Morphology of hypertrophied basal septum contributes to left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy: a retrospective case-control study.

Background:Detailed assessment of basal septal morphology is essential for understanding the morphological mechanism of left ventricular outflow tract (LVOT) obstruction. We aimed to analyze the morphological alterations of the basal septum (BS) and its surrounding structures and explore their role in LVOT obstruction (LVOTO) in patients with hypertrophic cardiomyopathy (HCM).Methods:During January 2019 and December 2019, 239 patients were diagnosed with HCM at Fuwai Hospital. We retrospectively reviewed echocardiographic data sets from 105 consecutive patients with HCM [64 with hypertrophic obstructive cardiomyopathy (HOCM) and 41 with hypertrophic non-obstructive cardiomyopathy (HNOCM)] and 28 healthy controls. For quantitatively assessing the basal septal morphology, a novel measurement method was used to obtain the IVSa (the area of the BS protruding into the LVOT), LA (the largest distance of the BS protruding into the LVOT), LB (IVSa length in the direction perpendicular to the LA), and S-IVSa (IVSa divided by LB). Echocardiographic parameters associated with LVOTO were analyzed using multivariable logistic regression analyses.Results:There was no significant difference in the maximal basal septal thickness between the HOCM and HNOCM patients (P>0.99). Among the three groups, there were significant differences in the length of the anterior and posterior mitral leaflets (AML and PML), the angle between the mitral valve orifice and ascending aorta (MV-AO) angle, IVSa, LA, LB, and S-IVSa (all P<0.001). Compared with HNOCM patients, HOCM patients had significantly longer AML and PML, as well as larger MV-AO angle, IVSa, LA, and S-IVSa (P<0.001, P<0.001, P<0.001, P=0.002, P<0.001, and P=0.03, respectively). In the multivariate analysis, AML, MV-AO angle, IVSa, and S-IVSa were associated with LVOTO {odds ratio (OR) [95% confidence interval (CI)]: 0.649 (0.462-0.911), P=0.01; 0.842 (0.768-0.923), P<0.001; 1.025 (1.001-1.049), P=0.04; and 0.276 (0.101-0.754), P=0.01, respectively}.Conclusions:Morphological alterations of the BS relative to the LVOT may provide additional value for estimating the extent of LVOTO. The length of AML, MV-AO angle, IVSa, and S-IVSa were associated with LVOTO.

The Role of the Submitral Apparatus in Hypertrophic Obstructive Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease, is characterized by unexplained hypertrophy of any myocardial segment, and has a prevalence of 0.2% to 0.5% among the general population. As one of the phenotypes of hypertrophic cardiomyopathy, left ventricular outflow tract obstruction (LVOTO) is associated with high morbidity and mortality, including cardiac death. The integration of various factors, including septal hypertrophy, malformation of the mitral valve apparatus, and an anomalous mitral subvalvular apparatus, may contribute to the occurrence of LVOTO. Previous studies have thoroughly discussed the role of the mitral valve in the mechanisms of systolic anterior motion and LVOTO. Recent studies have shown the importance of determining the potential mechanism of the submitral apparatus in inducing systolic anterior motion and LVOTO. The authors review recent advances in knowledge regarding the submitral apparatus of patients with hypertrophic cardiomyopathy.

Accuracy of aortic annulus measurements by three-dimensional transesophageal echocardiography and predictive value for thoracic aorta aneurysm in patients with aortic regurgitation.

