The relationship between tissue Doppler imaging and seric NTproBNP levels in sinus rhythm patients: a prospective study

N-terminal pro-brain natriuretic peptide (NTproBNP) correlates with left ventricular (LV) filling pressure. The ratio between early diastolic transmitral velocity and early mitral annular diastolic velocity (E/Ea) reflects LV filling pressure in a variety of cardiac diseases. However this relationship was not validated in some categories of patients. Our aim was to evaluate the correlation between tissue Doppler velocities of the mitral annulus and NTproBNP levels in sinus rhythm patients. Methods Echocardiography was performed in 111 consecutive patients simultaneously with NTproBNP measurement. E/Ea and E/(Ea × Sa) were calculated (Sa is the maximal systolic velocity of mitral annulus); the average of the velocities of septal and lateral mitral annulus was used. Results Simple regression analysis demonstrated a significant linear correlation between E/(Ea × Sa) and NTproBNP (r = 0.71, P < 0.0001), superior to E/Ea correlation (r = 0.58, P < 0.0001). Significant but weaker correlations were found between NTproBNP and Sa, pulmonary artery systolic pressure, Ea, mitral E/A (early/late diastolic transmitral velocity), E wave, mitral E deceleration time and LV ejection fraction (LVEF). The optimal E/(Ea × Sa) cut-off for prediction of NTproBNP levels > 900 pg/ml was 1.5 (sensitivity = 81%, specificity = 70%). Among analyzed parameters, E/(Ea × Sa) was best correlated with NTproBNP levels in patients with LVEF ≥ 50% (r = 0.80, P < 0.0001), with depressed LVEF (<50%) (r = 0.66, P < 0.0001), with regional wall motion abnormalities (r = 0.75, P < 0.0001), and with E/Ea 8 to 15 (r = 0.58, P < 0.0001). Conclusions E/(Ea × Sa) strongly correlates with NTproBNP, regardless of LVEF, and can be a simple and accurate echocardiographic index in patients in sinus rhythm, particularly in those with regional wall motion abnormalities or intermediate E/Ea.     

腰椎间盘突出症患者受压神经根DTI与临床表现的相关性

目的 探讨腰椎间盘突出症患者受压神经根DTI相关参数的变化,及其与基于临床症状的Oswestry功能障碍指数（ODI）、视觉模拟评分（VAS）的相关性。方法 25例经临床和手术证实为单侧神经根受压的腰椎间盘突出症患者纳入本研究,全部患者术前均接受DTI扫描和ODI与VAS评分,ODI、VAS用于评价患者受压神经根对应的特征性下肢疼痛区域。结果 腰椎间盘突出症患者患侧与健侧神经根FA值分别为0.26±0.05、0.36±0.05,ADC值分别为（1.69±0.32）×10^-3 mm²/s、（1.56±0.21）×10^-3 mm²/s;患侧FA值与ODI （r=-0.88,P < 0.01）及VAS评分（r=-0.66,P < 0.01）呈负相关,ADC值与ODI （r=0.30,P=0.15）及VAS评分（r=0.36,P=0.08）无相关关系。结论 DTI的FA值可能是量化神经根结构改变的重要参数,腰椎间盘突出症患者神经根结构的损伤可能是产生临床症状的重要原因。     

Strain and strain rate echocardiography for evaluation of right ventricular dysfunction in patients with idiopathic pulmonary arterial hypertension

Optimizing the non-invasive imaging of right ventricular (RV) function is of increasing interest for therapy monitoring and risk stratification in patients with idiopathic pulmonary hypertension (IPAH). Therefore, this study evaluated strain and strain rate echocardiography as a tool for comprehensive assessment of RV function and disease severity in IPAH patients. In 30 IPAH patients [WHO functional classes II–IV; mean pulmonary artery pressure (mPAP) 48.8 ± 12.5 mmHg; pulmonary vascular resistance (PVR) 7.9 ± 5.3 Wood units] and in 10 matched healthy control subjects’ two-dimensional echocardiography, 6-MWD and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were obtained. In IPAH patients when compared with controls, RV systolic strain (−18.8 ± 4.3 vs. −34.5 ± 3.8%, p = 0.0016) and strain rate (−1.6 ± 0.6 vs. −2.7 ± 0.5 s⁻¹, p = 0.018) were significantly altered and correlated significantly with elevated NT-proBNP levels (r = 0.73 and r = 0.62; p < 0.001, respectively) and reduced 6-MWD (r = −0.76 and r = −0.81; p < 0.001). In IPAH patients, reduced strain correlated with both mPAP (r = 0.61, p = 0.01 for strain; and r = 0.55, p = 0.04 for strain rate, respectively), and PVR (r = 0.84, p < 0.001 for strain; and r = 0.67, p < 0.001 for strain rate, respectively). This study gives first comprehensive evidence that strain echocardiography allows accurate non-invasive assessment of RV function and disease severity in patients with IPAH.     

