Evaluación de las velocidades de pared de la aurícula izquierda mediante Doppler pulsado tisular. Una nueva aproximación al estudio de la función auricular

Tissue Doppler Imaging and strain rate of the left atrial lateral wall: age related variations and comparison with parameters of diastolic function

Background

Strain Rate Imaging (SRI) is one of the most used techniques to study left atrial (LA) and diastolic function. Its availability in low-income countries is diminished since it requires additional expensive software, among other limitations. In contrast, Tissue Doppler Imaging (TDI) is widely available and easy to use. We hypothesize TDI could detect changes in LA and diastolic function associated with age similarly to SRI. The aim of this study is to evaluate the effects of age on LA and diastolic function assessed by LA lateral wall TDI online by spectral pulse, and to compare them with age-related variations of LA SRI and other parameters of diastolic function in a population of healthy adults.

Materials and methods

Ninety-one healthy adults were prospectively evaluated. In apical four - chamber view the LA lateral wall was divided in three portions. Peak velocities of basal and mid portions were measured with TDI online by spectral pulse and with SRI by speckle tracking. A first positive wave (S’la and SRS) and two negative waves (E’la and SRE, and A’la and SRA respectively) were obtained. E’la/A’la ratio and SRE/SRA ratio were analyzed. The distribution of the variables by age subgroups was described and analyzed. Correlation analyses were performed.

Results

The median age was 42 years old and 54.9% were female. E’la/A’la showed a negative good correlation with age. E’la/A’la and SRE/SRA ratios changed from > 1 to < 1 in the age group of 41–50 years old, while this occurred in the group of 51–60 years old for the E/A ratio. Lateral and septal mitral annulus E´ showed decrease with age and prolongation of E-wave deceleration time was observed in the age group over 61 years old.

Conclusion

Normal values​​ according to age group of TDI of the LA lateral wall were obtained. Age-related changes in LA and diastolic function could be detected as early with TDI as with SRI. Future studies are required to explore if this method could be used to address in part LA or diastolic function in other populations with established cardiovascular disease or at risk of presenting it, which could be useful in low-income settings, where SRI is not available.

Tissue Doppler imaging of the atrial lateral wall: Correlation with atrial strain rate and parameters of diastolic function

OBJECTIVE

To evaluate the velocity profile of the lateral wall of the left atrium (LA) using pulsed-wave color tissue Doppler imaging (TDI) on line and its correlation with two-dimensional strain rate imaging (SRI) by speckle tracking, of equal segments and phases, and other parameters of diastolic function in a population of individuals without known cardiovascular disease.

MATERIALS AND METHODS

A total of 91 adults aged 18-74 years, without cardiovascular history, hypertension, diabetes, dyslipidemia or obesity, were evaluated. A Doppler echocardiogram was performed. The lateral wall of the LA was divided subjectively into three portions, the atrial roof was excluded; the peak velocities of the basal and midportions, and their average, were measured with pulsed-wave TDI on line and SRI. Using both techniques, a first positive wave (S'la and SRS-reservoir phase) and two negative waves (E'la and SRE-conduit phase-and A'la and SRA-atrial systole-respectively) were obtained. E'la/A'la ratio and SRE/SRA ratio were analyzed.

RESULTS

The median age was 42 years, and 54.9% of the subjects were female. S'la presented moderate correlation with S' lateral mitral annulus. Both E'la and the E'la/A'la relationships showed moderate to good correlation with various diastolic dysfunction parameters evaluated and SRI. A'la did not present a statistically significant correlation with any of the variables evaluated.

CONCLUSION

Evaluation of the lateral wall of the LA by pulsed-wave color TDI on line is feasible in the vast majority of patients. In the conduit phase, E'la and the E'la/A'la relationship showed correlation with the parameters that evaluate diastolic function and SRI.

Left atrial deformation: Useful index for early detection of cardiac damage in chronic mitral regurgitation

In chronic mitral regurgitation (MR) left atrium is one of the first cardiac structures that is involved in remodeling and ultrastructural changes for a progressive volume overload. Severe left atrial (LA) dilation on echocardiography and new onset of atrial fibrillation in asymptomatic patients with preserved Left Ventricular (LV) function, appeared as a Class IIb recommendation for consideration for surgical mitral valve repair in the actual guidelines. However, before atrial dilatation and dysfunction, several ultrastructural changes appear in the atrial muscle tissue that are difficult to identify with the standard echocardiography. Speckle tracking echocardiography (STE) can analyze LA function: it has been showed that it can indirectly identify structural tissue modifications from excessive atrial effort in the early stages of MR up to the full depression of atrial function in the late stages where there are advanced ultrastructural alterations. This review aims to summarize current knowledge on the role of atrial strain identifying early structural alterations of the atrial tissue in the rising stages of MR considering that Left Atrial Peak Longitudinal Strain (PALS) considered useful parameter for a more extensive evaluation of MR patients.

Assessment of left-atrial strain parameters in patients with frequent ventricular ectopic beats without structural heart disease

Ventricular ectopic beats (VEBs) are often encountered in daily clinical practice. Clinical significance of VEBs seen in patients without structural cardiovascular diseases is controversial. We aimed to investigate the effects of VEBs on left atrium (LA) function using speckle tracking echocardiography with LA strain parameters. Patients with frequent VEBs (more than 30 times in 1 h, according to the Lown classification) were identified. Identified patients were evaluated by speckle tracking methods. There were 40 patients with frequent VEBs and 40 controls in our study. The general characteristics were similar of the study population. The LA global longitudinal strain parameters were significantly different. Global Peak atrial longitudinal strain (PALS) (38.39 ± 7.93 vs. 44.15 ± 6.71, p = 0.001) and peak atrial contraction strain (PACS) (16.37 ± 4.58 vs. 20.49 ± 3.65, p = 0.000) were revealed significantly lower in the VEBs group. Time to peak longitudinal strain (TPLS) was found significantly longer in the VEBs group [485.5 (352-641) vs. 435 (339-516.5) p = 0.000]. Number of VEBS was correlated with TPLS (r = 0.499, p = 0.000). PALS and PACS were negatively correlated with number of VEBs (r = -0.348, p = 0.002 and r = -0.444, p = 0.000, respectively). We described that in this study, The LA functions are affected by VEBs adversely. This deterioration is increasing as the number of VEBs.

Feasibility and reference values of left atrial longitudinal strain imaging by two-dimensional speckle tracking

Background

The role of speckle tracking in the assessment of left atrial (LA) deformation dynamics is not established. We sought to determine the feasibility and reference ranges of LA longitudinal strain indices measured by speckle tracking in a population of normal subjects.

Methods

In 60 healthy individuals, peak atrial longitudinal strain (PALS) and time to peak longitudinal strain (TPLS) were measured using a 12-segment model for the left atrium. Values were obtained by averaging all segments (global PALS and TPLS) and by separately averaging segments measured in the two apical views (4- and 2-chamber average PALS and TPLS).

Results

Adequate tracking quality was achieved in 97% of segments analyzed. Inter and intra-observer variability coefficients of measurements ranged between 2.9% and 5.4%. Global PALS was 42.2 ± 6.1% (5–95° percentile range 32.2–53.2%), and global TPLS was 368 ± 30 ms (5–95° percentile range 323–430 ms). The 2-chamber average PALS was slightly higher than the 4-chamber average PALS (44.3 ± 6.0% vs 40.1 ± 7.9%, p < 0.0001), whereas no differences in TPLS were found (p = 0.93).

Conclusion

Speckle tracking is a feasible technique for the assessment of longitudinal myocardial LA deformation. Reference ranges of strain indices were reported.