Peak Left Ventricular Torsion Research Articles

Left ventricular rotational deformation changes by speckle tracking imaging before and 24hours after transcatheter closure of large secundum atrial septal defects in children.

Large atrial septal defects (ASDs) in children cause increased volume overload of the right side of the heart which in turn lead to impairment of left ventricular (LV) performance. The aim of this study was to evaluate immediate LV rotational deformation changes in children with large ASDs post-device closure and removal of right ventricle (RV) volume overload. Twenty children who underwent transcatheter closure (TCC) of large secundum ASDs were included in the study. LV rotational deformation was assessed pre- and 24hours post-device closure using speckle tracking imaging (STI). 55% were females with mean age 6.1±3.5years. LV peak basal clockwise rotation improved significantly (-6.9±2.6° before vs -10.3±4.1° after TCC, P=.005), and time to peak clockwise rotation (345.1±124.7 milliseconds (ms) before vs 282.2±82.9ms after closure, P=.02). There was no significant difference in apical rotational parameters including peak counterclockwise rotation (P>.05 for both). LV twist (11.3±3.8° before vs 17.5±7.1° after closure, P=.001) and torsion (2.1±0.7°/cm before vs 3.1±1.2°/cm after closure, P=.01) were significantly improved, mainly as the result of improvement of LV basal rotation. LV revealed a significant increase in LV end-diastolic volumes (P=.02) 24hour after TCC with no significant change (P>.05) in end-systolic volumes after closure. Increased peak LV twisting and torsion were attributed to the improved peak systolic clockwise basal rotation after TCC of large ASDs in children.

Left Ventricular Torsion Deformation in Atrial Septal Defect Patients Undergoing Transcatheter Device Closure

Introduction: Atrial septal defects (ASD) considered being one of the known congenital heart diseases. ASD causes increased volume overload of the right heart. The purpose of this study was to evaluate left ventricular (LV) torsion deformation in ASD patients undergoing transcatheter device closure.Methods: All adult patients who underwent transcatheter device closure with ostium secundum ASD were included in the study. We assessed LV torsion in ostium secundum ASD patient’s pre and post device closure by using speckle tracking echocardiography.Results: A total of 37 patients (22 females and 15 males) were included in this study. The average age was 28 ± 19 years. LV peak basal rotation improved significantly (P = 0.028) in post transcatheter closure. LV torsion (2.88 ± 0.99˚/cm before vs. 3.40 ± 1.41˚/cm after closure, P = 0.009) and twisting (15.12 ± 4.69˚ before vs. 17.95 ± 6.21˚ after closure, P = 0.005) were statistically significant in post transcatheter closure. Volumetric assessment of LV including end-diastolic volume and systolic volume showed significant improvement (P = 0.02, P < 0.01) post device closure.Conclusions: The increased peak LV twisting and torsion was mainly attributed to the improved peak systolic clockwise rotation after ASD device closure. The LV twisting at a younger age was improved after the closure of ASD.

Blood pressure is normal, but is the heart?

There is no detailed strain analysis of cardiac functions in treated hypertensive pediatric patients. The aim of this study was to evaluate the cardio-protective effects of different drug classes in treated pediatric hypertensive patients. Sixty non-obese-treated hypertensive patients with preserved left ventricular (LV) systolic function and 45 age-, sex-, and body mass index-matched healthy subjects underwent clinical evaluation, including 24-h ambulatory blood pressure monitoring, standard echocardiographic examination, tissue Doppler imaging, and two-dimensional Speckle Tracking Echocardiography. The patients were divided into two subgroups based on the effects of the drugs on the Renin Angiotensin Aldosterone System. The subgroup hypertension (HT) 1 received angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, and HT 2 subgroup received calcium channel blocker, β-blocker, or diuretics. There was no difference between the two groups and subgroups with respect to clinical, demographic, ABPM, ventricular volumes, ejection fraction, and tissue Doppler imaging (TDI) parameters. For patients and controls, respectively, global longitudinal strain was - 18.70 ± 3.41 versus - 21.01 ± 3.82 (P < 0.001), and global radial strain was 40.6 ± 9.8 versus 54.8 ± 12.8 (P = 0.004). Peak LV twist and peak LV torsion were not significantly different. The patient subgroup analyses with each other revealed no difference in systolic and diastolic myocardial deformation properties. Strain parameters were reduced in all treated hypertensive children compared to normotensive children, and the various cardiac mechanic parameters were similarly abnormal no matter what type of antihypertensive agent was used.

