Stroke volume and mitral annular velocities

Current and Clinically Relevant Echocardiographic Parameters to Analyze Left Atrial Function

The evaluation of the left atrial (LA) size using the LA volume index (LAVI) is clinically relevant due to its prognostic significance in various conditions. Nonetheless, adding a LA function assessment to the LAVI provides further clinical and prognostic information in different cardiovascular (CV) diseases. The assessment of LA function by echocardiography primarily includes volumetric measurements (LA ejection fraction [LAEF]), tissue Doppler imaging (TDI) (mitral annular late diastolic velocity [a']), and speckle-tracking methods, such as LA longitudinal reservoir strain (LA strain). This review analyzes and discusses the current medical evidence and potential clinical usefulness of these different methods to analyze LA function.

Assessment of myocardial function of the systemic right ventricle in patients with D-transposition of the great arteries after atrial switch operation by tissue Doppler echocardiography

INTRODUCTION

The long-term follow-up of patients with D-transposition of the great arteries after atrial switch operation shows specific problems such as tricuspid valve insufficiency, rhythm disturbances and failure of the morphologic right ventricle in systemic position. Assessment of the myocardial contractility of the subaortic right ventricle by conventional echocardiography is limited. The usage of tissue Doppler echocardiography with strain combined with strain rate imaging provides a new approach for quantitative analysis of longitudinal myocardial function. The aim of this study was to assess patterns of wall motion and regional contractile function of the systemic right ventricle in patients after atrial switch operation for D-transposition of the great arteries and to compare them to those of normal subjects.

PATIENTS AND METHODS

Twenty-four patients with Dtransposition of the great arteries after atrial switch operation with a mean age of 21.3 (range, 13 to 31) years and a postoperative period of 16.9 years were examined and compared to 22 control individuals with a mean age of 21.5 (range, 3 to 43) years. Tissue Doppler studies were obtained from apical 4- chamber view to determine regional systolic (Syst(T)) and diastolic (E(T), A(T)) velocities as well as E(T)/A(T) ratio at the basal free wall. The presystolic isovolumic contraction peak was assessed and the ratio of the presystolic peak velocity to the isovolumic acceleration time as the IVA index was calculated. Strain and peak systolic and diastolic strain rates were assessed on basal, middle and apical segments of the right ventricular free wall. Data obtained from the morphologic right systemic ventricle in patients were compared to those derived from the left and the right ventricle in controls.

RESULTS

The right ventricular free wall systolic velocities were significantly reduced in patients compared to velocities obtained from the normal right and left ventricle. On the other hand, the IVA index was only reduced in patients compared to the IVA index in the normal subpulmonary right ventricle. Compared to data obtained from the normal systemic left ventricle, the IVA index in patients was not significantly different. In contrast, strain and strain rate parameters in all analyzed segments mostly showed a highly significant reduction compared to normal right and left ventricular data.

CONCLUSION

Tissue Doppler echocardiography is a promising tool for the evaluation of regional myocardial contractile function of the morphologic right systemic ventricle in patients following atrial switch operation for D-transposition of the great arteries. Presystolic, systolic and diastolic regional ventricular function was reduced in the systemic right ventricle. However, further comparative studies using other quantitative parameters of global and regional myocardial function derived from cardiac catheterization or MRI should be performed in order to evaluate the reliability of tissue Doppler echocardiography for the assessment of global right ventricular function in these patients.

Stroke Volume and Mitral Annular Velocities: Insights from Uremic Patients with Significant Valvular Regurgitation

OBJECTIVE

This study investigates the change in new diastolic indices in uremic patients who undergo regular hemodialysis (H/D).

MATERIALS AND METHODS

We studied uremic patients receiving regular H/D. All patients were sinus rhythm before H/D. They had normal left ventricular systolic performance without regional wall motion abnormality. Patients were separated into two groups according to whether they had significant aortic or mitral regurgitation (AR or MR) or not. They received complete transthoracic echocardiographic examinations. Stroke volume (SV) was calculated as the product of the time-velocity integral (TVI) and cross-sectional area of aortic annulus. Flow propagation velocity (FPV) was measured by color M-mode echocardiography in apical four-chamber view. Mitral annulus tissue Doppler velocities--peak systolic (Sa), early diastolic, and late diastolic--were measured from septal and lateral wall. All these parameters were obtained immediately before and after H/D. Paired data were compared.

RESULT

H/D amount was strongly correlated with the change of SV. After H/D, the reduction of SV in patients without AR or MR (control group) was obvious but it was not significant in patients with significant AR or MR (study group). There were significant differences in mitral inflow velocities, FPV, and mitral annular velocities (except septal Sa) in the control group. In the study group, predialytic and postdialytic parameters of new diastolic indexes had no statistical difference.

CONCLUSION

New echocardiographic indexes of uremic patients with significant AR or MR were relatively preload-independent. The phenomenon was possibly related to insignificant change of SV after H/D.