Clinical implications of left atrial function assessed by speckle tracking echocardiography

Evaluation of left atrial strain imaging and integrated backscatter as predictors of recurrence in patients with paroxysmal, persistent, and long-standing persistent atrial fibrillation undergoing catheter ablation

BACKGROUND

Impaired left atrial (LA) strain predicts atrial fibrillation (AF) recurrence after catheter ablation (CA), but currently there is no cut-off to guide patient selection for CA. Integrated backscatter (IBS) is a promising tool for noninvasive quantification of myocardial fibrosis. The aim of this study was to compare LA strain and IBS between paroxysmal, persistent, and long-standing persistent AF and evaluate their association with AF recurrence after CA.

METHODS

Analysis of consecutive patients with symptomatic paroxysmal and persistent AF who underwent CA. LA phasic strain, strain rate and IBS were assessed by two-dimensional speckle-tracking at baseline.

RESULTS

We analyzed 78 patients, 31% with persistent AF (46% long-standing AF), 65% male, mean age 59 ± 14 years, who underwent CA and were followed-up for 12 months. AF recurrence occurred in 22 (28%) patients. LA phasic strain parameters were significantly impaired in patients with AF recurrence and were independent predictors of AF recurrence in a multivariable analysis. LA reservoir strain (LASr) < 18% predicted AF recurrence with 86% sensitivity and 71% specificity, with a higher predictive power compared to LA volume index (LAVI). LASr < 22% in paroxysmal AF and LASr < 12% in persistent AF correlated with AF recurrence. Increased IBS was a predictor of AF recurrence in patients with paroxysmal AF.

CONCLUSION

LA phasic strain parameters were predictors of AF recurrence after CA, independently of LAVI and AF subtype. LASr < 18% showed a higher predictive power compared to LAVI. Further studies are needed to investigate the role of IBS as a predictor of AF recurrence.

The effect of body weight on left atrial function determined by longitudinal strain analysis in young adults

PURPOSE

Obesity is a risk factor for various cardiovascular disorders. Left atrial (LA) function is vital for predicting adverse outcomes in many diseases. LA strain was recently proposed as a noninvasive and valuable parameter for LA functional evaluation. We investigated the effect of body mass index (BMI) values on left atrial functions determined by longitudinal strain analysis in young adults without concomitant disease.

METHODS

We prospectively included 134 subjects in our study. Participants were categorized into three subgroups, obese, overweight, and control, according to their BMI. Conventional echocardiographic measurements and strain analysis were performed on all patients.

RESULTS

There were 41 patients (30.5%) in the obesity group, 46 patients (34.3%) in the overweight group, and 47 patients (35.0%) in the control group. Obese patients had significantly larger LA volume (46.9 ± 12.1 ml; p < 0.001) compared to overweight and control subjects; however, LA volume index (21.4 ± 6.1 ml/m2 vs. 22.4 ± 6.1 ml/m2 vs. 22.4 ± 5.0 ml/m2; p = 0.652) were similar between groups. In the LA strain analysis, obese patients were found to have lower left atrial reservoir longitudinal strain (LASr) compared to both the overweight and control group (44.2 ± 5.8% vs. 39.1 ± 3.7% vs. 36.5 ± 4.9%; p < 0.001); moreover obese patients had significantly worse left atrial contraction phase longitudinal strain (LASct) (-15.1 ± 3.1% vs. -13.1 ± 2.5%; p = 0.007) and left atrial conduit phase longitudinal strain (LAScd) (-29.0 ± 7.1% vs. -23.3 ± 5.4%; p < 0.001) values compared to the control group. However, LASct and LAScd values did not differ between overweight and obese patients.

CONCLUSION

LA function determined by LA strain analysis was impaired in obese and overweight individuals compared to the control group, even in the early stages of life. The prognostic significance of this finding should be investigated in prospective studies.

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.

A systematic review and meta-analysis of left atrial strain in hypertrophic cardiomyopathy and its prognostic utility

Despite advances in noninvasive imaging modalities to identify atrial fibrillation (AF) risk in Hypertrophic Cardiomyopathy (HCM), there is a paucity of evidence concerning the impact of low Left Atrial strain (LAS) on AF and major adverse cardiac events (MACE) incidence in these patients. This study investigated the diagnostic and prognostic significance of LAS in predicting AF and MACE in HCM. Findings revealed lower LA reservoir (MD: -11.79, 95% CI -14.83, -8.74; p<0.00001), booster (MD: -4.10, 95% CI -6.29, -1.91; p=0.0002), and conduit (MD: -7.52, 95% CI -9.39, -5.65; p<0.00001) strains in HCM patients versus healthy controls, and also indicated a significant association between low LA reservoir/conduit/booster strain and the development of new AF as well as MACE prevalence in HCM patients. The results from this study suggest the valuable role of LA strain in HCM and its utility in predicting the development of new AF and cardiac events in HCM patients.

The role of galectin-3 in patients with permanent and paroxysmal Atrial Fibrillation and echocardiographic parameters of left atrial fibrosis

BACKGROUND

Biochemical markers and imaging tests have been used with the aim of stratifying the risk and detecting atrial fibrosis. Speckle-tracking echocardiography (STE) is used for the detection of atrial fibrosis and Gal-3 provides an important prognostic value. The objective of the study was to assess the association between atrial fibrosis markers and serum levels, genetic polymorphisms and genic expression of galectin-3.

METHODS

206 patients with permanent AF and 70 patients with paroxysmal AF were included in the study. Real time PCR (TaqMan) system was used to study SNPs rs4652 and 4644 of the gene LGALS3. Serum levels of Gal-3 were determined by ELISA and STE was performed to assess fibrosis.

RESULTS

Mean age of individuals with permanent AF was 66.56 ± 12 years. As for the echocardiography results, those patients showed an decrease in the following parameters peak atrial longitudinal strain (PALS) (p = 0.002) when compared to the same parameters from the paroxysmal AF group of patients. There was a correlation between serum levels of Gal-3 and PALS in the group of patients with permanent AF; the lower the levels of gal-3, the lower the LA strain (r = 0.24; p = 0.01).