Background:Accurate assessment of the aortic annulus (AA) dimension and judgment of thoracic aorta aneurysm is crucial for patients with aortic regurgitation (AR) before surgery. The aim of this study was to evaluate the accuracy and reproducibility of three-dimensional transesophageal echocardiography (3D-TEE) methods for AA measurement and explore the predictive value of the AA dimensions obtained by 3D-TEE for high-risk thoracic aorta aneurysms using the gold standard of multi-slice computed tomography (MSCT).Methods:3D-TEE was performed on 111 patients with pure moderate-to-severe AR, and MSCT examination was conducted simultaneously. AA dimensions were obtained using reconstruction software for these two imaging techniques. Thoracic aortic diameters at standard anatomic landmarks were also measured by MSCT. All patients were divided into two groups depending on the presence of high-risk thoracic aorta aneurysms.Results:Compared to MSCT, 3D-TEE overestimated all AA parameters. However, no statistically significant differences were found in the average bias between methods (minimum diameter: 26.07±3.57 vs. 25.88±3.68 mm, P=0.52; maximum diameter: 32.30±2.68 vs. 31.78±4.06 mm, P=0.11; area: 669.76±155.19 vs. 660.05±168.28 mm2, P=0.44; perimeter: 93.52±10.42 vs. 92.26±11.71 mm, P=0.12). 3D-TEE demonstrated good correlations with MSCT measurement for AA minimum diameter, maximum diameter, area, and perimeter (r=0.63, 0.64, 0.74, 0.69, P<0.05 for all). According to the multivariate logistic regression analysis, the AA minimum diameter obtained by 3D-TEE was the best predictor for the presence of high-risk thoracic aorta aneurysms. The sensitivity and specificity for prediction were 84.6% and 63.9%, respectively, for an AA minimum diameter ≥25.74 mm (AUC: 0.759, 95% CI: 0.668-0.850).Conclusions:AA measurements obtained by the 3D-TEE method are feasible and reliable for patients with pure AR. The AA minimum diameter measured by 3D-TEE can effectively predict the presence of high-risk thoracic aorta aneurysms.

Mitral Annulus Geometry and Dynamic Motion Changes in Patients With Aortic Regurgitation: A Three-Dimensional Transesophageal Echocardiographic Study.

OBJECTIVE:The aim of the present study was to investigate the mitral annulus (MA) geometry and dynamic motion changes in patients with aortic regurgitation (AR) before and after aortic valve replacement (AVR). Moreover, the difference in the effect of the type of prosthetic aortic valve on MA was compared.DESIGN:Prospective observational study.SETTING:Cardiac operating room at a single hospital.PARTICIPANTS:Eighty-two patients with isolated moderate-to-severe AR who underwent AVR. Forty patients with normal valves were enrolled as controls.INTERVENTIONS:None.MEASUREMENTS AND MAIN RESULTS:The MA geometry and dynamic motion throughout the cardiac cycle were evaluated semiautomatically by three-dimensional transesophageal echocardiography. The severity of functional mitral regurgitation was intraoperatively evaluated. All patients were divided into 2 groups depending on the type of prosthetic valve (mechanical valve and bioprosthetic valve groups). Before AVR, compared with the control group without AR, the AR group demonstrated larger MA dimensions and the MA geometry was flatter. The contraction fraction of the MA area, perimeter, and height during the whole cardiac cycle were larger in the AR group (p < 0.05 for all). After AVR, most MA geometric and dynamic parameters decreased and functional mitral regurgitation also improved. In the postoperative subset analyses, the mechanical valve group showed a larger contraction fraction of the MA area and perimeter than the bioprosthetic valve group (p < 0.05 for both).CONCLUSIONS:The MA geometry and dynamic motion changed markedly in patients with AR. These spatial and dynamic changes were restored to a certain extent after surgical correction of the aortic valve. However, the effects produced by mechanical and bioprosthetic valves on MA were different.

The role of left atrial strain in patients with functional tricuspid regurgitation before and after annuloplasty: a long-term follow-up study.

BACKGROUND:Functional tricuspid regurgitation (TR) is common among patients with left heart disease and may recur during the follow-up period after selective tricuspid valve annuloplasty (TVA). This study aims to analyse the relationship between left atrial (LA) strain and the degree of preoperative functional TR and to explore the role of LA strain in predicting TR recurrence.METHODS:This study included 63 patients with rheumatic mitral stenosis who underwent mitral valve replacement and concomitant TVA. Additionally, 20 healthy controls were enrolled. Preoperative conventional LA echocardiographic parameters and LA strain were measured. The association between LA strain and preoperative functional TR severity was analysed by Pearson correlation. Predictors of recurrent TR were determined by multivariate logistic regression analyses.RESULTS:Compared with the control group, the mitral stenosis group developed a significant impairment in terms of LA strain. The degree of preoperative functional TR exhibited moderate correlations with LA reservoir strain (r = - 0.57) and LA conduit strain (r = 0.48). During a median follow-up period of 66.4 ± 36.4 months, TR recurred in 18 patients. Preoperative LA reservoir strain and the mean transmitral gradient were predictors of postoperative TR recurrence. When the two indexes were combined to establish a prediction, the sensitivity and specificity of prediction increased. The area under the receiver operating characteristic curve of the combined indicator was higher than those of the single indicators (0.90 vs. 0.70 and 0.72).CONCLUSIONS:LA strain correlates with preoperative functional TR severity in patients with rheumatic mitral stenosis. The LA reservoir strain and preoperative mean transmitral gradient are independent predictive factors for recurrent TR after TVA.

