comparison between methods used to extract maximum and minimum myocardial velocities by spectral pulsed-TDI

Tissue Doppler imaging is an echocardiographic useful method in the assessment of left ventricular myocardial function in the clinical condition. Pulsed Doppler interrogation measures the instantaneous velocities of the myocardium which passes through the sample volume during the cardiac cycle. The present study attempts to verify a computerized method to determine myocardial maximum and minimum velocities throughout the cardiac cycles using spectral pulsed-tissue Doppler imaging. The data of curves might be used to calculate myocardial physical and mechanical parameters throughout the cardiac cycle. Spectral pulsed-TDI was performed to evaluate longitudinal function in 23 healthy volunteers by using a sample volume placed in 170 left ventricular segments. The velocities were extracted automatically based on four common edge detection algorithms using Matlab software. Labeling of connected components in boundary of spectrum allowed comparing the methods. In addition to analysis of variance and t-test, linear correlation and Bland-Altman analysis were calculated to assess the relationships and agreements between the systolic and diastolic results of measurements before and after using the computed program. Comparison of the means of the four edge detection methods showed that there are statistically significant differences between methods [number of labels were 12 3 for Canny, 20 4 for Roberts, 31 4 for Sobel and 39 5 for Prewitt respectively, P<0.05]. There were not significant differences between measured velocities in the segments; before and after application of the Canny method. There was significant correlations [r=0.99 and r=0.96, P=0.01] at the base and mid segments, respectively with Bland-Altman analysis significant agreements between the measurements. It is concluded that the proposed method automatically extracts myocardial velocities using spectral pulsed images. Canny method showed relatively favorable results and seems to be a preferable option to extract velocities from the spectral images. Correlation study and Bland-Altman analysis confirmed a good agreement between the measurements

Prevalence of left ventricular diastolic asynchrony in patient with systolic heart failure

To study the occurence of left ventricular [LV] diastolic asynchrony in patients with systolic heart failure [HP] and its relationship to diastolic function regardless of QRS duration. Recent work has demonstrated that intraventricular asynchrony is a common finding in patients with systolic heart failure. Little attention has been paid to diastolic asynchrony in patients with systolic heart failure. We have therefore decided to determine the extent to whuch patients with systolic heart failure have evidence of diastolic asynchrony and wheather or not diastolic asynchrony is correlated with diastolic dycfunction. Tissue Doppler echocardiography was performed in 50 HF patients [LV EF=23 +/- 8%]. Diastolic and systolic asynchrony was determined by tissue synchronization imaging using a 6 basal, 6 mid-segmental model. Systolic and diastolic asynchrony were assessed by the maximal difference in time to peak systolic and early diastolic velocities between any two of 12 LV segments, and the standard deviation of time to peak systolic and early diastolic velocities of the 12 LV segments. The mean +/- SD maximal difference in time to peak systolic velocity [controls: 17.2 +/- 9.6 ms versus narrow QRS: 66.7 +/- 38.0 ms versus wide QRS: 76.5 +/- 34.6 ms, both P<0.05 versus controls] and in standard deviation of time to peak systolic velocity of 12 LV segments [controls: 15 +/- 6.1 ms versus narrow QRS: 25.9 +/- 15.3 ms versus wide QRS: 28.6 +/- 14.4ms, both P<0.05 versus controls] was prolonged in both the narrow and wide QRS groups compared with normal controls. Similarly, the maximal difference in time to peak diastolic velocity [controls: 39 +/- 16.8 ms versus narrow QRS: 73.1 +/- 58ms versus wide QRS: 108.5 +/- 168 ms, both P<0.05 versus controls] and in standard deviation of time to peak early diastolic velocity of 12 LV segments [controls: 15.3 +/- 5.8ms versus narrow QRS: 25.1 +/- .13.8ms versus wide QRS: 25.5 +/- 14.9ms, both P<0.05 versus controls] was prolonged in both the narrow and wide QRS groups. The respective prevalence of systolic and diastolic asynchrony was 31.4% and 20%, in the narrow QRS group, and 40% and 28.6%, in the wide QRS group respectively.Stepwise multiple regression analysis showed that low ejection fraction and low mitral annular early diastolic velocity were independent predictors of both systolic and diastolic asynchrony. QRS complex duration was found to correlate only with diastolic asynchrony. LV systolic and diastolic mechanical asynchrony is common in patients with HF regardless of QRS duration. Selection for cardiac resynchronization treatment should also be based on information about systolic and diastolic synchronicity

Estimation of septal wall thickness by processing sequential echocardiographic images

