In a multivariable analysis adjusted for other co-morbidities, LA volume was a significant predictor for HF development [per 10 ml/m²; hazard ratio (HR) 1.14, 95% confidence interval (CI) 1.06 to 1.22, p <0.001], independently of age (per 10 years; HR 1.71, 95% CI 1.16 to 2.52, p <0.01), LV ejection fraction (per 10%; HR 0.67, 95% CI 0.52 to 0.86, p <0.01), and indexed LV mass (per 10 g/m²; HR 1.13, 95% CI 1.03 to 1.24, p <0.05). Also, LA volume had an incremental effect for prediction of HF development to these conventional risk factors (p <0.0001). In conclusion, LA volume provides prognostic information for the prediction of future HF events in patients with AF.

Immediate Preoperative Transthoracic Echocardiography for the Prediction of Postoperative Atrial Fibrillation in High-Risk Cardiac Surgery

OBJECTIVE

The present study aimed to validate the utility of bedside cardiac ultrasound to identify patients for the risk of postoperative atrial fibrillation (POAF).

DESIGN

A prospective cohort study of consecutive patients.

SETTING

Single-center tertiary referral center.

PARTICIPANTS

After Institutional Review Board consent, 169 patients undergoing elective cardiac surgery were enrolled in the study.

INTERVENTIONS

A preoperative transthoracic echocardiographic interrogation assessing diastolic function was performed. Measurements were assessed offline with experienced echocardiographers blinded to clinical outcomes.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was POAF during the first 72 hours after surgery. A total of 169 patients completed the study, 44 of whom (26.0%) developed POAF, and 39 (25.2%) had diastolic dysfunction. Patients with POAF had a higher rate of postoperative heart failure, reintubation within 24 hours of surgery, and length of stay (p = 0.002, 0.01, and 0.0006, respectively). Predictors significant for POAF included increasing age, left atrial volume indexed to body surface area (LAVI), and diastolic dysfunction (p = 0.02, 0.0001, and 0.001, respectively). Multivariate spline regressions demonstrated a nonlinear correlation between increasing LAVI and risk of POAF.

CONCLUSION

Left atrial volume can be assessed efficiently preoperatively to provide superior risk stratification over clinical factors and diastolic parameters alone for the prediction of POAF. Furthermore, the present study demonstrated that the cutoffs of chamber quantification currently used do not appropriately capture the increased risk of POAF. Thus, LAVI provides a simple measure to identify patients who are in need of targeted prophylaxis for POAF.

Exercise Rehabilitation Improves Cardiac Volumes and Functional Capacity in Patients With Endomyocardial Fibrosis: A RANDOMIZED CONTROLLED TRIAL

PURPOSE

Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy associated with low functional capacity and high mortality rates. Exercise training has been proved to be a nonpharmacological treatment of cardiovascular diseases. Therefore, the purpose of this study was to determine the effects of exercise rehabilitation in EMF patients.

METHODS

Twenty-two EMF patients, functional classes II and III (New York Heart Association [NYHA]), were randomized to the control (C-EMF) or exercise rehabilitation (Rehab-EMF) group. Patients in the Rehab-EMF group underwent 4 mo of exercise rehabilitation, whereas patients in the C-EMF group were instructed to maintain their usual daily routine. Peak oxygen uptake ((Equation is included in full-text article.)O2), cardiac function, and quality of life were evaluated. All assessments were performed at baseline and after 4 mo.

RESULTS

After 4 mo of rehabilitation, peak (Equation is included in full-text article.)O2 increased in the Rehab-EMF group (17.4 ± 3.0 to 19.7 ± 4.4 mL/kg/min, P < .001), whereas the C-EMF group showed no difference (15.3 ± 3.0 to 15.0 ± 2.0 mL/kg/min, P = .87). Also, post-intervention, peak (Equation is included in full-text article.)O2 in the Rehab-EMF group was greater than that in the C-EMF group (P < .001). Furthermore, the Rehab-EMF group, when compared to the C-EMF group, showed an increase in left ventricular end-diastolic volume (102.1 ± 64.6 to 136.2 ± 75.8 mL vs 114.4 ± 55.0 to 100.4 ± 49.9 mL, P < .001, respectively) and decrease in left atrial diastolic volume (69.0 ± 33.0 to 34.9 ± 15.0 mL vs 44.6 ± 21.0 to 45.6 ± 23.0 mL, P < .001, respectively). Quality-of-life scores also improved in the Rehab-EMF group, whereas the C-EMF group showed no change (45 ± 23 to 27 ± 15 vs 47 ± 15 to 45 ± 17, P < .001, respectively).