Right ventricular myocardial isovolumic relaxation time and pulmonary pressure

Aims: Non‐invasive assessment of pulmonary artery systolic pressure (PASP) has several limitations. As previously described by Burstin, the right ventricular (RV) isovolumic relaxation time (IVRt) is sensitive to changes in PASP. We therefore compared RV myocardial IVRt, derived by Doppler tissue imaging (DTI), with simultaneously measured invasive PASP. Methods and results: Twenty‐six consecutive patients (18 males, mean age 52 ± 12 years, range 23–75) underwent a simultaneous Doppler echocardiography, including DTI, and cardiac catheterization examination for measurement of PASP and right atrial mean pressures. IVRt was measured using the myocardial velocities by pulsed DTI at both basal and mid cavity segments of the RV free wall. As diastolic time intervals are influenced by heart rate IVRt was corrected for heart rate (IVRt/RR%). A significant correlation was found between PASP and regional IVRt/RR% at both the basal (r = 0·42, P<0·05) and mid cavity segment (r = 0·71, P<0·001). Furthermore, when only patients with normal right atrial pressures (<7 mmHg) were taken into account, the correlation coefficient improved at both basal and mid cavity segments (r = 0·74, P<0·05 and r = 0·83, P<0·01). Conclusion: Pulsed Doppler‐derived IVRt correlates well with PASP. The use of pulsed DTI for measurement of IVRt is simple, reproducible and easy to obtain. We propose this method as an additional non‐invasive tool in the assessment of PASP.     

Angiographically uncertain left main coronary artery narrowings: correlation with multidetector computed tomography and intravascular ultrasound

Background Angiographic assessment of left main coronary artery (LMCA) stenosis is often difficult and unreliable. To date, intravascular ultrasound (IVUS) is used to determine the significance of lesions in patients with LMCA stenosis of uncertain significance. We aimed to prospectively show the ability of multidetector computed tomography (MDCT) to assess LMCA luminal and plaque dimensions, and to characterize atherosclerotic plaque, as compared to IVUS and quantitative coronary angiography (QCA), in patients with angiographically uncertain LMCA stenosis. Methods Twenty patients, with angiographically uncertain LMCA stenosis, underwent coronary evaluation with IVUS, QCA and 16-slice MDCT. Minimal lumen diameter (MLD), minimal lumen area (MLA), lumen area stenosis (LAS) and plaque burden (PB) were assessed. Results The MLD (median [interquartile range]) was 3.2 mm (2.5–3.7) by IVUS, 2.8 mm (2.3–3.3) by QCA (r = 0.52, P < 0.05), and 2.8 mm (2.5–3.8) by MDCT (r = 0.77, P < 0.01). MDCT estimated MLA as 10.7 mm² (7.1–12.6) Vs. 9.9 mm² (6.5–13.5) by IVUS (r = 0.93, P < 0.01). Very high correlations were observed between MDCT and IVUS in assessing LAS (mean ± SD) (25.8 ± 19.1% and 29.0 ± 24.9% respectively, r = 0.83, P < 0.01), and PB (49.2 ± 15.8% and 49.2 ± 19.7% respectively, r = 0.94, P < 0.01). MDCT assigned plaque as being non-calcified with a sensitivity of 100%, while calcified plaques with a sensitivity of 75%. Conclusion A high degree of correlation was found between MDCT and IVUS regarding the assessment of minimal lumen diameter and area, lumen area stenosis and plaque burden as well as plaque characterization in patients with angiographically borderline LMCA stenosis. Therefore, in patients selected for non-invasive coronary tree evaluation, MDCT may provide a valuable tool for the assessment, decision-making and follow-up of patients with uncertain LMCA disease.     

