Evaluation of Ventricular-vascular Coupling in Patients with Type 2 Diabetes Mellitus Using 2-Dimensional Speckle Tracking Imaging

The elastic and functional coupling of heart and vessels makes the stroke work （SW） of the heart optimal. Speckle tracking imaging （STI） can evaluate the myocardial strain and function. We studied ventricular-vascular coupling in 80 diabetic patients with different systolic function using STI. The patients were divided into two groups according to ejection fraction （EF）： the diabetes mel- litus with normal EF （DMN） group and the diabetes mellitus with abnormal EF （DMA） group. Forty-two volunteers served as control group. The relative wall thickness （RWT）, left ventricular mass index （LVMI）, stroke volume （SV）, SW, rate-pressure product （RPP）, systemic vascular resis- tance index （SVRI）, left ventricular end-systolic elastance （Ees）, effective arterial elasticity （Ea） and ventricular-vascular coupling index （VVI） were measured and calculated by conventional echocardi- ography. The longitudinal strain （LS） at basement （LSBA）, papillary muscle （LSvM） and cardiac apex （LSAv） was assessed with STI. It was found： （A） compared with control group, in DMN and DMA groups, LSBA, LSvM and LSAp decreased, and they were lower in DMA group. （B） VVI, RPP and SVRI increased, and they were higher in DMN group; Ees decreased, and it was lower in DMA group. （C） LSBA, LSpM, and LSAv had negative correlation with VVI. LSAp, RWT, LVMI and SW were independent predictors for VVI. The area under the receiver operating characteristic （ROC） curves was used for identification of DMA and DMN with LSBA, LSpM, and LSAp, and the area under the ROC of LSAp was the largest. This study supports that myocardial LS could reflect the ventricu- lar-vascular coupling. Different segments had an order to “respond to” the state of the coupling, and the cardiac apex might be the earliest.

Ultrasound Speckle Tracking Imaging Contributes to Early Diagnosis of Impaired Left Ventricular Systolic Function in Patients with Type 2 Diabetes Mellitus

To investigate the value of ultrasound speckle tracking imaging （STI） in the assessment of the short-axis and long-axis systolic function of the left ventricle （LV） in patients with type 2 diabetes mellitus （DM）, 100 subjects with normal ejection fraction were studied, including 41 patients with DM only （DM group）, 22 patients with both DM and left ventricular hypertrophy （DH group）, and 37 healthy subjects （control group）. Left ventricle systolic function in the long axis defined as longitudinal strain, and that in the short axis defined as radial strain, apical and basal LV rotations, and LV twist were assessed respectively. The results showed that average peak strain in the long axis at basal, middle and apical levels, and global peak strain were significantly decreased in the patient groups when compared with the control group （P〈0.001 for each）. The parameters in DH group were significantly lower than those in DM group （P〈0.01 for each）. There were no significant differences in average radial peak strain in the short axis at different levels, and global peak strain among the three groups （P〉0.05）. Apical and basal LV rotations, and LV twist were greater in the patient groups than in the control group （P〈0.01 for each）. Basal LV rotation and LV twist were greater in DH group than those in DM group （P〈0.01）. It was concluded that STI may be used to identify early abnormalities in patients with type 2 DM that have normal left ventricular systolic function.

Assessment of Right Ventricular Free Wall Longitudinal Myocardial Deformation Using Speckle Tracking Imaging in Normal Subjects

To assess fight ventficular free wall longitudinal myocardium deformation and examine the changes with normal age by speckle tracking imaging （STI）, myocardial systolic peak strain （ε）, systolic peak strain rate （SRs）, early diastolic peak strain rate （SRe）, late diastolic peak strain rate （SRa）, the ratio of SRe/SRa were measured in the basal, middle and apical segments of right ventficular free wall in 75 healthy volunteers （age range： 21-71 y） by STI from the apical 4-chamber view. RV longitudinal strain and strain rate were highest in the basal segment of the free wall. Older subjects had lower early diastolic strain rate （SRe） than younger subjects, but they had higher late diastolic strain rate （SRa）. A negative correlation between age and the ratio of SRe/SRa was found in all RV free wall segments （r=-4）.466 - -0.614, P〈0.01）. It is concluded that RV diastolic strain rate changes with age and STI can be used for the study of RV myocardial deformation.