Cardiac Rotational Mechanics As a Predictor of Myocardial Recovery in Heart Failure Patients Undergoing Chronic Mechanical Circulatory Support: A Pilot Study.

Impaired qualitative and quantitative left ventricular (LV) rotational mechanics predict cardiac remodeling progression and prognosis after myocardial infarction. We investigated whether cardiac rotational mechanics can predict cardiac recovery in chronic advanced cardiomyopathy patients. Sixty-three patients with advanced and chronic dilated cardiomyopathy undergoing implantation of LV assist device (LVAD) were prospectively investigated using speckle tracking echocardiography. Acute heart failure patients were prospectively excluded. We evaluated LV rotational mechanics (apical and basal LV twist, LV torsion) and deformational mechanics (circumferential and longitudinal strain) before LVAD implantation. Cardiac recovery post-LVAD implantation was defined as (1) final resulting LV ejection fraction ≥40%, (2) relative LV ejection fraction increase ≥50%, (iii) relative LV end-systolic volume decrease ≥50% (all 3 required). Twelve patients fulfilled the criteria for cardiac recovery (Rec Group). The Rec Group had significantly less impaired pre-LVAD peak LV torsion compared with the Non-Rec Group. Notably, both groups had similarly reduced pre-LVAD LV ejection fraction. By receiver operating characteristic curve analysis, pre-LVAD peak LV torsion of 0.35 degrees/cm had a 92% sensitivity and a 73% specificity in predicting cardiac recovery. Peak LV torsion before LVAD implantation was found to be an independent predictor of cardiac recovery after LVAD implantation (odds ratio, 0.65 per 0.1 degrees/cm [0.49-0.87]; P=0.014). LV rotational mechanics seem to be useful in selecting patients prone to cardiac recovery after mechanical unloading induced by LVADs. Future studies should investigate the utility of these markers in predicting durable cardiac recovery after the explantation of the cardiac assist device.

Left ventricular torsion assessed by two‐dimensional echocardiography speckle tracking as a predictor of left ventricular remodeling and short‐term outcome following primary percutaneous coronary intervention for acute myocardial infarction: A single‐center experience

Left ventricular (LV) torsion is a novel method to assess systolic LV function. This study aimed at exploring the utility of 2D speckle tracking-based assessment of left ventricular torsion in patients with acute myocardial infarction (AMI) undertaking primary percutaneous intervention (pPCI) in predicting left ventricular remodeling. The study included 115 patients (mean±SD, age 52.2±9.67, males 84.3%) who underwent pPCI for AMI. Echocardiographic assessment of LV torsion by two-dimensional speckle tracking was performed early after the index pPCI. Patients underwent repeat echocardiography at 6months to detect remodeling. LV torsion in the acute setting was significantly lower in those who demonstrated LV remodeling at follow-up compared to those without remodeling (7.56±1.95 vs 15.16±4.65; P<.005). Multivariate analysis identified peak CK & CK-MB elevation (β=-0.767 and -0.725; P<.001), SWMA index (β=-0.843; P<.001), and Simpson's derived LV ejection fraction (LVEF; β=0.802; P<.001) as independent predictors of baseline LV torsion. It also identified peak LV torsion (β: 0.27; 95% CI: 0.15-0.5, P=.001) and SWMA index (β:1.07, 95% CI: 1.03-1.12, P=.005) as independent predictors of LV remodeling. Baseline Killip's grades II and higher (β: 48.6; 95% CI 5.5-428, P<.001) and diabetes mellitus (β: 29.7; 95% CI 1.1-763, P<.05) were independent predictors of mortality. Left ventricular torsion in acute MI setting is impaired and predicts subsequent LV remodeling at 6-month follow-up.

