The volume-time curve change in patients with normal left ventricular (LV) diastolic function and diastolic dysfunction was evaluated by real-time three-dimensional echocardiography (RT3DE). LV diastolic dysfunction was defined by E'ventricular septal (IVS) of mitral annulus. In 24 patients with LV diastolic dysfunction, including 12 patients with delayed relaxation (delayed relaxation group) and 12 patients with pseudo-normal function (pseudo-normal group) and 24 normal volunteers (control group), data of full-volume image were acquired by real-time three-dimensional echocardiography and subjected to volume-time curve analysis. EDV (end-diastolic volume), ESV (end-systolic volume), LVEF (left ventricular ejection fraction), PER (peak ejection rate), PFR (peak filling rate) from RT3DE were examined in the three groups. Compared to the control group, PFR (diastolic filling index of RT3DE) was significantly reduced in the delayed relaxation group and pseudo-normal group (P<0.05). There were no significant differences in EDV, ESV, LVEF, PER (P>0.05). It is concluded that PFR, as a diastolic filling index of RT3DE, can reflect the early diastolic function and serve as a new non-invasive, quick and accurate tool for clinical assessment of LV diastolic function.
Diastole/physiology ; Echocardiography, Three-Dimensional/*methods ; Ventricular Dysfunction, Left/physiopathology ; Ventricular Dysfunction, Left/*ultrasonography ; Ventricular Function, Left/*physiology

BACKGROUNDFrequent premature ventricular complexes from the right ventricular outflow tract (RVOT-PVCs) are associated with left ventricular dysfunction. This study adopted two-dimensional speckle tracking imaging to evaluate global and regional left ventricular myocardial function in patients with frequent RVOT-PVCs.

METHODSThis study included 30 patients with frequent RVOT-PVCs and 30 healthy subjects. Aortic systolic velocity-time integral (AoVTI) and myocardium strain in circumferential (CS), radial (RS) and longitudinal (LS) directions were evaluated by conventional echocardiography and speckle tracking imaging. All values of patients with RVOT-PVCs were recorded during sinus (PVC-S) and PVC beats (PVC-V).

RESULTSSignificant differences were demonstrated in global CS, RS and LS between the control subjects and the PVC-V (CS: (17.46 ± 2.48)% vs. (11.52 ± 3.28)%, RS: (48.26 ± 10.20)% vs. (20.92 ± 9.78)%, LS: (19.89 ± 2.62)% vs. (11.79 ± 3.66)%, P < 0.01), and in segmental RS and LS of nearly all the left ventricular segments. Statistical differences in segmental CS between the PVC-V and the control subjects were only observed in anterior, anteroseptal and septal segments (only seen in anteroseptal and septal segments at apex). Furthermore, V/S AoVTI (AoVTI during the PVC beat divided by AoVTI during the sinus beat, then multiplied by 100%) correlated with coupling interval (r = 0.67, P < 0.001) and global strain (CS: r = 0.48, P = 0.007; RS: r = 0.65, P < 0.001; LS: r = 0.65, P < 0.001).

CONCLUSIONSFrequent RVOT-PVCs can induce global and regional left ventricular systolic dysfunction. The reduction of hemodynamic parameters relates to the coupling interval and the global systolic function.

Adult ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Ventricular Function, Left ; physiology ; Ventricular Premature Complexes ; physiopathology

OBJECTIVETo exacted analysis each time interval in isovolumic relaxation time (IVRT) of normal subjects through observin the changes of cardiac structure and hemodynamics during the IVRT. Then to provide the evidence of cardiac resynchronization therapy.