Right ventricular peak systolic longitudinal strain is a sensitive marker for right ventricular deterioration in adult patients with tetralogy of Fallot

The aim of this study was to evaluate the feasibility of right ventricular (RV) longitudinal peak systolic strain (LPSS) assessment for the follow-up of adult patients with corrected tetralogy of Fallot (TOF). Adult patients (n = 18) with corrected TOF underwent echocardiography and CMR twice with a time interval of 4.2 ± 1.7 years. RV performance was derived from CMR, and included RV volumes and ejection fraction (EF). LPSS was calculated globally (GLPSS) and in the RV free wall (LPSS FW), with echocardiographic speckle-tracking strain-analysis. Baseline (G)LPSS values were compared between patients and healthy controls; the relation between (G)LPSS and CMR parameters was evaluated and the changes in (G)LPSS and CMR parameters during follow-up were compared. GLPSS and LPSS FW were significantly reduced in patients as compared to controls (−14.9 ± 0.7% vs. −21.6 ± 0.9% and −15.5 ± 0.9% vs. −22.7 ± 1.5%, P < 0.01). Moderate agreement between LPSS and CMR parameters was observed. RV EF remained unchanged during follow-up, whereas GLPSS and LPSS FW demonstrated a significant reduction. RVEF showed a 1% increase, whereas GLPSS decreased by 14%, and LPSS FW by 27%. RV LPSS is reduced in TOF patients as compared to controls; during follow-up RV EF remained unchanged whereas LPSS decreased suggesting that RV LPSS may be a sensitive marker to detect early deterioration in RV performance.     

多普勒组织成像技术评价充血性心力衰竭患者左室功能改变

目的:采用组织多普勒技术(DTI)观察充血性心力衰竭(心衰)患者心肌收缩功能指标与NYHA心功能分级的关系及其治疗前后左室收缩、舒张功能的改变。方法:以34例心衰患者为心衰组,34例正常人作为对照组,采用DTI测量二尖瓣环的后间隔和侧壁处(心尖四腔切面观)及前壁和下壁处(心尖二腔切面观)4个位点的收缩期、舒张早期和舒张晚期运动速度峰值(分别为Sa,Ea,Aa)。计算Ea/Sa、二尖瓣环4个位点平均收缩速度VMS。结果:二尖瓣环侧壁位点的收缩速度与NYHA心功能分级相关性较好(rs=-0.65,P<0.0001),而VMS与NYHA心功能分级相关性最好(rs=-0.69,P<0.0001)。心衰组治疗前4个位点的Sa和Ea均显著低于正常组(P<0.001),Ea/Sa较正常组增高(P<0.01)。心衰组治疗后4个位点的Sa和Ea均显著高于治疗前(P<0.001),Ea/Sa较治疗前减低(P<0.01)。结论:DTI可定量分析心衰患者左室壁的舒缩功能及动态变化。二尖瓣环4个位点平均收缩峰值速度VMS与NYHA心功能分级关系最密切。     

Correlation of the myocardial performance index with plasma B-type natriuretic peptide levels in patients with mitral regurgitation

Objective The Myocardial performance index (MPI) is an echocardiographic index of combined systolic and diastolic function, calculated as isovolumetric relaxation time plus isovolumetric contraction time divided by ejection time. The aim of this study was to define the correlation of the MPI with plasma B-type natriuretic peptide (BNP) levels and echocardiographic parameters in patients with chronic mitral regurgitation (MR). Methods About 33 patients with at least moderate MR of organic etiology were enrolled to the study. All patients undergone complete 2D and Doppler echocardiography. Plasma BNP levels were studied. Results BNP levels in NYHA classes I–III were 9.3 ± 2.2 pg/ml, 61.3 ± 12.2 pg/ml, and 199.6 ± 55.2 pg/ml, respectively (I vs. II P < 0.001, I vs. III P < 0.001 and II vs. III P = 0.004). Myocardial performance index were 0.42 ± 0.02, 0.49 ± 0.02, and 0.52 ± 0.03 in MR patients with NYHA I–III, respectively. MPI was significantly higher in patients with NYHA class III compared to NYHA I (P = 0.001) and NYHA II (P = 0.005). There were no correlations between MPI and left atrial diameter, MR jet area, MR index and systolic pulmonary artery pressure whereas left ventricle (LV) end-systolic volume (r = 0.38), LV end-diastolic volume (LVDV) (r = 0.40), LV ejection fraction (r = −0.59), NYHA class (r = 0.51) and plasma BNP levels (r = 0.67) were strongly correlated. Only independent variable affecting MPI was plasma BNP level (odds ratio [CI]: 2.18[0.002−0.098], P = 0.041). Conclusions MPI is a powerful index in assessing the severity of left ventricular function and symptom severity in patients with MR. Plasma BNP is an independent predictor of MPI where both parameters assess combined systolic and diastolic LV function, effectively.     