Non-invasive thoracic electrical bioimpedance technique-derived hemodynamic reference ranges in Chinese Han adults.

Quantification of chronic aortic regurgitation using left and right ventricular stroke volumes obtained from two new automated three-dimensional transthoracic echocardiographic software: feasibility and accuracy.

The present study aimed to evaluate the feasibility and accuracy of chronic aortic regurgitation (CAR) quantification using left and right ventricular stroke volumes (LVSV and RVSV, respectively) obtained from two new automated three-dimensional transthoracic echocardiographic software-Dynamic HeartModel (DHM) and 3D Auto RV. Patients (n=116) with more than mild isolated CAR were included and divided into two groups: central (n=53) and eccentric CAR (n=63) groups. LVSV and RVSV were automatically measured by DHM and 3D Auto RV. Next, aortic regurgitant volume (ARVol) was calculated three ways: as the difference between LVSV and RVSV, by the two-dimensional proximal isovelocity surface area (PISA) method, and using effective regurgitant orifice area derived from real-time three-dimensional echocardiography (RT3DE) multiplied by CAR velocity time integral (the reference standard). DHM plus 3D Auto RV correlated well with RT3DE in ARVol measurement in both groups (central, r = 0.90; eccentric, r = 0.96), with no significant difference based on consistency analysis. In the eccentric group, PISA led to an obvious underestimation (mean difference= - 4.20 ml, P < 0.05). The kappa agreement between DHM plus 3D Auto RV and RT3DE in grading CAR severity in both groups was good (central, k = 0.89; eccentric, k = 0.86), but that between PISA and RT3DE in the eccentric CAR group was suboptimal (k = 0.74). This study indicates that ARVol quantification using DHM plus 3D Auto RV is feasible and reproducible in patients with more than mild isolated CAR. This new method has great correlation and agreement with RT3DE in ARVol measurement, with evident advantages over PISA in eccentric CAR.

Evaluation of the Left Ventricular Hemodynamic Status of Double-Root Translocation Patients Through Vector Flow Mapping.

The double-root translocation (DRT) procedure is considered as a new choice for surgical management of complex congenital heart disease. Our study aims to investigate the left ventricular hemodynamic status after DRT by energy loss (EL), involving 42 patients who underwent DRT as well as 42 healthy volunteers as controls. The EL of left ventricle (LV) during different periods (rapid filling-RF, atrial contraction-AC, isovolumic contraction-IVC, rapid ejection-RE) of the same cardiac cycle were obtained and analyzed. Compared to the controls, global LV and apical three chamber-EL at AC and IVC periods in DRT group were higher (p < 0.05), and EL at RE period of DRT group was moderately lower. In the correlation analysis, the global EL at the RF was correlated with E wave (r = 0.47, p = 0.03), E/e' (r = 0.50, p = 0.02), BSA (r = - 0.54, p = 0.01), and age (r = - 0.67, p < 0.001). AC and RE- global EL were significantly correlated with E/e' (r = 0.49, r = 0.59, p < 0.05). There was a strong positive correlation between E/e' and global EL at the IVC (r = 0.62, p = 0.003) and a moderate negative correlation with age (r = - 0.44, p = 0.04). The present study confirms that EL is a feasible and reproducible indicator for quantitatively evaluating LV hemodynamic status in patients who underwent DRT and reveals that DRT can lead to approximatively normal long-term hemodynamic performance of LV.

