Assessment of Age-related Changes in Left Ventricular Twist by Two-dimensional Ultrasound Speckle Tracking Imaging

To assess the normal value of left ventricular twist （LVtw） and examine the changes with normal aging by 2-dimensional ultrasound speckle-tracking imaging （STI）, 121 healthy volunteers were divided into three age groups： a youth group （19-45 y old）, a middle-age group （46-64 y old ） and an old-age group （≥65 y old）. Basal and apical short-axis images of left ventricular were acquired to analyse LV rotation （LVrot） and LVrot velocity. LVtw and LVtw velocity was defined as apical LVrot and LVrot velocity relative to the base. Peak twist （Ptw）, twist at aortic valve closure （AVCtw）, twist at mitral valve opening （MVOtw）, untwisting rate （UntwR）, half time of untwisting （HTU）, peak twist velocity （PTV）, time to peak twist velocity （TPTV）, peak untwisting velocity （PUV）, time to peak untwisting velocity （TPUV） were separately measured. The results showed that the normal LV performs a wringing motion with a clockwise rotation at the base and a counterclock- wise rotation at the apex （as seen from the apex）. The LVtw velocity showed a systolic counterclockwise twist followed by a diastolic clockwise twist. Peak twist develops near the end of systole （96%±4.2% of systole）. With aging, Ptw, AVCtw, MVOtw, HTU and PUV increased significantly （P〈0.05） and UntwR decreased significantly （P〈0.05）. However, no significant differences in TPUV, PTV and TPTV were noted among the 3 groups （P〉0.05）. It is concluded that LV twist can be measured non-invasively by 2-dimensional ultrasound STI imaging. The age-related changes of LVtw should be fully taken into consideration in the assessment of LV function.     

超声二维斑点追踪显像技术评价肥厚型心肌病左心室旋转和扭转运动

目的采用超声二维斑点追踪显像技术(STI)探讨肥厚型心肌病(HCM)患者左心室扭转运动(LVtw)的特征。方法随机选取心功能正常的HCM患者及正常对照者各20例,取胸骨旁左心室心尖和心底短轴观二维图像对左心室旋转进行测量分析,计算心底部旋转角度峰值(MV-Prot)及其达峰时间、心尖部旋转角度峰值(AP-Prot)及其达峰时间、扭转角度峰值(Ptw)及达峰时间、收缩期末扭转角度(AVCtw)、等容舒张期末扭转角度(MVOtw)、解旋率(UntwR)、解旋减半时间(HTU),并比较两组间上述各参数的差别。结果(1)与对照组相比,HCM组MV-Prot、AP-Prot、Ptw、AVCtw、MVOtw和HTU测值增加,UntwR测值减低(P均<0.05)。(2)HCM组左心室扭转角度达峰时间测值较对照组明显增加(P<0.05)。(3)HCM组内左心室旋转心尖部达峰时间较心底部测值明显增加(P<0.05)。结论应用STI可无创性评价HCM患者左心室旋转及扭转运动特征,HCM患者左心室旋转运动力学参数较正常人有明显异常改变。     

Assessment of age-related changes in left ventricular twist by two-dimensional ultrasound speckle tracking imaging

Summary To assess the normal value of left ventricular twist (LVtw) and examine the changes with normal aging by 2-dimensional ultrasound speckle-tracking imaging (STI), 121 healthy volunteers were divided into three age groups: a youth group (19–45 y old), a middle-age group (46–64 y old) and an old-age group (≥65 y old). Basal and apical short-axis images of left ventricular were acquired to analyse LV rotation (LVrot) and LVrot velocity. LVtw and LVtw velocity was defined as apical LVrot and LVrot velocity relative to the base. Peak twist (Ptw), twist at aortic valve closure (AVCtw), twist at mitral valve opening (MVOtw), untwisting rate (UntwR), half time of untwisting (HTU), peak twist velocity (PTV), time to peak twist velocity (TPTV), peak untwisting velocity (PUV), time to peak untwisting velocity (TPUV) were separately measured. The results showed that the normal LV performs a wringing motion with a clockwise rotation at the base and a counterclock-wise rotation at the apex (as seen from the apex). The LVtw velocity showed a systolic counterclock-wise twist followed by a diastolic clockwise twist. Peak twist develops near the end of systole (96%±4.2% of systole). With aging, Ptw, AVCtw, MVOtw, HTU and PUV increased significantly (P<0.05) and UntwR decreased significantly (P<0.05). However, no significant differences in TPUV, PTV and TPTV were noted among the 3 groups (P>0.05). It is concluded that LV twist can be measured non-invasively by 2-dimensional ultrasound STI imaging. The age-related changes of LVtw should be fully taken into consideration in the assessment of LV function.     