Intraoperative validation of a new system for invasive continuous cardiac output measurement

Objective  Although bolus thermodilution technique for cardiac output (CO) measurement has widespread acceptance, new systems are currently available. We evaluated a continuous CO system (TruCCOMS, Aortech International Inc.) that operates on the thermal conservation principle and we compared it with the reference standard transit time flow measurement (TTFM). Materials and methods  Nine consecutive cardiac surgery patients were evaluated. After general anesthesia and intubation, a TruCCOMS catheter was percutaneously placed in the pulmonary artery (PA). After median sternotomy and pericardiotomy, a TTFM probe was placed around the main PA. Right ventricular (RV) CO measurements were recorded with both TruCCOMS and TTFM at different times: before cardiopulmonary bypass (CPB) (T0), during weaning from CPB (T1), and prior to sternal closure (T2). Data analysis included paired student t test, Pearson correlation test, and Bland–Altman plotting. Results  TruCCOMS CO values were significantly lower at T0 (TruCCOMS 4.0 ± 1.0 vs. TTFM 4.5 ± 1.0 L/min; P < 0.0001) and T1 (TruCCOMS 3.6 ± 0.5 vs. TTFM 4.2 ± 0.7 L/min; P < 0.0001), and comparable at T2 (TruCCOMS 4.5 ± 0.7 vs. TTFM 4.6 ± 0.8 L/min; P = 0.4). Pearson test showed a significant correlation between TruCCOMS and TTFM CO measurements (RT0 = 0.9, RT1 = 0.8, RT2 = 0.6; P < 0.0001). Bland–Altmann plotting showed a bias of −0.53 ± 0.43 L (−12%) at T0, −0.64 ± 0.43 L (−14.5%) at T1, and −0.1 ± 0.66 L (−0.8%) at T2. Conclusion  Although TruCCOMS may significantly underestimate CO, measurement trends correlate with TTFM. For this reason, a negative trend in RV output should trigger more specific diagnostic procedures.     

组织多普勒成像定量评估心梗患者左室收缩功能的可靠性

目的　探讨DTI收缩指标的变化与心肌缺血程度的关系。方法　观察对象共 5 4人 ,观测项目为患者左室壁节段及二尖瓣环DTI s波形改变 ,并与相应的ECT指标进行了比较。结果　ECT室壁节段放射性测值心梗组非缺血区与对照组差别不显著 ,分别为 0 .76± 0 .2～ 0 .98± 0 .1与 0 .77± 0 .2～ 0 .96± 0 .1,缺血区则明显减低 0 .3 1± 0 .2～ 0 .88± 0 .2 (P<0 .0 5 )。ECT心血池显像心梗组左室射血分数为 (4 6.6± 8.9) % ,较对照组 (64 .4± 9.7) %低 (P <0 .0 5 ) ,心梗组反映左室整体功能的二尖瓣环处平均DTI s波幅为 8.4± 1.6～ 10 .5± 3 .8cm /s ,也明显低于对照组 12 .5± 2 .2～ 16.6± 4.9cm/s ,s波速度高低与ECT EF有良好的线性关系 (r =0 .67,P <0 .0 5 ) ;同时心梗组缺血节段的DTI s波速度 4.8± 0 .5～ 6.8± 1.5cm/s明显低于对照组 6.6± 1.5～ 12 .5± 3 .8cm /s(P <0 .0 5 ) ,其DTI s波幅的高低与放射性的疏密成正相关 (r =0 .68,P<0 .0 5 )。结论　如以ECT结果作为判断标准 ,DTI s波用于缺血壁段及左室收缩功能定量评价有较高的可靠性。     

Echocardiographic assessment of left atrial ejection force and kinetic energy in chronic heart failure

Background There is limited information regarding left atrial (LA) systolic adaptation to chronic heart failure (HF) in humans. Therefore, the aim of our study was to determine the LA ejection force (LAEF) and kinetic energy in patients with HF. Methods and results 58 HF patients (63.8% in NYHA II) and 48 controls were studied. LA volumes were echocardiographically determined using the biplane area-length method. LA systolic function was assessed with the: (a) active emptying volume (ACTEV) and fraction (ACTEF), (b) ejection force (kdynes/m²), calculated with Manning’s method [LAEF = 0.5 * ρ * mitral orifice area * A²; ρ: blood density, Α: late transmitral flow velocity] and a modification incorporating parameters of LA function [LAEFm = 0.5 * ρ * LA volume at onset of atrial systole * ACTEF * A²/VTl_A], and (c) kinetic energy [LA-ke (kdynes.cm/m²) = 0.5 * ρ * ACTEV * A²]. LA maximal volume and ACTEV were lower (42.9 ± 14.4 vs. 59.7 ± 14.7 cm³, P < 0.0001; 10.9 ± 3.3 vs. 13 ± 3.3 cm³, P = 0.0001, respectively), whereas ACTEF (%) was higher (36.3 ± 7 vs. 29.3 ± 7.6 cm³, P < 0.0001) in controls than HF. LAEF, LAEFm, and LA-ke were lower in controls than HF (7.68 ± 5.1 vs. 10.16 ± 3.7 kdynes/m², P = 0.006; 3.63 ± 2.05 vs. 5.02 ± 1.74 kdynes/m², P = 0.0004; 2.41 ± 1.91 vs. 3.99 ± 2.1 kdynes.cm/m², P < 0.0004, respectively). Conclusion Despite the decreased LA systolic shortening, overall LA systolic performance is augmented in chronic HF due to LA dilation.     

