Role of speckle tracking echocardiography in detecting early left atrial dysfunction in hypertensive patients

Advanced echocardiography techniques (AETs) to assess left atrial structure and function in individuals with resistant hypertension

AIMS

Resistant hypertension (RH) is a challenging phenotype within the hypertension (HTN) spectrum, requiring careful assessment and follow-up. Evaluation of left atrial function may be clinically informative, but is usually neglected. Advanced Echocardiography Techniques (AETs), such as Strain Analysis and three-dimensional echocardiography (3D ECHO) may be useful complementary tools to assess atrial function in patients with RH.

METHODS AND RESULTS

Ninety-six eligible adult patients were categorized into three groups: resistant hypertensive (RH), controlled hypertensive (CH), and normotensive (N), and underwent AETs to identify morphofunctional changes in the left atrium (LA) across different HTN phenotypes. The LA reservoir strain was significantly lower among RH than in N and CH patients (p < .001). Accordingly, LA conduit strain showed a gradient through the groups: higher among N, followed by CH and RH patients (p = .015). LA contraction strain was higher among CH than in N and RH patients (p = .02). Maximum indexed, pre-A, and minimum atrial volumes obtained by 3D ECHO showed differences between N and the others (p < .001), but not between CH and RH. N patients showed a higher fraction of passive emptying of the LA than the others (p = .02), with no difference between CH and RH. Total emptying of the LA only differed between N and RH patients, while active emptying of the LA showed no difference between the groups (p = .82).

CONCLUSION

The left atrium may present early functional changes in response to HTN, which are detectable by AETs. AETs, especially S-LA, allowed to identify markers of atrial myocardial damage in both RH and CH patients.

Left atrial evaluation by cardiovascular magnetic resonance: sensitive and unique biomarkers

Left atrial (LA) imaging is still not routinely used for diagnosis and risk stratification, although recent studies have emphasized its importance as an imaging biomarker. Cardiovascular magnetic resonance is able to evaluate LA structure and function, metrics that serve as early indicators of disease, and provide prognostic information, e.g. regarding diastolic dysfunction, and atrial fibrillation (AF). MR angiography defines atrial anatomy, useful for planning ablation procedures, and also for characterizing atrial shapes and sizes that might predict cardiovascular events, e.g. stroke. Long-axis cine images can be evaluated to define minimum, maximum, and pre-atrial contraction LA volumes, and ejection fractions (EFs). More modern feature tracking of these cine images provides longitudinal LA strain through the cardiac cycle, and strain rates. Strain may be a more sensitive marker than EF and can predict post-operative AF, AF recurrence after ablation, outcomes in hypertrophic cardiomyopathy, stratification of diastolic dysfunction, and strain correlates with atrial fibrosis. Using high-resolution late gadolinium enhancement (LGE), the extent of fibrosis in the LA can be estimated and post-ablation scar can be evaluated. The LA LGE method is widely available, its reproducibility is good, and validations with voltage-mapping exist, although further scan-rescan studies are needed, and consensus regarding atrial segmentation is lacking. Using LGE, scar patterns after ablation in AF subjects can be reproducibly defined. Evaluation of 'pre-existent' atrial fibrosis may have roles in predicting AF recurrence after ablation, predicting new-onset AF and diastolic dysfunction in patients without AF. LA imaging biomarkers are ready to enter into diagnostic clinical practice.

Contemporary narrative review on left atrial strain mechanics in echocardiography: cardiomyopathy, valvular heart disease and beyond

Left atrial (LA) strain mechanics refer to the measurement of LA myocardial deformation expressed as a percentage, and have been gathering interest over the last decade with expanding research supporting their utility in multiple cardiovascular disorders. Measured through advanced dynamic imaging techniques which include tissue Doppler imaging (TDI) and two-dimensional (2D) speckle tracking echocardiography (STE), LA strain mechanics are affected by left ventricular diastolic dysfunction prior to the onset of functional and structural changes in the left ventricle (LV). There is a need for practising cardiologists to become more familiar with the clinical utility of LA strain mechanics. In this article, we begin by reviewing the physiologic function of the LA, using this as a basis for understanding LA strain mechanics. The focus of this review article is to provide a contemporary update on the utility of LA strain mechanics in a range of cardiovascular disorders, including atrial fibrillation (AF), hypertrophic cardiomyopathy (HCM), valvular pathologies, coronary artery disease (CAD) as well as systemic diseases, such as hypertension (HTN), obesity and diabetes mellitus (DM). This article also highlights the current limitations in more widespread clinical applications of LA strain mechanics, as well as outlining the future perspectives on the clinical applications of LA strain mechanics.

