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

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. 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. 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. 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

Noninvasive localization of accessory pathways in patients with Wolff-Parkinson-White syndrome: a strain imaging study

Noninvasive techniques for the localization of the accessory pathways [APs] might help guide mapping procedures and ablation techniques. We sought to examine the diagnostic accuracy of strain imaging for the localization of the APs in Wolff-Parkinson-White syndrome. We prospectively studied 25 patients [mean age = 32 +/- 17 years, 58.3% men] with evidence of pre-excitation on electrocardiography [ECG]. Electromechanical interval was defined as the time difference between the onset of delta wave and the onset of regional myocardial contraction. Time differences between the onset of delta wave [delta] and the onset of regional myocardial contraction [delta-So], peak systolic motion [delta-Sm], regional strain [delta-epsilon], peak strain [delta-epsilonp], and peak strain rate [delta-SRp] were measured. There was a significant difference between time to onset of delta wave to onset of peak systolic motion [mean +/- SD] in the AP location [A] and normal segments [B] versus that in the normal volunteers [C] [A: [57.08 +/- 23.88 msec] vs. B: [75.20 +/- 14.75] vs. C: [72.9 0 +/- 11.16]; p value [A vs. B] = 0.004 and p value [A vs. C] = 0.18] and [A: [49.17 +/- 35.79] vs. B: [67.60 +/- 14.51] vs. C: [67.40 +/- 6.06 msec]; p value [A vs. B] < 0.001 and p value [A vs. C] = 0.12, respectively]. Our study showed that strain imaging parameters [[delta-So] and [delta-Strain]] are superior to the ECG in the localization of the APs [84% vs. 76%]

Tissue doppler imaging and doppler studies in patients with transmural and non-transmural myocardial infarction

Myocardial longitudinal shortening play an important role in cardiac contraction [1,2]. Tissue velocity imaging [TVI] is an ultrasonographic technique that measure myocardial motion and providing a quantitative agreement of left ventricular regional myocardial function in different modalities [3]. The present review discusses the most recent development in the application of TDI in coronary artery disease. Seventy patients with myocardial infarction [transmural and nontransmural] were included in the study. These subjects were diagnosed with recent myocardial infarction wall [septal side of mitral annulus] and basal segment of base of RV free wall were examined for tissue Doppler study with complete transthoracic echocardiography study. Mean age in group of inferior MI, anterior MI and non Q wave MI are as follows: 61.87 +/- 10.7, 57.04 +/- 10.7, 58.45 +/- 9.2. Sm was significantly reduced in anterior MI groups than non Q wave MI [PV=0.01]. In patients with inferior myocardial infarction 88% of patients had left ventricular ejection fraction [LVEF]>45% and in patients with anterior MI 18.2% patients had EF>45%. In non Q wave MI groups 60% patients had LVEF>45%. Except for Sm, other TDI parameters had no significant difference between two groups [transmural and nontransmural infarction] but it has significant changes in reduced left ventricle function and could be of determinants for prognosis

assessment of left ventricular time-varying radius using tissue doppler imaging

Left ventricular twist/torsion is believed to be a sensitive indicator of systolic and diastolic performance. To obtain circumferential rotation using tissue Doppler imaging, we need to estimate the time-varying radius of the left ventricle throughout the cardiac cycle to convert the tangential velocity into angular velocity. The aim of this study was to investigate accuracy of measured LV radius using tissue Doppler imaging throughout the cardiac cycle compared to two-dimensional [2D] imaging. A total of 35 subjects [47 +/- 12 years old] underwent transthoracic echocardiographic standard examinations. Left ventricular radius during complete cardiac cycle measured using tissue Doppler and 2D-imaging at basal and apical short axis / levels. For this reason, the 2D-images and velocity-time data derived and transferred to a personal computer for off-line analysis. 2D image frames analyzed via a program written in the MATLAB software. Velocity-time data from anteroseptal at basal level [or anterior wall at apical level] and posterior walls transferred to a spreadsheet Excel program for the radius calculations. Linear correlation and Bland-Altman analysis were calculated to assess the relationships and agreements between the tissue Doppler and 2D-measured radii throughout the cardiac cycle. There was significant correlation between tissue Doppler and 2D-measured radii and the Pearson correlation coefficients were 0.84 to 0.97 [P<0.05]. Bland-Altman analysis by constructing the 95% limits of agreement showed that the good agreements existed between the two methods. It can be concluded from our experience that the tissue Doppler imaging can reasonably estimate radius of the left ventricle throughout the cardiac cycle

Percutaneous mitral balloon valvotomy; single center experience: a review of outcome

