Left Atrial Filling Time Index (LAFTI) Evaluated by 2D Speckle Tracking Echocardiography Predicts Poor Cardiac Prognosis in Patients with Heart Failure

Left atrial (LA) dysfunction is known to be a more sensitive prognostic marker than left ventricular (LV) dysfunction in patients with heart failure (HF). Persistent LA overload increases LA stiffness which impairs LA relaxation. The aim of this study was to investigate whether LA filling time is associated with clinical outcomes in patients with HF. Two-dimensional speckle tracking echocardiography (2DSTE) was performed at discharge, to measure LA and LV strain in 179 HF patients admitted to our hospital. The LA filling time index (LAFTI) was defined as the time from onset of the R wave to the peak LA systolic strain divided by the R-R interval. All patients were prospectively followed with cardiac events including cardiac death and rehospitalization for HF. There were 64 cardiac events during a median follow-up period of 451 days. There were no significant differences in heart rate, severity of HF at discharge, etiology of HF, severity of mitral regurgitation, or LV global longitudinal strain between the cardiac event group and no cardiac event group. Patients with cardiac events had significantly higher levels of brain natriuretic peptide (BNP), ratio of the E wave to e' (E/e'), left atrial volume index (LAVI), and lower LAFTI than those without. Kaplan-Meier analysis showed that patients with lower LAFTI were associated with higher cardiac event rates. Multivariate Cox hazard analysis showed that LAFTI was independently associated with the cardiac events after adjustment for confounding factors. In conclusion, LAFTI is a feasible predictor for cardiac events in patients with HF.

Challenges for 'diastology': contributions from Japanese researchers

Diastology is a study to treat diastole of the heart. Transmitral flow and pulmonary venous flow velocities recorded by pulsed Doppler echocardiography provide more important information about left ventricular (LV) diastolic dysfunction [left atrial (LA)-LV coupling] than cardiac catheterization in clinical practice; however, these waveforms are influenced by loading conditions, particularly preload. The early diastolic mitral annular and LV wall motion indices measured by tissue Doppler echocardiography can evaluate LV relaxation abnormality and filling pressure by being relatively preload independent. In addition, the role of concomitant systolic longitudinal dysfunction is well characterized in asymptomatic patients and in patients with heart failure and preserved ejection fraction. Two-dimensional speckle tracking echocardiography is an angle-independent method, and has the potential to evaluate the contraction and relaxation abnormalities in the longitudinal, circumferential, and radial directions of the LV myocardium as well as LV torsion/untwisting and, moreover, deformation of the LA myocardium and large arterial wall. As a result, this new technique can facilitate the early detection of impaired LA-LV-arterial coupling in patients before occurrence of overt heart failure symptoms.

Association of left atrial reservoir function with left atrial structural remodeling related to left ventricular dysfunction in asymptomatic patients with hypertension: evaluation by two-dimensional speckle-tracking echocardiography

Left atrial (LA) structural and functional abnormalities are vital steps on the pathway toward heart failure with preserved ejection fraction in asymptomatic patients. The purpose of this study was to assess the relationship of LA function, particularly reservoir function, with LA structural remodeling related to the left ventricular (LV) dysfunction in asymptomatic patients with hypertension (HT) using conventional, tissue Doppler, and 2-D speckle-tracking echocardiography. Fifty age-matched healthy individuals and 140 patients with HT, including 75 with LA volume index (LAVI)<29 ml/m2 (normal LA group) and 65 with LAVI≥29 ml/m2 (large LA group), were enrolled. We defined peak early diastolic transmitral flow velocity/peak early diastolic mitral annular motion velocity (E/e')/peak systolic LA strain (S-LAs) as LA diastolic stiffness. The LV mass index, relative LV wall thickness, peak atrial systolic transmitral flow velocity, LA total, active, and passive emptying volume indexes, and E/e'/S-LAs were greatest, and S-LAs, peak early diastolic LA strain, peak systolic LV longitudinal strain and circumferential strain rate, and peak early diastolic LV radial strain rate were lower in the large LA group compared with control and/or normal LA group. Multivariate linear regression analysis revealed that aging, LA remodeling, and LV systolic and diastolic dysfunction are defined as strong predictors related to increased LA diastolic stiffness in the large LA group. HT alters LA dynamics significantly, with resultant increased LA volume and diastolic stiffness related to LV diastolic and systolic dysfunction, even in asymptomatic patients. Earlier treatment with renin–angiotensin system inhibitors may improve abnormal LA-LV interaction in this patient population.

