Echocardiography is the most common diagnostic method for assessing atrial function but the technique has some limitations. Traditionally, assessment of left atrial function has been performed by measuring volumes wit...Echocardiography is the most common diagnostic method for assessing atrial function but the technique has some limitations. Traditionally, assessment of left atrial function has been performed by measuring volumes with 2D echocardiography. Additionally, it can be assessed with transmitral Doppler and pulmonary vein Doppler. Recently, an alternative method has been incorporated, namely, measurement of myocardial deformation with color tissue Doppler-derived strain. However, this method has several limitations, such as suboptimal reproducibility, angle-dependence, signal artifacts and the fact that it only measures regional strain and does not obtain information about the curved portion of the atrial roof. To overcome these limitations in the quantification of atrial function, the use of speckle tracking echocardiography (STE) strain has been proposed. This technique is not derived from Doppler but rather from 2D echocardiography; it is angle-independent and allows one to measure global as well as regional atrial strain. In this editorial, we describe the physical and pathophysiological concepts of STE and underline the clinical usefulness of this new technique.展开更多
AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patient...AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patients(mean age 53 ± 16 years,range:18-81 years,10 were male),with apical HCM. We measured global longitudinal peak systolic strain(GLPSS) in the midwall and endocardium of the left ventricle. RESULTS The diastolic thickness of the 4 apical segments was 16.25 ± 2.75 mm. All patients had a normal global systolicfunction with a fractional shortening of 50% ± 8%. In spite of supernormal left ventricular(LV) systolic function,midwall GLPSS was decreased in all patients,more in the apical(-7.3% ±-8.8%) than in basal segments(-15.5% ±-6.93%),while endocardial GLPPS was significantly greater and reached normal values(apical:-22.8% ±-7.8%,basal:-17.9% ±-7.5%). CONCLUSION This study shows that two-dimensional strain was decreased mainly confined to the mesocardium,while endocardium myocardial deformation was preserved in HCM and allowed to identify subclinical LV dysfunction. This transmural heterogeneity in systolic strain had not been previously described in HCM and could be explained by the distribution of myofibrillar disarray in deep myocardial areas. The clinical application of this novel finding may help further understanding of the pathophysiology of HCM.展开更多
Chronic functional mitral regurgitation(FMR) is a frequent finding of ischemic heart disease and dilated cardiomyopathy(DCM), associated with unfavourable prognosis. Several pathophysiologic mechanisms are involved in...Chronic functional mitral regurgitation(FMR) is a frequent finding of ischemic heart disease and dilated cardiomyopathy(DCM), associated with unfavourable prognosis. Several pathophysiologic mechanisms are involved in FMR, such as annular dilatation and dysfunction, left ventricle(LV) remodeling, dysfunction and dyssynchrony, papillary muscles displacement and dyssynchrony. The best therapeutic choice for FMR is still debated. When optimal medical treatment has already been set, a further option for cardiac resynchronization therapy(CRT) and/or surgical correction should be considered. CRT is able to contrast most of the pathophysiologic determinants of FMR by minimizing LV dyssynchrony through different mechanisms: Increasing closing forces, reducing tethering forces, reshaping annular geometry and function, correcting diastolic MR. Deformation imaging in terms of two-dimensional speckle tracking has been validated for LV dyssynchrony assessment. Radial speckle tracking and three-dimensional strain analysis appear to be the best methods to quantify intraventricular delay and to predict CRT-responders. Speckle-tracking echocardiography in patients with mitral valve regurgitation has been usually proposed for the assessment of LV and left atrial function. However it has also revealed a fundamental role of intraventricular dyssynchrony in determining FMR especially in DCM, rather than in ischemic cardiomyopathy in which MR severity seems to be more related to mitral valve deformation indexes. Furthermore speckle tracking allows the assessment of papillary muscle dyssynchrony. Therefore this technique can help to identify optimal candidates to CRT that will probably demonstrate a reduction in FMR degree and thus will experience a better outcome.展开更多