CONCLUSION

Exercise rehabilitation is a nonpharmacological intervention that improves functional capacity, cardiac volumes, and quality of life in EMF patients after endocardial resection surgery. In addition, exercise rehabilitation should be prescribed to EMF patients to improve their clinical condition.

Assessment of left atrial volume in dogs: comparisons of two-dimensional and real-time three-dimensional echocardiography with ECG-gated multidetector computed tomography angiography

INTRODUCTION

We hypothesized that real-time three-dimensional echocardiography (RT-3DE) was superior to two-dimensional echocardiography for the estimation of left atrial volume (LAV), using electrocardiographic (ECG)-gated multidetector computed tomography angiography (MDCTA) as a volumetric gold standard. The aim was to compare maximum LAV (LAV_max) and minimum LAV (LAV_min) measured by biplane area-length method (ALM), biplane method of disk (MOD) and RT-3DE with 64-slice ECG-gated MDCTA in dogs ANIMALS: The study included twenty dogs, anaesthetized for various diagnostic purposes and without evidence of cardiovascular disease.

METHODS

Left atrial volume was estimated by ALM, MOD and RT-3DE following ECG-gated MDCTA. The results were compared with LAV from MDCTA and correlations were performed. The limits of agreement (LoA) between methods were evaluated using Bland-Altman analysis and intraclass correlations. Coefficients of variation were calculated.

RESULTS

Area-length method (r = 0.79 and 0.72), MOD (r = 0.81 and 0.70) and RT-3DE (r = 0.94 and 0.82) correlated with MDCTA for LAV_max and LAV_min, respectively (all p < 0.05). Biases for LAV_max (-0.96 mL, 95% LoA: -5.6 to 3.7) and LAV_min (-0.67 mL, 95% LoA: -5.4 - 4.1) were minimal with RT-3DE, reflecting a slight underestimation. Conversely, MOD (LAV_maxbias = 3.19 mL, 95% LoA: -5.7 - 12.1; LAV_minbias = 1.96 mL, 95% LoA: -4.6 - 8.5) and ALM (LAV_maxbias = 4.05, 95% LoA: -5.7 - 13.8; LAV_minbias = 2.80 mL, 95% LoA: -3.9 - 9.5) suggested LAV overestimation. Intraobserver and interobserver variability were adequate.

CONCLUSIONS

Real-time three-dimensional echocardiography is a non-invasive, accurate and feasible method with superior accuracy to two-dimensional methods.

Value of Syntax Score II in Prediction of New-Onset Atrial Fibrillation in Patients With NSTE-ACS Undergoing Percutaneous Coronary Intervention

New-onset atrial fibrillation (NOAF) has been associated with poor outcome in patients with acute coronary syndromes (ACSs). The objective of this study was to investigate the relationship between the development of NOAF and severity of coronary artery disease using the SYNTAX score (SS) and SYNTAX score II (SSII) in patients with non-ST-segment elevation ACS (NSTE-ACS) who were treated with percutaneous coronary intervention (PCI). A total of 662 patients with NSTE-ACS were consecutively enrolled. The incidence of NOAF was 11.4% among the patients with NSTE-ACS. Mean age was significantly higher in NOAF group ( P = .011). White blood cell count, peak troponin I, high sensitivity C-reactive protein, uric acid, left atrial volume index, and ratio between early mitral inflow velocity and mitral annular early diastolic velocity were significantly higher in NOAF group (respectively, P = .024, P = .017, P = .002, P = .009, P = .025, P < .001, and P < .001). The hemoglobin, ejection fraction, and post PCI thrombolysis in myocardial infarction grade <3 were significantly lower in NOAF group ( P = 001, P = .010, P = .038). The SS and SSII were significantly higher in NOAF group (all P < .001). According to the results of multivariate logistic regression analysis, the SSII was correlated with NOAF ( P < .001) in the study groups. We demonstrated that high SSII is significantly associated with NOAF.

Echocardiographic Abnormalities and Determinants of 1-Month Outcome of Stroke Among West Africans in the SIREN Study

Background

Little is known about the relationship between echocardiographic abnormalities and outcome among patients with acute stroke. We investigated the pattern and association of baseline echocardiographic variables with 1‐month disability and mortality among patients with stroke in the SIREN (Stroke Investigative Research and Education Network) study.