Evaluation of Left Ventricular Rotation and Twist Using Speckle Tracking Imaging in Patients with Atrial Septal Defect

Speckle tracking imaging （STI） was employed to investigate the effect of right ventricular （RV） volume and pressure overload on left ventricular （LV） rotation and twist in 35 patients with atrial septal defect （ASD）, 18 of which with pulmonary hypertension, and 21 healthy subjects serving as controls. The peak rotations of 6 segments at the basal and apical short-axises and the average peak rotation and interval time of the 6 segments in the opposite direction during early systolic phase were measured respectively. LV twist versus time profile was drawn and the peak twist and time to peak twist were calculated. LV ejection fraction （EF） was measured by Biplane Simpson. Compared to ASD patients without pulmonary hypertension and healthy subjects, the peak rotations of posterior, inferior and postsept walls at the basal level were lower （P〈0.05）, and the average counterclockwise peak rotation of 6 segments at the basal level during early systolic phase was higher （P〈0.05）, and the average interval time was delayed （P〈0.05）. LV peak twist was also lower （P〈0.05）, and had a significant negative correlation with pulmonary arterial systolic pressure （r=-0.57, P=0.001）. No significant differences were found in LVEF among the three groups. It was suggested that although RV volume overload due to ASD has no significant effects on LV rotation and twist, LV peak twist is lower in ASD patients with pulmonary hypertension. Thus LV twist may serve as a new indicator of the presence of pulmonary hypertension in ASD patients.     

Assessment of left ventricular torsion in patients with anterior wall myocardial infarction before and after revascularization using speckle tracking imaging

Background Rotation of the left ventricular （LV） apex to the base, or LV torsion, is related to myocardial contractility and structure and has recently been recognized as a sensitive indicator of cardiac performance, but it has been difficult to measure. The recent development of 2-dimensional （2D） speckle tracking imaging （STI） may provide a powerful means of assessing LV torsion. This study was conducted to evaluate the global and regional LV twist in patients with anterior wall myocardial infarction （AMI） disease before and after revascularization by STI. Methods 2D STI was performed in 35 AMI patients before and one month after revascularization, as well as in 32 normal controls. Left ventricular global and regional rotations were obtained at basal and apical short-axis levels; LV torsion was defined as apical rotation relative to the base. The time sequences were normalized to the percentage of systolic and diastolic duration. Results Before revascularization, LV peak regional and global torsion in patients with AMI were significantly reduced as the result of reduced apical and basal rotation relative to those of normal control group （all P〈0.001）; most significantly in the anterior and anterior-septal regions （P 〈0.001）; one month after revascularization, there were significant changes in peak rotation at either the base or apex relative to pre-revascularization values （all P 〈0.001）. Similarly, peak regional and global LV torsion were increased significantly （all P 〈0.001）. Global torsion inversely correlated with EDV （r=-0.605, P=0.028） and ESV （r=-0.638, P=0.019）; and positively correlated with LVEF （r=0.630, P=-0.021）. Tight relations were also found between torsion and LV longitudinal and short axis function. Conclusions Systolic torsion was decreased in AMI patients. Revascularization therapy can improve the LV function of the AMI patients. STI has a potential to quantify left ventricular global and segment torsion in patients with AMI, and may make     

Ultrasound Speckle Tracking Imaging Contributes to Early Diagnosis of Impaired Left Ventricular Systolic Function in Patients with Type 2 Diabetes Mellitus

