Circumferential Function Research Articles

Left ventricular absolute myocardial work measured by cardiovascular magnetic resonance: a proof-of-concept

Abstract Background Myocardial Work Index (MWI) is a load-independent and non-invasive method for assessing cardiac systolic function [1]. However, MWI does not directly measure absolute myocardial work (AMW), since it does not consider the effect of variations in left ventricular (LV) wall thickness and regional wall curvature. Therefore, a direct comparison of MWI results may be difficult. Cardiovascular magnetic resonance (CMR) is the gold standard for assessing the LV geometry and therefore can be used to directly measure the AMW by calculating the area of the stress-strain curve. Purpose This study aims to measure and compare CMR-based AMW in three groups with different work profiles: healthy subjects, patients with ST-elevation myocardial infarction (STEMI), and patients with severe aortic valve stenosis (AS). Additionally, it aims to compare AMW with strain to provide additional insights into remodelling. Methods A total of 78 participants were included in our study; 38 healthy subjects from the CENS study [2], 19 STEMI patients 3-7 days post-PCI from the ASSAIL study [3], and 21 patients with AS scheduled for operation. Collected data were not adjusted for age or sex. Stress was estimated using Laplace’s equation [4]. Intra-ventricular pressure was calculated from brachial cuff pressure as previously described [5]. Mid-ventricular circumferential strain was calculated using CMR-based tissue phase mapping [4]. AMW was calculated both as Myocardial Work per unit endocardial Surface (MWS, in J/m^2) and per unit Mass (MWM, in mJ/g), both serving as measurements of global circumferential systolic function. Results Mean circumferential strain did not differ significantly between the AS and the healthy groups (p=0.37), but it was significantly lower in the STEMI group compared to the healthy group (p<0.001). MWS was significantly higher in the AS group (p<0.001) and lower in the STEMI group (p<0.001) compared the healthy group. This suggests that each unit of endocardial surface in the myocardium performed, on average, more work in the AS group and less work in the STEMI group relative to the healthy group. MWM was not significantly different between the AS and the healthy group (p=0.74), while in the STEMI group, it was significantly lower (p=0.001) than in healthy subjects. Conclusion Our results indicate that in patients with AS, the myocardium did more work per unit surface, while each gram of the myocardium did the same amount of work. This is likely due to concentric hypertrophy and the increase of afterload. In contrast, in patients with STEMI, the myocardium did, on average, less work per unit surface and per mass. This is expected due to the direct loss of mechanical function in the infarcted myocardium. Our results indicate that AMW enhances traditional strain analysis, improves myocardial function evaluation, and may provide deeper insight into myocardial remodeling in diverse cardiac conditions.

Multidirectional myocardial function in bicuspid aortic valve stenosis patients: a three-dimensional speckle tracking analysis.

The impact of aortic stenosis (AS) severity on multidirectional myocardial function in patients with bicuspid aortic valve (BAV) remains unclear, despite the recognized presence of early left ventricular longitudinal myocardial dysfunction in BAV patients with normal valve function. The aim of the study was to evaluate the multidirectional myocardial functions of BAV patients. A total of 86 BAV patients (age 46.71 ± 13.62 years, 69.4% men) with normally functioning (BAV-nf), mild AS, moderate AS, and severe AS with preserved left ventricular ejection fraction (LVEF ≥ 52%) were included. 30 healthy volunteers were recruited as the control group. Multidirectional strain and volume analysis were performed by three-dimensional speckle tracking echocardiography(3D-STE). Global longitudinal strain (GLS), and global radial strain (GRS) were reduced in BAV-nf patients compared with the controls. With each categorical of AS severity from BAV-nf to severe AS, there was an associated progressive impairment of GLS and GRS (all P < 0.001). Global circumferential strain (GCS) did not show a significant decrease from BAV-nf to mild AS but began to decrease from moderate AS. Multiple linear regressions indicated that indexed aortic valve area (AVA/BSA), as a measure of AS severity, was an independent determinant of GLS, GCS and GRS. Left ventricular longitudinal myocardial reduction is observed even in patients with well-functioning bicuspid aortic valves. With each categorical increase in the grade of AS severity from normally functioning to severe aortic stenosis, there was an associated progressive impairment of longitudinal myocardial function. Furthermore, circumferential myocardial function was starting damaged from moderate AS. AVA/BSA was independently associated with multidirectional myocardial function injuries.

Assessing heterogeneity on cardiovascular magnetic resonance imaging: a novel approach to diagnosis and risk stratification in cardiac diseases.