Methods and Results

We enrolled and followed up consecutive 1020 adult patients with acute stroke with baseline transthoracic echocardiography from west Africa. To explore the relationship between echocardiographic variables and 1‐month disability (using modified Rankin scale >3) and fatality, regression models were fitted. Relative risks were computed with 95% CIs. The participants comprised 60% men with a mean age of 59.2±14.6 years. Ischemic stroke was associated with smaller aortic root diameter (30.2 versus 32.5, P=0.018) and septal (16.8 versus 19.1, P<0.001) and posterior wall thickness at systole (18.9 versus 21.5, P=0.004). Over 90% of patients with stroke had abnormal left ventricular (LV) geometry with eccentric hypertrophy predominating (56.1%). Of 13 candidate variables investigated, only baseline abnormal LV geometry (concentric hypertrophy) was weakly associated with 1‐month disability (unadjusted relative risk, 1.80; 95% CI, 0.97–5.73). Severe LV systolic dysfunction was significantly associated with increased 1‐month mortality (unadjusted relative risk, 3.05; 95% CI, 1.36–6.83).

Conclusions

Nine of 10 patients with acute stroke had abnormal LV geometry and a third had systolic dysfunction. Severe LV systolic dysfunction was significantly associated with 1 month mortality. Larger studies are required to establish the independent effect and unravel predictive accuracy of this association.

Evaluation of left atrial volume and functions by real time three-dimensional echocardiography in patients with subclinical hypothyroidism before and after levothyroxine therapy

BACKGROUND/AIMS

The cardiovascular system is one of the major targets of thyroid hormones. Subclinical hypothyroidism (SCH) is a common disease that can represent "early" thyroid failure. Our aim was to evaluate left atrial (LA) volume and functions in patients with SCH using real time three-dimensional echocardiography (RT3DE) and also to investigate changes in LA parameters after the levothyroxine treatment.

METHODS

In total, 44 patients with SCH and 40 age- and gender-matched controls were studied. Assessments included history, physical examination and echocardiography. All patients with SCH were followed up with replacement therapy until the euthyroid status was achieved.

RESULTS

In patients with SCH, LA total emptying volume, passive emptying volume, and passive ejection fraction were significantly reduced while LA minimal volume, active emptying volume, and active emptying fraction were significantly increased than in control group. Following the levothyroxine treatment, LA volume and function parameters were observed to be significantly improved. A negative correlation between the change of thyroid stimulating hormone (TSH) and change of LA active emptying volume and a positive correlation between the change of TSH level and change of LA passive emptying volume were found.

CONCLUSION

It was shown that volume and functions of LA were impaired in patients with SCH. However, impaired parameters were improved after the levothyroxine treatment. These findings may be indicative of subclinical heart involvement that could lead to functional and structural changes in patients with SCH.

Comparison of Left Atrial Measurements Using 2- and 3-Dimensional Transesophageal Echocardiography

OBJECTIVES

To assess the correlation between left atrial measurements using 2- and 3-dimensional transesophageal echocardiography.

DESIGN

Prospective, observational study.

SETTING

Single, tertiary care, academic medical center.

PARTICIPANTS

The study comprised 63 consecutive patients undergoing cardiac surgery with cardiopulmonary bypass and intraoperative transesophageal echocardiography.

INTERVENTIONS

In addition to the standard comprehensive intraoperative transesophageal examination, study images were obtained by designated anesthesiologists from the study team.

MEASUREMENTS AND MAIN RESULTS

The 2-dimensional transesophageal echocardiography views included 4-chamber, 2-chamber, aortic valve short axis, and aortic valve long axis. For the 3-dimensional images, full-volume (90 × 90) data sets were acquired from 4-chamber and aortic valve short-axis views over 4 beats with apnea. Left atrial height, mediolateral length, anteroposterior length, and area were measured in 2- and 3-dimensional images. Left atrial length in the short- and long-axis views of the aortic valve also were measured in 2- and 3-dimensional images. Results indicate that for all patients in this study, the 2- and 3-dimensional measurements correlate well and the 2 observers were in agreement with each other.

CONCLUSIONS

Two- and 3-dimensional measurements of the left atrium correlated well. Measurements made using 3-dimensional transesophageal echocardiography were subject to similar limitations as those made using 2-dimensional echocardiography. The benefits of 3-dimensional transesophageal echocardiography and multiplanar reconstruction could be expanded by improvements in ultrasound technology and software.

The value of syntax score to predict new-onset atrial fibrillation in patients with acute coronary syndrome

BACKGROUND AND AIM

New-onset atrial fibrillation (NOAF) has been associated with poor outcome in patients with acute coronary syndromes (ACS). Also, Syntax score (SS) is a scoring system that is derived from angiographic images and is associated with long-term mortality and major adverse cardiac events. In this study, we aimed to assess the relationship between SS and NOAF with known predictors of atrial fibrillation.

METHODS

In a prospective, single-center, cross-sectional study, 692 patients who were diagnosed with coronary artery disease for the first time were enrolled consecutively. NOAF was defined as atrial fibrillation, which was documented after hospital admission. SS was calculated by a computer software. Multivariable logistic regression analyzes were used to detect the relationship between variables and NOAF.