To investigate the value of ultrasound speckle tracking imaging （STI） in the assessment of the short-axis and long-axis systolic function of the left ventricle （LV） in patients with type 2 diabetes mellitus （DM）, 100 subjects with normal ejection fraction were studied, including 41 patients with DM only （DM group）, 22 patients with both DM and left ventricular hypertrophy （DH group）, and 37 healthy subjects （control group）. Left ventricle systolic function in the long axis defined as longitudinal strain, and that in the short axis defined as radial strain, apical and basal LV rotations, and LV twist were assessed respectively. The results showed that average peak strain in the long axis at basal, middle and apical levels, and global peak strain were significantly decreased in the patient groups when compared with the control group （P〈0.001 for each）. The parameters in DH group were significantly lower than those in DM group （P〈0.01 for each）. There were no significant differences in average radial peak strain in the short axis at different levels, and global peak strain among the three groups （P〉0.05）. Apical and basal LV rotations, and LV twist were greater in the patient groups than in the control group （P〈0.01 for each）. Basal LV rotation and LV twist were greater in DH group than those in DM group （P〈0.01）. It was concluded that STI may be used to identify early abnormalities in patients with type 2 DM that have normal left ventricular systolic function.     

斑点追踪显像技术评价原发性高血压病患者早期左心室旋转及扭转功能

目的探讨斑点追踪显像(speckle tracking imaging,STI)评价原发性高血压(EH)患者早期左心室旋转和扭转运动改变的价值。方法对35例左心房、左心室正常构型的EH患者(高血压组)和35例健康者(对照组),经胸采集左心室短轴心尖水平和心底水平的二维图像,计算心底水平旋转角度峰值(MV-Prot)、心尖水平旋转角度峰值(AP-Prot)、扭转角度峰值(Ptw)。结果两组受检者心尖部旋转角度均显著大于心底部旋转角度,差异均有统计学意义(P<0.01);但两组达峰时间比较,差异无统计学意义(P>0.05);高血压组患者心尖部旋转角度显著大于对照组,差异有统计学意义(P<0.05)。结论 EH患者早期左室整体心肌扭转运动主要表现为逆时针方向扭转,扭转运动增强。     

超声斑点追踪显像技术评价正常人左室扭转运动

目的应用二维超声斑点追踪显像技术（STI）探讨正常人左室旋转（LVrot）和左室扭转（LVtw）运动特点,分析其与常规左室收缩功能参数之间的关系及年龄、心率等生理因素对其影响,评价左室运动同步性。方法50例健康志愿者为研究对象,经胸采集标准短轴左室心尖位、心底位的图像并存储,运用EchoPAC超声工作站进行脱机分析。计算左室心尖位旋转角度、心底位旋转角度、左室扭转峰值及相应达峰时间。结果（1）正常人扭转运动主要表现为心底位顺时针旋转和心尖位逆时针旋转,心脏整体表现为心动周期内逆时针方向为主的扭转运动。（2）正常人左室射血分数（LVEF）、短轴缩短率（FS）与左室扭转峰值（peak tw ist,Ptw）呈正相关（r=0.468和0.456,P均〈0.05）。（3）年龄与Ptw呈正相关（β=0.320,P〈0.05）,其中Ⅱ组Ptw（14.55±3.94）°高于Ⅰ组Ptw（12.52±4.63）°（P〈0.05）。心率、、性别、身高、体重与Ptw无相关性（P〉0.05）。（4）心尖位和心底位旋转角度达峰时间差异无统计学意义（P〉0.05）。结论STI技术可无创评估正常人左室旋转和扭转运动特点。常规左室收缩功能参数LVEF、FS与Ptw正相关。临床应用扭转参数评价左室收缩功能时应考虑年龄因素的影响。左室心尖位和心底位旋转角度达峰时间可作为评价左室运动同步性指标之一。     

超声斑点追踪显像技术评价扩张型心肌病左室扭转特点

目的应用超声斑点追踪显像技术（STI）探讨扩张型心肌病患者（DCM）左室旋转（LVrot）和左室扭转（LVtw）运动特点及左室运动同步性,分析其与常规左室收缩功能参数的关系。方法选择24例DCM患者及与之年龄匹配的24例正常人为研究对象,经胸采集标准短轴左室心尖位、心底位的图像并存储,运用EchoPAC超声工作站进行脱机分析。计算左室心尖位旋转角度、心底位旋转角度、左室扭转峰值及相应达峰时间。结果 DCM患者扭转运动主要表现为心底位顺时针旋转和心尖位逆时针旋转,心脏整体表现为心动周期内逆时针方向为主的扭转运动,正常人也主要表现为心底位顺时针旋转和心尖位逆时针旋转及心脏整体逆时针方向为主的扭转运动。但DCM患者左室扭转峰值[（4.62±1.55）°/（13.85±2.77）°,P〈0.001]显著减低。DCM患者左室扭转峰值（peak tw ist,Ptw）与左室射血分数（LVEF）正相关（r=0.534,P〈0.05）。DCM患者心尖位和心底位旋转角度达峰时间不一致,差异有统计学意义（P〈0.05）。结论 DCM在短轴方向表现为左室旋转和扭转运动减低及整体运动不同步的特点。Ptw减低显示左室收缩功能减低,Ptw与常规左室收缩功能参数LVEF正相关。     