Cardiac disease affects the heart non-uniformly. Examples include focal septal or apical hypertrophy with reduced strain in hypertrophic cardiomyopathy, replacement fibrosis with akinesia in an infarct-related coronary artery territory, and a pattern of scarring in dilated cardiomyopathy. The detail and versatility of cardiovascular magnetic resonance (CMR) imaging mean it contains a wealth of information imperceptible to the naked eye and not captured by standard global measures. CMR-derived heterogeneity biomarkers could facilitate early diagnosis, better risk stratification, and a more comprehensive prediction of treatment response. Small cohort and case-control studies demonstrate the feasibility of proof-of-concept structural and functional heterogeneity measures. Detailed radiomic analyses of different CMR sequences using open-source software delineate unique voxel patterns as hallmarks of histopathological changes. Meanwhile, measures of dispersion applied to emerging CMR strain sequences describe variable longitudinal, circumferential, and radial function across the myocardium. Two of the most promising heterogeneity measures are the mean absolute deviation of regional standard deviations on native T1 and T2 and the standard deviation of time to maximum regional radial wall motion, termed the tissue synchronization index in a 16-segment left ventricle model. Real-world limitations include the non-standardization of CMR imaging protocols across different centres and the testing of large numbers of radiomic features in small, inadequately powered patient samples. We, therefore, propose a three-step roadmap to benchmark novel heterogeneity biomarkers, including defining normal reference ranges, statistical modelling against diagnosis and outcomes in large epidemiological studies, and finally, comprehensive internal and external validations.

Preservation of Circumferential and Radial Left Ventricular Function as a Mitigating Mechanism for Impaired Longitudinal Strain in Early Cardiac Amyloidosis

In patients with cardiac amyloidosis (CA), left ventricular ejection fraction (LVEF) is frequently preserved, despite commonly reduced global longitudinal strain (GLS). We hypothesized that nonlongitudinal contraction may initially serve as a mitigating mechanism to maintain cardiac output and studied the relationship between global circumferential (GCS) and radial (GRS) strain with LVEF and extracellular volume (ECV), a marker of amyloid burden. Patients with CA who underwent cardiac magnetic resonance (CMR; n=140, 70.7±11.5years, 66% male) or echocardiography (n=67, 71±13years, 66% male) and normal controls (CMR, n=20; echocardiography, n=45) were retrospectively identified, and GCS, GLS, and GRS were quantified using feature-tracking CMR or speckle-tracking echocardiography and compared between CA patients with preserved and reduced LVEF (CAHFpEF, CAHFrEF) and controls. The prevalence of impaired strain (magnitudes <2.5th percentile of the controls) was compared between CAHFpEF and CAHFrEF and between ECV quartiles. While echocardiography-derived GLS was impaired in both CAHFpEF (-13.4%±3.1%, P<.003) and CAHFrEF (-9.1%±3.2%, P<.003), compared with controls (-20.8%±2.4%), GCS was more impaired in CAHFrEF compared with both controls (-15.6%±5.0% vs -32.3%±3.3%, P<.003) and CAHFpEF (-30.4%±5.7%, P<.003) and did not differ between CAHFpEF and controls (P=.24). The prevalence of abnormal CMR-derived GCS (P<.0001) and GRS (P<.0001) but not GLS (P=.054) varied significantly across ECV quartiles. Among CA patients with preserved LVEF, preserved GCS and GRS, despite near-universally impaired GLS, may be explained by an initial predominantly subendocardial involvement, where mostly longitudinal fibers are located. If confirmed in future studies, these findings may facilitate identification of patients with early stages of CA, when treatments may be most effective.

Sacubitril/Valsartan Improves Left Atrial and Ventricular Strain and Strain Rate in Patients with Heart Failure with Reduced Ejection Fraction.

Data on the impact of sacubitril/valsartan (SV) therapy on phasic left atrial (LA) and left ventricular (LV) strain in heart failure with reduced ejection fraction (HFrEF) are limited. The aim of this study was to evaluate changes in two-dimensional speckle tracking (2D-STE) parameters with SV therapy in HFrEF patients. Prospective evaluation of HFrEF patients receiving optimized medical therapy. Two-dimensional speckle tracking (2D-STE) parameters were assessed at baseline and after 6 months of SV therapy. LA strain and strain rate (SR) in reservoir, conduit, and contraction phases were compared with LV longitudinal, radial, and circumferential strain and SR and stratified according to heart rhythm and HFrEF etiology. A total of 35 patients completed the 6-month follow-up, with a mean age of 59 ± 11 years, 40% in atrial fibrillation, 43% with ischemic etiology, and LVEF of 29 ± 6%. There were significant improvements in LA reservoir, conduit, and contractile strain and SR following SV therapy, particularly among patients in sinus rhythm. There were significant improvements in longitudinal, radial, and circumferential LV function indices. SV therapy in HFrEF was associated with improved longitudinal, radial, and circumferential function, particularly among patients in sinus rhythm. These findings can provide insights into the mechanisms underlying the improvement of cardiac function and help assess subclinical responses to the treatment.

Biomechanical effects of medial meniscus radial tears on the knee joint during gait: A concurrent finite element musculoskeletal framework investigation.

