LAV Max Research Articles

Left atrial expansion index predicts left ventricular filling pressure in ischemic cardiomyopathy

The aim of the study was to assess the power of left atrial expansion index (LAEI) to predict left ventricular filling pressures and its relation with N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in patients with ischemic cardiomyopathies. This prospective study analyzed 66 patients (mean age 62 ± 11 years, range 37–89, 86.4% male) with ischemic cardiomyopathy (mean Left ventricular ejection fraction 46.4 ± 12.8%). All patients underwent transthoracic echocardiography and NT-proBNP measurement within 24 hours. The LAEI was calculated as (Vol max − Vol min) × 100%/Vol min, where Vol max was defined as maximal LA volume and Vol min was defined as minimal volume. Simple regression analysis demonstrated a significant linear correlation between LAEI and Log NT-proBNP( r = 0.723, P < 0.0001). Significant but weaker correlations were found between Log NT-proBNP and E/E’ ( r = 0.504, P < 0.0001), indexed LA maximum volume (LAVI max) ( r = 0.308, P = 0.012), mitral deceleration time (TDE) ( r = 0.365, P = 0.003), E/A ( r = 0.362, P = 0.003). Significant correlations were also found between LAEI and E/E’ ( r = −0.543, P < 0.0001), LAVI max ( r = 0.360, P = 0.003), E/A ( r = 0.403, P = 0.001). The receiver-operating characteristic curve showed that LAEI had good diagnostic power for E/E’ > 15 at cutoff value of 66.8% with a sensitivity of 74.5% and a specificity of 83.3% while the area under the curve was of 0.875. Multivariate analysis techniques with Log-NT-proBNP as dependent variable and age, E/A, TDE, E/E’, LAVI max and LAEI as predictors, showed that the relation to LAEI was the strongest ( β = −0.725). We suggest that evaluation of LAEI may be useful to predict LV filling pressures in ischemic cardiomyopathies. The power of this index exceeds that of other well-established echocardiographic parameters such as E/E’ and LVAI max.

Left atrial remodeling in patients undergoing percutaneous mitral valve repair with the MitraClip system: an advanced echocardiography study.

The goal of this study was to determine changes in left atrial (LA) function with two-dimensional speckle tracking echocardiography (2DSTE) and real-time full-volume three-dimensional echocardiography (RT3DE) after percutaneous mitral valve repair with the MitraClip system. Furthermore, we investigated whether baseline and/or changes in LA function after MitraClip repair had any impact on prognosis. A total of 25 consecutive patients (age: 57±12years, 76% male) with moderate-to-severe or severe mitral regurgitation (MR) were included. Patients underwent 2DSTE and RT3DE before the clip implantation and after the 12-month follow-up. Prognostic data were also recorded via the use of telephone calls and follow-up visits for 12months after the procedure. Compared with the baseline, the LA reservoir strain (LA-Res) (7.66±4.3% vs 11.15±7.5%, P<.001) and LA contraction strain (LA-Pump) (4.64±4.3% vs 7.63±5.8%, P=.001) improved significantly after MitraClip repair; significant improvements were also seen in three-dimensional (3D) minimum LA volume index (LAV min) and maximum LA volume index (LAV max). On the other hand, conventional LA indices did not change. In total, eleven major adverse cardiac events (MACE) were observed at the 1-year follow-up. In univariate analyses, the preprocedural echocardiographic parameters that were associated with the MACE within 1year after MitraClip repair were 3D-LAV min and LA-Res. Furthermore, these indices significantly correlated with improved functional parameters and MR reduction. In conclusion, a successful MitraClip procedure can reverse the process of LA remodeling within 12months, and this can be detected by 2DSTE and RT3DE. Also, patients with preprocedural lower LA-Res and higher 3D-LAV min had the worst prognoses at the 1-year follow-up.