Characterisation of left ventricular relaxation in the isolated guinea pig heart

The time constant of left ventricular pressure fall, τ, has frequently been used as a measure of myocardial relaxation in the blood-perfused, ejecting heart. The aim of the present study was to characterise τ in relation to β-adrenergic activation, coronary perfusion pressure and flow as well as cardiac oxygen supply and demand in the isolated, isovolumically beating heart. Therefore, τ was analysed from digitised left ventricular pressure data in a total of 23 guinea pig hearts perfused with saline at constant pressure (60 cmH₂O). The coronary venous adenosine concentration ([ADO]) served as an index of myocardial oxygenation. Isoprenaline (0.4–3.2 nmol l⁻¹) decreased and propranolol (3–9 μmol l⁻¹) increased τ dose-dependently (linear regression τ vs lg ([isoprenaline]),r=0.74; τ vs. lg([propranolol]),r=0.66, bothP<0.05). During graded reductions in cardiac oxygen supply from 96.1±12.6(SEM) to 44.4±4.4 μl min⁻¹ g⁻¹, τ was prolonged from 61.5±12.7 to 109.9±22.6 ms while left ventricular developed pressure (LVDP) decreased from 90.7±7.2 to 40.7±5.1 mmHg. In parallel, [ADO] increased from 23.7±9.1 to 58.0±19.1 pmol ml⁻¹ (P<0.05). Increasing oxygen supply to 165.4±32.4 μl min⁻¹ g⁻¹ augmented LVDP to 102.7±7.3 mmHg but did not change τ or [ADO]. There was a dual response of τ to changes in cardiac oxygen supply or demand. As long as oxygen supply and demand matched, τ remained constant. However, when the oxygen supply was less than 100 μl min⁻¹g⁻¹, left ventricular relaxation was prolonged in parallel to the reduction in oxygen supply. In addition, a close relationship was observed between [ADO] as an indicator of myocardial oxygenation and τ (Spearman correlation,r=0.99,P<0.005). We conclude that the time constant of left ventricular pressure fall, τ, sensitively reflects myocardial relaxation in the isolated, isovolumically beating guinea pig heart. Moreover, in this model left ventricular relaxation is not influenced by alterations in coronary perfusion pressure or flow as long as cardiac oxygen demand is matched by an adequate supply. Rather, relaxation is strictly coupled to myocardial oxygenation as reflected by coronary venous adenosine concentrations.     

Pharmacokinetics and influence of arbekacin on renal function in low-birth-weight infants

Arbekacin (ABK) is an aminoglycoside with excellent antibacterial activity against methicillin-resistantStaphylococcus aureus (MRSA). Although ABK is expected to be a useful drug for MRSA infection in newborns, there have been few reports concerning its pharmacokinetics, efficacy, and safety. Ten low-birth-weight infants were treated with ABK. Their mean gestational age was 29.4±5.3 weeks and their mean birth weight was 1204±532 grams. At the time of initial ABK administration, the mean postconceptional age was 33.9±4.2 weeks. ABK was infused over a period of 30 minutes every 12 hours at doses ranging between 2.2 and 3.1 mg/kg. Trough (predose) and peak (30 minute postdose) serum ABK concentrations were determined. TheN-acetyl-β-d-glucosaminidase (NAG) index (NAG:creatinine ratio) was measured before and after ABK therapy. The mean peak serum ABK concentration was 8.49±2.06 μg/mL and the mean trough concentration was 3.93±2.14 μg/mL, with a mean half-life of 11.4±6.1 hours. A significant negative correlation existed between postconceptional age and ABK half-life (r=0.64;P<0.05), and there was a positive correlation between postconceptional age and ABK clearance (r=0.83;P<0.05). The NAC index significantly increased after ABK therapy (P<0.05), and a significant positive correlation was found between the though level of ABK and the NAG index after ABK therapy (r=0.84;P<0.05). ABK, similar to other aminoglyoosides, should be used with caution in low-birth-weight infants with careful attention given to their renal function.     