The biomechanical variation in the knee during walking that accompanies medial meniscal radial tears stemming from knee osteoarthritis (OA) has not been explored. This study introduced a finite element musculoskeletal model using concurrent lower limb musculoskeletal dynamics and knee joint finite element analysis in a single framework and expanded the models to include knees with medial meniscal radial tears and total medial meniscectomy. The radial tears involved three locations: anterior horn, midbody, and posterior horn with grades of 33%, 50%, and 83% of the meniscus width. The shear and hoop stresses of the tear meniscus and tibial cartilage contact load, accompanying tears, and postmeniscectomy were evaluated during the stance phase of the gait cycle using the models. In the 83% width midbody tear group, shear stress at the end of the tear was significantly greater than in the intact meniscus and other tear groups, and the maximum shear stress was increased by 310% compared to the intact meniscus. A medial meniscus radial tear has a much smaller effect on the tibial cartilage load (even though in the 83% width tear, the cartilage/total load ratio increased by only 9%). However, the contact force on the tibial cartilage with total postmeniscectomy was increased by 178.93% compared with a healthy intact meniscus, and the peak contact pressure after meniscectomy increased from 11.94 to 12.45 MPa to 17.64 and 13.76 MPa, at the maximum weight acceptance and push-off, respectively. Our study shows that radial tears with larger medial meniscus widths are prone to high stress concentrations at the end of the tears, leading to the potential risk of complete meniscal rupture. Furthermore, although the tears did not change the cartilage load distribution, they disrupted the circumferential stress-transmitting function of the meniscus, thus greatly increasing the likelihood of the onset of knee OA. The significant increase in the tibial cartilage load with total postmeniscectomy indicates a potential risk of OA flare-ups. This study contributes to a better understanding of meniscal tear-induced OA biomechanical changes during human activities and offers some potential directions for surgical guidance of meniscectomies and the prophylaxis and treatment of OA.

Dynamic Change of Left Ventricular Mechanics in Patients with Acute Myocarditis with Preserved Left Ventricular Systolic Function: A 2-Year Follow-up Study.

Acute myocarditis mimics acute coronary syndrome due to its clinical course and presentation. This study aimed to evaluate left ventricular longitudinal and circumferential functions during the acute phase and late phase of acute myocarditis with preserved left ventricular ejection fraction using 2-dimensional speckle tracking echocardiography. Forty-one consecutive acute myocarditis patients with preserved left ventricular ejection fraction confirmed by cardiac magnetic resonance imaging underwent 2-dimensional speckle tracking echocardiography within the first week of hospital admission. Findings were compared with age and sex-matched 40 healthy controls. Left ventricular mechanics of the study group were reevaluated by 2-dimensional speckle tracking echocardiography during follow- up (23.85 ± 6.65 months later). Myocardial lesions with late gadolinium enhancement on cardiac magnetic resonance imaging were mostly localized in the subepicardial layer (91.40%) and commonly observed in the inferolateral wall (42.94%). Consistent with the cardiac magnetic resonance imaging findings, 2-dimensional speckle tracking echocardiography showed the localization of the involved myocardial segments with prominent impairment in global longitudinal peak systolic strain and global circumferential strain of the inferolateral wall of the left ventricle. In the acute phase, global longitudinal peak systolic strain (-17.32 ± 2.02 vs -20.59 ± 2.38) and global circumferential strain (-22.33 ± 2.27 vs -24.85 ± 3.19) were found to be lower in patients with acute myocarditis compared to healthy controls (both P &lt; .001). While global circumferential strain was improved in the late phase compared with the acute phase (from -22.28 ± 2.32 to -22.90 ± 2.65; P = .003). Global longitudinal peak systolic strain was not significantly changed during follow-up (from -17.30 ± 2.09 to -17.62 ± 2.19; P = .072). Subtle left ventricular systolic function impairment can be detected by the 2-dimensional speckle tracking echocardiography technique in patients with acute myocarditis with preserved left ventricular ejection fraction and improvement in circumferential function could be observed during follow-up.

Acute impact of transcatheter edge-to-edge repair for mitral regurgitation on left ventricular function

Abstract Introduction Transcatheter Edge-to-Edge repair (TEER) for the therapy of mitral valve regurgitation (MR) is an alternative to surgery for high risk patients. It is a minimal invasive procedure but the acute impact of the pre- and afterload decrease, due to the reduction of both MR and mitral valve area (MVA), on the left ventricle (LV) systolic function was never formally evaluated. Method Fifty patients with mixed MR etiologies from our TEER register with complete 3D datasets of the LV before and after TEER were included in this study. LV volumes and function, as evaluate by ejection fraction (LVEF), global longitudinal strain (LV-GLS) and global circumferential strain (LV-GCS), and the MR (3D vena contracta area, 3D VCA) were evaluated before and at the end of the therapy. Results The majority of patients suffered from secondary MR (54%), one TEER device was implanted in 64% and two in 36% of the population. TEER leads to a significant reduction of all the LV volume and function parameters excepted for the end-diastolic volume which increased non-significantly (Table 1). The decrease of the LVEF was linked to a decrease of both GLS and GCS in a multivariate analysis (r 0.85), the decrease of GCS having a higher influence (beta −0.606 vs −0.435). In the univariate linear analysis, the reduction of LVEF, GLS and GCS were inverse proportional to the LVEF before TEER and direct proportional to the reduction of the 3D VCA. LVEF decrease was also directly linked to MVA percental reduction. After multivariate evaluation, LVEF reduction kept linked to LVEF before TEER and VCA 3D reduction (r=0.51, p=0.001), GCS decrease only to VCA 3D reduction (r=0.371, P=0.08) and GLS diminution only to LVEF before TEER (r=0.313, p=0.027). Conclusion After TEER, left ventricular function reduction seems principally linked to the afterload increase (i.e. the MR reduction); the circumferential function and the left ventricles with the highest ejection fractions being apparently maximally impacted. Funding Acknowledgement Type of funding sources: None.