The present study investigated the application of echocardiography to evaluation of cardiac dyssynchrony in patients with congestive heart failure（CHF）. A total of 348 consecutive CHF patients who were admitted for ...The present study investigated the application of echocardiography to evaluation of cardiac dyssynchrony in patients with congestive heart failure（CHF）. A total of 348 consecutive CHF patients who were admitted for cardiac resynchronization（CRT） and presented with low ejection fraction（EF） and wide QRS duration were enrolled in this study, along with 388 healthy individuals. Dyssynchrony was assessed based on filling time ratio（FT/RR）, left ventricular pre-ejection delay（PED）, interventricular mechanical delay（IVMD）, longitudinal opposing wall delay（LOWD） and radial septal to posterior wall delay（RSPWD）. Response to CRT was defined as a ≥15% increase in EF. The results showed that FT/RR was decreased while PED, IVMD, LOWD and RSPWD were increased in the CHF group compared with the control group（P〈0.01）. In the CHF group, FT/RR was negatively correlated with the QRS duration, LV end-diastolic diameter（LVESd）, LV end-diastolic volume（LVEDV） and LV end-systolic volume（LVESV）（P〈0.01）, but positively with the LVEF（P〈0.01）. Additionally, PED, IVMD, LOWD and RSPWD were positively correlated with the QRS duration, LVESd, LVEDV and LVESV（P〈0.01）, but negatively with the LVEF（P〈0.01）. The CHF group was divided into three subgroups according to the varying degrees of LVEF. FT/RR decreased successively from the LVEF-1 group to the LVEF-2 group to the LVEF-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order（P〈0.01）. The CHF group was divided into three subgroups according to the varying degrees of QRS duration, and FT/RR decreased successively in a sequence from the QRS-1 group to the QRS-2 group to the QRS-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order（P〈0.01）. Speckle tracking radial dyssynchrony ≥130 ms was predictive of an EF response in patients in QRS-1 group（78% sensitivity, 83% specificity）, those in QRS-2 group（83% sensitivity, 77% specificity） and in QRS-3 group（89% sensitivity, 79% specificity）. In conclusion, echocardiography is a convenient and sensitive method for evaluating cardiac dyssynchrony in patients with CHF.展开更多
Background: Arterial hypertension determines distinct adaptive left ven tricula r geometric responses, which may differently affect left ventricular function an d left atrial performance. Objectives: In this study, th...Background: Arterial hypertension determines distinct adaptive left ven tricula r geometric responses, which may differently affect left ventricular function an d left atrial performance. Objectives: In this study, the effect of left ventr ic ular geometry on left atrial size and function, and the relationship between lef t atrial size and left ventricular mass were assessed in 336 patients with syste mic arterial hypertension who had undergone Doppler echocardiography. Methods an d results: Patients were classified into concentric (110 patients with concentri c left ventricular geometry defined as relative wall thickness ≥0.44) and eccen tric groups (226 patients with relative wall thickness< 0.44). Comparison to the latter, the former had greater left atrial size, left atrial ejection force, le ft ventricular mass and lower left ventricular midwall fractional shortening. Le ft ventricular concentric, rather than eccentric, geometry emerged by multivaria te analysis as a factor independently associated with the highest degree of left atrial ejection force. Left atrial size was positively related to left ventricu lar mass in the whole population (r=0.65, SEE=6 ml, P < 0.00001). This relations hip was maintained in the subgroups with concentric(r=0.65, SEE =6 ml, P < 0.000 01) or eccentric geometry (r=0.59,SEE= 6 ml, P < 0.00001). Conclusions: Our resu lts indicate that the relationship of left ventricular geometry to both left atr ial size and ejection force in hypertensive patients is relevant. Concentric lef t ventricular geometry is associated with greater left atrial size and ejection force than eccentric geometry, suggesting that increased left ventricular stiffn ess has a greater effect in stimulating left atrial performance than left ventri cular endsystolic stress. The degree of left atrial enlargement similarly depend s on left ventricularmass in patients with concentric and eccentric geometry.展开更多