Morphology of hypertrophied basal septum contributes to left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy: a retrospective case-control study.

Background:Detailed assessment of basal septal morphology is essential for understanding the morphological mechanism of left ventricular outflow tract (LVOT) obstruction. We aimed to analyze the morphological alterations of the basal septum (BS) and its surrounding structures and explore their role in LVOT obstruction (LVOTO) in patients with hypertrophic cardiomyopathy (HCM).Methods:During January 2019 and December 2019, 239 patients were diagnosed with HCM at Fuwai Hospital. We retrospectively reviewed echocardiographic data sets from 105 consecutive patients with HCM [64 with hypertrophic obstructive cardiomyopathy (HOCM) and 41 with hypertrophic non-obstructive cardiomyopathy (HNOCM)] and 28 healthy controls. For quantitatively assessing the basal septal morphology, a novel measurement method was used to obtain the IVSa (the area of the BS protruding into the LVOT), LA (the largest distance of the BS protruding into the LVOT), LB (IVSa length in the direction perpendicular to the LA), and S-IVSa (IVSa divided by LB). Echocardiographic parameters associated with LVOTO were analyzed using multivariable logistic regression analyses.Results:There was no significant difference in the maximal basal septal thickness between the HOCM and HNOCM patients (P>0.99). Among the three groups, there were significant differences in the length of the anterior and posterior mitral leaflets (AML and PML), the angle between the mitral valve orifice and ascending aorta (MV-AO) angle, IVSa, LA, LB, and S-IVSa (all P<0.001). Compared with HNOCM patients, HOCM patients had significantly longer AML and PML, as well as larger MV-AO angle, IVSa, LA, and S-IVSa (P<0.001, P<0.001, P<0.001, P=0.002, P<0.001, and P=0.03, respectively). In the multivariate analysis, AML, MV-AO angle, IVSa, and S-IVSa were associated with LVOTO {odds ratio (OR) [95% confidence interval (CI)]: 0.649 (0.462-0.911), P=0.01; 0.842 (0.768-0.923), P<0.001; 1.025 (1.001-1.049), P=0.04; and 0.276 (0.101-0.754), P=0.01, respectively}.Conclusions:Morphological alterations of the BS relative to the LVOT may provide additional value for estimating the extent of LVOTO. The length of AML, MV-AO angle, IVSa, and S-IVSa were associated with LVOTO.

The Role of the Submitral Apparatus in Hypertrophic Obstructive Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease, is characterized by unexplained hypertrophy of any myocardial segment, and has a prevalence of 0.2% to 0.5% among the general population. As one of the phenotypes of hypertrophic cardiomyopathy, left ventricular outflow tract obstruction (LVOTO) is associated with high morbidity and mortality, including cardiac death. The integration of various factors, including septal hypertrophy, malformation of the mitral valve apparatus, and an anomalous mitral subvalvular apparatus, may contribute to the occurrence of LVOTO. Previous studies have thoroughly discussed the role of the mitral valve in the mechanisms of systolic anterior motion and LVOTO. Recent studies have shown the importance of determining the potential mechanism of the submitral apparatus in inducing systolic anterior motion and LVOTO. The authors review recent advances in knowledge regarding the submitral apparatus of patients with hypertrophic cardiomyopathy.

Accuracy of aortic annulus measurements by three-dimensional transesophageal echocardiography and predictive value for thoracic aorta aneurysm in patients with aortic regurgitation.