Impaired Left Ventricular Circumferential Midwall Systolic Performance Appears Linked to Depressed Preload, but Not Intrinsic Contractile Dysfunction or Excessive Afterload, in Paradoxical Low-Flow/Low-Gradient Severe Aortic Stenosis.

Paradoxical low-flow/low-gradient aortic stenosis (P-LFLG-AS) occurs in about one-third of patients with severe AS and preserved left ventricular (LV) ejection fraction (EF). Our aim was to differentiate between altered LV loading conditions and contractility as determinants of subtle LV systolic dysfunction in P-LFLG-AS. We retrospectively analyzed medical records of patients with isolated severe degenerative AS and preserved EF (30 subjects with P-LFLG-AS and 30 patients with normal-flow/high-gradient severe AS (NFHG-AS)), without relevant coexistent diseases (e.g., diabetes, coronary artery disease and chronic kidney disease) or any abnormalities which could account for a low-flow state. Patients with P-LFLG-AS and NFHG-AS did not differ in aortic valve area index and most clinical characteristics. Compared to NFHG-AS, subjects with P-LFLG-AS exhibited smaller LV end-diastolic diameter (LVd) (44 ± 5 vs. 54 ± 5 mm, p < 0.001) (consistent with lower LV preload) with pronounced concentric remodeling, higher valvulo-arterial impedance (3.8 ± 1.1 vs. 2.2 ± 0.5 mmHg per mL/m2, p < 0.001) and diminished systemic arterial compliance (0.45 ± 0.11 vs. 0.76 ± 0.23 mL/m2 per mmHg, p < 0.001), while circumferential end-systolic LV midwall stress (cESS), an estimate of afterload at the LV level, was similar in P-LFLG-AS and NFHG-AS (175 ± 83 vs. 198 ± 69 hPa, p = 0.3). LV midwall fractional shortening (mwFS) was depressed in P-LFLG-AS vs. NFHG-AS (12.3 ± 3.5 vs. 14.7 ± 2.9%, p = 0.006) despite similar EF (61 ± 6 vs. 59 ± 8%, p = 0.4). By multiple regression, the presence of P-LFLG-AS remained a significant predictor of lower mwFS compared to NFHG-AS upon adjustment for cESS (β ± SEM: −2.35 ± 0.67, p < 0.001); however, the significance was lost after further correction for LVd (β = −1.10 ± 0.85, p = 0.21). In conclusion, the association of P-LFLG-AS with a lower cESS-adjusted mwFS, an index of afterload-corrected LV circumferential systolic function at the midwall level, appears secondary to a smaller LV end-diastolic cavity size according to the Frank–Starling law. Thus, low LV preload, not intrinsic contractile dysfunction or excessive afterload, may account for impaired LV circumferential midwall systolic performance in P-LFLG-AS.

Thermal vibration analysis of functionally graded conical-cylindrical coupled shell based on spectro-geometric method

In this article, an analytical model is presented for vibration analysis of functionally graded conical–cylindrical coupled shell (FG-CCCS) subjected to thermal environment. In the present model, effective material parameters are temperature-dependent and are varied along the thickness direction. Firstly, artificial spring techniques are utilized to simulate the boundary and coupling conditions. The energy equations of FG-CCCS under thermal environment are derived within the framework of the first-order shear deformation theory (FSDT). Then, an efficient and accurate spectro-geometric method (SGM) and the form of the sum of the products of the circumferential Fourier harmonic function are employed to standardize the displacement admissible functions. On this basis, the governing differential equation for free vibration and transient vibration of FG-CCCS is derived using the Rayleigh–Ritz method. By comparing the present results with some existing data and finite element method (FEM) results, the accuracy and stability of present model are proved. Finally, some parametric studies are carried out to explore the influence of material properties, geometric properties, boundary conditions and thermal conditions on the free vibration and transient vibration characteristics of FG-CCCS.