Decrease of Cardiac Base Rotation in 2D Speckle Tracking Indicates Drug-induced Cardiomyopathy After Chemotherapy in Children With Cancer.

Drug-induced cardiomyopathy can be life-threatening in patients with cancer. Our objective was to explore early detection of drug-induced cardiomyopathy in children with cancer. We enrolled pediatric outpatients diagnosed with cancer between 2012 and 2013. In addition, we recruited pediatric outpatients in good general condition without cardiac disease or cancer, as controls. We measured the serum levels of biomarkers and performed chest radiography, electrocardiography, and ultrasound cardiography (UCG). We analyzed left ventricular (LV) torsion and torsion-related parameters using 2-dimensional (2D) speckle tracking on UCG. In total, 35 pediatric patients were enrolled. All patients showed negative findings for plasma troponin T, radiography, and electrocardiography. During 2D speckle tracking, 9 patients were excluded due to inappropriate dynamic echo images. We compared UCG findings between 26 patients and 16 controls. Although there was no difference in ejection fraction between patients and controls, peak LV torsion tended to be lower in patients than in controls, and the absolute basal rotation value at the timing of peak LV torsion was significantly lower in patients than in controls. In conclusion, a decrease of basal rotation in 2D speckle tracking might indicate the initial changes leading to myocardial disorder after chemotherapy.

Left ventricular shape and mass impact torsional dynamics in asymptomatic patients with chronic aortic regurgitation and normal left ventricular ejection fraction.

Chronic aortic regurgitation (AR) is associated with a unique pattern of left ventricular (LV) volume and pressure overload, leading to LV remodelling. LV torsional motion, a key component of LV performance, can be altered in this setting. We aimed to assess the impact of LV remodelling on LV torsional dynamics parameters using speckle-tracking echocardiography (STE) in asymptomatic AR patients. We prospectively enrolled 60 patients with chronic AR and LVEF > 50% and 55 healthy controls. LV rotation, twisting and untwisting were assessed using STE. Patients with AR had higher LV diameters, volumes and mass, a more spherical LV shape than controls, but similar LVEF. In AR patients we found reduced peak LV apical rotation and decreased (2.1 ± 0.8 vs 2.9 ± 0.9°/cm, p < 0.001) and delayed (time to peak LV twist: 0.94 ± 0.12 vs 0.99 ± 0.09, p = 0.004) peak LV torsion. Also, peak LV untwisting velocity was decreased (-123.5 ± 41.5 vs -152.3 ± 55.0°/s, p = 0.002) due to lower peak LV apical diastolic rotation rate. LV shape influenced LV torsional dynamics, a more spherical LV displaying reduced peak LV apical rotation and diastolic rotation rate and decreased LV twist. A more hypertrophied LV had a lower peak LV torsion, peak LV apical diastolic rotation rate and peak LV untwisting velocity. LV apical rotation and torsion are decreased and LV twist is delayed in patients with chronic AR and normal LVEF, detecting early subclinical LV dysfunction before LVEF declines. Also, LV untwisting is reduced in these patients. LV remodelling impairs LV torsional dynamics parameters in this setting.

Altered ventricular torsion and transmural patterns of myocyte relaxation precede heart failure in aging F344 rats