CONCLUSIONS

Echocardiographic findings showed association with the groups, and with serum levels of Gal-3 in patients with permanent AF. The distribution of allelic and genotypic frequencies, and of the haplotypes of polymorphism LGALS3 rs4652 and rs4644 did not present statistical variation, which suggests that those SNPs are not associated with the AF clinical forms (permanent and paroxysmal).

Left atrial strain superior to structural remodeling in identifying occult atrial fibrillation

OBJECTIVE

Occult atrial fibrillation (AF) is a significant risk factor for occult stroke but is difficult to detect. Myocardial strain, based on speckle tracking echocardiography (STE), can detect subclinical changes in left atrial (LA) function. This study aimed to investigate the diagnostic value of LA strain in identifying asymptomatic AF patients with normal electrocardiograms and healthy volunteers.

METHODS

A total of 354 subjects were retrospectively enrolled. Patients were divided into two groups based on whether they had AF during echocardiography. Patients with sinus rhythm during echocardiography were further divided into healthy control group and occult AF group. Patients with AF during echocardiography were further divided into paroxysmal AF group and persistent AF group. LA mechanical function measured by STE was compared between patients with asymptomatic AF and volunteers. Conventional echocardiographic indicators were measured. The diagnostic value of LA strain for identifying asymptomatic AF was assessed by univariate and multivariate regression analysis and receiver operating characteristic (ROC) curves.

RESULTS

Occult AF patients had higher NT-proBNP levels, larger RA area, larger LAVmax and decreased LAEF than control group. However, occult AF patients had lower NT-proBNP levels, RA area and LAVmax and higher LAEF than paroxysmal and persistent AF. The measured LA reservoir strain (LASr), LA conduit strain (LAScd), LA contraction strain (LASct) of occult AF group was significantly lower than that of control group. However, occult AF patients had preserved LAScd and LASct than paroxysmal and persistent AF. RA area, LAEF and LASr were remarkable correlation with occult AF after adjustment for NT-proBNP, LAVmax, and LAScd. The area under curve of ROC for LASr was the greatest among RA area, LAEF and LASr, with a cut-off value of 34.1% (sensitivity: 75.4%, specificity: 87.6%).

CONCLUSION

LASr can identify occult AF in the asymptomatic population. Patients with LASr values ≤34.1% have a higher incidence of occult cardiac dysfunction. These findings help identify patients with occult AF and further risk stratification for the AF population.

Peak atrial longitudinal strain represents atrial fibrillation burden in daily practice: clinical implication of routine left atrial strain measurements

BACKGROUND

Usefulness of left atrial (LA) strain measurements using speckle tracking echocardiography has been reported in various clinical settings. However, clinical implication of routine LA strain measurements in daily practice remains unclear. The purpose of this study was to evaluate clinical utility of routine LA strain measurements in daily practice.

METHODS

From January 6, 2020 to December 28, 2021, 338 consecutive patients underwent echocardiography in Takagi Cardiology Clinic, and all comers were enrolled to the study. Echocardiographic measurements including peak atrial longitudinal strain (PALS) measurement using speckle tracking echocardiography were attempted in all patients.

RESULTS

PALS was obtained in 335 patients (age 71 ± 16 years, male 43%, hypertensive 74%), and mean value was 22.3 ± 11.5%. PALS was progressively impaired with worsening atrial fibrillation (AF) burden. PALS in patients without AF, in patients with history of AF (paroxysmal AF &/or ablation therapy), and in patients with AF onsite were 26.8 ± 9.8%, 20.3 ± 7.9%, and 8.1 ± 3.3%, respectively (anova p < 0.0001). In patients without history of AF at the time of echocardiography, using cut-off value of 15.0% (i.e., mean + 2SD of PALS in AF patients), Kaplan-Meier analysis revealed that impaired PALS was associated with increased new-onset AF during follow-up period (log-rank p < 0.0001).

CONCLUSION

In daily practice, PALS represents AF burden. Furthermore, impaired PALS is associated with increased new-onset AF. Therefore, routine LA strain measurements using speckle tracking echocardiography will be useful in risk stratification of AF in daily practice.

Plasma FGF23 is associated with left atrial remodeling in children on hemodialysis

BACKGROUND

FGF23 mediates cardiac fibrosis through the activation of pro-fibrotic factors in in vitro models and is markedly elevated in kidney disease. Left atrial global longitudinal strain (LA GLS) derived by echocardiographic speckle-tracking measures longitudinal shortening of the LA walls, quantifies atrial performance and may enable detection of early LA remodeling in the setting of normal ventricular function. We hypothesized that LA GLS is abnormal in children on hemodialysis (HD) compared to healthy controls of comparable age/sex distribution and that, among HD patients, greater FGF23 levels are associated with abnormal LA GLS.

METHODS

Clinical and echocardiographic data from 29 children receiving HD and 13 healthy controls were collected in a cross-sectional single-center study. Plasma FGF23 concentrations were measured using ELISA. The primary outcome was LA GLS measured using 2D speckle-tracking strain analysis. Linear regression analysis was used to investigate predictors of LA GLS in HD.

RESULTS

Median dialysis vintage was 1.5 (IQR 0.5-4.3) years. Median intact FGF23 levels were substantially higher in the HD vs. control group (1206 [215, 4707] vs. 51 [43, 66.5] pg/ml; P = 0.0001), and LA GLS was 39.9% SD 11.6 vs. 32.8% SD 5.7 (P = 0.04). Among HD patients, higher FGF23 was associated with lower LA GLS (β per unit Ln-FGF23: - 2.7; 95% CI slope - 5.4, - 0.1; P = 0.04 after adjustment for age, body size, and HD vintage. FGF23 was not associated with LA phasic reservoir, conduit, or contractile strain.

CONCLUSIONS

In children on HD and preserved left ventricular ejection fraction, greater FGF23 is associated with lower LA GLS (indicative of impaired atrial performance). A higher resolution version of the Graphical abstract is available as Supplementary information.