Association of left ventricular systolic dysfunction with coronary artery dilation in Kawasaki disease patients: Assessment with cardiovascular magnetic resonance

PurposeTo quantify global and regional left ventricular (LV) strain parameters in patients with Kawasaki disease (KD) using cardiovascular magnetic resonance (CMR) tissue tracking and assess the association of coronary artery dilation (CA dilation) with LV systolic dysfunction. MethodsThirty-one KD patients with CA dilation, 22 patients without CA dilation and 27 age- and sex-matched normal controls underwent 3.0 T CMR examination. Z score of >2 was defined as CA dilation. Global LV strain parameters and regional LV strain parameters in 16 American Heart Association segmentation, including radial, circumferential and longitudinal peak strain (PS) and LV function were measured and compared among groups. ResultsNo significant difference in LV ejection fraction has been observed among controls, KD patients with CA dilation and without CA dilation (all p > 0.05). However, global longitudinal PS (GLPS) was lower in groups with CA dilation than those without CA dilation (−12.6 ± 4.1% vs −14.9 ± 2.6%, p < 0.05). For regional strain parameters, the segments with CA dilation (n = 301) were lower than those in both normal controls (n = 416) and segments without CA dilation (n = 547) in regional radial, circumferential and longitudinal PS (all p < 0.05). The severity of CA dilation was positively correlated to GLPS and regional longitudinal PS (r = 0.388 and r = 0.222; both p < 0.05) in KD patients. After adjusting for clinical characteristics, the multivariate analysis demonstrated that Z score was independently associated with GLPS in KD patients (β = 0.469, p = 0.000, model R2 = 0.355). ConclusionsCMR tissue tracking could sensitively identify subclinical LV dysfunction in KD patients with CA dilation. LV systolic dysfunction occurs particularly in the myocardium dominated by the dilated coronary artery. CA dilation is an independent predictor of LV systolic dysfunction.

Association of arterial hemodynamics with left ventricular systolic function in hypertensive patients: A longitudinal study

BACKGROUND Left ventricular (LV) systolic impairment, particularly in the longitudinal direction, is considered an early and sensitive marker of hypertensive heart disease and increased cardiovascular risk. The evidence indicates that aortic stiffness and central hemodynamic factors are important determinants of LV performance, mediating the interaction between the heart and vascular load. Despite the existence of cross-sectional analyses linking central blood pressure (BP) parameters with LV mechanics, no longitudinal data are available which include serial measurements in the course of antihypertensive treatment. OBJECTIVES To investigate the associations between changes in LV longitudinal and circumferential function with alterations in arterial hemodynamics and ventricular-arterial coupling (VAC) in patients with uncomplicated hypertension during a 12-month follow-up. MATERIAL AND METHODS In this retrospective study, 216 patients (age 64.3 ±7.6 years) underwent echocardiography including left ventricular longitudinal (GLS) and circumferential strain (GCS) analysis, brachial BP measurements, VAC (combining echocardiography and brachial BP), and arterial hemodynamics using radial tonometry at baseline and after 12 months of antihypertensive therapy. Patients were grouped into 2 subsets: with improvement in GLS (n = 103) and with deterioration in GLS (n = 113). RESULTS No significant differences were observed in the majority of cardiovascular, demographic or clinical characteristics between the groups. The subset with improvement in GLS demonstrated more favorable changes over follow-up in pulse wave velocity (p = 0.03), central augmentation pressure (p = 0.01) and ventricular-arterial coupling (p = 0.04) compared to patients showing deterioration in GLS. In the multivariable analysis, independent determinants of changes in GLS were: GLS at baseline (-0.48; p < 0.001), changes from baseline to follow-up in central augmentation pressure (-0.29; p = 0.002) and ventricular-arterial coupling (-0.25; p = 0.004). Independent determinants of analogous changes in GCS were: GCS at baseline (-0.46; p < 0.001) and changes in central augmentation pressure (-0.22; p = 0.02). CONCLUSIONS Left ventricular longitudinal and circumferential functional remodeling over time in hypertensive patients is associated with arterial hemodynamics and ventricular-arterial coupling.

Right Ventricular Contraction Patterns in Patients Undergoing Transcatheter Tricuspid Valve Repair for Severe Tricuspid Regurgitation.

This study investigated patterns of right ventricular (RV) contraction by using cardiac magnetic resonance (CMR) imaging in patients undergoing transcatheter tricuspid valve repair (TTVR). The role of RV function in patients with severe tricuspid regurgitation undergoing TTVR is poorly understood. Global RV dysfunction was defined as CMR-derived RV ejection fraction (RVEF)≤45% and longitudinal RV dysfunction was defined as tricuspid annular plane systolic excursion (TAPSE)<17mm on echocardiography. Patients were stratified into 3 types of RV contraction: type I, TAPSE≥17 and RVEF >45%; type II, TAPSE<17 and RVEF >45%; and type III, TAPSE<17 and RVEF≤45%. CMR feature tracking was performed to assess longitudinal and circumferential RV strain. The primary outcome was a composite of all-cause mortality or first heart failure hospitalization. Of 79 patients (median age 79 years, 51% female), 18 (23%) presented with global and 40 (51%) presented with longitudinal RV dysfunction. The composite outcome occurred in 22 patients (median follow-up 362days). Global RV dysfunction but not longitudinal RV dysfunction (hazard ratio: 6.62; 95% confidence interval: 2.77-15.77; and hazard ratio: 1.30; 95% confidence interval: 0.55-3.08, respectively) was associated with the composite outcome. Compared with type I RV contraction, patients with type II RV contraction exhibited increased circumferential strain, with a preservation of RVEF despite diminished longitudinal strain. Patients with type III RV contraction exhibited both diminished longitudinal and circumferential strain, resulting in an impaired RVEF. Patients with type III RV contraction showed the worst survival (P< 0.001). Global RV dysfunction is a predictor of outcomes among TTVR patients. Tricuspid regurgitation patientscan be stratified into 3 types of RV contraction, in which a loss of longitudinal function can be compensated by increasing circumferential function, preserving RVEF and favorable outcomes.