METHODSQuantitative analysis was performed for 60 subjects. The dual-channel echocardiography(DCE), pulse wave doppler (PW) and tissue wave dapper (TDI) examination of all the subjects were recorded, and IVRT was divided into two intervals, isovolumic relaxation time of early intervals (IVRTe) and isovolumic relaxation time of late interval (IVRT1). Then measured the time of each interval. Indicators were used including: (1) IVRT; (2) IVRTe; (3) IVRTI; (4) IVRTI/IVRT; calculating the data after heart rate corrected; (5) cIVRT; (6) clVRTe; (7) clVRTI; (8) clVRTI/clVRT; (9) measuring the time difference in mitral blood and tissue (TE-é) of DCE group.

RESULTSThe i-wave within IVRT in PW images was found in 45 subjects, and the i-wave was about 1/2 of IVRT (49.17 +/- 5.37) ms. IVRT was divided into IVRTe and IVRTI by a turning point at descending branch of i-wave as t-point. The j-wave was observed in 84% TDI images, and the j-wave was about 1/2 of IVRT (43.13 +/- 4.83) ms. IVRT was divided into IVRTe and IVRTI by a turning point of the onset of j-wave as t-point. A significant difference was found between PW and TDI with measurement of IVRT, IVRTe, IVRTI (P < 0.05). There were no significant differences between the common group and DCE group (P > 0.05). After heart rate corrected, the data showed no significant difference using pairwise comparisons among the three groups (P > 0.05). The mean and standard deviation of IVRTI/IVRT, cIVRTI/clVRT were (0.50 +/- 0.12) ms. There were little difference of time intervals and good consistenc using DCE measured IVRT with multiple tests confinmed.

CONCLUSIONThe study found that IVRT might be divided into IVRTe and IVRT1 phases. There were i-wave in IVRTe and j-wave in IVRT1. The t-point was nearly midpoint inisovolumic relaxation time.

Adult ; Diastole ; physiology ; Echocardiography ; Female ; Healthy Volunteers ; Humans ; Male ; Middle Aged ; Ventricular Function, Left ; physiology

There have been insufficient numerical methods for particular description and quantitative evaluation of left ventricular diastolic function in the studies in this area. We therefore have summarized the computational models of the affecting factors for diastolic function from five aspects, i. e. the geometry shape of left ventricular, myocardial stiffness, myocardial viscosity, myocardial relaxation and ventricular interaction respectively. Controlling the sensitive parameters and having a mathematical description on left ventricular diastolic dysfunction can provide numerical methods for clinical diagnosis and quantitative evaluation of the disease.
Computer Simulation ; Diastole ; physiology ; Humans ; Models, Theoretical ; Numerical Analysis, Computer-Assisted ; Ventricular Function, Left ; physiology

OBJECTIVETo study the differences of cardiovascular system between men and women in response to exercise stress.

METHODSForty healthy youth were tested according to Bruce protocol of exercise stress. They were detected by ultrasonography during the rest, peak exercise, and recovery stages, respectively. The left ventricular diastolic elastance (Ed), effective arterial elastance (Ea), left ventricular end-systolic elatance (Ees), ventricular-vascular coupling index (VVI), and total stiffness index (TSI) were measured and calculated according to the formulas. The results of all stages were compared according to genders.

RESULTSAll stages, the Ed, TSI, and VVI of women were higher than those of men, but the Ees was lower than that of men (all P<0.05); there was no significant difference in Ea between men and women. The Ed, Ees, Ea, and TSI were closely related with left ventricular oxygen consumption and heart function, and women showed more closely. Before and after exercise, the changes were different in Ed, Ees, Ea, TSI, and VVI (all P<0.05), and VVI changed least.

CONCLUSIONSBefore and after exercise, the ventricular stiffness matched well with arterial stiffness and maintained within a narrow range. For women, the tolerance of exercise was lower than that of men.

Adult ; Diastole ; physiology ; Exercise ; physiology ; Female ; Humans ; Male ; Sex Characteristics ; Vascular Resistance ; physiology ; Vascular Stiffness ; physiology ; Ventricular Function, Left ; physiology

Adult ; Echocardiography, Three-Dimensional ; methods ; Heart Ventricles ; diagnostic imaging ; Humans ; Stroke Volume ; physiology ; Ventricular Function ; Ventricular Function, Left ; Ventricular Function, Right

BACKGROUNDSince the size of ischemic myocardium is closely related with both global and regional function of the myocardium, it is of great significance to measure the size of ischemic myocardium with non-invasive methods.