Clinical utility of left atrial strain in predicting atrial fibrillation recurrence after catheter ablation: An up-to-date review

Rhythm control is the core part of the integrated management of atrial fibrillation (AF), especially in the early stages. Despite advances in catheter ablation (CA), the recurrence rate of AF after CA remains high. As a result, stratification and early management of AF recurrence after CA are critical. Currently, predictors of recurrence of AF after CA are mostly based on dysfunction caused by structural remodeling, apart from traditional risk factors. Atrial strain is a recently developed important parameter for detecting the deformability of atrial myocardium during the cardiac cycle prior to atrial remodeling. Although there is only preliminary evidence, atrial strain is still a promising parameter in predicting the recurrence of AF after CA at an early stage. This review focuses on the evaluation of atrial strain, the current applications of atrial strain in assessing atrial function, and predicting the recurrence of AF after CA. We summarize the contents related as follows: (1) CA for rhythm control in AF; (2) Evaluation methods of atrial strain; (3) Atrial strain in the remodeling and reverse remodeling of AF; and (4) Clinical applications of atrial strain in predicting the recurrence of AF after CA. Although there is accumulating evidence on the role of decreased atrial strain in the early prediction of AF recurrence, atrial strain is limited in clinical practice for lacking exact cut-off values and difficulty in distinguishing specific function phases of the atrium. More research is needed in the future to add strength to the early prediction value of atrial strain in AF recurrences.

Left atrial contractile strain predicts recurrence of atrial tachyarrhythmia after catheter ablation

BACKGROUND

Despite improvement in treatment strategies of atrial fibrillation (AF), a considerable number of patients still experience recurrence of atrial tachyarrhythmia (ATA) following catheter ablation (CA). This study aimed to investigate the prognostic value of left atrial (LA) deformation analysis in a large group of patients undergoing CA for AF.

METHODS

This study included 678 patients with AF. Echocardiography including two-dimensional speckle tracking echocardiography (2DSTE) was performed in all patients prior to CA. Logistic regression analysis was used to assess the association between ATA recurrence and LA strain during reservoir phase (LASr), LA strain during contraction phase (LASct), and LA strain during conduit phase (LAScd).

RESULTS

During one-year follow-up, 274 (40%) experienced ATA recurrence. Median age of the included study population was 63.2 years (IQR: 55.5, 69.5) and 485 (72%) were male. Patients with recurrence had lower LASr (22.6% vs. 25.1%, p = 0.001) and LASct (10.7% vs. 12.4%, p < 0.001). No difference in LAScd was observed. After adjusting for potential clinical and echocardiographic confounders LASr (OR = 1.04, CI95% [1.01; 1.07], p = 0.015, per 1% decrease) and LASct (OR = 1.06, CI95% [1.02; 1.11], p = 0.007, per 1% decrease) remained independent predictors of recurrence. However, in patients with a normal-sized LA (LA volume index<34 mL/m²), only LASct remained an independent predictor of recurrence (OR = 1.07, CI95% [1.01; 1.12], p = 0.012, per 1% decrease).

CONCLUSION

In patients undergoing CA for AF, LA deformation analysis by 2DSTE could be of use in risk stratification in clinical practice regarding ATA recurrence, even in patients with a normal-sized LA.

Impact of Left Atrial Appendage Closure Combined with Catheter Ablation on Endocrine and Mechanical Cardiac Function in Patients with Atrial Fibrillation

Background

The combined procedure of left atrial appendage closure (LAAC) and catheter ablation (CA) is a safe and feasible therapy to treat patients with atrial fibrillation (AF). However, the effect of the combined procedure on cardiac function remains unclear. This study aimed to investigate the changes in endocrine and mechanical function of the heart following the combined procedure.

Methods

This retrospective study included 62 consecutive patients who underwent the combined procedure of AF ablation and WATCHMAN LAAC and 62 sex and age-matched patients who only received AF ablation. During follow-up, patients were examined for brain natriuretic peptide (BNP) levels to represent endocrine cardiac function. Mechanical cardiac function was assessed during echocardiographic examination by means of the LA ejection fraction, LA strain (Ƹ), and LA strain rate (SR).

Results

(1) The BNP levels decreased acutely after the procedure, rose at day 3 postoperation, but trended downwards at 3 months postoperation in both groups. No significant difference was observed between the two groups. (2) LA ejection fraction, LA Ƹ, and SR exhibited a continuous upward trend over a 3-month follow-up in both groups. There was no significant difference in LA ejection fractions, SRe (the parameter of LA conduit function), and SRa (the parameter of LA booster pump function) between the two groups. However, the Ƹ and SRs (the parameters of LA reservoir function) improved in patients treated with CA alone.

Conclusions

The combined procedure of LAAC and CA significantly improved the endocrine and mechanical function of the heart. Compared to simple CA, based on CA with LAAC intervention, it does not significantly change LA endocrine function but may lead to a decline in the LA reservoir function.

Left atrial strain in cardiac surveillance of bone marrow transplant patients with prior anthracycline exposure

BACKGROUND

Bone marrow transplantation (BMT) has significantly improved survival rates in various hematological malignancies. However, this has led to an increased prevalence of long-term cardiotoxicity, particularly in those with prior anthracycline (AC) therapy.

OBJECTIVES

To evaluate changes in left atrial (LA) volume and function, including LA strain, in BMT patients with prior AC exposure and evaluate its utility as a marker of diastolic dysfunction.

METHODS

This was a cross-sectional analysis of 79 BMT patients with prior AC exposure who underwent a comprehensive surveillance transthoracic echocardiogram compared to age-matched healthy volunteers. Left ventricular (LV) and LA parameters were evaluated between the 2 groups. BMT patients were stratified using traditional measures of diastolic function and additionally utilizing LA strain.

RESULTS

LV systolic dysfunction with reduced LVEF (13/79) or global longitudinal strain (29/79) was present in BMT patients. There were no differences in LA volumes between the two groups. LA reservoir strain (30.1 ± 11.2% vs 34.1 ± 9.6%, p < 0.001) and LA conduit strain (13.6 ± 8.4% vs 17.0 ± 10.5%, p < 0.001) were reduced in the BMT group compared to controls. LA reservoir strain had modest correlation with mitral annular e' velocity (r = 0.468, p < 0.001). Using current diastolic function guidelines, 26/79 BMT patients had evidence of diastolic dysfunction. However, utilizing LA reservoir strain, an additional 35 patients were identified.

