Left atrial mechanics evaluated by two-dimensional strain analysis: alterations in essential hypertension.

BACKGROUND: Hypertension is a cardiovascular risk factor that predisposes to cardiac structural alterations namely increased left ventricular (LV) wall thickness, reduced LV compliance and diastolic dysfunction, with consequent left atrial (LA) dilation and functional impairment. In this article, we evaluated differences in left atrial structure and function using two-dimensional speckle tracking echocardiography in patients with hypertension compared with controls. METHODS: This was a retrospective cross-sectional study of 208 hypertensive patients and 157 controls who underwent a comprehensive transthoracic echocardiogram. Patients with hypertension were stratified by the presence of left ventricular hypertrophy (LVH). RESULTS: Non-LVH hypertension patients had lower left atrial reservoir strain (LAS RES ) (34.78 ±â€Š29.78 vs. 29.78 ±â€Š6.08; P  = 0.022) and conduit strain (LAS CD ) (19.66 ±â€Š7.29 vs. 14.23 ±â€Š4.59; P  = 0.014) vs. controls despite similar left atrial volumes (LAV) . Left atrial contractile strain (LAS CT ) was not significantly different between non-LVH hypertension patients and controls (15.12 ±â€Š3.77 vs. 15.56 ±â€Š3.79; P  = 0.601). Left atrial mechanical dispersion was significantly higher in the LVH group compared with the non-LVH hypertension group (42.26 ±â€Š13.01 vs. 50.06 ±â€Š14.95; P  = 0.009). In multivariate regression analysis, LVH correlated with left atrial mechanical dispersion ( P  = 0.016). An age-hypertension interaction independently correlated with LAS CT ( P  < 0.001). CONCLUSION: Hypertension results in functional left atrial changes even before development of LV hypertrophy and structural left atrial changes with increased left atrial volume. We demonstrate both a likely hypertension-associated left atrial myopathy that prevents age-related compensatory increase in left atrial contractile function, and impact of LVH in hypertension on left atrial dyssynchrony.

A novel echocardiographic risk score for light-chain amyloidosis.

Aims: The prognosis of light-chain (AL) amyloidosis, a plasma cell dyscrasia, is largely determined by the presence of cardiac involvement. Conventional staging is achieved using cardiac biomarkers (high-sensitivity troponin, N-terminal pro-beta natriuretic peptide) and free light-chain difference (Mayo staging). We sought to evaluate the role of echocardiographic parameters as prognostic markers in AL amyloidosis and examine their utility compared with conventional staging. Methods and results: Seventy-five consecutive patients with AL amyloidosis reviewed at a referral amyloid clinic who underwent comprehensive echocardiographic assessment were retrospectively identified. The evaluated echocardiographic parameters included left ventricular (LV) ejection fraction, mass, diastolic function parameters, global longitudinal strain (GLS), and left atrial (LA) volume. Mortality was assessed through a review of clinical records. During a median follow-up of 51 months, 29/75 (39%) patients died. Patients who died had a larger LA volume (47 ± 12 vs. 35 ± 10 mL/m2, P < 0.001) and a higher E/e' (18 ± 10 vs. 14 ± 6, P = 0.026). Univariate clinical and echocardiographic predictors of survival included LA volume, E/e', e', LVGLS, and Mayo stage (at significance of P < 0.1). Left atrial volume and LVGLS were significant determinants of mortality when examined using clinical cut-offs, although E/e' was not. A composite echocardiographic risk score comprising LA volume and LVGLS provided similar prognostic performance to Mayo stage [area under the curve (AUC) 0.75, 95% confidence interval (CI) 0.64-0.85 vs. AUC 0.75, 95% CI 0.65-0.858, P = 0.91]. Conclusion: Left atrial volume and LVGLS were independent predictors of mortality in AL amyloidosis. A composite echocardiographic score combining LA volume and LVGLS has similar prognostic power to Mayo stage for all-cause mortality.

Strain by speckle tracking echocardiography correlates with electroanatomic scar location and burden in ischaemic cardiomyopathy.

AIMS: Ventricular tachycardia (VT) in ischaemic cardiomyopathy (ICM) originates from scar, identified as low-voltage areas with invasive high-density electroanatomic mapping (EAM). Abnormal myocardial deformation on speckle tracking strain echocardiography can non-invasively identify scar. We examined if regional and global longitudinal strain (GLS) can localize and quantify low-voltage scar identified with high-density EAM. METHODS AND RESULTS: We recruited 60 patients, 40 ICM patients undergoing VT ablation and 20 patients undergoing ablation for other arrhythmias as controls. All patients underwent an echocardiogram prior to high-density left ventricular (LV) EAM. Endocardial bipolar and unipolar scar location and percentage were correlated with regional and multilayer GLS. Controls had normal GLS and normal bipolar and unipolar voltages. There was a strong correlation between endocardial and mid-myocardial longitudinal strain and endocardial bipolar scar percentage for all 17 LV segments (r = 0.76-0.87, P < 0.001) in ICM patients. Additionally, indices of myocardial contraction heterogeneity, myocardial dispersion (MD), and delta contraction duration (DCD) correlated with bipolar scar percentage. Endocardial and mid-myocardial GLS correlated with total LV bipolar scar percentage (r = 0.83; 0.82, P < 0.001 respectively), whereas epicardial GLS correlated with epicardial bipolar scar percentage (r = 0.78, P < 0.001). Endocardial GLS -9.3% or worse had 93% sensitivity and 82% specificity for predicting endocardial bipolar scar >46% of LV surface area. CONCLUSIONS: Multilayer strain analysis demonstrated good linear correlations with low-voltage scar by invasive EAM. Validation studies are needed to establish the utility of strain as a non-invasive tool for quantifying scar location and burden, thereby facilitating mapping and ablation of VT.

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.