PP.08.16

Objective: Hypertension(HTN) has severe consequences to the heart, leading to morphological and functional remodeling of left atrium. We sought to assess left atrial(LA) mechanical function in a group of hypertensives, matching it with healthy controls. Design and method: We prospectively enrolled 35 consecutive hypertensive patients (mild, moderate and severe HTN but pharmacological treated subjects). The secondary causes of hypertension, as well as significant valvular disease, thyroid dysfunctions, diabetes mellitus or any other important organ abnormality were excluded. LA diameters(antero-posterior, tranverse and longitudinal) LA volumes were measured by echocardiography, using the modified biplane Simpson method: maximal LA(LAV max), preatrial contraction LA(LAV preA) and minimal LA volume(LAV min). LA emptying functions were calculated: LA total EF(LAV max-LAVmin)/LAV max, LA passive EF = (LAVmax-LAVpreA)/LAVmax and LA active EF(LAVpreA-LAVmin)/LAVpreA. Peak longitudinal strain of LA walls were analysed using 2D speckle-tracking echocardiography. The results were compared with a group of 37 age-matched healthy controls. Results: In the HTN group the mean time of arterial hypertension diagnosis was 33 months and the mean blood pressure(24 hour ambulatory blood pressure monitoring) was 139/74mmHg. LA antero-posterior diameter and all the volumes(LAVmax, LAVmin and LAVpreA) were significantly greater in hypertensives compared to controls(p < 0.0001), while the transversal and longitudinal diameters were similar. LA active EF was similar between the two groups, but we found significantly lower LA passive and total EF in hypertensives than in the control group(p < 0.0001). The peak strain values were also significantly lower in HTN group compared to control(22.7 versus 35.1, p < 0.0001). Conclusions: In our study, arterial hypertension was associated with increased LA size (anteroposterior diameter and volumes), a decrease in LA passive EF and in LA total EF, with preserved atrial pump function. LA dysfunction was also demonstrated through low peak strain values.

Assessment of left ventricular and atrial diastolic function using two‐dimensional (2D) strain imaging in patients with β‐thalassemia major

β-thalassemia major is a unique disease characterized by early severe diastolic dysfunction, due to iron myocardial deposition alone, while left ventricular systolic dysfunction and failure seem to be multifactorial in aitiology. The purpose of this study was to investigate left ventricular diastolic dysfunction using a new echo index as speckle tracking in comparison with the conventional methods. Eighty-eight consecutive patients (38 male, 50 female) aged 36±8.2yr with β-thalassemia major and preserved LV ejection fraction (LVEF>55%) were studied. Patients were divided into two groups according to the E mitral/E mitral annulus ratio (E/E'): group A patients with E/E' ratio ≤8 and group B patients with E/E' >8. Cutoff value of eight was used to separate patients with normal and abnormal diastolic function. All subjects were studied thoroughly by tissue Doppler echocardiography as also by 2D left ventricular and atrial strain imaging 2-4d following blood transfusion. Blood samples were also taken for plasma BNP measurements at the same time. Left atrial volumes(LAV max, LAV min) as also left atrial index were significantly higher in patients with diastolic dysfunction compared with patients without diastolic dysfunction(LAV max: 57.6±19.4 vs. 71.3±22.9, P<0.01,LAV min: 20.2±11.4 vs. 33.9±18, P<0.01, LAVI: 37.66±12.18 vs. 47.13±14.77, P<0.01). Radial 2D strain (RS) and peak atrial 2D strain (AS) were significantly reduced in patients with suspected diastolic dysfunction compared with patients without diastolic dysfunction (RS: 43.48±13.92 vs. 35.58±11.32, P<0.05; AS: 36.36±8.45 vs. 29.85±9.25, P<0.01). Using ROC analysis, peak atrial 2D strain at a cutoff of 41.1cm/s was highly accurate (AUC: 0.66, P<0.05 in ruling out diastolic dysfunction (E/E'<8) with a sensitivity of 90% and a specificity of 81%. B-thalassemic major patients with preserved left ventricular systolic function had impaired left atrial function at the longitudinal axis and left ventricular function at the radial axis. The new echo markers have better prognostic value than the traditional echo indexes in detecting latent diastolic dysfunction in β-thalassemia major, earlier than E/E' ratio.