CONCLUSIONS

LA strain can identify early diastolic dysfunction in BMT patients with prior AC treatment. With diastolic dysfunction known to precede systolic dysfunction post AC, changes in LA reservoir strain may identify more patients with cardiac dysfunction, prompting increased surveillance and treatment.

Assessment of the Left Atrial Reservoir Function and Left Atrial Volume After Percutaneous Balloon Mitral Valvuloplasty Using Peak Atrial Longitudinal Strain

Objective

To evaluate the impact of successful percutaneous balloon mitral valvuloplasty (BMV) on left atrial (LA) reservoir function and LA volume in patients with severe mitral stenosis (MS) using peak atrial longitudinal strain (PALS).

Method

This was a prospective, non-randomized observational study conducted at the Laxmipat Singhania (LPS) Institute of Cardiology, Kanpur from August 2018 to February 2020 among patients with severe rheumatic MS undergoing BMV to assess LA reservoir function and its volume after BMV using PALS. Inclusion criteria were symptomatic severe rheumatic MS (NYHA ≥II), normal ventricular systolic function, and suitable valve morphology. Exclusion criteria were the coexistence of aortic valve involvement, left atrial appendage clot, mitral leak more than mild, pregnancy, hypertension, diabetes, and coronary artery disease. To assess LA reservoir function and its volume after BMV, PALS was used. LA was divided into six regions of interest and longitudinal strain curves of individual segments together with global strain were recorded. PALS was calculated at baseline 24 hours following the intervention, and at three months of follow-up.

Result

Successful BMV was performed in 260 patients (109 or 41.9% males and 151 or 58.1% females), resulting in significant improvement in mitral valve area (MVA) (0.89±0.11 cm² vs. 1.83±0.3 cm²; p<0.001). The mean age of patients was 26.7±4.7 years; 214 (82.3%) patients were in normal sinus rhythm (NSR) while 46 (17.7%) had atrial fibrillation (AF).

Significant improvement in PALS was noted immediately following the procedure (6.5±11.6% vs. 7.7±10.5%; p< 0.001) and it continued to improve at three months of follow-up (6.5±11.6% vs. 11.3±12.5%; p<0.001), which was 24% and 74% improvement from baseline respectively. Significant reduction in indexed left atrial (LA) volume was observed immediately following the procedure (56.8±14.3 ml/m² vs 48.4±12.5 ml/m²; p=0.003), and at three months of follow-up (56.8±14.3 ml/m² vs. 45.4±13.3 ml/m²; p=0.002). Those with AF had lesser improvement in PALS in comparison to those with NSR (60% vs. 84%; p=0.044) at three months of follow-up. At three months, the increase in PALS was also lower in patients with a history of stroke as compared to those without it (55% vs 80%; p=0.039). Both LA volume and indexed LA volume reduced significantly immediately at 24 hours and during follow-up.

Conclusion

LA reservoir function, as assessed by PALS, is reduced in patients with severe MS. It improved significantly within 24 hours following BMV and continued to improve at three months of follow-up. It is an underutilized modality among patients of MS for decision-making prior to intervention and to assess the effect of the intervention.

Normal values and reference ranges for left atrial strain by speckle-tracking echocardiography: the Copenhagen City Heart Study

AIMS 

Left atrial (LA) function assessed by two-dimensional speckle-tracking echocardiography has shown increasing clinical and prognostic significance. We sought to establish age- and sex-based normative values of LA strain in the general population and to assess the prognostic yield of lower limits of normality of LA strain in relation to future atrial fibrillation (AF).

METHODS AND RESULTS 

We determined normative values of peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and LA strain during the conduit phase (LACS) in 1641 healthy participants included in the fifth Copenhagen City Heart Study. In a secondary analysis, a validation cohort of 2016 participants, regardless of health status, were included to assess the prognostic value of the established reference values. In the healthy cohort, median age was 46 years (interquartile range 32-57), 62% were female. Median PALS, PACS, and LACS and corresponding limits of normality in the healthy participants were 39.4% (23.0-67.6%), 15.5% (6.4-28.0%), and 23.7% (8.8-44.8%), respectively. There was a tendency of lower values of PALS and LACS in males and older participants, while PACS tended to increase with advancing age. The established lower limits of normality showed high specificity (range 93-94%) regarding future AF, implying a low risk of developing AF in participants with LA strain above the lower limits of normality in their respective sex and age group.

CONCLUSION 

We report normal values for LA strain stratified by sex and age. The lower limits of normality showed high specificity regarding future AF.

Assessment of atria function after percutaneous closure of atrial septal defect using 2D speckle tracking echocardiography

BACKGROUND

Percutaneous occlusion of atrial septal defect (ASD) has recently become a standard therapeutic strategy, but little is known about atria function thereafter. Strain analysis by two-dimensional speckle tracking echocardiography (2D-STE) is considered to be a new tool to assess myocardial function.

METHODS

This study aimed to evaluate atria function by quantifying longitudinal strain in patients with chronic RV volume overload due to ASD before and after percutaneous closure using 2D-STE. 28 consecutive patients underwent percutaneous closure of ASD (18 female, 10 male) were examined, clinical and echocardiographic evaluation one day before, 1 day, and one month after percutaneous closure of ASD. Peak longitudinal systolic strain and strain rate of both atria were analyzed by 2D-STE.

RESULTS

Mean age of the patients was 15.07 ± 8.39 years; mean diameter of ASD was 16.01 ± 2.78 mm; left atrium (LA) diameter significantly increased after ASD closure; and peak longitudinal strain of RA increased significantly one day and one month after ASD closure (48. 77 ± 4.40, vs.55.36 ± 3.70 and, vs. 62.13 ± 3.81%, p = 0.001). LA longitudinal strain significantly decreased after ASD closure (42.55 ± 4.57, vs. 34.79 ± 3.20%, p = 0.001). Furthermore, negative correlation was found between the size of the ASD and delta LA systolic strain and strain rate.