Non-invasive quantitative analysis of the heart wall 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 assessment of wall stress, wall thickening and viability parameters. The measurement of interventricular septum wall thickness by conventional manual method is more dependent on sonographer's experiment.This encouraged researchers to develop a semi-automatic computer algorithm to access interventricular septum segments thickness. We proposed and developed a computerized algorithm for wall thickness measurements in 2D echocardiographic image frames. In this program, wall thickness measurement is based on intensity profile function and adaptive bilateral thresholding operation. For validation, thicknesses of septum base and mid segments were estimated in constituent image frames using proposed technique followed by comparing them with conventional manual results from same images of the cardiac cycle by statistical methods. In our sample image frames [240 corresponding segments; with different range of image quality], a bias of 0.10 mm and 0.12 mm with SD differences of +/- 0.81 mm 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 technique [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 with high concordance with CMM

Presentation of anomalous origin of the left coronary artery from the pulmonary artery with left sided coronary ostium in an adult patient

An anomalous origin of the left coronary artery from the pulmonary artery [ALCAPA] is a rare congenital coronary anomaly. It usually presents in infancy with intractable left sided heart failure. Most patients die in infancy, but survival into adulthood is possible. Patients may complain of dyspnea, syncope or effort angina. They may remain asymptomatic; or experience sudden death after exercise. A 56-year-old woman presented with a twomonth history of exertional chest discomfort. Echocardiography showed a coronary anomaly with preserved systolic function and no resting regional wall motion abnormality. The coronary and CT [computed tomography] angiography studies revealed the anomalous origin of the left coronary artery. A review of ALCAPA studies is presented along with images from the echocardiogram, coronary angiogram and CT scan performed for this case

Correlation of right ventricular DP/DT with functional capacity and RV function in patients with mitral stenosis

Evaluation of right ventricular [RV] contractility and systolic function in patients with right sided heart disease is an essential component of clinical management. The aim of this study was to assess RV systolic function by qualitative and quantitative methods and compare it to rate of ventricular pressure change during the isovolumic contraction period [dP/dt] as RV contractility index in patients with rheumatic mitral stenosis. In 56 consecutive patients with moderate to severe mitral stenosis, RV systolic function, RV dP/dt and dP/dt/Pmax, were calculated and compared. There was significant correlation between RV dP/dt and RV function [P < 0.001] and between RV dP/dt and New York Heart Association [NYHA] functional capacity [P < .001]. The mean of dP/dt was decreased with increasing severity of RV dysfunction [mean dP/dt was 648 +/- 159 for normal RV function, 592 +/- 126 for mild RV dysfunction, 319 +/- 146 for moderate RV dysfunction and 166 +/- 150 for severe RV dysfunction] Severity of tricuspid regurgitation and pulmonary hypertension had no significant effect on RV dP/dt and RV function. RV dP/dt/Pmax had also significant relationship with RV function and functional capacity [P < 0.001]. Measurements of dP/dt and dP/dt/Pmax, are practical methods for estimating RV contractility and results have a good correlation with RV systolic function and functional capacity

Coronary flow reserve measurement in the coronary sinus in pre and post CABG status

Coronary flow reserve [CFR] is defined as a maximal [hyperemic] to resting ratio of coronary blood flow. It is a physiologic parameter of coronary circulation and depends on the patency of the epicardial coronary arteries and integrity of the microvascular circulation.CFR measurement has many clinical applications including functional assessment of intermediate stenosis, detection of critical stenosis monitoring of coronary flow in the post angioplasty period, assessment of post infarct blood flow and assessment of coronary graft patency. The aim of this study was to measure CFR in the coronary sinus through the transthoracic echocardiographic approach, in patients who were candidate for coronary artery bypass graft surgery [CABG] before and one month after operation. The present study included 19 patients [mean age=56 +/- 9.1] including 15 males and 4 females, admitted for CABG. All patients had a sinus rhythm, normal wall thickness, normal RV systolic pressure, and tricuspid valvular regurgitation equal or less than grade 2. The antegrade phase of coronary flow in the coronary sinus moving into the right atrium was analyzed in two phases [systolic and diastolic]. Each wave was determined considering the peak velocity and velocity time integral [VTI]. The volumetric blood flow in the coronary sinus calculated at the baseline and then in hyperemic phase was used for determination of CFR both before and after CABG. There was a significant increase in the diameter of the coronary sinus after CABG [9.4 +/- 1.2mm] compared with that of before CABG values [8.6 +/- 1.05mm]. Also there was a trend of increasing the diameter in the hyperemic phase before and after CABG. The absolute increase in mean coronary sinus diameter was 0.5 mm before and 1.5 mm after CABG. Coronary flow reserve [CFR] was significantly higher after surgery, despite a significant increase in systolic velocity ratio [hyperemic/baseline] after CABG. This is also true for systolic velocity time integral [VTI] and diastolic VTI ratios, but there was an insignificant increase in diastolic velocity ratio. Our study in accordance with previous studies, denotes that transthoracic measurement of the coronary flow reserve can be used as a feasible and reproducible method to monitor the changes in cardiac perfusion after revascularization