斑点追踪成像评价无心肌肥厚高血压病人左心室功能

目的 应用斑点追踪成像技术（STI）评价无心肌肥厚的原发性高血压病人早期左心室心肌的功能。方法 选取左心室充盈正常的高血压病人40例（Ⅱ组）、左心室松弛性减低的高血压病人40例（Ⅲ组）、健康对照者30例（对照组）、应用STI分别测量各组左心室长轴切面、心尖四腔心切面、两腔心切面整体心肌和心内膜下心肌二尖瓣水平、乳头肌水平、心尖水平收缩期长轴应变,通过左心室短轴心底水平和心尖水平分别计算扭转角度峰值（Ptw）、收缩末期扭转角度（AVCtw）、等容舒张末期扭转角度（MVOtw）、扭转速度达峰时间（PTV）、解旋速度峰值（PUV）、等容解扭转率（UntwR）、解旋减半时间（UHT）等左心室扭转-解旋参数。结果 与对照组比较,Ⅱ组基底段、中间段、心尖段心内膜下心肌收缩期峰值应变减低,Ptw、AVCtw、MVOtw、PTV、PUV增加,UntwR减低,UHT延长,差异均有显著性（F=3.34-23.75,q=1.69-13.51,P〈0.05）;Ⅲ组基底段、中间段、心尖段的心内膜下心肌收缩期峰值应变减低,差异有显著性（F=9.13-11.91,q=2.94-3.64,P〈0.01）。Ⅲ组与Ⅱ组比较,基底段、中间段、心尖段的整体心肌收缩期峰值应变减低,UntwR减低,差异有显著意义（q=3.12-3.59,P〈0.05）。结论 STI可用于评价原发性高血压病人左心室心肌功能的早期受损情况。     

二维应变超声在冠心病患者左心室扭转中的应用

[目的]探讨应用二维应变超声心动图(2DSE)评价冠心病(CHD)患者的左心室旋转和扭转运动的临床价值.[方法]应用GE Vivid 7 Dimension超声心动图仪采集35例冠心病患者(冠心病组)及30例正常人(对照组)左心室短轴二尖瓣环及心尖水平切面的二维灰阶图像,计算左心室心尖部和心底部的旋转角度及旋转率、左心...     

二维超声斑点追踪显像技术评价高血压患者左心室旋转和扭转运动的临床应用

目的:采用二维超声斑点追踪成像技术测定高血压患者左心室旋转和扭转运动,评价其临床应用价值。方法:20例正常人和44例原发性高血压患者[包括左心室构型正常组(LVN组)21例和左心室重构组(LVR组)23例]获得心尖水平和基底水平左室短轴清晰二维图像存盘,运用QLAB超声工作站进行脱机分析,得到内膜旋转峰值、外膜旋转峰值、平面旋转峰值及平面扭转峰值,计算左心室整体的扭转峰值。结果:①基底水平:与正常组比较,LVN组内膜旋转峰值、跨壁扭转峰值显著增高(P<0.05);LVR组内膜旋转峰值、平面旋转峰值、跨壁扭转峰值显著增高(P<0.05)。与LVN组比较,LVR组内膜旋转峰值、外膜旋转峰值、平面旋转峰值和跨壁扭转峰值均显著增高(P<0.05)。②心尖水平:与正常组比较,LVR组内膜旋转峰值、平面旋转峰值和跨壁扭转峰值显著增高(P<0.05)。与LVN组比较,LVR组内膜旋转峰值、外膜旋转峰值、平面扭转峰值显著增高(P<0.05)。③左心室整体扭转:与正常组比较和与LVN组比较,LVR组扭转峰值均显著增高(P<0.05)。结论:超声二维斑点追踪显像技术可以准确评价高血压患者左心室旋转和扭转运动,高血压患者旋转与扭转运动力学参数较正常人整体上有明显增高。     

