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ABSTRACT: The purpose of this study was to investigate whether myocardial systolic dysfunction and perfusion impairment occur in diabetic rats, and to assess their relationship using velocity vector imaging (VVI) and myocardial contrast echocardiography (MCE). Forty-six rats were randomly divided into either control or the diabetes mellitus (DM) groups. DM was induced by intraperitoneal administration of streptozotocin. Twelve weeks later, 39 survival rats underwent VVI and MCE in short-axis view at the middle level of the left ventricle, both at rest and after dipyridamole stress. VVI-derived contractile parameters included peak systolic velocity (V(s) ), circumferential strain (ε(c) ), strain rate (SR(c) ), and their reserves. MCE-derived perfusion parameters consisted of myocardial blood flow (MBF) and myocardial flow reserve (MFR). At rest, SR(c) in the DM group was significantly lower than in the control group, V(s) , ε(c) , and MBF did not differ significantly between groups. After dipyridamole stress, all VVI parameters and their reserves in the DM group were significantly lower than those in the control group, MBF and MFR were substantially lower than those in the control group, too. Meanwhile, significant correlations between VVI parameter reserves and MFR were observed in the DM group. Both myocardial systolic function and perfusion were impaired in DM rats. Decreased MFR could be an important contributor to the reduction in myocardial contractile reserve.
Echocardiography 08/2012; · 1.24 Impact Factor
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Haibin Zhang,
Jun Zhang,
Xiaoxing Zhu,
Lulu Chen,
Liwen Liu,
Yunyan Duan,
Ming Yu,
Xiaodong Zhou,
Ting Zhu,
Miaozhang Zhu,
Hongling Li
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ABSTRACT: The purpose of this study was to characterize left ventricular (LV) intracavitary flow during the isovolumic contraction (IVC) period in humans using vector flow mapping.
Color flow Doppler imaging was performed from the apical long-axis view in 61 patients with heart failure and 58 healthy volunteers. Doppler flow data obtained during IVC were analyzed offline with vector flow mapping.
A large vortex was formed from the LV inflow toward the outflow during IVC. In normal subjects, the area of the vortex was sustained, but the flow volume decreased significantly during IVC (P < 0.001). A significant apex-to-base flow velocity gradient was shown along the outflow axis on aortic valve opening. However, both the area and flow volume of the vortex decreased more severely during IVC in the patients (P < 0.001). The apex-to-base flow velocity gradient along the outflow axis disappeared and a reversed velocity gradient was observed at the basal-mid level on aortic valve opening. In multivariate models, a decreased LV ejection fraction was the only independent predictor of the percentage decrease in area of the vortex during the IVC (P < 0.001), and a larger QRS width (P = 0.028) and LV end-systolic long diameter (P = 0.002) were independent predictors of the percentage decrease in flow volume of the vortex.
The vortex across the LV inflow-outflow region during IVC facilitates the ejection of blood during early systole, and an unsustained vortex may be associated with impaired cardiac function.
Echocardiography 02/2012; 29(5):579-87. · 1.24 Impact Factor
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ABSTRACT: The aim of this study was to investigate whether velocity vector imaging (VVI) combined with stress echocardiography could detect potential diffused myocardial impairment of the left ventricle (LV) in diabetic rats.
Thirty-five male SD rats were randomly divided into either the control group or the diabetes mellitus (DM) group (induced with STZ). VVI was performed both at rest and after dipyridamole stress in all rats 12 weeks later. Segmental peak systolic velocity (V(s)), diastolic velocity (V(d)), radial strain (epsilon(r)), circumferential strain (epsilon(c)), systolic and diastolic radial strain rate (SR(r)), and circumferential strain rate (SR(c)) were measured from six segments at the mid-level of the LV.
At rest, systolic and diastolic SR(c) in the DM group were significantly lower than those in the control group. After dipyridamole stress, all VVI parameters in the DM group were significantly lower than those in the control group, although all values increased significantly after dipyridamole stress compared to those at rest in both groups.
The VVI-derived V(s,) V(d), epsilon(r), epsilon(c), systolic and diastolic SR(r) and SR(c), combined with dipyridamole stress are all effective parameters in evaluating potential myocardial impairment due to ultrastructural alterations of cardiocytes and microcirculation disturbances in DM rats. Systolic and diastolic SR(c) may be more sensitive indices that could be useful in detecting myocardial impairment at rest.
Echocardiography 08/2008; 25(6):609-16. · 1.24 Impact Factor
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ABSTRACT: To investigate the characteristics of myocardial acceleration in normal left ventricular walls, velocity vector imaging was performed in 30 normal volunteers. Peak accelerations during early systole and early diastole and time to peak acceleration during early systole were calculated for each segment of the standard 16-segment model. A gradient of accelerations from base to apex and a homogeneity of accelerations among different walls at the same level were observed. There were homogeneities of time to peak acceleration during early systole in both longitudinal and latitudinal directions on left ventricular walls. In 82.29% of all segments, the onset of contraction acceleration during early systole could not be identified. Further research with larger populations is needed to clarify the role of myocardial acceleration in the assessment of the site of initial electrical stimulation and the sequence of ventricular depolarization.
Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 08/2008; 21(7):813-7. · 2.98 Impact Factor
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ABSTRACT: Application of two-dimensional myocardial acceleration map derived from tissue Doppler imaging is limited by inherent angle dependency and substantial reader variability in the visualization of the origin of ventricular activation site. In this study we investigated the characteristics of myocardial acceleration in normal left ventricular (LV) walls with velocity vector imaging (VVI).