Assessment of Left Ventricular Global Twist in Essential Hypertensive Heart by Speckle Tracking Imaging

The left ventricular twist was evaluated by 2-dimensional ultrasound speckle-tracking imaging （STI） in 50 patients with hypertension with normal geometric left ventricle （LV） and 45 normal subjects as control group. The mean value of LV rotation was obtained at each plane Using STI. LV twist and twist velocity were defined as apical rotation/rotation rate relative to the base respectively. To adjust the intersubject differences in heart rates, the time sequence were normalized. The results showed that peak twist developed near the end of systole. Peak LV twist was significantly higher in patients with hypertension than normal controls （P〈0.001）. The diastolic untwisting mainly occurred in early diastole （=38%）. Compared with normal controls, untwisting rate （Untw R） in patients with hypertension was significantly reduced （P〈0.001）, and untwisting half-time （UHT） was significantly delayed （P〈0.05）. This study demonstrated that STI has a potential ability to evaluate the early change of heart function in patients with hypertension by measuring the twist of LV.

Assessment of Age-related Changes in Left Ventricular Twist by Two-dimensional Ultrasound Speckle Tracking Imaging

To assess the normal value of left ventricular twist （LVtw） and examine the changes with normal aging by 2-dimensional ultrasound speckle-tracking imaging （STI）, 121 healthy volunteers were divided into three age groups： a youth group （19-45 y old）, a middle-age group （46-64 y old ） and an old-age group （≥65 y old）. Basal and apical short-axis images of left ventricular were acquired to analyse LV rotation （LVrot） and LVrot velocity. LVtw and LVtw velocity was defined as apical LVrot and LVrot velocity relative to the base. Peak twist （Ptw）, twist at aortic valve closure （AVCtw）, twist at mitral valve opening （MVOtw）, untwisting rate （UntwR）, half time of untwisting （HTU）, peak twist velocity （PTV）, time to peak twist velocity （TPTV）, peak untwisting velocity （PUV）, time to peak untwisting velocity （TPUV） were separately measured. The results showed that the normal LV performs a wringing motion with a clockwise rotation at the base and a counterclock- wise rotation at the apex （as seen from the apex）. The LVtw velocity showed a systolic counterclockwise twist followed by a diastolic clockwise twist. Peak twist develops near the end of systole （96%±4.2% of systole）. With aging, Ptw, AVCtw, MVOtw, HTU and PUV increased significantly （P〈0.05） and UntwR decreased significantly （P〈0.05）. However, no significant differences in TPUV, PTV and TPTV were noted among the 3 groups （P〉0.05）. It is concluded that LV twist can be measured non-invasively by 2-dimensional ultrasound STI imaging. The age-related changes of LVtw should be fully taken into consideration in the assessment of LV function.

Assessment of Left Ventricular Radial Deformation by Speckle Tracking Imaging

The left ventricular radial strain in the inner and outer layers was evaluated by using two-dimensional speckle tracking imaging （2DS）. Twenty-five piglets were studied. The short axis views were acquired. Peak systolic radial strain was measured from 6 circumferential points related to 6 standard segments in the inner and outer layers respectively using 2DS methods. The peak positive first derivative （dp/dt） of left ventricular pressure was compared to the radial strain from 2DS. The inner band showed higher peak radial strain values as compared to the outer band at all of the segments （P〈0.0001）, but the differences had significance just in anteroseptal, posterior, inferior and septal segments （P〈0.05）. Good correlation could be found between radial strain of inner and outer layers and peak dp/dt （P〈0.001）. These preliminary results showed that the degree of local deformation or wall thickening of the ventricular wall in its inner layer was more obvious than its outer layer. It is suggested that the 2DS technique is useful and sensitive for better understanding the regional and global myocar- dial motion and its relationship to the complex architecture of myocardium.