The purpose of this study was to identify and explain changes in ventricular and cellular function that contribute to aging-associated cardiovascular disease in aging F344 rats. Three groups of female F344 rats, aged 6, 18, and 22 mo, were studied. Echocardiographic measurements in isoflurane-anesthetized animals showed an increase in peak left ventricular torsion between the 6- and the 18-mo-old groups that was partially reversed in the 22-mo-old animals (P < 0.05). Epicardial, midmyocardial, and endocardial myocytes were subsequently isolated from the left ventricles of each group of rats. Unloaded sarcomere shortening and Ca(2+) transients were then measured in these cells (n = >75 cells for each of the nine age-region groups). The decay time of the Ca(2+) transient and the time required for 50% length relaxation both increased with age but not uniformly across the three regions (P < 0.02). Further analysis revealed a significant shift in the transmural distribution of these properties between 18 and 22 mo of age, with the largest changes occurring in epicardial myocytes. Computational modeling suggested that these changes were due in part to slower Ca(2+) dissociation from troponin in aging epicardial myocytes. Subsequent biochemical assays revealed a >50% reduction in troponin I phosphoprotein content in 22-mo-old epicardium relative to the other regions. These data suggest that between 18 and 22 mo of age (before the onset of heart failure), F344 rats display epicardial-specific myofilament-level modifications that 1) break from the progression observed between 6 and 18 mo and 2) coincide with aberrant patterns of cardiac torsion.

Obesity reduces left ventricular strains, torsion and synchrony in mouse models: a cine DENSE MRI study

Left ventricular sub-epicardial strain was significantly lower in the obese mice with a 40% reduction in circumferential strain (p<0.001), a 19% reduction in longitudinal strain (p=0.03), and a 53% reduction in radial strain (p=0.06). By contrast, left ventricular sub-endocardial strain was modestly reduced in the obese mice in the circumferential direction by 12% (p=0.01), and not significantly different in the radial (p=0.63) or longitudinal (p=0.44) directions. Peak left ventricular torsion was reduced by 34% in the obese mice (p=0.06). Finally, the radial uniformity of strain index showed a reduction in the synchrony of contraction in the left ventricle (p=0.01) with a time delay in the septal to free wall direction.

Abstract 9351: Left Ventricular Torsion is Preload Dependent. A Study in Healty Volunteers After Blood Donation

Introduction: Left ventricular (LV) rotation plays an important role in LV contraction and relaxation. Hypothesis: Aim of this study is to investigate preload effect on LV torsion in normal volunteers of blood donation. Methods and Results: LV end-diastolic volume, LV apical and basal rotation, peak systolic LV Torsion were measured by speckle-tracking echocardiography in normal volunteers (n=26) before and after 450ml blood donation.Blood donation led to a significant decrease in end-diastolic LV internal diameter (48.7 + 0.4 versus 46.4+0.4 mm; P&lt;0.001) and cardiac output (6.2 + 1.0 versus 5.1+ 0.7 L/min; P&lt;0.001). There was a significant decrease in the magnitude of peak systolic apical rotation (4.4 +1.9° versus 2.9 + 1.5°; P&lt;0.001) but no change in basal rotation (2.6 +1.4° versus 2.7+ 1.6°; P=0.81). Peak systolic LV Torsion decreased after blood donation (6.9 +1.9 ° versus 5.7+2.1°; P=0.028). Conclusions: LV apical and peak systolic LV torsion are preload dependent. Preload changes should be considered when interpreting LV torsion

Left Ventricular Rotational Dynamics in Beta Thalassemia Major: A Speckle-Tracking Echocardiographic Study