The diagnostic value of 2D-speckle tracking echocardiography for identifying subclinical ventricular dysfunction in subjects with early repolarization pattern.

Early repolarization pattern (ERP) can exist a silent substrate for arrhytmic events in accordance with the previous studies which have shown there has been evidence of morphological changes in left ventricle (LV) in ERP subjects. Despite structural changes in ERP subjects, it has not exactly known whether a change in LV functional parameters occur in ERP. The aim of our study was to investigate LV functional parameters in ERP athletes evaluated by 2D- speckle tracking echocardiography (2D-STE). In this study, athletes with ERP (n=50) and athletes without ERP (n=50) were recruited between April 2018 and September 2018. For each case, 2D- TTE and 2D- STE evaluation were performed by the same cardiologist. Left ventricle mean global longitudinal strain (GLS) (P<.001) and GLS at all apical chamber views (P<.001), longitudinal peak systolic strain rate (SRS) at A3C (P: .011), early diastolic strain rate (SRE) at A3C (P<.001) and late diastolic strain rate (SRA) at A3C (P: .034) in the ERP athletes were significantly lower than those in the athletes without ERP. LV basal segment circumferential SRS (P: .002) and SRE (P: .006) were significantly lower in ERP athletes compared to athletes without ERP. LV mechanical dispersion was significantly higher in ERP athletes compared to athletes without ERP (P<.001). Our study suggests ERP can be more associated with impaired LV longitudinal function than circumferential function. In addition, both LV inferolateral region and basal segment can be more affected functionally in ERP athletes.

Association of Myocardial Energetic Efficiency with Circumferential and Longitudinal Left Ventricular Myocardial Function in Subjects with Increased Body Mass Index (the FATCOR Study).

Lower myocardial mechanic-energetic efficiency (MEEi), expressed as stroke volume/heart rate ratio (SV/HR) in mL/s/g of the left ventricular (LV) mass, is associated with the incidence of heart failure in subjects with cardiometabolic disorders. We explored the association of MEEi with LV systolic circumferential and longitudinal myocardial function in 480 subjects with increased body mass index (BMI) without known cardiovascular disease (mean age 47 ± 9 years, 61% women, 63% obese, 74% with hypertension) participating in the fat-associated cardiovascular dysfunction (FATCOR) study. Insulin resistance was assessed by the homeostasis model assessment insulin-resistance index (HOMA-IR). SV was calculated by Doppler echocardiography. The LV systolic circumferential myocardial function was evaluated by midwall fractional shortening (MFS) and longitudinal function by global longitudinal strain (GLS). Patients were grouped into MEEi quartiles. The lowest MEEi quartile (<0.41 mL/s per g) was considered low MEEi. The association of MEEi with MFS and GLS were tested in multivariable linear regression analyses. Patients with low MEEi were more frequently men, with obesity and hypertension, dyslipidemia and higher HOMA-IR index (all p for trend <0.05). In multivariable analyses, lower MEEi was associated with lower LV myocardial function by MFS and GLS independent of higher LV mass and clinical variables, including older age, male sex, presence of hypertension and a higher triglycerides level (all p < 0.05). In conclusion, in subjects with increased BMI without known cardiovascular disease participating in the FATCOR study, reduced MEEi was associated with lower LV myocardial function both in the circumferential and longitudinal direction, independent of cardiometabolic factors.

Left ventricular radial strain impairment precedes hypertrophy in Anderson-Fabry disease.