Percutaneous balloon mitral valvotomy [BMV] has been accepted as an alternative to surgical mitral commissurotomy in the treatment of patients with symptomatic rheumatic mitral stenosis. Despite the worldwide use of the BMV technique, no studies have been hitherto designed to assess the outcome of the patients undergoing BMV in Iran. The present study reports the outcome of 3138 BMV procedures at Shaheed Rajaei Cardiovascular, Medical and Research Center during a 15-year time period. A total of 2531 patients underwent 3138 BMV procedures at Shaheed Rajaei Cardiovascular, Medical and Research Center between 1992 and 2006. Seventy-three percent [2278] of the cases were followed for 48 +/- 41 months. Recurrent stenosis in 802 [25.8%], mitral valve replacement [MVR] in 213 [6.9%], immediate good result in 3110 [99.1%], and successful outcome in 2000 [72.9%] cases were the outcome of the BMV procedures in the current study. Concordant to the similar studies, we concluded that BMV produces a good clinical outcome in a high percentage of patients. The recent study demonstrated that the successful outcome of BMV was multi factorial and the selection of patients with rheumatic mitral stenosis is recommended to be based on both anatomic and clinical characteristics of the individuals. The procedure-related variables must also be considered in order to predict the outcome

Non-invasive assessment of coronary artery stenosis with estimation of myocardial wall stress

More diagnostic techniques require a better understanding of the forces and stresses developed in the wall of the left ventricle. The aim of this study was to differentiate significant coronary artery disease [CAD] patients using a non-invasive quantification of myocardial wall stress in the diastole phase. Sixty male subjects with sinus rhythm [30 patients with significant and 30 with moderate left anterior descending coronary artery stenosis in the proximal portion] as well as 35 healthy subjects as the control group were recruited into the present study. By two-dimensional, pulsed wave, and tissue Doppler echocardiography, the average end-diastolic wall stress was calculated at the left ventricle anterior and interventricular septum wall segments using regional wall thickness, meridional and circumferential radii, and non-invasive left ventricular end-diastolic pressure. A comparison of the calculated end-diastolic myocardial wall stress between the patients with significant and moderate coronary stenosis on the one hand and the healthy subjects on the other showed statistically significant differences in the anterior and septum wall segments [p value < 0.05]. The patients with significant left anterior descending coronary artery stenosis had higher end-diastolic myocardial wall stress than did those with moderate stenosis and the healthy group in all the anterior and septum wall segments. It is concluded that non-invasive end-diastolic myocardial wall stress in coronary artery disease patients is an important index in evaluating myocardial performance

Approach to the patient with combined coarctation of aorta and Wolf-Parkinson-White syndrome

At the present time the treatment of choice for postductal coarctation of aorta is percutaneous angioplasty and stenting. One crucial step for successful stenting of coarctation is accurate positioning of the stent across the lesion, which is difficult due to high pressure blood flow at the site of the coarct. To solve this problem, rapid pacing has been used to decrease cardiac output and blood pressure for a few seconds and prevent excessive motion of the stent during deployment. However, if coarctation is combined with pre-excitation syndrome, rapid atrial/ventricular pacing could cause life-threatening tachyarrhythmias. In this paper, we report a 28-year-old women with combined coarctation of aorta and Wolf-Parkinson-White syndrome who underwent radio frequency catheter ablation of the accessory pathway and then stenting angioplasty of the coarctation was performed without any complication

Assessment of regional myocardial displacement via spectral tissue doppler compared with color tissue tracking

The recent developments in tissue Doppler imaging [TDI] now more than ever permit the quantification of the myocardial function. In the current systems, tissue tracking or displacement curves are generated from color tissue Doppler data through the instantaneous temporal integral of velocity-time curves. The purpose of the present study was to assess regional myocardial displacement via spectral TDI. Maximum myocardial velocities were extracted from spectral pulsed tissue Doppler images using a developed computer program and were integrated throughout the cardiac cycle. Spectral tissue Doppler echocardiography was performed to evaluate longitudinal and radial functions in 20 healthy men, and the calculated end-systolic displacements were subsequently compared with the displacements measured from the same areas via color tissue tracking. According to the Bland-Altman analysis between spectral tissue tracking and color tissue tracking, the significant arithmetic mean was 7.34 mm with SD mean differences of +/- 2.24 mm in all of the evaluated segments. Despite significant differences [p < 0.001], there was a good significant correlation between the two methods [r=0.79, p < 0.001]. A verification study showed that the proposed approach had the ability to assess regional myocardial displacement using spectral TDI, which can be used in a wider range of equipment than is currently possible