Evaluation of Left Ventricular Rotation and Twist Using Speckle Tracking Imaging in Patients with Atrial Septal Defect

Speckle tracking imaging （STI） was employed to investigate the effect of right ventricular （RV） volume and pressure overload on left ventricular （LV） rotation and twist in 35 patients with atrial septal defect （ASD）, 18 of which with pulmonary hypertension, and 21 healthy subjects serving as controls. The peak rotations of 6 segments at the basal and apical short-axises and the average peak rotation and interval time of the 6 segments in the opposite direction during early systolic phase were measured respectively. LV twist versus time profile was drawn and the peak twist and time to peak twist were calculated. LV ejection fraction （EF） was measured by Biplane Simpson. Compared to ASD patients without pulmonary hypertension and healthy subjects, the peak rotations of posterior, inferior and postsept walls at the basal level were lower （P〈0.05）, and the average counterclockwise peak rotation of 6 segments at the basal level during early systolic phase was higher （P〈0.05）, and the average interval time was delayed （P〈0.05）. LV peak twist was also lower （P〈0.05）, and had a significant negative correlation with pulmonary arterial systolic pressure （r=-0.57, P=0.001）. No significant differences were found in LVEF among the three groups. It was suggested that although RV volume overload due to ASD has no significant effects on LV rotation and twist, LV peak twist is lower in ASD patients with pulmonary hypertension. Thus LV twist may serve as a new indicator of the presence of pulmonary hypertension in ASD patients.

Assessment of left ventricular torsion in patients with anterior wall myocardial infarction before and after revascularization using speckle tracking imaging

Background Rotation of the left ventricular （LV） apex to the base, or LV torsion, is related to myocardial contractility and structure and has recently been recognized as a sensitive indicator of cardiac performance, but it has been difficult to measure. The recent development of 2-dimensional （2D） speckle tracking imaging （STI） may provide a powerful means of assessing LV torsion. This study was conducted to evaluate the global and regional LV twist in patients with anterior wall myocardial infarction （AMI） disease before and after revascularization by STI. Methods 2D STI was performed in 35 AMI patients before and one month after revascularization, as well as in 32 normal controls. Left ventricular global and regional rotations were obtained at basal and apical short-axis levels; LV torsion was defined as apical rotation relative to the base. The time sequences were normalized to the percentage of systolic and diastolic duration. Results Before revascularization, LV peak regional and global torsion in patients with AMI were significantly reduced as the result of reduced apical and basal rotation relative to those of normal control group （all P〈0.001）; most significantly in the anterior and anterior-septal regions （P 〈0.001）; one month after revascularization, there were significant changes in peak rotation at either the base or apex relative to pre-revascularization values （all P 〈0.001）. Similarly, peak regional and global LV torsion were increased significantly （all P 〈0.001）. Global torsion inversely correlated with EDV （r=-0.605, P=0.028） and ESV （r=-0.638, P=0.019）; and positively correlated with LVEF （r=0.630, P=-0.021）. Tight relations were also found between torsion and LV longitudinal and short axis function. Conclusions Systolic torsion was decreased in AMI patients. Revascularization therapy can improve the LV function of the AMI patients. STI has a potential to quantify left ventricular global and segment torsion in patients with AMI, and may make the assessment more available in clinical and research cardiology.