应用超声斑点追踪技术评价房间隔缺损封堵前后心脏旋转运动的变化

目的:探讨房间隔缺损(ASD)患者右室容量负荷增加及右室重构对左室心尖部?基底部的旋转运动的影响,并评价经皮房间隔缺损封堵术对左室旋转运动的急性期影响?方法:应用超声斑点追踪显像技术分别测量25例单纯房间隔缺损的患者术前及封堵术后3天的左室基底部及心尖部短轴6个节段的收缩期的旋转角度峰值及平均峰值,绘出左室基底部及心尖部短轴的平均旋角度—时间曲线;双平面Simpson法测左室射血分数(LVEF)?25例年龄性别匹配的正常人作为对照?结果:与对照组相比,ASD组术前基底部前间隔?侧壁?后壁?下壁?后间隔的顺时针旋转角度峰值减低(P < 0.05),前壁的旋转角度峰值也减低,但差异无统计学意义?而术前左室心尖部短轴6个节段的收缩期的旋转角度峰值均较对照组降低,但是差异无统计学意义?而ASD组术后基底部前间隔?侧壁?后壁?下壁?后间隔的顺时针旋转角度峰值较术前升高(P < 0.05),前壁的旋转角度峰值也升高,但差异无统计学意义?术后左室心尖部短轴6个节段的收缩期的旋转角度峰值较术前升高,但是差异无统计学意义?与正常对照组而言,ASD患者术后除侧壁仍较低外,其余各节段的旋转角度均接近正常对照组?结论:ASD引起的右室容量负荷增加及右室重构对左室基底部的旋转和左室整体扭转运动有影响,对心尖部的旋转运动的影响不明显?经皮房间隔缺损封堵术可以改善左室基底部的旋转因而也改善了左室整体扭转运动?     

二维超声斑点追踪成像技术评价正常构型原发性高血压患者左心室收缩功能

目的:探讨二维超声斑点追踪成像技术评价正常构型原发性高血压(EH)患者左心室局部和整体收缩功能的临床价值。方法:左心室构型正常(LVN)的原发性高血压患者26例,健康对照组25例,获取其心尖四腔、三腔及二腔二维图像,测定左室各节段心内膜下纵向收缩期峰值应变,并计算左室基底段水平、中间段水平、心尖段水平各6节段收缩期平均峰值应变及左室18节段平均应变。结果:与对照组比较,高血压病组左室各节段心内膜下纵向收缩期峰值应变显著降低(P<0.05或P<0.01);与对照组比较,高血压病组基底段水平、中间段水平、心尖段水平各6节段纵向收缩期平均应变值及左室18节段平均应变值显著降低(P<0.01)。结论:超声斑点追踪成像技术可以早期准确地评价原发性高血压患者左心室局部和整体心肌收缩功能。     

应用超声斑点追踪技术评价室间隔缺损封堵前后心脏扭转运动的变化

目的:运用二维超声斑点追踪技术评价经皮室间隔封堵术前后患者心脏扭转运动的变化.方法:检测18例室间隔缺损患者封堵术前、术后第3天、术后1个月、术后3个月的常规心脏二维多普勒超声参数,并运用二维斑点追踪技术对患者的左心室旋转及扭转运动进行分析,以探讨室间隔缺损封堵术对其心脏扭转运动的影响.结果:封堵术后第3天,舒张期末左室内径(LVEDd)、左室舒张末容积(LVEDV)较术前减低较明显,左心室的基底部、心尖部的旋转角度及整体的扭转运动的角度较术前稍有减低.术后1个月、术后3个月,LVEDd、LVEDV较术前仍有降低,但降低的程度有减小的趋势;而左心室的基底部、心尖部的旋转角度及整体的扭转运动的角度仍有降低,降低的程度以术后1个月最明显,以后降低程度减小.患者封堵术前、术后第3天、术后1个月、术后3个月的LVEF稍有改变,但差异尤统计学意义.无论是封堵术前、术后第3天、术后1个月、还是术后3个月有,病人的左心室的基底部、心尖部的旋转角度峰值及整体的扭转运动的角度峰值均和LVEF呈线性相关,且以左室整体的扭转运动的角度峰值和LVEF的相关性最好.结论:经皮室间隔缺损封堵术通过逆转左室的重构而改善左室的扭转运动,且左室整体的扭转运动与LVEF的相关性最好.     