CONCLUSIONS

2D-STE can be considered a feasible and simple technique for assessment of atrial deformation in ASD patients, and it useful to assess the effect of percutaneous ASD closure on atrial reservoir function by measuring peak atrial longitudinal strain.

Importance of left ventricular contraction for left atrial reservoir function

BACKGROUND

The determinants of left atrial (LA) reservoir function have not been clarified.

METHODS

To elucidate the effect of left ventricular (LV) contraction on LA reservoir volume (ΔV_LA), volume change due to mitral annular downward motion and aortic root anterior motion, which are related to LV contraction during systole, was calculated in 72 consecutive subjects [42 patients without any cardiac disease (control group), 13 patients with heart failure with reduced ejection fraction (HFrEF group) and 17 with preserved ejection fraction (HFpEF group)]. LA volume was calculated using the modified Simpson's method of bi-plane 2-D echocardiograms. ΔV_LA was the difference between the maximum and minimum LA volumes. LA volume change according to mitral annular motion (ΔV_MA) and aortic root motion (ΔV_AR) were calculated by assuming an oval frustum and dented wedge, respectively.

RESULTS

In the normal control group, ΔV_AR + ΔV_MA was 11.7 ml on average, correlating to ΔV_LA (r = 0.55, p < 0.01), and the contribution rate to LA reservoir volume ((ΔV_AR + ΔV_MA)/ΔV_LA) was 56% on average. In both, the HFrEF and HFpEF groups, ΔV_AR, ΔV_MA, and the contribution rate were significantly smaller than those in normal control group. Stroke volume correlated to ΔV_AR and ΔV_MA. The larger the maximum LA volume was, the smaller the contribution rate was. The smaller the rate was, the higher the systolic pulmonary artery pressure was.

CONCLUSIONS

Both mitral annular motion and aortic root anterior motion, which are related to ventricular contraction, are important for the LA reservoir volume recruitment.

Speckle-tracking echocardiography can predict atrial fibrillation in patients with supraventricular tachycardia

PURPOSE

Atrioventricular nodal reentry tachycardia (AVNRT) is the most common supraventriculer arrhythmia in daily clinical practice. Comorbidity of AVNRT and atrial fibrillation (AF) has been well documented in some patients and AF development has been observed more frequently in AVNRT patients during their long-term follow-up. This study was conducted in order to investigate the left atrial two-dimensional-speckle-tracking echocardiographic (STE) parametres as the predictors of the occurence of AF in long-term follow-up in patients with spontaneously developed AF during AVNRT ablation.

METHODS

Two hundred and thirty two consecutive AVNRT patients who developed spontaneous AF during ablation procedure were included in the study. The patients were followed up for a mean follow-up period of 6.2 ± 2.1 years. All patients were evaluated using the 2D-STE method. AF was developed in 34 patients during the follow-up period. Cox regression analysis was performed in order to identify the independent predictors of AF occurence.

RESULTS

Left atrial LA-res, LA-pump, LA-SRs, LA-SRe, and LA-SRa values were found to be significantly decreased in the group of patients that developed AF during the follow-up period (p < .001 for all aforementioned values). Multivariate cox regression analysis revealed that LA-res (hazard ratio [HR], 0.367; 95% confidence interval [CI], 0.161-0.0.683, p < .001) and SRe (HR, 0.472; 95% CI, 0.346-0.825, p = .006) were independent risk factors associated with the occurrence of AF.

CONCLUSION

In conclusion, it was demonstrated for the first time with this study that 2D-STE can effectively predict the development of AF in long-term follow-up in patients with spontaneously developed AF during AVNRT ablation.

Correlations between Left Ventricular and Left Atrial Function Assessed by Speckle Tracking Echocardiography in Patients with Treated Well-Controlled Arterial Hypertension

Introduction. Even in patients with well-controlled arterial hypertension (AH) and without significant comorbidities, left ventricular (LV) and left atrial (LA) strain abnormalities may sometimes be found in speckle-tracking echocardiography. Therefore, the aim of this study was to investigate the correlation between LA strain and LV diastolic and systolic function in a group of patients with treated, well-controlled AH. Material and methods. LA contractile, conduit, and reservoir function, together with echocardiographic signs of LV diastolic function and LV global longitudinal strain (LV GLS), were assessed in 101 patients with treated, well-controlled AH who met the standard criteria of normal LV ejection fraction (LVEF) and normal LV diastolic function. Results. A relevant percentage of study participants presented lower than reference LV (−18.7% for LV GLS) and LA strain (32.9% for LAS during reservoir phase, LASr; −15.9% for LAS during contraction phase, LASct; and −13.9% for LAS during conduit phase, LAScd) values. Moreover, there were statistically significant differences in LA longitudinal strain (LAS) values (LASr (31.43 vs. 36.33; $p$  = 0.0007) and LAS LAScd (−13.09 vs. −15.79; $p$  = 0.008)) between patients with high (>the absolute value of −20%) and lower (≤the absolute value of −20%) LV GLS, confirmed by significant correlations between LASr, LAScd, and GLS. In the correlations analysis between LAS values and LV diastolic function parameters, statistical significance was obtained for the following: LASct (contraction) versus e’avg, LASct versus E/A, LASct versus A, LAScd versus e’avg, LAScd versus E/A, and LAScd versus A. Conclusions. LV and LA strain abnormalities occurred within a significant percentage of patients with treated, well-controlled AH. Impaired LA strain is associated with lower LV strain and reduced LV diastolic function parameters, reflecting both the passive and active properties of the LA.