Background:Accurate assessment of the aortic annulus (AA) dimension and judgment of thoracic aorta aneurysm is crucial for patients with aortic regurgitation (AR) before surgery. The aim of this study was to evaluate the accuracy and reproducibility of three-dimensional transesophageal echocardiography (3D-TEE) methods for AA measurement and explore the predictive value of the AA dimensions obtained by 3D-TEE for high-risk thoracic aorta aneurysms using the gold standard of multi-slice computed tomography (MSCT).Methods:3D-TEE was performed on 111 patients with pure moderate-to-severe AR, and MSCT examination was conducted simultaneously. AA dimensions were obtained using reconstruction software for these two imaging techniques. Thoracic aortic diameters at standard anatomic landmarks were also measured by MSCT. All patients were divided into two groups depending on the presence of high-risk thoracic aorta aneurysms.Results:Compared to MSCT, 3D-TEE overestimated all AA parameters. However, no statistically significant differences were found in the average bias between methods (minimum diameter: 26.07±3.57 vs. 25.88±3.68 mm, P=0.52; maximum diameter: 32.30±2.68 vs. 31.78±4.06 mm, P=0.11; area: 669.76±155.19 vs. 660.05±168.28 mm2, P=0.44; perimeter: 93.52±10.42 vs. 92.26±11.71 mm, P=0.12). 3D-TEE demonstrated good correlations with MSCT measurement for AA minimum diameter, maximum diameter, area, and perimeter (r=0.63, 0.64, 0.74, 0.69, P<0.05 for all). According to the multivariate logistic regression analysis, the AA minimum diameter obtained by 3D-TEE was the best predictor for the presence of high-risk thoracic aorta aneurysms. The sensitivity and specificity for prediction were 84.6% and 63.9%, respectively, for an AA minimum diameter ≥25.74 mm (AUC: 0.759, 95% CI: 0.668-0.850).Conclusions:AA measurements obtained by the 3D-TEE method are feasible and reliable for patients with pure AR. The AA minimum diameter measured by 3D-TEE can effectively predict the presence of high-risk thoracic aorta aneurysms.

Mitral Annulus Geometry and Dynamic Motion Changes in Patients With Aortic Regurgitation: A Three-Dimensional Transesophageal Echocardiographic Study.

OBJECTIVE:The aim of the present study was to investigate the mitral annulus (MA) geometry and dynamic motion changes in patients with aortic regurgitation (AR) before and after aortic valve replacement (AVR). Moreover, the difference in the effect of the type of prosthetic aortic valve on MA was compared.DESIGN:Prospective observational study.SETTING:Cardiac operating room at a single hospital.PARTICIPANTS:Eighty-two patients with isolated moderate-to-severe AR who underwent AVR. Forty patients with normal valves were enrolled as controls.INTERVENTIONS:None.MEASUREMENTS AND MAIN RESULTS:The MA geometry and dynamic motion throughout the cardiac cycle were evaluated semiautomatically by three-dimensional transesophageal echocardiography. The severity of functional mitral regurgitation was intraoperatively evaluated. All patients were divided into 2 groups depending on the type of prosthetic valve (mechanical valve and bioprosthetic valve groups). Before AVR, compared with the control group without AR, the AR group demonstrated larger MA dimensions and the MA geometry was flatter. The contraction fraction of the MA area, perimeter, and height during the whole cardiac cycle were larger in the AR group (p < 0.05 for all). After AVR, most MA geometric and dynamic parameters decreased and functional mitral regurgitation also improved. In the postoperative subset analyses, the mechanical valve group showed a larger contraction fraction of the MA area and perimeter than the bioprosthetic valve group (p < 0.05 for both).CONCLUSIONS:The MA geometry and dynamic motion changed markedly in patients with AR. These spatial and dynamic changes were restored to a certain extent after surgical correction of the aortic valve. However, the effects produced by mechanical and bioprosthetic valves on MA were different.

The role of left atrial strain in patients with functional tricuspid regurgitation before and after annuloplasty: a long-term follow-up study.

BACKGROUND:Functional tricuspid regurgitation (TR) is common among patients with left heart disease and may recur during the follow-up period after selective tricuspid valve annuloplasty (TVA). This study aims to analyse the relationship between left atrial (LA) strain and the degree of preoperative functional TR and to explore the role of LA strain in predicting TR recurrence.METHODS:This study included 63 patients with rheumatic mitral stenosis who underwent mitral valve replacement and concomitant TVA. Additionally, 20 healthy controls were enrolled. Preoperative conventional LA echocardiographic parameters and LA strain were measured. The association between LA strain and preoperative functional TR severity was analysed by Pearson correlation. Predictors of recurrent TR were determined by multivariate logistic regression analyses.RESULTS:Compared with the control group, the mitral stenosis group developed a significant impairment in terms of LA strain. The degree of preoperative functional TR exhibited moderate correlations with LA reservoir strain (r = - 0.57) and LA conduit strain (r = 0.48). During a median follow-up period of 66.4 ± 36.4 months, TR recurred in 18 patients. Preoperative LA reservoir strain and the mean transmitral gradient were predictors of postoperative TR recurrence. When the two indexes were combined to establish a prediction, the sensitivity and specificity of prediction increased. The area under the receiver operating characteristic curve of the combined indicator was higher than those of the single indicators (0.90 vs. 0.70 and 0.72).CONCLUSIONS:LA strain correlates with preoperative functional TR severity in patients with rheumatic mitral stenosis. The LA reservoir strain and preoperative mean transmitral gradient are independent predictive factors for recurrent TR after TVA.