Evaluation of left ventricular systolic dyssynchrony by two-dimensional speckle tracking imaging and real-time three-dimensional echocardiography

Background Two-dimensional speckle tracking imaging （2D-STI） and real-time three-dimensional echocardiography （RT-3DE） have more advantages in evaluating left ventricular （LV） systolic dyssynchrony than traditional echocardiographic techniques. The study aimed to evaluate LV dyssynchrony parameters by both 2D-STI and RT-3DE, and the correlation between these two techniques. Methods A total of 43 chronic heart failure （CHF） patients and 27 healthy volunteers were enrolled. There were 23 dyssynchrony parameters selected to evaluate left ventricular systolic synchronization, involving 15 from 2D-STI and 8 from RT-3DE. Results Few of the dyssynchrony parametersshowednegative correlations with LV ejection fraction （LVEF） in the CHF group. The difference between time to peak-systolic radial strain of the anteroseptal and posterior segments at the level of papillary muscles [AS-P（RS）] from 2D-STI showed positive correlations with parts of the parameters from RT-3DE （P 〈 0.05）. Conclusions LV systolic dysfunction does not correlate with dyssynchrony. Moreover, there is a weak association between 2D-STI and RT-3DE in assessment of left ventricular dyssynchrony.

Two-dimension speckle tracking imaging assessment of right ventricular function in patients with acute inferior and anterior myocardial infarction

Background Acute inferior and anterior myocardial infarction often leads to right ventricular （RV） function decrease. Estimation of RV function is challenging due to the complex RV geometry. Few studies have been conducted to investiogate the effects of acute myocardial infarction （AMI）on right ventricular functions （RVFs）. Two-dimension Speckle Tracking Imaging （STI） is a novel method that allows for a segment based measurement of myocardial deformation and may have the potential to quantify RV dysfunction more precisely than the conventional parameters of RV function. Therefore, in this study we analyzed the RV function in AMI patients by using this novel technique. Methods Thirty-four patients with acute inferior myocardial infarction （AIMI）, 31 patients with acute anterior myocardial infarction （AAMI and 30 agematched healthy individuals were enrolled for the study. 2D speckle tracking imaging （STI） was used to obtain 2D imaging at the apical fourchamber view under rest condition. Peak systolic strains and strain rates of all segments in right ventricular free wall were analyzed. Results Compared to the normal control group, longitudinal peak systolic strain （e）, strain rate （SRs）, early diastolic strain rate （SRe） and late diastolic strain rate （SRa） in all segments of right ventricular free wall were significantly lower in AMI patients, e, SRs, SRe and SRa of each segment of RV in the AIMI group were decreased significantly than those of the normal control group （P 〈 0.05）. e, SRs, SRe and SRa of each segment of RV in the AAMI group were lower than these in the control group. Except for basal segmental SRa, there were significant differences among other parameters （P 〈 0.05）. Conclusions RVFs are impaired in AMI patients. RVFs could be accurately and sensitively assessed with STI.

Left Ventricular Systolic Strain of the Cardiac Allograft Evaluated with Three-dimensional Speckle Tracking Echocardiography

Three-dimensional speckle tracking echocardiography was employed to evaluate the changes of left ventricular systolic strain in 23 heart transplant recipients at 1 st, 3rd, 6th and 12th month after heart transplantation, and 23 healthy subjects served as controls. The three-dimensional full-volume echocardiographic images of left ventricle were recorded and then were analyzed using EchoPAC software. The strain curves and peak systolic strain values for each segment and overall left ventricular wall were obtained. Left ventricular global peak longitudinal strain （GPSL）, global peak radial strain （GPSR）, global peak circumferential strain （GPSC） and global peak area strain （GPSA） were measured and then statistically analyzed. There were no significant differences in left ventricular ejection fraction （LVEF） and cardiac output （CO） between heart transplant recipients and controls. The GPSL in heart transplant recipients at 1st month after surgery was significantly lower than that in controls, but close to the normal value at 3rd month after surgery and later. The GPSC, GPSA and GPSR were significantly lower in heart transplant recipients at 1 st, 3rd, 6th and 12th month after surgery than those in controls. It is suggested that three-dimensional speckle tracking echocardiography can be used for monitoring changes of left ventricular systolic strains and evaluating left ventricular systolic function in cardiac allograft.