Prognostic implications of left atrial dilation evaluated by echocardiographic volume in patients with normal left atrial antero-posterior dimensions

BACKGROUND

The purpose of this study was to clarify the clinical characteristics and prognostic implications of left atrial (LA) dilation evaluated echocardiographic volume in patients with normal LA dimension (LAD).

METHODS

A total of 140 consecutive patients (81 men, mean age: 57 ± 18 years) with normal LAD (<39 mm for women and <41 mm for men) who underwent conventional echocardiography and tissue Doppler imaging were enrolled. LA volume (LAV) ≥29 ml/m(2) was defined as abnormal LAV. Hospitalization for heart failure (HF) and cardiac death were defined as cardiac events.

RESULTS

Eighty-seven (62%) of the patients had LA dilation, defined as a normal LAD but an abnormal LAV. Patients with LA dilation were significantly older and had a significantly higher left ventricular (LV) mass index (LVMI) and incidences of hypertension and HF than did patients with both normal LAD and normal LAV. Logistic regression analysis revealed that increased LVMI was an independent (p < 0.01) determinant of LA dilatation. During a follow-up period of 16 ± 10 months, ten patients had cardiac events. Patients with cardiac events had a higher incidence of LA dilation than those without cardiac events (100 vs. 59%, p < 0.05). A Kaplan-Meier survival curve showed that patients with LA dilation had a significantly lower survival rate than those with both normal LAD and normal LAV (log rank 6.1, p = 0.014).

CONCLUSIONS

LV hypertrophy is an independent determinant of LA dilation in patients with normal LAD. Assessment of LA morphology using LAV can contribute to risk stratification in patients with normal LAD.

Clinical significance of anterior mitral leaflet fibrillation in patients with nonvalvular atrial fibrillation: comparison with blood flow and wall motion of the left atrial appendage

BACKGROUND AND PURPOSE

Diastolic fibrillation of the anterior mitral leaflet (AML) is seen in patients with atrial fibrillation (AF). However, its clinical significance has been unclear. On the other hand, reduced blood flow velocity in the left atrial appendage (LAA) may be associated with LA thrombus formation. In this study, we investigate the relationship between the flow velocity and the wall motion velocity of the LAA and diastolic fibrillation of the AML in patients with nonvalvular AF.

METHODS

We performed transthoracic echocardiography (TTE) in 45 consecutive patients with chronic nonvalvular AF. The LAA flow velocity was measured by pulsed Doppler echocardiography with the sample volume positioned at the center of the LAA. The LAA wall motion velocity was measured by pulsed Doppler tissue imaging (DTI) with the sample volume at the medial wall of the LAA. The AML fibrillation velocity was measured by pulsed DTI with the sample volume at the AML tip.

RESULTS

The AML fibrillation velocity could be measured in 44 patients (97.8%), and the LAA flow and wall motion velocities were measurable in 35 (77.8%) and 42 (93.3%) patients, respectively. The AML fibrillation velocity had a range from 4 to 21 cm/s and showed significant positive correlation with the LAA flow velocity (r = 0.82, P < 0.001) and the wall motion velocity (r = 0.80, P < 0.001) of the LAA. An AML fibrillation velocity of ≤7 cm/s predicted patients having a tendency to LA thrombus formation (LAA flow velocity ≤20 cm/s) with high sensitivity (87.5%) and specificity (88.9%).

CONCLUSION

The AML fibrillation velocity seems to be a viable substitute for the LAA flow velocity in the detection of flow stagnation in the LA.