Background: Tissue Doppler imaging(TDI) is useful in the evaluation of systolic and diastolic function. It allows assessment of ventricular dynamics in its longitudinal axis. We sought to investigate the difference in...Background: Tissue Doppler imaging(TDI) is useful in the evaluation of systolic and diastolic function. It allows assessment of ventricular dynamics in its longitudinal axis. We sought to investigate the difference in systolic and diastolic longitudinal function in patients with chronic heart failure(CHF) with normal and reduced ejection fraction. Methods and Results: One hundred ten outpatients with CHF and 68 controls were included. Ejection fraction(EF) was obtained and longitudinal systolic(S) and diastolic(E′ and A′ ) wall velocities were recorded from basal septum. Group A(controls) were normal and CHF patients were classified by EF in Group B1: >45% and B2: ≤ 45% . In A, B1 and B2 the mean S peak was 7.74; 5.45 and 4.89 cm/s(p< 0.001); the mean E′ peak was 8.56; 5.72 and 6.1 cm/s(p< 0.001); and the mean A′ peak was 10.2; 7.3 and 5.3 cm/s(p< 0.001). Also, isovolumic contraction and relaxation time were different among control and CHF groups,(both p< 0.001). The most useful parameters for identifying diastolic CHF were IVRT and S peak, with area under ROC curves of 0.93 and 0.89. The cut-off of 115 ms for IVRT and 5.8 cm/s for S peak showed a sensitivity of 94 and 97% , with a specificity of 82 and 73% , respectively. Conclusion: These findings suggest that impairment of left ventricular systolic function is present even in those with diastolic heart failure, and that abnormalities may have an important role to identifying the condition.展开更多
Objective: We evaluated the cardiovascular pathologic condition in the recipient twin in twin- to- twin transfusion syndrome and the influence of amnioreduction. Study design: Fetal echocardiograms and medical records...Objective: We evaluated the cardiovascular pathologic condition in the recipient twin in twin- to- twin transfusion syndrome and the influence of amnioreduction. Study design: Fetal echocardiograms and medical records of 54 pregnancies that were complicated by twin-to-twin transfusion syndrome were reviewed. Recipient twin right and left ventricular wall thickness, diameters, systolic and diastolic function, valve regurgitation, and structural cardiac defects were assessed at examination and after amnioreduction. Results: At examination (n = 28 pregnancies), cardiomegaly because of right ventricular and/or left ventricular hypertrophy was observed in 58% of recipient twins, and biventricular hypertrophy was observed in 33% of recipient twins, without ventricular dilation. Biventricular diastolic dysfunction was present in two thirds of recipient twins, and right ventricular systolic dysfunction and significant atrioventricular valve regurgitation was observed in one third of recipient twins. Serial assessment (n = 21 pregnancies) revealed progressive biventricular hypertrophy and right ventricular systolic and biventricular diastolic dysfunction in most recipient twins. Steeper progression of hypertrophy, diastolic dysfunction, and structural or functional right ventricular outflow disease (20% incidence) were associated with an increased perinatal mortality rate. Conclusion: In twin- to- twin transfusion syndrome, the recipient twin has progressive biventricular hypertrophy with predominant right ventricular systolic and biventricular diastolic dysfunction. Despite amnioreduction, the cardiovascular disease persists and even progresses in many recipient twins.展开更多
Background and Purpose -We evaluated the association between electrocardiographic left atrial abnormality (ECG-LAA) and ischemic stroke, especially whether ECG-LAA provides additional prognostic information to that pr...Background and Purpose -We evaluated the association between electrocardiographic left atrial abnormality (ECG-LAA) and ischemic stroke, especially whether ECG-LAA provides additional prognostic information to that provided by echocardiography. Methods -A population-based, case-control study included 146 patients with first ischemic stroke and 195 age-, gender-, and race/ethnicity-matched community control subjects. ECG-LAA was defined as either P-wave duration > 120 ms or P-terminal force in precordial lead V1 (PTFV1)>40 ms·mm. Results - TFV1 >40 ms·mm was associated with ischemic stroke after adjustment for other stroke risk factors (odds ratio [OR], 2.32; 95%CI, 1.29 to 4.18). The association remained significant after adding echocardiographic left atrial diameter to the model (OR, 2.31; 95%CI, 1.28 to 4.17). PTFV1 was independently associated with stroke in patients in the upper half of echocardiographically determined left ventricular mass (adjusted OR, 4.5; 95%CI, 2.20 to 9.15) but not in those in the lower half (OR, 0.58; 95%CI, 0.20 to 1.65; P=0.0008). Conclusions-ECG-LAA can supplement 2D echocardiography in assessing the risk of ischemic stroke, especially in subjects with increased left ventricular mass.展开更多