Iron-mediated cardiomyopathy is the leading cause of death in patients with thalassemia major (TM). The identification of subclinical cardiac involvement in the early phases of the disease is important to optimize therapeutic strategies. The aim of this study was to identify early markers of cardiac dysfunction through new parameters of cardiac rotational dynamics and to look for a relationship with parameters of iron overload. Twenty-seven asymptomatic patients with TM and 27 healthy control subjects were prospectively enrolled. All subjects underwent standard echocardiography and subsequent offline analysis to assess left ventricular (LV) rotation and longitudinal mechanics using speckle-tracking echocardiography. In all patients with TM, ferritin levels were measured, and a subgroup underwent cardiac magnetic resonance imaging. All subjects had normal parameters of cardiac function, although patients with TM showed significantly lower S' values (P= .030) and E' values (P= .025), with increased E/E' ratio (P= .003) and indexed left atrial volumes (P= .022). Compared with controls, patients with TM had significantly reduced systolic apical rotation (P= .006), LV twist (P= .002), and LV torsion (P= .001). Systolic and diastolic rotational peak velocities at the apical level were also significantly decreased in the TM group (P= .003 and P= .011, respectively) with reductions of twisting and untwisting rates (P= .003 and P= .001, respectively). Patients with TM also showed a significant reduction of longitudinal displacement from the two-chamber apical view (P= .042) but preserved longitudinal strain and strain rate. Patients with T2* values > 20 msec had preserved rotational function, while those with T2* values < 20 msec showed significantly lower mean values of LV peak basal systolic rotation (-3.1 ± 1.4° vs -6.2 ± 2.6°, P= .016), LV peak apical systolic rotation (3.4 ± 1.3° vs 6.4 ± 3.1°, P= .045), LV twist (4.8 ± 2.5° vs 10.9 ± 4.9°, P= .012), and LV torsion (0.6 ± 0.2°/cm vs 1.4 ± 1.6°/cm, P= .010). LV torsion was negatively related to ferritin levels (r= -0.47, P= .013) and directly to T2* values (r= 0.64, P= .007). LV rotational dynamics in asymptomatic patients with TM are negatively related to iron overload. Rotational function of the left ventricle is preserved in patients with normal T2* values. These new parameters are useful for an early diagnosis of cardiac involvement.

Left Ventricular Twisting and Untwisting Motion in Childhood Cancer Survivors

Anthracycline has been shown to degrade titin that plays a role in myocardial twisting and untwisting. This study aimed to test the hypothesis that left ventricular (LV) twisting and untwisting motion may be altered in children after anthracycline therapy. Thirty-six childhood leukemia survivors aged 15.6 ± 5.5 years and 20 healthy controls aged 16.8 ± 7.7 years (P = 0.54) were studied. LV twisting and untwisting motion was determined using speckle tracking imaging, whereas LV ejection fraction and systolic and diastolic mitral annular velocities were determined respectively by three-dimensional and tissue-Doppler echocardiography. Compared with controls, patients had significantly lower LV ejection fraction (P = 0.01) but similar systolic and diastolic mitral annular velocities (all P > 0.05). Their peak LV torsion (P = 0.003), systolic twisting velocity (P < 0.001), and diastolic untwisting velocity (P = 0.04) were significantly lower than controls, which could be attributable to their reduced apical rotation (P = 0.03) and apical untwisting rate (P = 0.002). For the whole cohort, LV systolic torsion and twisting velocity correlated significantly with apical untwisting rate (P < 0.001) and LV diastolic untwisting velocity (P < 0.001). In patients, none of the twisting or untwisting parameters were found to correlate with cumulative anthracycline dose (all P > 0.05). Twenty-eight (78%) patients had LV ejection fractions ≥50%. Although their systolic and diastolic mitral annular velocities were similar to those of controls, their peak LV torsion (P = 0.005), apical untwisting rate (P = 0.01), and LV systolic twisting velocity (P = 0.001) remained significantly lower. Impairment of LV twisting and untwisting motion is evident in children after anthracycline therapy, even in those with "normal" LV ejection fractions.

Reduced Left Ventricular Torsion Early After Myocardial Infarction Is Related to Left Ventricular Remodeling