Relation between left atrial structure and lacunar infarction in patients with hypertension

A lacunar infarction (LACI) can cause damage to the surrounding brain tissue and place an individual at greater risk for future major stroke. LACI is associated with hypertension and hypertension is associated with left atrial enlargement. It is important to identify a high-risk patient who is more vulnerable to suffering a LACI in hypertensive group. So, we studied whether left atrium size is an independent risk predictor for LACI in hypertensive patients. We performed cross-sectional analysis of 365 patients with hypertension at Shanghai Ninth People's Hospital from January 2016 to January 2017. The results showed that left atrial diameter(LAD), left atrial volume (LAV) and the ratio of left atrial diameter to left ventricular diameter (LAD/LVD) were significantly associated with LACI in hypertensive patients. Based on the ROC curve analysis, the area under the ROC curve (AUC) of LAV used to predict LACI was 0.737 (95% CI: 0.686 - 0.788), and the AUC of LAD/LVD was 0.784 (95% CI: 0.737 - 0.830). The optimal cut-off value for LAV was 30.14, and the sensitivity and specificity were 72% and 63%, respectively. The optimal cut-off value for LAD/LVD was 0.757, and the sensitivity and specificity were 77% and 70%, respectively. LAV or LAD/LVD played an important role in LACI with hypertension and could be an independent risk factor in hypertensive patients.

Left atrial strain as sensitive marker of left ventricular diastolic dysfunction in heart failure

Aims

The purpose of this retrospective analysis was to examine the association of left atrial (LA) strain (i.e. LA reservoir function) with left ventricular diastolic dysfunction (DD) in patients with heart failure with reduced and preserved left ventricular ejection fraction (LVEF).

Methods and results

We analysed the baseline echocardiographic recordings of 300 patients in sinus rhythm from the SOCRATES‐PRESERVED and SOCRATES‐REDUCED studies. LA volume index was normal in 89 (29.7%), of whom 60.6% had an abnormal LA reservoir strain (i.e. ≤23%). In addition, the extent of LA strain impairment was significantly associated with the severity of DD according to the 2016 American Society of Echocardiography recommendations (DD grade I: LA strain 22.2 ± 6.6, rate of abnormal LA strain 62.9%; DD grade II: LA strain 16.6 ± 7.4, rate of abnormal LA strain 88.6%; DD grade III: LA strain 11.1 ± 5.4%, rate of abnormal LA strain 95.7%; all P < 0.01). In line with these findings, LA strain had a good diagnostic performance to determine severe DD [area under the curve 0.83 (95% CI 0.77–0.88), cut‐off 14.1%, sensitivity 80%, specificity 77.8%], which was significantly better than for LA volume index, LA total emptying fraction, and the mitral E/e′ ratio.

Conclusions

The findings of this analysis suggest that LA strain could be a useful parameter in the evaluation of DD in patients with heart failure and sinus rhythm, irrespective of LVEF.

Impact of left atrial appendage occlusion on left atrial function-The LAFIT Watchman study

BACKGROUND

Left atrial (LA) strain and strain rate (SR) analysis by two-dimensional speckle tracking echocardiography is a novel way of LA function assessment. From prior study, we know that LA appendage closure with LARIAT appears to improve LA function.

OBJECTIVE

The purpose of this study was to assess the impact of LAA closure via Watchman device on LA function via strain and volumetric analyses using two-dimensional speckle tracking echocardiography (2D-STE).

METHODS

Twenty-five patients who underwent Watchman device implantation (WDI) were included. LA function parameters (volumetric, strain indices) were calculated from apical four chamber views with the reference point set at QRS using 2D-STE before and after WDI. LA expansion index, strain and strain rate during ventricular systole represent LA reservoir function. Passive emptying fraction, strain and strain rate during early ventricular diastole represent LA conduit function.

RESULTS

Mean age was 76 ± 6.9 years with 60% males. There was significant improvement in conduit function (LA passive emptying fraction; post 28.6 (21.9-35.9) vs pre 21.0 (13.8-34.7), p = 0.032), reservoir function (LA expansion index; post 75.3 (52.3-98.0) vs pre 58.1 (37.8-85.2), p = 0.026), and booster function (LA active emptying fraction; post 13.3 (9.7-29.9) vs pre 12.6 (8.8-25.5), p = 0.04) by volumetric indices. No significant improvement was noted with strain indices in conduit function (SRe; post - 0.56 (0.43-0.93) vs pre - 0.58 (0.46-0.87); p = 0.518) and reservoir function (SRs; post + 0.58 (0.28-0.40) vs pre + 0.52 (0.35-0.86); p = 0.851).

CONCLUSIONS

WDI resulted in discrepancy of volumetric and strain indices in LA function assessment.