In Anderson-Fabry disease (AFD), left ventricular (LV) radial function has been scarcely investigated. We hypothesized that LV function may be affected by disease specific mechanisms and sought to comprehensively evaluate LV radial, circumferential and longitudinal function in a large population of AFD patients looking at the influence of LV geometry and fibrosis. We prospectively studied 94 consecutive AFD patients (41.5 ± 14.5 years; 41 men) with preserved LV ejection fraction (EF) utilizing speckle-tracking echocardiography. A subset of patients underwent gadolinium-enhanced cardiac magnetic resonance. Cases were compared to 48 healthy subjects matched for age and sex. LV concentric hypertrophy was found in 33 AFD patients while LV concentric remodeling (relative wall thickness ≥ 0.43) in 16 out 61 patients with normal LV mass. AFD patients had lower radial, longitudinal and circumferential strains than controls, independently by LV geometry pattern. Patients with LV hypertrophy showed reduced global longitudinal strain (p < 0.001) and early diastolic untwisting rate (p = 0.002) as compared to patients with normal geometry. In the whole AFD population, neither radial strain nor circumferential strain correlated with LV mass, while global longitudinal strain and early diastolic untwisting rate did (both p < 0.001). Late gadolinium enhancement was significantly associated with longitudinal strain, twisting rate and early diastolic untwisting rate, with twisting rate being the most powerful independent predictor (β = - 0.461; p = 0.002). Findings demonstrate impairment of LV radial strain in AFD patients with preserved EF, even in a pre-hypertrophic stage. Development of LV hypertrophy and fibrosis make worse mostly longitudinal dysfunction.

Interrelation between midwall mechanics and longitudinal strain in newly diagnosed and never-treated hypertensive patients without clinically defined hypertrophy.

In hypertensive patients, an impairment of midwall myocardial mechanics was described in presence of left ventricular (LV) concentric geometry. Under these circumstances, also LV longitudinal dysfunction was found. Our aim was to evaluate longitudinal and circumferential systolic function and correlations between these two functional components in newly diagnosed hypertensive patients without clinically defined LV hypertrophy (LVH). One hundred and thirty-eight newly diagnosed, never-treated hypertensive patients without LVH and a control group of 105 healthy normotensive individuals underwent two-dimensional and speckle tracking echocardiography. Global longitudinal strain (GLS) was derived (in absolute value) and midwall fractional shortening (MFS) computed. In addition, the hypertensive population was divided into two groups according to GLS: normal GLS (≥20%, n = 94) and reduced GLS (<20%, n = 44). Hypertensive patients had lower MFS (P < 0.001) and GLS (P < 0.0001) than healthy controls. By dividing hypertensive patients according to GLS thresholds of normalcy, MFS was lower in patients with GLS less than 20% (P < 0.0001) while no significant difference was found in LV geometry, ejection fraction and diastolic parameters in comparison with patients with GLS at least 20%. In the pooled hypertensive population, GLS resulted positively related to MFS (r = 0.33, P < 0.0001). By a multiple linear regression analysis, after adjusting for female sex, age, BMI, circumferential end-systolic stress, average e', ejection fraction and relative wall thickness, MFS remained independently associated with GLS (β = 0.222, P < 0.005). In newly diagnosed and never-treated hypertensive patients without LVH, an early LV systolic dysfunction is testified by the reduction of both MFS and GLS. These two parameters resulted independently associated after adjusting for several confounders.

P1354 Prognostic value of the left ventricular longitudinal and circumferential function in patients with takotsubo syndrome during the acute phase

Abstract Background Takotsubo syndrome is generally considered a benign disease with a reversible condition; however, hemodynamic and electrical instability during the acute phase exposes patients to the risk of serious adverse in-hospital events. The purpose of this study was to investigate the prognostic value of the left ventricular longitudinal and circumferential function in patients with TTS during the acute phase. Methods We divided the 27 patients with TTS (77.4 ± 10.2 years old, 21 females) into two groups; the severe group (SG) of 9 patients (in-hospital death, mechanical assist devices such as IABP or ECMO, oozing rupture) and non-severe group (NSG) of 18 patients. The echocardiographic examination on admission, catheter hemodynamic assessment, and laboratory data, and ST-T change in electrocardiogram were compared between two groups. Results There were no differences in age, laboratory data, electrocardiogram findings between the two groups. The LVEF was lower in SG (35.3 ± 6.1% vs. 45.9 ± 13.5%, p = 0.03). The index of Ballooning, the ratio of the systolic left ventricular diameter of ballooning segments to that of basal segments, was higher in SG (2.07 ± 0.61% vs.1.60 ± 0.32%, p = 0.016). The circumferential fractional shortening (CFS) of ballooning segments was lower in SG (4.6 ± 3.2% vs. 18.2 ± 8.2%, p = 0.00007), CFS of basal segments was not different between the two groups, and the ratio of CFS of ballooning segments to CFS of basal segments (CFS imbalance index) was lower in SG (5.60 ± 3.84 vs. 10.83 ± 3.92, p = 0.00003). The left ventricular longitudinal fractional shortening was lower in SG (0.12 ± 0.09 vs. 0.46 ± 0.19, p = 0.00003). The absolute value of GLS was lower in SG (7.6 ± 4.3% vs. 13.0 ± 3.6%, p = 0.002). In all three cases of in-hospital death, the CFS imbalance index was lower than 0.14. Conclusion In patients with TTS, left ventricular longitudinal and circumferential function could be related to serious adverse in-hospital events.

