Two-dimensional speckle-tracking echocardiography evaluation of left atrial function according to glycemic state in patients with coronary artery disease

Coronary artery disease is associated with impaired atrial function regardless of left ventricular filling pressure

BACKGROUND

Left atrial (LA) strain is impaired in left ventricular (LV) diastolic dysfunction, associated with increased LV end diastolic pressure (LVEDP). In patients with preserved LV ejection fraction (LVEF), coronary artery disease (CAD) is known to impair LV diastolic function. The relationship of LVEDP with CAD and impact on LA strain is not well studied.

METHODS AND RESULTS

Patients with LVEF >50% (n = 37, age 61 ± 7 years) underwent coronary angiography, high-fidelity LV pressure measurements and cardiac magnetic resonance imaging. LA volumes, LA emptying fraction (LAEF), LA reservoir strain (LARS) and LA long-axis shortening (LALAS) were measured. By coronary angiography, patients were assigned into 3 groups: severe-CAD (n = 19, with obstruction of major coronary arteries >70% and/or history of coronary revascularization), mild-to-moderate-CAD (n = 10, obstruction of major coronary arteries 30-60%), and no-CAD (n = 8, obstruction of major coronary arteries and branches <30%). Overall, LVEF was 65 ± 8% and LVEDP was 14.4 ± 5.6 mmHg. Clinical characteristics, LVEDP and LV function measurements were similar in 3 groups. Severe-CAD group had lower LAEF, LALAS and LARS than those in no-CAD group (P < 0.05 all). In regression analysis, LARS and LALAS were associated with CAD severity and treatment with Nitrates, whereas LAEF and LAEFactive were associated with CAD severity, treatment with Nitrates and LA minimum volume (P < 0.05 all). LAEFpassive was associated with LVED volume (P < 0.05).

CONCLUSIONS

LA functional impairment may be affected by coexistent CAD severity, medications, in particular, Nitrates, and loading conditions, which should be considered when assessing LA function and LA-LV interaction. Our findings inspire exploration in a larger cohort.

Determinants of the Volumetric Markers of Left Atrial Contraction Function in Coronary Artery Disease: A Cross-sectional Study

BACKGROUND

A body of research advocates the prognostic role and usefulness of the volumetric markers of left atrial (LA) phasic functions in the diagnosis of LA dysfunction. We aimed to determine the independent determinants of the volumetric markers of LA contraction function in candidates for coronary artery bypass graft (CABG) surgery.

METHODS

This cross-sectional study enrolled 516 candidates for CABG. The biplane maximal, minimal, and pre-P volumes of the LA were measured with two-dimensional echocardiography, and LA active emptying fraction was calculated. The standardized correlation coefficient for the correlation between each factor and LA active emptying fraction was calculated by using univariate and backward multivariable regression analyses.

RESULTS

The multivariable regression analysis demonstrated that the heart rate (β = 0.15; p = 0.001), S (β = 0.09; p = 0.036), E/e′ ratio (β = −0.11; p = 0.014), left ventricle (LV) ejection fraction (β = 0.15; p = 0.001), and LA enlargement (β = −0.19; p < 0.001) were the independent determinants of LA active emptying fraction.

CONCLUSIONS

The independent determinants of LA contraction function were the heart rate, S, LV ejection fraction, LA enlargement, and E/e′ ratio in candidates for CABG surgery.

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.

The evaluation of right ventricular function in patients with diabetes mellitus and significant stenosis at the proximal portion of the right coronary artery

PURPOSE

Previous studies have indicated that right ventricular (RV) function is damaged in diabetes mellitus (DM); however, it is not clear whether in the presence of chronic ischemia, RV function is different between patients with and without DM (DM + and DM - , respectively).

METHODS

This cross-sectional study enrolled 90 consecutive candidates for coronary artery bypass graft surgery and allocated them to 3 groups: 24 DM - patients with the absence of stenosis of more than 50% in the proximal and mid parts of the right coronary artery (the DM - RCA - group [control]), 33 DM - patients with the presence of significant stenosis (> 70%) in the proximal part of RCA (the DM - RCA + group), and 33 DM + patients with RCA + (the DM + RCA + group). RV function was evaluated based on longitudinal deformation markers, measured via the 2D speckle-tracking echocardiographic examination of right ventricular free wall (RVFW).

RESULTS

The systolic strain value, systolic strain rate, and late diastolic strain rate of RVFW were not statistically significantly different between the three groups. Our adjusted post hoc analysis showed that the early diastolic strain rate of RVFW in the DM + RCA + group was lower than that in the DM - RCA + and DM - RCA - groups (1.5 s^-1 ± 0.4 vs 1.7 s^-1 ± 0.5 vs 1.7 s^-1 ± 0.4).

CONCLUSIONS

Diastolic function in the presence of DM was impaired irrespective of RCA - or RCA + . Additionally, RCA + had no effect on systolic and diastolic RV functions at rest in our DM - patients.

Prediabetes, heart mechanics, and echocardiography: A narrative review

Prediabetes is a dysglycemic state that affects many around the world and is a known risk factor for the occurrence of type 2 diabetes mellitus in the future, accompanied by vascular complications. Evidence abounds regarding myocardial involvement in prediabetes. We herein review studies having applied tissue Doppler imaging or speckle-tracking echocardiography to evaluate myocardial function in subjects with prediabetes to depict a picture of cardiac mechanics in individuals with prediabetes in comparison with patients suffering from diabetes mellitus and individuals in the normoglycemic state. Finally, we present the detrimental effects of prediabetes on cardiac mechanics.

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.