Left ventricular (LV) torsion is emerging as a sensitive parameter of LV systolic myocardial performance. The aim of the present study was to explore the effects of acute myocardial infarction (AMI) on LV torsion and to determine the value of LV torsion early after AMI in predicting LV remodeling at 6-month follow-up. A total of 120 patients with a first ST-segment elevation AMI (mean+/-SD age, 59+/-10 years; 73% male) were included. All patients underwent primary percutaneous coronary intervention. After 48 hours, speckle-tracking echocardiography was performed to assess LV torsion; infarct size was assessed by myocardial contrast echocardiography. At 6-month follow-up, LV volumes and LV ejection fraction were reassessed to identity patients with LV remodeling (defined as a > or =15% increase in LV end-systolic volume). Compared with control subjects, peak LV torsion in AMI patients was significantly impaired (1.54+/-0.64 degrees /cm vs 2.07+/-0.27 degrees /cm, P<0.001). By multivariate analysis, only LV ejection fraction (beta=0.36, P<0.001) and infarct size (beta=-0.47, P<0.001) were independently associated with peak LV torsion. At 6-month follow-up, 19 patients showed LV remodeling. By multivariate analysis, only peak LV torsion (odds ratio=0.77; 95% CI, 0.65-0.92; P=0.003) and infarct size (odds ratio=1.04; 95% CI, 1.01-1.07; P=0.021) were independently related to LV remodeling. Peak LV torsion provided modest but significant incremental value over clinical, echocardiographic, and myocardial contrast echocardiography variables in predicting LV remodeling. By receiver-operating characteristics curve analysis, peak LV torsion < or =1.44 degrees /cm provided the highest sensitivity (95%) and specificity (77%) to predict LV remodeling. LV torsion is significantly impaired early after AMI. The amount of impairment of LV torsion predicts LV remodeling at 6-month follow-up.

Normal Rotational, Torsion and Untwisting Data in Children, Adolescents and Young Adults

Left ventricular (LV) torsion and untwisting are important components of LV performance, but there is little information on the effect of age, particularly in younger populations. LV rotation and LV rotation rate, torsion, recoiling, and untwisting were measured in normal subjects (n=111) aged 3 to 40 years (mean age, 19.3 years) using speckle-tracking imaging. LV torsion increased with age because of the augmentation of apical LV rotation, but this disappeared when normalized by LV length. Although peak LV torsion and apical LV rotation increased with age, the normalized peak torsion rate decreased. As well, the peak untwisting rate decreased with age and was enhanced when normalized by LV length. Younger hearts demonstrated greater untwisting and recoiling of the apex during isovolumic relaxation and early diastole. The time difference between apical and basal events decreased with advancing age. The heart maintains a constant LV torsion and LV rotation profile when normalized by length and cardiac cycle. Younger hearts tend to twist, untwist, and deform faster.

Left ventricular torsion and untwisting during exercise in heart transplant recipients

Left ventricular (LV) rotation is the dominant deformation during relaxation and links systole with early diastolic recoil. LV torsion and untwisting rates during submaximal exercise were compared between heart transplant recipients (HTRs), young adults and healthy older individuals to better understand impaired diastolic function in HTRs. Two dimensional and colour M-mode echocardiography with speckle-tracking analysis were completed in eight HTRs (age: 61 +/- 9 years), six recipient age-matched (RM, age: 60 +/- 11 years), and five donor age-matched (DM, age: 35 +/- 8 years) individuals (all males) at rest and during submaximal cycle exercise. LV peak torsion, peak rate of untwisting and peak intraventricular pressure gradients (IVPGs) were examined. LV torsion increased with exercise in DMs (6.5 +/- 5.6 deg, P < 0.05), but not in RMs (-2.6 +/- 7.0 deg) or HTRs (-0.9 +/- 4.4 deg). The change from rest to exercise in the peak rate of untwisting was significantly greater for DMs (-2.1 +/- 0.5 rads s(-1), P < 0.05) compared to RMs (-0.7 +/- 1.3 rads s(-1)) and HTRs (-0.2 +/- 0.9 rads s(-1)). The amount of untwisting occurring prior to mitral valve opening substantially declined with exercise in RMs and HTRs only. The change in IVPGs was 1.3-fold greater in DMs versus HTRs or RMs (P > 0.05). Peak LV torsion and untwisting are blunted during exercise in HTRs and RMs compared to DMs. These factors may contribute to the impaired diastolic filling found in HTRs during exercise. Similarities between HTRs and RMs during exercise suggest functional accelerated ageing of the cardiac allograft.