速度向量成像技术评价扩张型心肌病心脏扭转运动

目的 应用超声心动图速度向量成像(VVI)技术对扩张型心肌病(DCM)患者心脏扭转运动的改变进行初步分析,进一步探讨VVI技术在评价心脏扭转运动方面的价值.方法 采用VVI技术对33名正常人和30例扩张型心肌病患者进行研究.选取胸骨旁左室二尖瓣水平、乳头肌水平、心尖水平短轴切面及心尖四腔心、两腔心切面的图像,测量收缩期左室基底部、中部及心尖部最大旋转角度、峰值旋转速度、圆周应变(CS),达峰值旋转速度时间(TPRV);舒张末期及等容舒张末期峰值解旋转速度,对比两组心脏旋转和扭转运动.结果 (1)正常组左室扭转运动:自心尖部向心底部观察,等容收缩期心底部逆时针旋转,心尖部顺时针旋转;收缩期心底部顺时针旋转,心尖部逆时针旋转;乳头肌水平旋转形式不固定.左室整体扭转方向为逆时针.(2)部分DCM患者心脏扭转运动形式改变:30例研究对象中4例患者左室扭转形式不同于正常人,其中2例表现为心尖和心底均呈逆时针旋转,1例表现为心尖和心底均呈顺时针旋转,1例表现为心底部呈逆时针旋转而心尖部呈顺时针旋转.(3)旋转形式未发生变化的26例DCM患者的有关旋转和扭转运动参数均明显减低,以心尖部减低更为明显.DCM组与正常组相比:左室扭转角度7.34°±3.65°比17.01°±4.81°、扭矩(0.09±0.04)°/mm比(0.23±0.06)°/nun、扭转速度(60.23±23.67)°/s比(148.24 4-56.23)°/s、解扭转率(0.37±0.19)%/m比(0.59 4-0.33)%/m;心底部旋转角度-3.60°±2.38°比-6.56°±3.18°(P=0.014)、心尖部旋转角度5.80°±3.55.比12.13.±2.05°(P=0.000)、心底部CS-8.09%±2.73%比-19.49%±5.51%(P=0.013)、心尖部CS-8.94%4-5.90%比-27.49%4±9.53%(P=0.000).(4)左室扭转角度与射血分数呈正相关(r=0.489,P<0.05),DCM组心尖部TPRV较正常组明显延长,存在旋转运动不同步性(400.26 ±70.15)ms比(328.13±66.95)ms,P=0.008.结论 (1)DCM心脏扭转功能呈弥漫性损伤,扭转功能受损对心脏整体功能的减低具有明显影响.(2)部分DCM心脏扭转运动形式表现与正常人不同.(3)VVI可客观反映DCM患者的心脏扭转功能.     

斑点追踪成像技术对慢性心力衰竭患者左心室扭转运动角度的测量及其临床意义

目的：应用斑点追踪成像（STI）技术测量慢性心力衰竭（CHF）患者左心室短轴方向旋转角度,探讨STI评价CHF患者左室扭转运动的临床价值。方法：采集31例CHF患者(CHF组)和32例健康体检者(对照组)的左室短轴(二尖瓣、乳头肌、心尖水平)二维高帧频图像,测量各节段的旋转角度（Rot）,各平面的内膜（endo-rot）、外膜(epi-rot)、平面旋转(bulk-rot)及跨壁扭转(mural-tor)峰值。结果：CHF组各节段的Rot值均显著低于对照组（P<0.01）,CHF组各平面的内膜、外膜、平面旋转及跨壁扭转峰值均显著低于对照组（P<0.05）,CHF组左室整体扭转显著低于对照组（P<0.01）。结论：CHF患者左心室短轴各平面及各节段的扭转角度均低于对照组,提示二维STI能够准确测量HF患者左室短轴各平面及各节段的扭转角度,敏感评价CHF患者心功能状态。     

