Assessment of subclinical left ventricular dysfunction in patients with chronic mitral regurgitation using torsional parameters described by tissue doppler imaging

Background: Left ventricular (LV) twist is due to oppositely directed apical and basal rotation and has been proposed as a sensitive marker of LV function. We sought to assess the impact of chronic pure mitral regurgitation (MR) on the torsional mechanics of the left human ventricle using tissue Doppler imaging. Methods: Nineteen severe MR patients with a normal LV ejection fraction and 16 non-MR controls underwent conventional echocardiography and apical and basal short-axis color Doppler myocardial imaging (CDMI). LV rotation at the apical and basal short-axis levels was calculated from the averaged tangential velocities of the septal and lateral regions, corrected for the LV radius over time. LV twist was defined as the difference in LV rotation between the two levels, and the LV twist and twisting/untwisting rate profiles were analyzed throughout the cardiac cycle. Results: LV twist and LV torsion were significantly lower in the MR group than in the non-MR group (10.38 ° ± 4.04 ° vs. 13.95 ° ± 4.27 °; p value = 0.020; and 1.29 ± 0.54 °/cm vs. 1.76 ± 0.56 °/cm; p value = 0.021, respectively), both suggesting incipient LV dysfunction in the MR group. Similarly, the untwisting rate was lower in the MR group (-79.74 ± 35.97 °/s vs.-110.96 ± 34.65 °/s; p value = 0.020), but there was statistically no significant difference in the LV twist rate. Conclusion: The evaluation of LV torsional parameters in MR patients with a normal LV ejection fraction suggests the potential role of these sensitive variables in assessing the early signs of ventricular dysfunction in asymptomatic patients

Determination of instantaneous interventricular septum wall thickness by processing sequential 2D echocardiographic images

Non-invasive quantitative analysis of the heart walls thickness is a fundamental step in diagnosis and discrimination of heart disease. Thickness measurements in 2D echocardiographic images have many applications in research and clinic for assessing of wall stress, wall thickening and viability parameters. Regarding to interventricular septum wall thickness measurement by conventional manual method is more dependent on sonographer experiment; this encouraged these researchers to develop a semi-automatic computer algorithm in accessing to interventricular septum segments thickness. We proposed and carried out a computerized algorithm for wall thickness measurements in 2D echocardiographic image frames. In this program, wall thickness measurement is based of intensity profile function and adaptive bilateral thresholding operation. For validation, thicknesses of septum base and mid segments were estimated in constituent image frames with use of proposed method and then were compared with conventional manual results at same images of the cardiac cycle by statistical methods. In our sample image frames (240 corresponding segments; with different rang of image quality), a bias of 0.10 and 0.12 mm with SD differences of ±0.81 and ±0.72 mm and correlation coefficients of 0.87 and 0.89 were found in base and mid segments, respectively. Interobserver variability using the Computer-Assisted Method (CAM) and Conventional Manual Method (CMM) were 4.0 and 4.7 for the basal and 2.8 and 3.9 for the middle segments. The method introduced in the present study permits precise thickness assessment of base and mid segments of the interventricular septum wall and has high concordance with CMM. © 2007 Asian Network for Scientific Information

Assessment of left atrial reservoir function in mitral valve disease by tissue doppler, strain and strain rate imaging

Introduction: Mitral valve stenosis and mitral valve regurgitation still result in significant morbidity and mortality. It has been shown that atrial remodeling and atrial fibrillation may occur in these patients. We sought to investigate how pressure or volume overload in the left atrium could impact atrial deformation properties obtained via Doppler-derived velocity and strain/strain rate imaging. Methods: Thirty-six patients, comprising 17 patients with a diagnosis of moderate to severe mitral stenosis and 19 patients with a diagnosis of moderate to severe mitral regurgitation, were compared with 16 healthy subjects. Two-dimensional, pulse Doppler, and tissue Doppler transthoracic echocardiographic study was performed. Measurement of regional velocity, strain and SR profiles, peak systolic velocity, peak strain, and strain rate was performed in two segments of the four left atrial walls. Results: There was a significant decline in peak systolic velocity in the mitral stenosis patients in both annular and roof segments, but the difference was not statistically significant between the mitral regurgitation patients and the healthy subjects. Total velocity was significantly lower in the mitral stenosis patients than in the healthy subjects, but the difference was not statistically significant between the healthy subjects and the mitral regurgitation patients. Comparison of total strain showed significant differences between the three groups mainly due to a decline in strain in the mitral stenosis patients in comparison with the other two groups. Comparison of total peak systolic strain rate between the groups showed significant differences due to a significant decline in the mitral stenosis group and a non-significant decline in the mitral regurgitation group by comparison with the healthy group. Conclusion: This reduction, especially in strain and strain rate, shows that the reservoir function of the left atrium could be compromised more severely in asymptomatic mitral stenosis patients. © 2014 American Scientific Publishers All rights reserved