Non-invasive thoracic electrical bioimpedance technique-derived hemodynamic reference ranges in Chinese Han adults.

Quantification of chronic aortic regurgitation using left and right ventricular stroke volumes obtained from two new automated three-dimensional transthoracic echocardiographic software: feasibility and accuracy.

The present study aimed to evaluate the feasibility and accuracy of chronic aortic regurgitation (CAR) quantification using left and right ventricular stroke volumes (LVSV and RVSV, respectively) obtained from two new automated three-dimensional transthoracic echocardiographic software-Dynamic HeartModel (DHM) and 3D Auto RV. Patients (n=116) with more than mild isolated CAR were included and divided into two groups: central (n=53) and eccentric CAR (n=63) groups. LVSV and RVSV were automatically measured by DHM and 3D Auto RV. Next, aortic regurgitant volume (ARVol) was calculated three ways: as the difference between LVSV and RVSV, by the two-dimensional proximal isovelocity surface area (PISA) method, and using effective regurgitant orifice area derived from real-time three-dimensional echocardiography (RT3DE) multiplied by CAR velocity time integral (the reference standard). DHM plus 3D Auto RV correlated well with RT3DE in ARVol measurement in both groups (central, r = 0.90; eccentric, r = 0.96), with no significant difference based on consistency analysis. In the eccentric group, PISA led to an obvious underestimation (mean difference= - 4.20 ml, P < 0.05). The kappa agreement between DHM plus 3D Auto RV and RT3DE in grading CAR severity in both groups was good (central, k = 0.89; eccentric, k = 0.86), but that between PISA and RT3DE in the eccentric CAR group was suboptimal (k = 0.74). This study indicates that ARVol quantification using DHM plus 3D Auto RV is feasible and reproducible in patients with more than mild isolated CAR. This new method has great correlation and agreement with RT3DE in ARVol measurement, with evident advantages over PISA in eccentric CAR.

Evaluation of the Left Ventricular Hemodynamic Status of Double-Root Translocation Patients Through Vector Flow Mapping.

The double-root translocation (DRT) procedure is considered as a new choice for surgical management of complex congenital heart disease. Our study aims to investigate the left ventricular hemodynamic status after DRT by energy loss (EL), involving 42 patients who underwent DRT as well as 42 healthy volunteers as controls. The EL of left ventricle (LV) during different periods (rapid filling-RF, atrial contraction-AC, isovolumic contraction-IVC, rapid ejection-RE) of the same cardiac cycle were obtained and analyzed. Compared to the controls, global LV and apical three chamber-EL at AC and IVC periods in DRT group were higher (p < 0.05), and EL at RE period of DRT group was moderately lower. In the correlation analysis, the global EL at the RF was correlated with E wave (r = 0.47, p = 0.03), E/e' (r = 0.50, p = 0.02), BSA (r = - 0.54, p = 0.01), and age (r = - 0.67, p < 0.001). AC and RE- global EL were significantly correlated with E/e' (r = 0.49, r = 0.59, p < 0.05). There was a strong positive correlation between E/e' and global EL at the IVC (r = 0.62, p = 0.003) and a moderate negative correlation with age (r = - 0.44, p = 0.04). The present study confirms that EL is a feasible and reproducible indicator for quantitatively evaluating LV hemodynamic status in patients who underwent DRT and reveals that DRT can lead to approximatively normal long-term hemodynamic performance of LV.