Heart rate profile during exercise in patients with early repolarization

Background Both early repolarization and altered heart rate profile are associated with sudden death. In this study, we aimed to demonstrate an association between early repolarization and heart rate profile during exercise.Methods A total of 84 subjects were included in the study. Comparable 44 subjects with early repolarization and 40 subjects with normal electrocardiogram underwent exercise stress testing. Resting heart rate, maximum heart rate, heart rate increment and decrement were analyzed.Results Both groups were comparable for baseline characteristics including resting heart rate. Maximum heart rate, heart rate increment and heart rate decrment of the subjects in early repolarization group had significantly decreased maximum heart rate, heart rate increment and heart rate decrement compared to control group （all P〈0.05）. The lower heart rate increment （〈106 beats/min） and heart rate decrement （〈95 beats/min） were significantly associated with the presence of early repolarization. After adjustment for age and sex, the multiple-adjusted OR of the risk of presence of early repolarization was 2.98 （95% CI 1.21-7.34） （P=0.018） and 7.73 （95% CI 2.84-21.03） （P 〈0.001） for the lower heart rate increment and heart rate decrement compared to higher levels, respectively.Conclusions Subjects with early repolarization have altered heart rate profile during exercise compared to control subjects. This can be related to sudden death.     

QRS波宽度正常的扩张型心肌病左室收缩同步性研究

目的：运用脉冲多普勒组织成像（PW-DTI）技术评价QRS波宽度正常的扩张型心肌病（DCM）慢性心力衰竭患者左室收缩同步性的分布特征,及其与左室收缩功能、心室重构、功能性二尖瓣返流（FMR）的关系。方法：应用PW-DTI技术测量47例DCM慢性心力衰竭患者（DCM组）和40例正常人（正常对照组）左室壁12个节段的收缩达峰间期（Ts）,计算Ts的极差(Ts-maxD)和标准差(Ts-SD)。结果：DCM组Ts-SD和Ts-maxD显著大于正常对照组（P＜0.01）;DCM组中Ts-maxD大于100 ms或Ts-SD大于34.4 ms患者有14人,即不同步率为29.8%(14/47),收缩延迟的部位以左室下壁多见;DCM慢性心力衰竭患者Ts-SD,Ts-maxD与左室射血分数（LVEF）呈负相关(P＜0.01),与左室舒张未容积（LVEDV）,左室收缩未容积（LVESV）,功能性二尖瓣返流（FMR）,纽约心脏协会（NYHA）心功能分级呈正相关(P＜0.01)。结论：部分QRS波宽度正常的DCM慢性心力衰竭患者左室存在机械收缩不同步;左室机械收缩不同步加重心功能损害,与左室重构亦有密切关系,并可能是DCM患者FMR的原因之一。     

Prognostic value of echocardiographic right/left ventricular end-diastolic diameter ratio in idiopathic pulmonary arterial hypertension

Background  An echocardiographic right/left ventricular end-diastolic diameter ratio (RV/LV ratio) ≥0.9 is an independent predictor of poor prognosis in patients with acute pulmonary embolism. Right ventricular dilation is a common characteristic of both acute pulmonary embolism and idiopathic pulmonary arterial hypertension (IPAH). However, the prognostic value of the RV/LV ratio in patients with IPAH is unknown.

Methods  Ninety-five consecutive patients with newly diagnosed IPAH were included, 17 were re-evaluated by echocardiography after 3–12 months of targeted therapy. Follow-up data were obtained by telephone interviews and review of the patients’ records.

Results  Higher RV/LV ratios were associated with greater functional impairment. The RV/LV ratio was positively correlated with pulmonary vascular resistance (r=0.549, P <0.001) and plasma N-terminal pro-brain natriuretic peptide level (r=0.575, P <0.001), but negatively correlated with cardiac output (r= –0.517, P <0.001) and mixed venous oxygen saturation (r= –0.599, P <0.001). Twenty-seven patients died during follow-up period. Sensitivity and specificity of an RV/LV ratio ≥0.84 for predicting death were 85.2% and 51.5%, respectively. The RV/LV ratio and body mass index were independent predictors of death by multivariate Cox analysis (P <0.01). A baseline RV/LV ratio ≥0.84 or a further increase in the RV/LV ratio during targeted therapy indicated a poor prognosis (P <0.01).  

Conclusion  The RV/LV ratio helps to assess the severity of IPAH and may serve as an independent predictor of prognosis in patients with IPAH.