VVI was applied to the parasternal short-axis two-dimensional echocardiographic images at basal, mid, and apical levels of the LV in 30 normal volunteers. Peak acceleration during early systole (ACC(s)) and time to ACC(s) (TACC(s)) were calculated for each segment of the standard 16-segment model.
The time point of onset of active myocardial contraction corresponding to the QRS complex could not be determined in 409 (85.21%) of all 480 segments. No significant differences were found in TACC(s) among different LV levels and walls. In LV-free walls, there were no significant differences in ACC(s) among different LV levels and walls.
The time point of onset of myocardial active contraction during early systole cannot be determined in most of normal myocardial segments. Also, there is homogeneity of the time to early systolic peak acceleration in the whole normal LV walls. Myocardial acceleration seems to have limited potential in the assessments of the site of initial electrical stimulation and the sequence of ventricular depolarization.
Echocardiography 05/2008; 25(7):699-705. · 1.24 Impact Factor
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ABSTRACT: The early diastolic peak velocity of left ventricular (LV) wall segment has always been regarded as appearing in the rapid filling phase. However, we find some segments of which early diastolic peak velocities appear in the isovolumic relaxation period (PVIVR segments). The present study aimed to investigate the characteristics of PVIVR segments.
Tissue Doppler imaging was performed in each of the 16 segments of LV wall in 99 patients with known or suspected coronary heart disease and 50 normal subjects. Early diastolic velocity pattern was classified as PVIVR, post-systolic shortening (PSS) and normal pattern.
The multivariate logistic regression analyses showed that the significant echocardiographic predictors of the presence of PVIVR in a patient were transmitral E/A ratio and isovolumic relaxation time. Segmental early diastolic velocity pattern was significantly associated with actual coronary stenosis, relative coronary stenosis and wall motion score. PVIVR segments had a lower early diastolic peak velocity than other segments.
PVIVR segments more frequently appear in the territory with the relatively mildest coronary stenosis, whereas PSS segments more frequently appear in the territory with the relatively most severe coronary stenosis. Patients with PVIVR have lower global LV diastolic function. A decreased early diastolic peak velocity of PVIVR segments does not necessarily mean impaired myocardial relaxation.
The International Journal of Cardiovascular Imaging 05/2008; 24(4):389-97. · 2.29 Impact Factor
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ABSTRACT: The early diastolic peak velocity of left ventricular (LV) wall segment has always been thought to appear in the rapid filling phase. However, we find a segmental early relaxation phenomenon (SERP), characterized by an early diastolic peak velocity lying in the isovolumic relaxation (IVR) period. The present study aimed to investigate the characteristics of SERP segments with tissue Doppler imaging (TDI) echocardiography.
TDI was performed in 119 patients with known or suspected coronary heart disease (CHD) and 60 normal subjects. The segmental early diastolic velocity pattern was classified as normal pattern (NP), postsystolic shortening (PSS) and SERP.
Segmental early diastolic velocity pattern was significantly associated with actual coronary diameter stenosis, relative coronary stenosis, wall motion score, and segmental location in LV wall. Compared with other segments, SERP segments had a higher IVR velocity and lower early diastolic peak velocity.
SERP most frequently occurs in the distribution of artery with the relatively mildest stenosis, and is more likely accompanied by simultaneous PSS elsewhere in LV wall, which occurs most frequently in the distribution of artery with the relatively most severe stenosis. A decreased early diastolic peak velocity of SERP segment dose not necessarily mean impaired myocardial relaxation.
Echocardiography 04/2008; 25(3):278-88. · 1.24 Impact Factor
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Haibin Zhang M.D,
Yan Song M.D,
Yongsheng Zhu M.D,
Hongling Li M.D,
Ting Zhu M.D,
Yunqiu Qian M.D,
Liwen Liu M.D,
Jun Zhang M.D,
Xiaodong Zhou M.D,
Ph.D. Miaozhang Zhu M.D, Haibin Zhang,
Yan Song,
Yongsheng Zhu,
Hongling Li,
Ting Zhu,
Yunqiu Qian,
Liwen Liu,
Jun Zhang,
Xiaodong Zhou,
Miaozhang Zhu
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ABSTRACT: Background: The early diastolic peak velocity of left ventricular (LV) wall segment has always been thought to appear in the rapid filling phase. However, we find a segmental early relaxation phenomenon (SERP), characterized by an early diastolic peak velocity lying in the isovolumic relaxation (IVR) period. The present study aimed to investigate the characteristics of SERP segments with tissue Doppler imaging (TDI) echocardiography. Methods: TDI was performed in 119 patients with known or suspected coronary heart disease (CHD) and 60 normal subjects. The segmental early diastolic velocity pattern was classified as normal pattern (NP), postsystolic shortening (PSS) and SERP. Results: Segmental early diastolic velocity pattern was significantly associated with actual coronary diameter stenosis, relative coronary stenosis, wall motion score, and segmental location in LV wall. Compared with other segments, SERP segments had a higher IVR velocity and lower early diastolic peak velocity. Conclusion: SERP most frequently occurs in the distribution of artery with the relatively mildest stenosis, and is more likely accompanied by simultaneous PSS elsewhere in LV wall, which occurs most frequently in the distribution of artery with the relatively most severe stenosis. A decreased early diastolic peak velocity of SERP segment dose not necessarily mean impaired myocardial relaxation.
Echocardiography 02/2008; 25(3):278 - 288. · 1.24 Impact Factor