Assessment of diaphragmatic function by ultrasonography:Current approach and perspectives

This article reports the various methods used to assess diaphragmatic function by ultrasonography.The excursions of the two hemidiaphragms can be measured using two-dimensional or M-mode ultrasonography,during respiratory maneuvers such as quiet breathing,voluntary sniffing and deep inspiration.On the zone of apposition to the rib cage for both hemidiaphragms,it is possible to measure the thickness on expiration and during deep breathing to assess the percentage of thickening during inspiration.These two approaches make it possible to assess the quality of the diaphragmatic function and the diagnosis of diaphragmatic paralysis or dysfunction.These methods are particularly useful in circumstances where there is a high risk of phrenic nerve injury or in diseases affecting the contractility or the motion of the diaphragm such as neuro-muscular diseases.Recent methods such as speckle tracking imaging and ultrasound shear wave elastography should provide more detailed information for better assessment of diaphragmatic function.

Clinical utility of left atrial strain in predicting atrial fibrillation recurrence after catheter ablation: An up-to-date review

Rhythm control is the core part of the integrated management of atrial fibrillation(AF),especially in the early stages.Despite advances in catheter ablation(CA),the recurrence rate of AF after CA remains high.As a result,stratification and early management of AF recurrence after CA are critical.Currently,predictors of recurrence of AF after CA are mostly based on dysfunction caused by structural remodeling,apart from traditional risk factors.Atrial strain is a recently developed important parameter for detecting the deformability of atrial myocardium during the cardiac cycle prior to atrial remodeling.Although there is only preliminary evidence,atrial strain is still a promising parameter in predicting the recurrence of AF after CA at an early stage.This review focuses on the evaluation of atrial strain,the current applications of atrial strain in assessing atrial function,and predicting the recurrence of AF after CA.We summarize the contents related as follows:(1)CA for rhythm control in AF;(2)Evaluation methods of atrial strain;(3)Atrial strain in the remodeling and reverse remodeling of AF;and(4)Clinical applications of atrial strain in predicting the recurrence of AF after CA.Although there is accumulating evidence on the role of decreased atrial strain in the early prediction of AF recurrence,atrial strain is limited in clinical practice for lacking exact cut-off values and difficulty in distinguishing specific function phases of the atrium.More research is needed in the future to add strength to the early prediction value of atrial strain in AF recurrences.

Evaluation of cardiac function in patients with arrhythmogenic right ventricular cardiomyopathy by echocardiography

Background Arrhythmogenic right ventricular cardiomyopathy （ARVC） mainly performs local myocardial abnormal movements and tissue Doppler and spot tracking technique can accurately reflect myocardial movement. However, the technique is still rarely used in research of ARVC. Methods The study enrolled 28 ARVC patients and 28 normal controls. Right ventricular parameters were measured by two-dimensional echocardiography, tissue Doppler imaging, speckle tracking imaging in order to compare the difference between two groups. Results Morphological indices （right ventricular inflow tract inner diameter and right ventricular outflow tract inner diameter） and functional indices （right ventricular peak S＇, right ventricular E＇/ A＇ ratio, tricuspid annular plane systolic excursion, right ventricular fractional area change and right ventricular inferior and lateral wall longitudinal strain） showed significant difference between the ARVC group and control group. All the above-mentioned indices were analyzed by receiver operating characteristic curve （ROC curves）. Area under the curve （AUC） of right ventricular inferior wall longitudinal strain was the largest one （AUC = 0.94） with an optimal cutoff value of -19.5%. Conclusion Compared with two- dimensional echocardiography and tissue Doppler imaging, right ventricular inferior wall longitudinal strain is a more sensitive predictor for changes of ARVC.