Current clinical applications of speckle tracking echocardiography for assessment of left atrial function

Two-dimensional speckle tracking echocardiography (2D-STE) enables assessment of left atrial (LA) function with better reproducibility and less load dependence than those with conventional methods. Data regarding LA functions determined by 2D-STE in patients with various cardiovascular diseases have recently been accumulating. LA strain has emerged as a novel parameter with the potential of improving the diagnostic accuracy of left ventricular diastolic dysfunction and the prognostic value in patients with heart failure and stroke. Furthermore, LA dysfunction determined by 2D STE can provide incremental prognostic information to conventional echocardiographic parameters in patients with cardiovascular diseases. Hence, 2D-STE appears to be a promising technique for diagnosis and therapeutic decision-making. Data regarding LA functions determined by three-dimensional speckle tracking echocardiography (3D-STE) have also been accumulating. Here, I review recent studies, especially those published after 2016, on clinical applications of LA function assessed by 2D-STE and 3D-STE and summarize the remaining problems to be solved for improving the clinical utility of these techniques.

Changes in left atrial phasic strain and mechanical dispersion: Effects of age and gender

PURPOSE

Left atrial (LA) function by two-dimensional (2D) strain is an emerging tool with increasing clinical utility. Age and gender are key modulators of strain parameters; however, the specific time course for LA structural and functional changes is not clearly defined.

METHODS

A total of 147 healthy individuals (20-69 years) underwent transthoracic echocardiography; subjects were evaluated by age (decade) and gender. LA and left ventricular (LV) volumetric and strain measurements were performed.

RESULTS

Left atrial reservoir (ƐR) and conduit strain (ƐCD) with negatively correlated with age (r =-.36; r = -.56; P < .001, respectively) being significantly lower by the 6th and 5th decades, respectively. Contractile strain (ƐCT) positively correlated with age (r = .36; P < .001), being significantly higher by the 6th decade. ƐR and ƐCD were higher in young females (20-34 years) compared to young males (P = .033 and P < .001, respectively). ƐCT was significantly higher in middle-aged adult males (35-50yrs; P = .010), though seen later in females (≥51 years; P = .005). Standard deviation of time to positive strain (SD-TPS) significantly higher by the 5th decade and correlated with age in both males (r = .44; P <.001) and females (r = .40; P = .001).

CONCLUSION

We demonstrate that ƐR and ƐCD are lower with age, with differing rates between males and females. As a compensatory mechanism for decline in ƐCD, ƐCT is higher, more notably in males; comparatively, females display a more prominent decline in ƐR and ƐCD with age. Alteration in electromechanical properties occurred in both genders with SD-TPS becoming higher with age.

Innovations in cardiovascular imaging

Cardiovascular diseases are culpable for the majority of mortalities the world over, hence the significance of advances in preventive medicine and imaging. Cardiovascular imaging constitutes the cornerstone of not only early but also precise diagnoses. Indeed, advanced imaging enables cardiologists to make efficacious management plans for various heart conditions. The present article discusses essential innovations in cardiovascular imaging.

Decreased longitudinal systolic strain rate of the left atrial myocardium as one of the earliest markers of atrial cardiomyopathy in subjects with brief paroxysmal atrial fibrillation

PURPOSE

Brief paroxysmal atrial fibrillation (BPAF) is defined as episodes of atrial fibrillation (AF) lasting less than 30 seconds and can be a sign of atrial cardiomyopathy. We aimed to evaluate left atrial (LA) function in patients with BPAF.

METHODS

This cross-sectional prospective study consecutively recruited 42 patients with BPAF on 24 to 48 hour electrocardiography Holter monitoring. We selected 50 volunteers as the control group after 24 hours electrocardiography Holter monitoring. Two-dimensional speckle-tracking echocardiography was performed to evaluate the longitudinal deformation variables of LA function.

RESULTS

Strain rate during LA reservoir phase was lower (P = .018) in patients with BPAF (2.0 ± 0.4 second^-1 ) than in controls (2.2 ± 0.5 second^-1 ). This difference remained significant after adjustments for left ventricular ejection fraction, LA maximal volume, and diabetes (β = 0.222, P = .036). Strain during LA reservoir, conduit, and contraction phases and strain rate during the conduit and contraction phases were not significantly different between the two groups.

CONCLUSIONS

The reservoir function of the LA evaluated by two-dimensional speckle-tracking echocardiography was lower in subjects than that without BPAF.

Interaction Effect of Diabetes and Acute Myocardial Infarction on the Left Atrial Function as Evaluated by 2-D Speckle-Tracking Echocardiography

The aim of the study described here was to investigate, using 2-D speckle-tracking echocardiography, whether myocardial infarction (MI) leads to diminished left atrial function in diabetic patients by comparison with non-diabetic patients. A total of 310 consecutive patients were divided into four groups based on the presence or absence of diabetes mellitus (DM) and acute ST-elevation MI. In the adjusted analysis, systolic and early diastolic strain and strain rate were reduced in the diabetic patients. Additionally, all deformation markers were impaired in the patients with MI. The DM-MI interaction was not statistically significant. Although reservoir, conduit and contraction functions of the left atrium were reduced in the patients with MI, left atrial reservoir and conduit functions were decreased in the diabetic patients. The reduction in left atrial function caused by MI was similar for diabetic and non-diabetic patients. Thus, DM and MI additively damaged left atrial function.

Influence of Percutaneous Occlusion of Atrial Septal Defect on Left Atrial Function Evaluated Using 2D Speckle Tracking Echocardiography

Percutaneous occlusion of atrial septal defect (ASD) has recently become a standard therapeutic strategy, but little is known about left atrial (LA) function thereafter. The present study aimed to determine LA function in 43 children with ASD and 13 controls based on LA strain measured by two-dimensional echocardiographic speckle tracking (2DE-ST). Among these children, 12 underwent surgery (ASD-S), 31 had device closure (ASD-D), and 13 were included as controls. LA strain was significantly decreased after ASD-D but was not significantly altered after ASD-S, indicating that percutaneous occlusion of an ASD might decrease LA function. Furthermore, the size of the ASD device negatively correlated with LA strain. These results imply that ASD occlusion devices negatively influence LA function and might be important when decided therapeutic strategies for ASD. LA strain measured by 2DE-ST should become a good indicator of LA function after ASD treatment in children.