OBJECTIVE: To precisely visualize cardiac anatomic structures and simultaneously depict electro-mechanical events for the purpose of precise underblood intervention. METHODS: Intracardiac high-resolution tissue Dopple...OBJECTIVE: To precisely visualize cardiac anatomic structures and simultaneously depict electro-mechanical events for the purpose of precise underblood intervention. METHODS: Intracardiac high-resolution tissue Doppler imaging was used to map real time myocardial contractions in response to electrical activation within the anatomic structure of the cardiac conductive system using a canine open-chest model. RESULTS: The detailed inner anatomic structure of the cardiac conductive system at different sites (i.e., sino-atrial, atrial wall, atrial-ventricular node and ventricular wall) with the inside onset and propagation of myocardial velocity and acceleration induced by electrical activation was clearly visualized and quantitatively evaluated. CONCLUSION: The simultaneous single modality visualization of the anatomy, function and electrical events of the cardiac conductive system will foster target pacing and precision ablation.展开更多
文摘Echocardiography is the most common diagnostic method for assessing atrial function but the technique has some limitations. Traditionally, assessment of left atrial function has been performed by measuring volumes with 2D echocardiography. Additionally, it can be assessed with transmitral Doppler and pulmonary vein Doppler. Recently, an alternative method has been incorporated, namely, measurement of myocardial deformation with color tissue Doppler-derived strain. However, this method has several limitations, such as suboptimal reproducibility, angle-dependence, signal artifacts and the fact that it only measures regional strain and does not obtain information about the curved portion of the atrial roof. To overcome these limitations in the quantification of atrial function, the use of speckle tracking echocardiography (STE) strain has been proposed. This technique is not derived from Doppler but rather from 2D echocardiography; it is angle-independent and allows one to measure global as well as regional atrial strain. In this editorial, we describe the physical and pathophysiological concepts of STE and underline the clinical usefulness of this new technique.
文摘AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patients(mean age 53 ± 16 years,range:18-81 years,10 were male),with apical HCM. We measured global longitudinal peak systolic strain(GLPSS) in the midwall and endocardium of the left ventricle. RESULTS The diastolic thickness of the 4 apical segments was 16.25 ± 2.75 mm. All patients had a normal global systolicfunction with a fractional shortening of 50% ± 8%. In spite of supernormal left ventricular(LV) systolic function,midwall GLPSS was decreased in all patients,more in the apical(-7.3% ±-8.8%) than in basal segments(-15.5% ±-6.93%),while endocardial GLPPS was significantly greater and reached normal values(apical:-22.8% ±-7.8%,basal:-17.9% ±-7.5%). CONCLUSION This study shows that two-dimensional strain was decreased mainly confined to the mesocardium,while endocardium myocardial deformation was preserved in HCM and allowed to identify subclinical LV dysfunction. This transmural heterogeneity in systolic strain had not been previously described in HCM and could be explained by the distribution of myofibrillar disarray in deep myocardial areas. The clinical application of this novel finding may help further understanding of the pathophysiology of HCM.
文摘Chronic functional mitral regurgitation(FMR) is a frequent finding of ischemic heart disease and dilated cardiomyopathy(DCM), associated with unfavourable prognosis. Several pathophysiologic mechanisms are involved in FMR, such as annular dilatation and dysfunction, left ventricle(LV) remodeling, dysfunction and dyssynchrony, papillary muscles displacement and dyssynchrony. The best therapeutic choice for FMR is still debated. When optimal medical treatment has already been set, a further option for cardiac resynchronization therapy(CRT) and/or surgical correction should be considered. CRT is able to contrast most of the pathophysiologic determinants of FMR by minimizing LV dyssynchrony through different mechanisms: Increasing closing forces, reducing tethering forces, reshaping annular geometry and function, correcting diastolic MR. Deformation imaging in terms of two-dimensional speckle tracking has been validated for LV dyssynchrony assessment. Radial speckle tracking and three-dimensional strain analysis appear to be the best methods to quantify intraventricular delay and to predict CRT-responders. Speckle-tracking echocardiography in patients with mitral valve regurgitation has been usually proposed for the assessment of LV and left atrial function. However it has also revealed a fundamental role of intraventricular dyssynchrony in determining FMR especially in DCM, rather than in ischemic cardiomyopathy in which MR severity seems to be more related to mitral valve deformation indexes. Furthermore speckle tracking allows the assessment of papillary muscle dyssynchrony. Therefore this technique can help to identify optimal candidates to CRT that will probably demonstrate a reduction in FMR degree and thus will experience a better outcome.