Association of high-density lipoprotein levels and carotid atherosclerotic plaque characteristics by magnetic resonance imaging

A low level of high-density lipoprotein cholesterol (HDL-C) is a risk factor for atherosclerotic disease. Magnetic resonance imaging (MRI) can provide detailed information on carotid atherosclerotic plaque size and composition. The purpose of this study was to correlate HDL levels with carotid plaque burden and composition by MRI. Thirty-four patients with coronary artery disease (CAD) receiving simvastatin plus niacin or placebo for both drugs for three years were randomly selected to undergo MRI of carotid arteries. Atherosclerotic plaque wall volumes (WVs) and plaque components including lipid rich/necrotic core (LR/NC), calcium, fibrous tissue, and loose matrix were measured. Mean WV or atherosclerotic burden was significantly associated with total HDL-C levels (r = −0.39, P = 0.02), HDL₂ (r = −0.36, P = 0.03), HDL₃ (r = −0.34, P = 0.04), and LDL/HDL ratio (r = 0.42, P = 0.02). Plaque lipid composition or LR/NC was significantly associated with HDL₃ (r = −0.68, P = 0.02). Patients with low HDL levels (≤35 mg/dL) had increased WV (97 ± 23 vs. 81 ± 19 mm³, P = 0.05) compared with patients with HDL levels > 35 mg/dL. Among CAD patients, low HDL-C levels were significantly associated with increased carotid atherosclerotic plaque burden and lipid content by MRI.     

早期新生儿脉冲组织多普勒超声心动图的研究

目的 探讨脉冲组织多普勒技术评价早期新生儿心功能并了解心动周期中各时间间期及其随心率的变化规律.方法 86例出生2天、3天、4天新生儿,采用TDI技术检测早期新生儿二、三尖瓣环运动,测量收缩期峰值速度(Sa),舒张早期峰值速度(Ea)与舒张晚期峰值速度(Aa)比值(Ea/Aa),E与Ea比值(E/Ea),以及TDI频谱各时间间期.分别以日龄和性别分组,比较组间以及左右室之间上述各指标差异性,并进行时间间期与心率的相关性分析.结果 Sa、Ea/Aa及E/Ea在不同H龄间差异均无显著性(P＞0.05).男性新生儿与女性二尖瓣环左室侧Ea/Aa(0.89±0.31 vs 1.09±0.29,P=0.005)及E/Ea(10.98±2.24 vs 9.38±2.62,P=0.008)、三尖瓣环与二尖瓣环Sa(5.74±0.10 vs 4.30±0.93,P=0.000)、Ea/Aa(0.85±0.25 vs 1.00±0.32,P=0.003)及E/Ea(7.22±2.42 vs 10.09±2.57,P=0.000)差异均有显著性.各时间间期在不同口龄组间差异无显著性;男性新生儿与女性左室总舒张时间(207.14±34.70 vs 230.00±48.16,P=0.013)差异具有显著性;除外舒张后期时间,所有时间间期指标左右室间差异均有显著性(P＜0.01).新生儿收缩时间与舒张时间之比约0.54/0.46.心率与舒张早期时间、舒张后期时间强负相关(r=-0.547,-0.687).与心房收缩时间无相关关系,而与等容收缩时间,射血时间均弱负柑关(r=-0.280,-0.374).结论 早期新生儿心功能日龄间无差异;女性新生儿的心室舒张功能优于男性,而收缩功能无性别差异.左室舒张时间男性新生儿短于女性;右室的收缩早于左室,并且右室的收缩时间比左室长.心率增快主要影响舒张后期时间和舒张早期时间,与心房收缩时间无相关关系.     