Effects of different ablation strategies on long-term left atrial function in patients with paroxysmal atrial fibrillation: a single-blind randomized controlled trial

Restoration of sinus rhythm in atrial fibrillation (AF) by radiofrequency catheter ablation (RFCA) is associated with a transient stunning of left atrial (LA) function. However, the long-term effects of different ablation strategies on LA function remain undetermined. We performed randomized controlled trial to evaluate the effects of RFCA, cryoablation, and 3D mapping-guided cryoablation on LA function of proximal AF patients within 1 year. The 3D mapping-guided cryoablation was defined as a maximum of two cryoablation procedures for each pulmonary vein accompanied by RFCA for additional points until complete pulmonary vein isolation was achieved. Conventional and speckle tracking echocardiographic analyses were performed to evaluate LA function. Among the 210 patients (70 in each group) included, a trend of decreasing LA systolic and diastolic function was observed in all groups, as evidenced by decreases in peak A-wave velocity, the global LA peak systolic strain, the peak strain rate, the peak early diastolic strain rate, and the peak late diastolic strain rate within 7 days to 3 months after ablation followed by gradual recovery thereafter. However, the temporal changes in the above four strain parameters among the three groups did not differ significantly within 1 year after ablation (all p > 0.05). Parameters of the LA emptying fraction and LA dimensions were not significantly affected. These results suggested that stunning of LA function occurred within 7 days to 3 months after ablation, and different strategies of AF ablation did not differentially affect the temporal changes in LA function up to 1 year after ablation.

Combined assessment of left atrial volume parameters for predicting recurrence of atrial fibrillation following pulmonary vein isolation in patients with paroxysmal atrial fibrillation

OBJECTIVES

Our aim was to test the hypothesis that comprehensive simplified left atrial (LA) assessment derived from routine echocardiography may be more useful than assessment of LA volume alone for predicting atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI).

METHODS

We studied 156 patients with paroxysmal AF (PAF) who had undergone PVI. Echocardiography was performed within two days before PVI. Maximum (Max-LAVi) and minimum LA volume index (Min-LAVi) were calculated with the biplane modified Simpson's method, and then normalized to the body surface area. On the basis of previous findings, the predefined cutoff value of Max-LAVi for AF recurrence was set at Max-LAVi ≥ 34 mL/m² . ΔLA volume index (ΔLAVi) was also calculated as Max-LAVi minus Min-LAVi. The follow-up period after PVI was 24 months.

RESULTS

AF recurrence was observed in 35 patients. Multivariate logistic regression analysis showed that ΔLAVi (odds ratio [OR]: 1.131; 95% confidence interval [CI]: 1.057-1.221; P < 0.001) was an independent predictor of AF recurrence. Sequential logistic regression models for predicting AF recurrence revealed that a model based on clinical variables including age, gender and AF duration (χ²  = 1.65) was improved by the addition of Max-LAVi ≥ 34 mL/m² (χ²  = 13.8; P < 0.001), and further improved by the addition of ΔLAVi (χ²  = 18.2; P = 0.036). Of note is that only 1.02 ± 0.10 minutes per patient was needed to obtain a comprehensive LA assessment that included Max-LAVi, Min-LAVi, and ΔLAVi.

CONCLUSION

This easy-to-use comprehensive simplified LA approach from routine echocardiography may well have clinical implications for better management of PAF patients.

Revival and modification of the Mustard operation

OBJECTIVE

The neonatal arterial switch operation is currently the procedure of choice for patients with transposition of the great arteries. However, a large number of patients present too late for the arterial switch operation and are best managed with the atrial switch operation.

METHODS

We have used the Mustard operation in its original form or following a new modification designed to enhance the atrial functions and filling of the left ventricle in an attempt to improve long-term results.

RESULTS

Between July 2013 and November 2018, a total of 101 patients underwent the Mustard operation, 86 with the new modification. The median age at operation was 16 months (6 months to 27 years). A total of 75 patients (74.3%) were male. Median preoperative oxygen saturation was 71%. There were no early deaths and there were 3 late deaths during a median follow-up period of 24.2 months (all in patients with large ventricular septal defect and established pulmonary vascular disease). At the latest follow-up, all patients were in stable sinus rhythm. There were no baffle leaks. Seven patients had asymptomatic narrowing of the superior baffle, and 1 patient required balloon dilatation. Follow-up is 100% complete and includes computed tomography and magnetic resonance imaging at regular intervals (75 patients to date). Computerized analysis of representative subsets showed enhanced rate and pattern of filling of the left ventricle in the modified operation compared with the classic operation.

CONCLUSIONS

The use of the Mustard operation, particularly the modified technique should play an important role in treating late-presenting patients with transposition of the great arteries. Improving the pattern of filling of the left ventricle could enhance the long-term results of the Mustard operation.

The Repeatability and Left Atrial Strain Analysis Obtained via Speckle Tracking Echocardiography in healthy Dogs

INTRODUCTION

In left atrial (LA) strain-derived two-dimensional speckle tracking echocardiography, the reference intervals in healthy dogs can provide useful information to evaluate the LA function in dogs with heart disease.

ANIMALS

Six laboratory beagles and 120 privately owned dogs without cardiac diseases were recruited.

MATERIALS AND METHODS

The LA strain and strain rate (SR) and echocardiographic indices were obtained in dogs who underwent standard echocardiography and offline analysis for LA strain and SR measurement by speckle tracking echocardiography.

RESULTS

The intra-observer within-day variations of strain variables showed adequate repeatability (coefficient of variation <20%). The mean values of strain were 25.37 for the LA reservoir function, 11.06 for the LA conduit function, and 14.17 for the LA booster-pump function; the strain was significantly correlated with the LA fractional volume change at each phasic function. The left atrial longitudinal strain during early ventricular diastole showed moderate correlation with the peak velocity of early diastolic transmitral flow (r = 0.5560) and ratio of peak velocity of early diastolic transmitral flow to peak velocity of late transmitral flow (r = 0.5515). In multiple regression analysis, only age was significantly related to the strain/SR and volumetric change indices, indicating conduit function.

CONCLUSIONS

Left atrial speckle tracking echocardiographic analysis provided useful information to assess the LA function in healthy dogs. The influencing factors on strain and SR variables including the age, body weight, and heart rate should be considered in interpretation of these parameters in a clinical setting.