文摘The present study investigated the application of echocardiography to evaluation of cardiac dyssynchrony in patients with congestive heart failure（CHF）. A total of 348 consecutive CHF patients who were admitted for cardiac resynchronization（CRT） and presented with low ejection fraction（EF） and wide QRS duration were enrolled in this study, along with 388 healthy individuals. Dyssynchrony was assessed based on filling time ratio（FT/RR）, left ventricular pre-ejection delay（PED）, interventricular mechanical delay（IVMD）, longitudinal opposing wall delay（LOWD） and radial septal to posterior wall delay（RSPWD）. Response to CRT was defined as a ≥15% increase in EF. The results showed that FT/RR was decreased while PED, IVMD, LOWD and RSPWD were increased in the CHF group compared with the control group（P〈0.01）. In the CHF group, FT/RR was negatively correlated with the QRS duration, LV end-diastolic diameter（LVESd）, LV end-diastolic volume（LVEDV） and LV end-systolic volume（LVESV）（P〈0.01）, but positively with the LVEF（P〈0.01）. Additionally, PED, IVMD, LOWD and RSPWD were positively correlated with the QRS duration, LVESd, LVEDV and LVESV（P〈0.01）, but negatively with the LVEF（P〈0.01）. The CHF group was divided into three subgroups according to the varying degrees of LVEF. FT/RR decreased successively from the LVEF-1 group to the LVEF-2 group to the LVEF-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order（P〈0.01）. The CHF group was divided into three subgroups according to the varying degrees of QRS duration, and FT/RR decreased successively in a sequence from the QRS-1 group to the QRS-2 group to the QRS-3 group, while the PED, IVMD, LOWD and RSPWD successively increased in the same order（P〈0.01）. Speckle tracking radial dyssynchrony ≥130 ms was predictive of an EF response in patients in QRS-1 group（78% sensitivity, 83% specificity）, those in QRS-2 group（83% sensitivity, 77% specificity） and in QRS-3 group（89% sensitivity, 79% specificity）. In conclusion, echocardiography is a convenient and sensitive method for evaluating cardiac dyssynchrony in patients with CHF.
文摘Background: Arterial hypertension determines distinct adaptive left ven tricula r geometric responses, which may differently affect left ventricular function an d left atrial performance. Objectives: In this study, the effect of left ventr ic ular geometry on left atrial size and function, and the relationship between lef t atrial size and left ventricular mass were assessed in 336 patients with syste mic arterial hypertension who had undergone Doppler echocardiography. Methods an d results: Patients were classified into concentric (110 patients with concentri c left ventricular geometry defined as relative wall thickness ≥0.44) and eccen tric groups (226 patients with relative wall thickness< 0.44). Comparison to the latter, the former had greater left atrial size, left atrial ejection force, le ft ventricular mass and lower left ventricular midwall fractional shortening. Le ft ventricular concentric, rather than eccentric, geometry emerged by multivaria te analysis as a factor independently associated with the highest degree of left atrial ejection force. Left atrial size was positively related to left ventricu lar mass in the whole population (r=0.65, SEE=6 ml, P < 0.00001). This relations hip was maintained in the subgroups with concentric(r=0.65, SEE =6 ml, P < 0.000 01) or eccentric geometry (r=0.59,SEE= 6 ml, P < 0.00001). Conclusions: Our resu lts indicate that the relationship of left ventricular geometry to both left atr ial size and ejection force in hypertensive patients is relevant. Concentric lef t ventricular geometry is associated with greater left atrial size and ejection force than eccentric geometry, suggesting that increased left ventricular stiffn ess has a greater effect in stimulating left atrial performance than left ventri cular endsystolic stress. The degree of left atrial enlargement similarly depend s on left ventricularmass in patients with concentric and eccentric geometry.