METHODSEleven mongrel dogs were subjected to occlusion of the left anterior descending coronary artery for acute ischemia. Strain rate imaging had M-mode of strain-rate (CAMM) curve pointed from the basal segment of the anterior wall to the basal segment of the inferior wall to detect the border of ischemia size. The strain rate (SR) defined the cut-off value of ischemic myocardium in a two-chamber apical view, and marked by the anterior and inferior wall on two-dimensional images respectively. Along the endocardium and epicardium, the ischemic size was curved on two-dimensional images by the trackball method and then compared with the pathologically ischemic size. And then longitudinal strain rates were compared in the cut-off value, adjacent non-ischemic and ischemic segments at which the cut-off point was defined by changing the curve M-mode of strain rate after ischemia.

RESULTSLinear correlation existed between pathology and strain rate ischemic size (r = 0.884, P < 0.001). The SR parameters were lower in ischemia and cut-off point than in non-ischemic segments. The peak SRs of systole (S(SR)), early diastole (E(SR)), late diastole (A(SR)), strain during ejection time (epsilon(et)), and the maximum length change during the entire heart cycle (epsilon(max)) in ischemic segments lowered (P < 0.05). Time to onset of regional relaxation (T(R)) was prolonged (P = 0.012).

CONCLUSIONSR imaging can accurately assess the size of ischemic myocardium.

Animals ; Dogs ; Echocardiography, Doppler ; methods ; Female ; Male ; Myocardial Ischemia ; diagnostic imaging ; pathology ; Ventricular Function, Left ; physiology

OBJECTIVETo evaluate left ventricular function in neonates with congenital hypothyroidism (CH) and its correlation with thyroid hormones serum levels.

METHODSM-mode echocardiography [left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS)], pulse wave Doppler [the peak early diastolic mitral inflow velocity (Em), the peak late diastolic mitral inflow velocity (Am)], quantitative tissue velocity imaging (QTVI) [the systolic peak mitral annular velocity (sm), the early diastolic peak mitral annular velocity (em), the late diastolic peak mitral annular velocity (am)] and tissue tracking imaging (TTI) [the systolic mitral annular displacement (MAD)] were evaluated in 35 neonates with congenital hypothyroidism aged 15-28 days and 30 normal neonates in this study. Correlation analysis was also made between left ventricular function and serum TT3, TT4 and TSH levels.

RESULTSLeft systolic function parameters (LVEF, LVFS, sm and MAD) were 0.62 +/- 0.08, (28.21 +/- 5.31)%, (2.58 +/- 0.59) cm/s and (0.27 +/- 0.07) cm, respectively, in CH group, and 0.67 +/- 0.06, (31.16 +/- 4.13)%, (3.24 +/- 0.52) cm/s and (0.41 +/- 0.08) cm in control group (P < 0.05, P < 0.01). Left diastolic function parameters (Am, Em/Am, em/am, Em and em) were (0.59 +/- 0.10) m/s, 0.98 +/- 0.18, 0.82 +/- 0.40, (0.57 +/- 0.11) m/s and (2.83 +/- 1.48) cm/s, respectively, in CH group, and (0.65 +/- 0.10) m/s, 1.14 +/- 0.20, 1.25 +/- 0.33, (0.73 +/- 0.11) m/s and (4.46 +/- 1.29) cm/s in control group (P < 0.05, P < 0.01). MAD, sm, Em and em in CH group were greatly lower than that in control group (P < 0.001). Left systolic function (LVEF, sm, MAD) and diastolic function (Em, Am, em, em/am) were positively correlated with TT3, TT4 serum levels (P < 0.05, P < 0.01), and negatively with TT4 serum levels (P < 0.05, P < 0.01). MAD, Em and em were highly correlated with TT4, TSH serum levels (r = 0.700, r = 0.564, r = 0.593, r = 0.564, P < 0.001; r = -0.674, r = -0.521, r = -0.578, r = -0.632, P < 0.001).