Left atrial function: evaluation by strain analysis

The left atrium has an important role in modulating left ventricular filling and is an important biomarker of cardiovascular disease and adverse cardiovascular outcomes. While previously left atrial (LA) size was utilised, the role of LA function as a biomarker is increasingly being evaluated, both independently and also in combination with LA size. Strain analysis has been utilised for evaluation of LA function and can be measured throughout the cardiac cycle, thereby enabling the evaluation of LA reservoir, conduit and contractile function. Strain evaluates myocardial deformation while strain rate examines the rate of change in strain. This review will focus on the various types of strain analysis for evaluation of LA function, alterations in LA strain in physiological and pathologic states that alter LA function and finally evaluate its utility as a prognostic marker.

Impaired Left Atrial Strain as a Predictor of New-onset Atrial Fibrillation After Aortic Valve Replacement Independently of Left Atrial Size

INTRODUCTION AND OBJECTIVES

Left atrial dysfunction in aortic stenosis may precede atrial enlargement and predict the occurrence of atrial fibrillation (AF). To test this hypothesis, we assessed left atrial function and determined its impact on the incidence of AF after aortic valve replacement.

METHODS

A total of 149 severe aortic stenosis patients (74±8.6 years, 51% men) with no prior AF were assessed using speckle-tracking echocardiography. Left atrial function was evaluated using peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and phasic left atrial volumes. The occurrence of AF was monitored in 114 patients from surgery until hospital discharge.

RESULTS

In multiple linear regression, PALS and PACS were inversely correlated with left atrial dilation, left ventricular hypertrophy, and diastolic function. Atrial fibrillation occurred in 36 patients within a median time of 3 days [interquartile range, 1-4] after aortic valve replacement. In multiple Cox regression, PALS and PACS were independently associated with the incidence of AF (HR, 0.946; 95%CI, 0.910-0.983; P=.005 and HR, 0.932; 95%CI, 0.883-0.984; P=.011, respectively), even after further adjustment for left atrial dimensions. Both reduced PALS and PACS were associated with the incidence of AF in patients with nondilated left atria (P value for the interaction of PALS with left atrial dimensions=.013).

CONCLUSIONS

In severe aortic stenosis, left atrial dysfunction predicted the incidence of postoperative AF independently of left atrial dilation, suggesting that speckle-tracking echocardiography before surgery may help in risk stratification, particularly in patients with nondilated left atria.

Left atrial strain assessed by three-dimensional speckle tracking echocardiography predicts atrial fibrillation recurrence after catheter ablation in patients with paroxysmal atrial fibrillation

BACKGROUND

Several studies have shown the utility of left atrial (LA) function determined by two-dimensional or three-dimensional speckle tracking echocardiography (2D- or 3D-STE) for identifying patients with paroxysmal atrial fibrillation (AF). However, whether 3D-STE is applicable for prediction of the recurrence of AF after catheter ablation (CA) remains unknown. We examined whether any 3D-STE parameters are better than 2D-STE parameters for the prediction of AF recurrence.

METHODS

Forty-two patients with paroxysmal AF (58 ± 10 years old, 69% male) underwent 2D- and 3D-STE within 3 days before first-time CA. The global peak LA longitudinal, circumferential, and area strains during systole (3D-GLSs, -GCSs, and -GASs, respectively) and those just before atrial contraction (3D-GLSa, -GCSa, and -GASa, respectively) were determined by 3D-STE and standard deviations of times to peaks of regional LA strains were calculated as indices of LA dyssynchrony. In 2D-STE, global LA longitudinal strains during systole and just before atrial contraction (2D-GLSs and -GLSa) were determined.

RESULTS

During follow-up of 441 ± 221 days, 12 patients (29%) had AF recurrence. In the univariate Cox proportional hazard analysis, age [hazard ratio (HR): 1.08, p = 0.04], 3D-GCSs (HR: 0.91, p = 0.03), and 3D-GASs (HR: 0.95, p = 0.01) were predictors of AF recurrence, though associations of recurrence with 2D-STE parameters, indices of LA synchrony, and LA volume were not significant. Multivariable analysis showed that 3D-GASs was an independent predictor of AF recurrence (HR: 0.96, p = 0.048).

CONCLUSIONS

LA strain determined by 3D-STE is a novel and better predictor of AF recurrence after CA than that determined by 2D-STE or other known predictors.

Left Atrial Strain at Different Stages of Myxomatous Mitral Valve Disease in Dogs

Background

Decreased function of the left atrium (LA) is a useful prognostic indicator in dogs with myxomatous mitral valve disease (MMVD). In humans, LA strain is a novel severity indicator of mitral regurgitation, but its clinical utility in dogs has not been confirmed.

Objectives

To examine whether LA strain as evaluated with speckle‐tracking echocardiography is associated with MMVD stage in dogs.

Animals

Fifty‐two client‐owned dogs with MMVD.

Methods

Cross‐sectional study. Dogs were classified as stage B1, B2, C, or D, according to the American College of Veterinary Internal Medicine consensus. Physical examination findings and echocardiographic variables were compared among the groups. To assess the comparative accuracy of echocardiographic variables in identifying dogs with the presence or history congestive heart failure (CHF), receiver operating characteristic curves and multivariate logistic analysis were used.

Results

There were no significant differences in parameters of LA strain between B1 and B2 groups. However, LA longitudinal strain during atrial contraction (ε_A) (median, 19.1%; interquartile range, 15.3–24.3% in B1, 19.6%; 14.1–21.4% in B2, 6.2%; 3.18–11.2% in C/D) and during ventricular systole (ε_S) (32.7%; 28.9–39.2% in B1, 35.6%; 31.7–41.9% in B2, 23.6%; 16.9–26.1% in C/D) were significantly lower in stages C/D than in stages B1 and B2. In multivariate logistic regression analysis, ε_A and peak early diastolic mitral inflow velocity were identified as independent indicators of stage C/D.

Conclusions and Clinical Importance

ε_A was the best predictor of the presence or history of CHF. Further studies are needed to determine the clinical implications of these findings for treatment decisions and prognosis determination.