P1410 Right ventricle to pulmonary circulation coupling is primarily defined by the circumferential right ventricle function

Abstract Background Right ventricle to pulmonary circulation (RV-PC) coupling plays a pivotal role during the physical effort. The RV-PC uncoupling can be easily identified by the TAPSE/SPAP ratio, a prognostic marker based on RV longitudinal function and its afterload (SPAP).We sought to explore the relationship between the functional capacity (peak VO2 and VE/VCO2) and the RV-PC coupling, using both a standard and 3D-based echocardiographic assessment of RV. Methods eighty-seven patients (age 72 ± 10 years; LV EF 53 ± 15%) underwent rest echocardiography with 3D RV assessment and cardiopulmonary exercise test. RV EF was measured using the 4D RV TomTec software. The 3D mesh of the RV model was post-processed using a custom developed software. This provided longitudinal (EFlong) and circumferential (EFcirc) components of EF. RV-PC coupling was assessed with the TAPSE/SPAP ratio and with similar parameters obtained by using 3D components of RV systolic function over SPAP (EF/SPAP, EFlong/SPAP and EFcirc/SPAP ratio). All variables were correlated with peakVO2 and VE/VCO2. Results Correlations between peakVO2 and TAPSE (0.409, p = 0.006), SPAP (-0.597, p &amp;lt; 0.001), RV EF (0.555, p &amp;lt; 0.001), RV EFlong (0.327, p = 0.03), RV EFcirc (0.587, p &amp;lt; 0.001) were modest, while TAPSE/SPAP (0.641, p &amp;lt; 0.001), EF/SPAP (0.751, p &amp;lt; 0.001), EFlong/SPAP (0.610, p &amp;lt; 0.001) and EFcirc/SPAP (0.775, p &amp;lt; 0.001) showed stronger correlations. VE/VCO2 showed a similar relationships although the correlations were weaker [TAPSE (-0.523, p &amp;lt;0.001), SPAP (0.617, p &amp;lt; 0.001), RV EF (-0.412, p = 0.006), RV EFlong (-0.232, p = 0.129), RV EFcirc (-0.454, p = 0.002), TAPSE/SPAP (-0.561, p &amp;lt; 0.001), EF/SPAP (-0.516, p = 0.001), EFlong/SPAP (-0.429, p = 0.008) and EFcirc/SPAP (-0.541, p &amp;lt; 0.001)]. Conclusions RV-PC coupling is associated with both peak VO2 and VE/VCO2. The use of 3D-derived markers of RV-PC coupling showed a better correlation with the peak VO2, while there were no differences for VE/VCO2. The circumferential component of RV systolic function seems to emerge as a dominant determinant of RV-PC coupling, as well as of functional capacity.

P1492Is early repolarization pattern only an ion channel disease?

Abstract Background Early repolarization pattern (ERP) has been generally described as a benign electrocardiographic (ECG) sign despite it is associated with the development of malign ventricular arrhythmias. Although the pathophysiological mechanism of malign ventricular arrhythmias in ERP has been explained only electrophysiologically, whether the presence of structural changes in myocardium has not been known yet. Purpose We hypothesized that ERP is not only an ion channel disease. The structural changes in myocardium begin in individuals with ERP sign on 12 lead surface ECG even if a young person. The aim of the present study was to determine myocardial dysfunction due to early decaying in myocardial structure in individuals with ERP sign by the use of 2D- speckle tracking echocardiography (STE). Method We prospectively included 99 individuals who admitted to our clinic between 01.04.2018 and 01.09.2018. 48 individuals had ERP. 12 lead surface ECG was taken from all individuals at admission, all individual's ECG were further analysed for presence of ERP and ERP was divided into three groups which were defined as presence of ST elevation, J wave and QRS slurring. 2D-STE (Philips Epiq 7C Ultrasound System for Cardiology (Andover, USA)) was performed in all individuals. All strain echocardiographic recordings were further analysed off- line by the use of associated software. Results ERP had significantly lower left ventricular (LV) global longitudinal strain (GLS), circumferential peak systolic strain rate (CPSSr) in basal segments of LV and left ventricular ejection fraction compared to controls. In addition, LV diastolic function especially in LV basal segments were significantly impaired in individuals with ERP when assessed by circumferential peak diastolic strain rate (CPDSr) compared to controls. GCS, LV- longitudinal peak systolic Sr (LPSSr) and LV- longitudinal peak diastolic Sr (LPDSr) in all of the apical chambers were similar between two groups (Table 1). There was not a relationship between type of ERP and all of these parameters including GLS, GCS, LPSSr, CPSSr, LPDSr, CPDSr. Finally, ST elevation pattern had higher GCS value while QRS slurring pattern had higher GLS value (Figure 1). Figure 1 and Table 1 Conclusion Our study firstly demonstrated ERP can be combined of structural and electrical heart disease. LV-GLS can be more closely associated with ERP than LV-GCS. In addition, the either of impaired of circumferential systolic and diastolic function in LV basal segments can be detected in individuals with ERP.