Reverse left ventricular apical rotation in dilated cardiomyopathy

Introduction: We describe a 56-year-old woman with dilated cardiomyopathy, whose clinical assessment, including two-dimensional echocardiography, demonstrated a spherical left ventricular geometry with severe left ventricular enlargement and dysfunction as well as reverse apical rotation. Left ventricular twist and torsion were evaluated via echocardiography with velocity vector imaging; the patient was found to have reverse rotational movement. We hereby address these issues from an echocardiographic point of view. Case Presentation: The patient was a 56-year-old woman, who referred to our clinic with complaints of dyspnea on exertion of 2 years� duration. By the time of her referral, the patient�s dyspnea had exacerbated and reached New York Heart Association (NYHA) functional class III Conclusions: These findings emphasize the potential clinical benefits of therapeutic procedures such as cardiac resynchronization therapy (CRT) or apex-sparing volume-reduction surgery in DCM. A better definition of the role and implications of reverse apical torsion in DCM and its importance and effectiveness in making therapeutic decisions like CRT implantation requires further studies. © 2015, Iranian Society of Echocardiography

Frame rate requirement for tissue Doppler imaging in different phases of cardiac cycle: Radial and longitudinal functions

Tissue Doppler imaging (TDI) has been suggested for quantitative analysis of regional myocardial function. Myocardial movement included different mechanical phases with different duration and tissue velocity profiles need to high sampling rate in the acquisition of tissue velocity imaging for phases with shorter duration. The aim of this study is determining of frame rate requirement for myocardial tissue velocity imaging for longitudinal and radial functions separately. Tissue velocity imaging recorded from 29 healthy volunteers by use of the apical and para-sternal views. Off-line analysis performed for extracting tissue velocity profiles of the myocardial longitudinal and radial functions. The frequency and subsequently the frame rate calculated separately for all LV segments during two consequent cardiac cycles. Segmental distribution of the time intervals measured in all cardiac phases and the minimum frame rate requirement calculated for each segment. We found significant differences between radial and longitudinal functions (P < 0.001) except early diastolic phases. The presented normal frame rate values for LV segments may useful for accurate studies of myocardial longitudinal and radial functions in different cardiac phases. We conclude that data sampling at a rate of at least 105 and 118 frames per second need for longitudinal and radial functions respectively. © Springer Science+Business Media B.V. 2007

Coronary flow reserve, strain and strain rate imaging during pharmacological stress before and after percutaneous coronary intervention: Comparison and correlation

Introduction: Coronary flow reserve (CFR) could apply reliable information about the coronary circulation, and strain (S) and strain rate imaging (SRI) are able to quantify the left ventricular myocardial performance. The aim of this study was to assess myocardial performance in relation to the function of the coronary circulation before and after successful percutaneous coronary intervention (PCI) of the left anterior descending artery. Material and Method: Fourteen patients (10 men, 4 women, mean age 53.2 ± 11.4 years) with severe left anterior descending stenosis who had a successful selective PCI were recruited into this study. CFR and myocardial deformity indices (S and SR) were recorded before and after percutaneous intervention, both at rest and during stress echo test. Results: CFR, S, and SR increased after intervention significantly. There was significant correlation between CFR ratio and poststress systolic strain (SS) ratio and early diastolic strain rate (ESR) ratio (P 0.6). Also CFR improvement had significant relationship with changes of poststress Systolic SR and poststress Systolic S (P 0.6). Based on regression analysis the amount of change in CFR was independently associated with change in SS during stress and systolic SR. Conclusion: PCI improves CFR (a marker of coronary perfusion), strain, and strain rate (markers of regional cardiac wall deformation). The independent association between CFR improvement and poststress systolic strain and strain rate means that SRI parameters can independently predict CFR changes after PCI. © 2011, Wiley Periodicals, Inc