弥散张量成像诊断新生儿和婴儿胆道闭锁

目的 探讨弥散张量成像（DTI）对新生儿和婴儿胆道闭锁（BA）的诊断价值。方法 收集疑诊为BA或其他胆道疾病的患儿46例,以手术探查、腹腔镜探查、术中造影、病理检查或临床治疗结果作为金标准,将患儿分为BA组与非BA组（non-BA组）。对所有患儿应用1.5T MR扫描仪,采用单次激发自旋回波平面成像DTI序列（b值为1000 s/mm²）行肝脏扫描,经后处理获得平均扩散系数（AvgDC）图及FA图,测量AvgDC值及FA值。结果 46例中,BA组24例,non-BA组22例,BA组的AvgDC值显著低于non-BA组［（1.27±0.16）×10^-3 mm²/s vs （1.43±0.15）×10^-3 mm²/s,P=0.001)］。在BA组中,不同肝脏纤维化分级患儿间AvgDC值、FA值的差异均无统计学意义（P>0.05）;INF1~INF3级炎症分级患儿AvgDC值逐渐降低,但差异无统计学意义（F=2.15, P=0.14）,FA值差异有统计学意义（F=5.51, P=0.01）。应用AvgDC、FA值诊断BA的ROC曲线下的面积分别为0.80±0.07、0.60±0.09;AvgDC界限值为1.33×10^-3 mm²/s时,诊断敏感度为75.00%（18/24）,特异度为77.27%（17/22）。结论 DTI的AvgDC值可用于诊断新生儿和婴儿BA,但其诊断敏感度与特异度仍有待提高。     

The relationship between apolipoprotein E and serum oxidation-related variables is apolipoprotein E phenotype dependent

To examine the relationship between apolipoprotein E and serum oxidation status, we assayed apolipoprotein E level, apolipoprotein E phenotype, and levels of lipid peroxides and transition metal ions and their binding proteins in sera from apparently healthy individuals. The study group included 129 women aged 22–63 years and 53 men aged 22–56 years. Among subjects with apolipoprotein E 4/3 phenotype, lipid peroxide levels were higher compared with E 3/2 phenotype (786±182 nmol/l vs. 659±174 nmol/l,P=0.015), and ceruloplasmin levels were slightly higher compared with apolipoprotein E 3/3 phenotype (0.28±0.08 mg/l vs. 0.26±0.06 mg/l,P=0.035). In the study group as a whole, there were significant associations between serum apolipoprotein E level, and serum levels of ceruloplasmin (r=0.266,P<0.001) and ferritin (r=0.2,P<0.007). Among subjects with apolipoprotein E 4/3 phenotype, there was a significant association between serum apolipoprotein E and lipid peroxide levels (r=0.470,P<0.01), which was not apparent among subjects with E 3/3 or E 3/2 phenotypes. In multivariate analysis, apolipoprotein E phenotype was a small but significant independent contributor to variation in serum lipid peroxide levels. These data suggest that there may be heterogeneity among apolipoprotein E phenotypes in their relationships with serum lipid oxidation status.     

Time Sensitivity: A Parameter Reflecting Tumor Metabolic Kinetics by Variable Dual-Time F-18 FDG PET Imaging

Objectives  The aim of this study was to define and investigate the time sensitivity of tumors by variable dual-time fluorodeoxyglucose positron emission tomography (FDG PET). Methods  Variable dual-time (t) protocol (P) FDG PET–computed tomography (CT) scans from 40 patients with pathologically proven head and neck tumors without brain metastasis were analyzed. The first protocol (P.I) consisted of 26 patients with early (E) and delayed (D) PET–CT obtained at 106 ± 15 and 135 ± 16 min after injection of 16.3 ± 1.9 mCi FDG. The second protocol (P.II) recruited 14 patients with E- and D-PET performed at 54 ± 13 and 151 ± 28 min after injection of 9.6 ± 1.7 mCi FDG. The maximum standardized uptake values (SUVs) were measured in the primary tumor (CA1) and the cerebellum (CBL). The time sensitivity (S) was defined as d{ln(SUV)}/d{ln(t)} and its value was obtained by linear regression of ln(D-SUV/E-SUV) vs ln(t _D/t _E). Patients with cerebellar variations greater than 30% in SUV between E- and D-PET was excluded from the analysis. Results  Two patients from P.I were excluded due to wide cerebellar SUV variations. D-SUV were significantly higher than E-SUV in CA1 for both P.I (18.9 ± 6.9 vs 14.8 ± 5.6, p < 0.0005) and P.II (11.5 ± 7.9 vs 9.7 ± 6.9, p = 0.013). The S values for CA1 in P.I and P.II were 0.67 and 0.17, respectively. The D-SUV were also higher than E-SUV in CBL for both P.I (12.5 ± 1.6 vs 11.6 ± 1.6, p < 0.0005) and P.II (7.6 ± 1.6 vs 7.0 ± 1.6, p = 0.008). The S values for CBL in P.I and P.II were 0.47 and 0.04, respectively, which were over 1.4-fold smaller than that of CA1, suggesting fundamental kinetic differences between CA1 and CBL. Conclusions  The time sensitivity factor reflects another kinetic parameter of tumor metabolism besides SUV when using variable dual-time FDG PET. It offers another useful diagnostic tool in optimizing choices of dual-time protocols for oncologic PET–CT and in reducing SUV variations due to time interval differences with corrections using S.     