RESULTS

New-onset atrial fibrillation was detected in 82 patients (11.8%). Patients with NOAF had higher SS (22, interquartile range 18.3-25.1, vs. 12, interquartile range 7-19.5, p < 0.001). According to multivariable logistic regression analysis for NOAF, SS were independently and significantly associated (OR, 1.103; 95% confidence interval, 1.047-1.163; p < 0.001). Other independent predictors of NOAF were TIMI flow <3, C reactive protein, left ventricular ejection fraction, left atrial volume index and E/E' ratio. The optimal cut-off value for SS was 18 for the development of NOAF with 82% sensitivity and 68% specificity (area under the curve: 0.795, 95% confidence interval 0.749-0.841, p < 0.001).

CONCLUSION

Syntax score may be helpful to identify for patients who would develop atrial fibrillation in the setting of ACS.

Left Atrial Volume during Stress Is Associated with Increased Risk of Arrhythmias in Patients with Hypertrophic Cardiomyopathy

Introduction:

In patients affected by hypertrophic cardiomyopathy (HCM), left atrial volume index (LAVi) is associated with an increased risk of tachyarrhythmias and major clinical events. To date, the clinical meaning of LAVi measured during exercise (stress LAVi [sLAVi]) has not yet been investigated in HCM. This study sought to evaluate the correlation between LAVi/sLAVi and clinical outcome (risk of arrhythmias and heart failure [HF]) in patients with HCM.

Methods and Results:

We enrolled a total of 51 consecutive patients with HCM (39 men; mean age: 39.41 ± 17.9 years) who underwent standard and stress echocardiography, following a common protocol. During follow-up (median follow-up was 1.82 years), the following composite endpoints were collected: ARRHYT endpoint (atrial fibrillation, paroxysmal supraventricular tachycardia, nonsustained ventricular tachycardia (VT), sustained VT, ventricular fibrillation, syncope of likely cardiogenic nature, and sudden cardiac death) and HF endpoint (worsening of functional class and left ventricular ejection fraction, hospitalization, and death for end-stage HF). Eight patients were lost at follow-up. ARRHYT endpoint occurred in 13 (30.2%) patients (8, 18.6%, supraventricular and 10, 23.2%, ventricular arrhythmias), whereas HF endpoint occurred in 5 (11.6%) patients. sLAVi (mean value of 31.16 ± 10.15 mL/m²) performed better than rLAVi as a predictor of ARRHYT endpoint (Akaike Information Criterion: 48.37 vs. 50.37, if dichotomized according to the median values). A sLAVi value of 30 mL/m² showed a predictive accuracy of 72.1% (C-statistics of 0.7346), with a high negative predictive value (87.5%).

Conclusion:

These findings encourage future studies on sLAVi, as a potential predictor of arrhythmias and adverse outcome in patients with HCM.

Validation of 3D echocardiographic volume detection of left atrium by human cadaveric casts

BACKGROUND

Left atrial volume is a prognostic factor in cardiac pathologies. We aimed to validate left atrial volume detection with 3D and 2D echocardiography (3DE and 2DE) by human cadaveric casts. 3DE facilitates measurement of atrial volume without geometrical assumptions or dependence on imaging angle in contrast to 2DE methods.

METHODS

For method validation, six water-filled balloons were submerged in a 20-l water tank and their volumes were measured with 3DE. Seven human cadaveric left atrial casts were prepared of silicone and were transformed into ultrasound-permeable casts. Casts were imaged in the same setting, so that 3DE and 2DE of casts represented transthoracic apical view. Left ventricle analysis softwares GE 4D Auto LVQ and TomTec 4D LV-Function were used for 3DE volumetry.

RESULTS

Balloon volumes ranged 37 to 255 ml (mean 126 ml). 3DE resulted in an excellent volumetric agreement with balloon volumes, absolute bias was - 3.7 ml (95% CI -5.9 to - 1.4). Atrial cast volumes were 38 to 94 ml (mean 56.6 ml). 3DE and 2DE volumes were excellently correlated with cast volumes (r = 0.96 to 0.99). Biases were for GE 4D LVQ -0.7 ml (95% CI -6.1 to 4.6), TomTec 4D LV-Function 3.3 ml (- 1.9 to 8.5) and 2DE 2.9 ml (- 4.0 to 9.9). 3DE resulted in lower limits of agreement and showed no volume-related bias in contrast to area-length method.

CONCLUSIONS

We conclude that measurement of human cadaveric left atrial cast volumes by 3DE is in excellent agreement with true cast volumes.