Effect of Mechanical Dyssynchrony and Cardiac Resynchronization Therapy on Left Ventricular Rotational Mechanics

Alterations in rotational mechanics can bring new aspects to the understanding of left ventricular (LV) dyssynchrony. The aims of this study were to investigate LV rotational mechanics in candidates for cardiac resynchronization therapy (CRT) and to assess the effect of CRT by speckle-tracking echocardiography. Fifty-four patients with heart failure and 33 healthy controls were studied. Thirty-three underwent CRT. Speckle tracking was applied to short- and long-axis views. Radial and longitudinal dyssynchrony were assessed as previously defined. Apical and basal rotations were measured as the average angular displacement about the LV central axis. LV twist and torsion were then calculated. Peak apical and basal rotation, peak LV twist and torsion, apical and basal rotation at aortic valve closure (AVC), and LV twist and torsion at AVC were significantly lower in patients than controls. Apical-basal rotation delay and AVC-to-peak LV twist interval were longer in patients and associated with decreased peak LV twist and LV twist at AVC, respectively. In patients, rotational indexes, particularly LV twist and torsion, were correlated strongly with radial dyssynchrony. LV torsion (cutoff 0.1 degrees /cm) and twist (cutoff 1 degrees ) at AVC had the highest sensitivity (90%) and specificity (77%) to predict CRT responders among all other parameters, including radial and longitudinal dyssynchrony. In conclusion, LV dyssynchrony is associated with discoordinate rotation of the apical and basal regions, which in turn significantly decreases peak LV twist and torsion and LV twist and torsion at AVC. CRT significantly restored the altered rotational mechanics in responders. These parameters have potential for predicting responders to CRT.

Age-Related Changes in Left Ventricular Torsion as Assessed by 2-Dimensional Ultrasound Speckle Tracking Imaging

Background and Objectives: The newly developed 2-dimensional ultrasound speckle tracking imaging (2D-STI) has enabled researchers to assess the changes of left ventricular (LV) rotation and torsion. The aims of the present study are to establish normal values and to examine the effect of advancing age on left ventricular torsion. Subjects and Methods: We enrolled 182 healthy persons in this study. After examined the standard clinical echocardiographic parameters, we obtained the degree of the LV rotation at the basal and apical levels of the short axis view with using a customized software program EchoPAC, GE. Results: Among the 182 healthy subjects, 109 healthy subjects were finally included (49 males and 60 females) due to the failure of obtaining reliable rotational patterns (feasibility: 59.8%). The basal and apical peak LV rotations during systole were 8.14±3.55 degrees and 8.48±3.70 degrees, respectively. The basal peak LV rotation and peak LV torsion had a tendency to increase with aging (r=0.277, p=0.004 and r=0.253, p=0.008, respectively). All the values of the basal LV rotation during systole tended to increase with aging. The apical LV rotation had no relationship with aging throughout the entire cardiac cycle. Conclusion: 2D-STI was a feasible methodology to measure the LV rotation. The peak LV torsion during systole shows statistically significant augmentation with advancing age, and this is mainly due to the increased basal LV rotation. (Korean Circ J 2008;38:529-535)

Maturational and Adaptive Modulation of Left Ventricular Torsional Biomechanics

Left ventricular (LV) torsional deformation, based in part on the helical myocardial fiber architecture, is an important component of LV systolic and diastolic performance. However, there is no comprehensive study describing its normal development during childhood and adult life. Forty-five normal subjects (25 children and 20 adults; aged 9 days to 49 years; divided into 5 groups: infants, children, adolescents, and young and middle-age adults) underwent assessment of LV torsion and untwisting rate by Doppler tissue imaging. LV torsion increased with age, primarily owing to augmentation in basal clockwise rotation during childhood and apical counterclockwise rotation during adulthood. Although LV torsion and untwisting overall showed age-related increases, when normalized by LV length, they showed higher values in infancy and middle age. The proportion of untwisting during isovolumic relaxation was lowest in infancy, increased during childhood, and leveled off thereafter, whereas peak untwisting performance (peak untwisting velocity normalized by peak LV torsion) showed a decrease during adulthood. We have shown the maturational process of LV torsion in normal subjects. Net LV torsion increases gradually from infancy to adulthood, but the determinants of this were different in the 2 age groups. The smaller LV isovolumic untwisting recoil during infancy and its decline in adulthood may suggest mechanisms for alterations in diastolic function.