Increased cardiac mRNA expression of matrix metalloproteinase-1 (MMP–1) and its inhibitor (TIMP–1) in DCM patients

Summary Left ventricular dilation and myocardial remodeling are hallmarks of dilated cardiomyopathy (DCM). It is assumed that left ventricular dilation is caused by the disintegration of the collagenous network by increased collagenolytic activity of matrix metalloproteinases (MMPs) and their adequate tissue inhibitors (TIMPs). In this study the myocardial MMP–1 and TIMP–1 mRNA expressions were investigated by using real–time quantitative PCR analysis from right septal endomyocardial biopsies of patients with dilated cardiomyopathy (n = 46) and control subjects (n = 11). The volume density (Vv%) of collagen was measured morphometrically. Classification was done according to LV diameters [left ventricular enddiastolic diameter (LVEDD, cm) calculated to body surface area (BSA, m²)] into three DCM groups: group I (LVEDD–BSA > 2.7–3.0 cm/m²), group II ( > 3.0–3.6 cm/m²), group III ( > 3.6 cm/m²), controls (< 2.7 cm/m²). Compared with controls, the MMP–1 expression in patients with DCM was significantly increased (119.2 ± 45.2 vs. 1.3 ± 0.4; p < 0.001) as was TIMP–1 expression (9.6 ± 1.2 vs. 1.3 ± 0.4; p < 0.01). Moreover the MMP–1 and TIMP–1 expression varied according to LV diameter: group I (MMP–1: 8.7 ± 3.5; p = 0.33; TIMP– 1: 4.5 ± 1.2; p < 0.01); group II (MMP–1: 211.4 ± 86.0; p < 0.001; TIMP–1: 12.5 ± 1.9 ; p < 0.001); group III (MMP–1: 38.8 ± 22.6; p < 0.01; TIMP–1: 8.1 ± 1.7; p < 0.001). Compared with controls, the collagen level in DCMPt. was significantly increased: 5.0 ± 0.6 vol% vs 1.2 ± 0.2 vol% p < 0.001 and correlates with LV diameter. This study reveals that the overexpression of MMP–1, which is associated with an increased ratio of MMP–1/TIMP–1 in DCM, indicates an activated collagenolytic system while replacement fibrosis is accumulating. The MMP–1 overexpression is mainly found in moderately dilated DCM hearts (group II) indicating the dynamic process of LV dilation and the importance of collagenases in the early phase of LV remodeling.     

Impact of intracardiac echocardiography on radiation exposure during adult congenital heart disease catheter-based interventions

Background Intracardiac echocardiography (ICE) is a widespread approach in many cardiovascular procedures in which it has the potential to reduce the fluoroscopy time and patients radiation exposure. We sought to assess the patient radiation exposure during transcatheter closure of interatrial communications with and without ICE-guidance. Methods In a prospective consecutive series of 25 consecutive patients who underwent transcatheter closure of interatrial communications between May and October 2005 with (15 patients) and without (10 patients) ICE-guidance in a single secondary care referral centre, we measured the dose-area product (DAP), the fluoroscopy dose-area product (FDAP), the total dose-area product (TDAP), and the mean procedural time. Results In patients underwent ICE-guided transcatheter closure procedure the mean fluoroscopy time, the mean DAP, mean FDAP, and mean TDAP resulted significantly lower than in control patients: 2.0 ± 0.21 (range 1.6–2.2) versus 5.05 ± 0.54 (range 4.2–5.8) minutes (P < 0.001) , 13.72 ± 9.03 (range 11.36–14.63) versus 21.95 ± 6.93 (range 20.90–23.93) Gycm2 (P < 0.001), 8.25 ± 1.22 (range 6.60–9.50) versus 20.15 ± 8.83 (range 18.90–20.93) Gycm2 (P < 0.001), and 29.33 ± 1.51(range 27.16–31.00) versus 32.61 ± 2.53 (range 29.20–35.55) Gycm2 (P < 0.01). On the contrary, the mean procedural time, was significantly higher in ICE-guided transcatheter closure patients: 30.2 ± 2.45 (range 23–40) versus 24.5 ± 2.45 (range 24–31) minutes (P = 0.03). Conclusion The radiation exposure during ICE-guided transcatheter closure of interatrial communications in this group of patients was quite lower than that reported in literature for such procedures and compared favourably with radiation exposure of patients in whom the intervention was performed without ICE guidance.