Left atrial compensatory function in subjects with early stage primary hypertension assessed by using left atrial volumetric emptying fraction acquired by transthoracic echocardiography

Purpose To evaluate left atrial (LA) function in subjects with early stage primary hypertension (HT) and without enlargement of LA, we used transthoracic echocardiogram and measured LA volumetric emptying fraction and compared the results with those in healthy volunteers. Materials and methods 42 subjects with early stage primary HT (21 males, aged 61 ± 12 years), within 1 year of HT diagnosis and starting initial treatment, were enrolled in the study. An additional inclusion criterion was normal sinus rhythm electrocardiogram without enlargement of LA. As the control group, 31 healthy volunteers with normal sinus rhythm electrocardiogram (13 male, aged 57 ± 11 years) were enrolled. Maximum and minimum volume of LA (LAV max and min, respectively) were selected manually and visually in B mode images acquired from a four-chamber view from apex of left ventricle (LV) using a modified Simpson method, and the LA emptying fraction (LAEF) was calculated by the following formula: LAV min / LAV max × 100 (%). Results There were no significant differences in age, male:female ratio, end-diastolic and end-systolic LV diameter, LA maximum volume, LV ejection fraction and E/A in mitral annulus between the two groups. However, we found that end-diastolic inter-ventricular septum thickness and end-diastolic LV posterior wall thickness were significantly larger in the HT group in comparison with the control group ( P < 0.01), but the HT group did not fit the classical criteria of LV myocardial hypertrophy. The systolic and diastolic blood pressure, the end-diastolic and end-systolic volume of LV, the total weight of LV myocardium and the LAEF were significantly higher in the HT group than in the control group ( P < 0.05). Conclusions In subjects with early stage primary HT with normal sinus rhythm, in spite of a normal LAV, the LAEF may increase. This increase of LAEF may be regarded as one of the compensatory reactions against preload to the left side of the heart and precedes the occurrence of LA enlargement.

Effect of cardiac resynchronization therapy on left atrial appendage function and pulmonary venous flow pattern

Background Previous studies have shown improvement in left ventricular function and development of the reverse remodeling in the left ventricle and left atrium after cardiac resynchronization therapy (CRT). The aim of this study was to investigate the effect of CRT on left atrial appendage (LAA) function and pulmonary venous flow pattern. Methods Eighteen patients with systolic heart failure and complete left bundle branch block underwent implantation of biventricular pacemaker devices. In order to follow changes in LAA, transthoracic and transesophageal echocardiographic examinations were performed 1 week before and repeated 1 and 6 months after pacemaker implantation. Results CRT resulted in significant clinical improvement and decrease in NYHA functional class in 17 patients (94%). Maximum and minimum areas of left atrial appendage (LAAA max and LAAA min) decreased, with a concomitant increase in LAA ejection fraction. [LAAA max: from 4.6±2 to 4.2±1.8 cm 2 at the first ( P<0.001) and to 4.0±1.8 cm 2 at the sixth month ( P<0.001); LAAA min: from 2.7±1.3 to 2.3±1.2 cm 2 at the first ( P<0.001) and to 2.2±1.2 cm 2 at the sixth month ( P<0.001) and LAA ejection fraction: from 41±12% to 46±10% at the first ( P=0.007) and to 47±8% at the sixth month ( P=0.003)]. LAA active emptying and filling flow and pulmonary venous systolic velocities also increased after CRT. The appendage active emptying velocity correlated significantly with left ventricular ejection fraction ( r=0.50, P=0.002), LAA ejection fraction ( r=0.51, P=0.002), left atrial maximal volume, LAV max ( r=−0.44, P=0.007), left atrial minimal volume, LAV min ( r=−0.50, P=0.002) and pulmonary vein systolic flow velocity ( r=0.33, P=0.05). Conclusion Treatment of heart failure by CRT results with marked improvements in LAA function and increases pulmonary venous systolic velocity.