CONCLUSIONSNeonates with CH have lower left systolic and diastolic function. Left ventricular function was affected by thyroid hormones. QTVI and TTI are more sensitive parameters in evaluating left ventricular function of neonates with congenital hypothyroidism than conventional echocardiography.

Congenital Hypothyroidism ; Echocardiography ; Female ; Humans ; Hypothyroidism ; physiopathology ; Infant, Newborn ; Male ; Ventricular Function, Left ; physiology

BACKGROUNDStrain and strain-rate imaging (SRI) have been found clinically useful in the assessment of cardiac systolic and diastolic function as well as providing new insights in deciphering cardiac physiology and mechanics in cardiomyopathies, and identifying early subclinical changes in various pathologies. The aim of this study was to evaluate the regional and global left ventricular (LV) myocardial function in metabolic syndrome (MS) with SRI so that we can provide more myocardial small lesions in patients with MS, which is robust and reliable basis for early detection of LV function.

METHODSThirty-nine adults with MS were enrolled in the study. There was a control group of 39 healthy adults. In addition to classic echocardiographic assessment of LV global functional changes, SRI was used to evaluate regional and global LV function. Including: Peak systolic strain (S), peak systolic strain-rate (SR-s), peak diastolic strain-rate (SR-e).

RESULTSThere were no statistically significant differences between MS and controls in all traditional parameters of LV systolic function. On the other hand, significant differences were observed between MS and the control group in most of the parameters of S, SR-s, SR-e in regional LV function. Multiple stepwise regression analyses revealed that S and SR significantly were negatively correlated with blood pressure, waist circumference, fasting plasma glucose, uric acid, suggesting that risk factories were relevant to regional systolic dysfunction.

CONCLUSIONIn MS with normal LV ejection fraction, there was regional myocardial dysfunction, risk factors contributed to the impairment of systolic and diastolic function of the regional myocardium. Assessment of myocardial function using SRI could be more accurate in MS patient evaluation than conventional echocardiography alone.

Echocardiography ; Female ; Humans ; Male ; Metabolic Syndrome ; physiopathology ; Middle Aged ; Ventricular Function, Left ; physiology

OBJECTIVETo investigate the changes of the cardiac hemodynamics after acute high altitude exposure in healthy young males and the relationship with acute mountain sickness(AMS).

METHODSLeft ventricular function and oxyhemoglobin saturation (SaO2), heart rate (HR), blood pressure (BP) were measured in 218 healthy young males before and after high altitude exposure within 24 h respectively. According to the lake louise score criteria, the subjects were divided into two groups: acute mountain sickness group (AMS group) and non acute mountain sickness group (non-AMS group).

RESULTSHR, diastolic blood pressure (DBP), mean arterial pressure (MAP), left ventricular ejection fraction (LVEF), stroke volume (SV), stroke index (SI) cardiac output (CO), cardiac index (CI) were significantly increased upon acute high altitude exposure (P < 0.05). Whereas SaO2 and end-systolic volume (ESV) were significantly decreased (P < 0.05). In addition, HR, systolic blood pressure (SBP) and MAP in AMS group were significantly higher than those in non-AMS group (P < 0.05). But stroke index (SI) and end-diastolic volume (EDV) in AMS group were significantly lower than those in non-AMS group (P < 0.05).

CONCLUSIONCardiac function in healthy young males upon acute high altitude exposure was enhanced. EDV, HR and SI might become the indexes of predicting the acute mountain sickness in the future.

Acute Disease ; Adult ; Altitude ; Altitude Sickness ; physiopathology ; Humans ; Male ; Ventricular Function, Left ; physiology