文摘Background: Tissue Doppler imaging(TDI) is useful in the evaluation of systolic and diastolic function. It allows assessment of ventricular dynamics in its longitudinal axis. We sought to investigate the difference in systolic and diastolic longitudinal function in patients with chronic heart failure(CHF) with normal and reduced ejection fraction. Methods and Results: One hundred ten outpatients with CHF and 68 controls were included. Ejection fraction(EF) was obtained and longitudinal systolic(S) and diastolic(E′ and A′ ) wall velocities were recorded from basal septum. Group A(controls) were normal and CHF patients were classified by EF in Group B1: >45% and B2: ≤ 45% . In A, B1 and B2 the mean S peak was 7.74; 5.45 and 4.89 cm/s(p< 0.001); the mean E′ peak was 8.56; 5.72 and 6.1 cm/s(p< 0.001); and the mean A′ peak was 10.2; 7.3 and 5.3 cm/s(p< 0.001). Also, isovolumic contraction and relaxation time were different among control and CHF groups,(both p< 0.001). The most useful parameters for identifying diastolic CHF were IVRT and S peak, with area under ROC curves of 0.93 and 0.89. The cut-off of 115 ms for IVRT and 5.8 cm/s for S peak showed a sensitivity of 94 and 97% , with a specificity of 82 and 73% , respectively. Conclusion: These findings suggest that impairment of left ventricular systolic function is present even in those with diastolic heart failure, and that abnormalities may have an important role to identifying the condition.
文摘Objective: We evaluated the cardiovascular pathologic condition in the recipient twin in twin- to- twin transfusion syndrome and the influence of amnioreduction. Study design: Fetal echocardiograms and medical records of 54 pregnancies that were complicated by twin-to-twin transfusion syndrome were reviewed. Recipient twin right and left ventricular wall thickness, diameters, systolic and diastolic function, valve regurgitation, and structural cardiac defects were assessed at examination and after amnioreduction. Results: At examination (n = 28 pregnancies), cardiomegaly because of right ventricular and/or left ventricular hypertrophy was observed in 58% of recipient twins, and biventricular hypertrophy was observed in 33% of recipient twins, without ventricular dilation. Biventricular diastolic dysfunction was present in two thirds of recipient twins, and right ventricular systolic dysfunction and significant atrioventricular valve regurgitation was observed in one third of recipient twins. Serial assessment (n = 21 pregnancies) revealed progressive biventricular hypertrophy and right ventricular systolic and biventricular diastolic dysfunction in most recipient twins. Steeper progression of hypertrophy, diastolic dysfunction, and structural or functional right ventricular outflow disease (20% incidence) were associated with an increased perinatal mortality rate. Conclusion: In twin- to- twin transfusion syndrome, the recipient twin has progressive biventricular hypertrophy with predominant right ventricular systolic and biventricular diastolic dysfunction. Despite amnioreduction, the cardiovascular disease persists and even progresses in many recipient twins.
文摘Background and Purpose -We evaluated the association between electrocardiographic left atrial abnormality (ECG-LAA) and ischemic stroke, especially whether ECG-LAA provides additional prognostic information to that provided by echocardiography. Methods -A population-based, case-control study included 146 patients with first ischemic stroke and 195 age-, gender-, and race/ethnicity-matched community control subjects. ECG-LAA was defined as either P-wave duration > 120 ms or P-terminal force in precordial lead V1 (PTFV1)>40 ms·mm. Results - TFV1 >40 ms·mm was associated with ischemic stroke after adjustment for other stroke risk factors (odds ratio [OR], 2.32; 95%CI, 1.29 to 4.18). The association remained significant after adding echocardiographic left atrial diameter to the model (OR, 2.31; 95%CI, 1.28 to 4.17). PTFV1 was independently associated with stroke in patients in the upper half of echocardiographically determined left ventricular mass (adjusted OR, 4.5; 95%CI, 2.20 to 9.15) but not in those in the lower half (OR, 0.58; 95%CI, 0.20 to 1.65; P=0.0008). Conclusions-ECG-LAA can supplement 2D echocardiography in assessing the risk of ischemic stroke, especially in subjects with increased left ventricular mass.
文摘OBJECTIVE: To precisely visualize cardiac anatomic structures and simultaneously depict electro-mechanical events for the purpose of precise underblood intervention. METHODS: Intracardiac high-resolution tissue Doppler imaging was used to map real time myocardial contractions in response to electrical activation within the anatomic structure of the cardiac conductive system using a canine open-chest model. RESULTS: The detailed inner anatomic structure of the cardiac conductive system at different sites (i.e., sino-atrial, atrial wall, atrial-ventricular node and ventricular wall) with the inside onset and propagation of myocardial velocity and acceleration induced by electrical activation was clearly visualized and quantitatively evaluated. CONCLUSION: The simultaneous single modality visualization of the anatomy, function and electrical events of the cardiac conductive system will foster target pacing and precision ablation.
