双脉冲多普勒技术评价糖尿病患者左心室舒张功能

探讨双脉冲多普勒技术评价2型糖尿病(DM)患者左心室舒张功能的应用价值,并分析影响DM患者左心室舒张功能的相关因素。连续纳入50例非肥胖、无高血压病史的2型DM患者和48名年龄、性别相匹配的志愿者。采用HITACHI Ascendus多普勒超声诊断仪,应用双脉冲多普勒同步取样技术测量二尖瓣口舒张期峰值流速(E峰、A峰)、减速时间(DT)、二尖瓣前瓣环舒张期峰值速度(e’峰),左心室等容舒张时间(IVRT),计算E/A、E/e’比值、Tei指数及E峰与e’峰的起始时间差(TE-e’)。随机选取20例受试者进行IVRT、TE-e’重复性分析。结果显示两组左心室舒张功能参数比较:DM组E/A比值、e’峰降低,E/e’比值、Tei指数升高,DT、IVRT、TE-e’延长,差异有统计学意义(P0.05);线性回归显示TE-e’与IVRT呈正相关(r=0.415,P=0.000);DM患者病程与TE-e’呈正相关(Beta=0.295,P=0.020),糖化血红蛋白(HbA1C)水平与TE-e’呈正相关(Beta=0.399,P=0.010);重复性分析显示IVRT、TE-e’测量组内和组间重复性均较好。双脉冲多普勒技术评价DM患者左心室舒张功能具有临床应用价值,TE-e’可作为评价左心室舒张功能的重要参考指标;DM患者的病程及HbA1C的控制水平与左心室舒张功能密切相关。     

左心房构型超声新表达指标评价高血压病左心室舒张功能的价值

目的以左心房构型超声新表达指标评价左心室舒张功能的改变。方法用二维超声于左心室收缩末期测量左心房最大内径(LAD)、面积(LAA)和容积(LAV),用体表面积标化出左心房内径指数(LADi)、面积指数(LAAi)和容积指数(LAVi),观察各危险层高血压患者LADi、LAAi、LAVi3项指标的变化,同时测量二尖瓣血流参数E/A比值。结果高血压患者LADi、LAAi、LAVi均较正常组增大,差异具有显著性(P<0.05)。并随危险度分层的增高,差异愈显著。不同危险层之间比较差异具有显著性(P<0.05)。而E/A比值仅在中危组以上与正常组比较差异具有显著性。结论左心房构型超声新表达指标评价左心室舒张功能优于E/A比值。     

原发性高血压PTFV_1改变的临床意义

目的探讨原发性高血压患者V1导联P波终末电势(PTFV1)改变的临床意义。方法选择80例原发性高血压患者,其中男性58例,女性22例;年龄23~80岁,平均年龄50岁。比较心电图上PTFV1≤-0.04mm·s的原发性高血压有左心房扩大的患者40例(观察组)和无左心房扩大的患者40例(对照组)的负向P波情况;心脏彩色超声检测比较两组患者的左心房扩大情况、左心室舒张功能E/A比值等。结果与对照组比较,观察组负向P波的时限明显增宽而有切迹,且余导联P波时限增宽。心脏彩色超声检查左心房均有不同程度的增大,并且左心室舒张功能(E/A比值)均有不同程度的减低;对照组中有37例患者的左心房均未增大,患者左心室舒张功能(E/A比值)出现减低的情况很少;两组差异均有显著统计学意义(P0.01)。结论 PTFV1≤-0.04 mm·s且负向P波的时限宽有切迹,则提示原发性高血压患者发生左心房扩大。     

原发性高血压患者血浆脑钠肽水平变化及意义

目的:观察原发性高血压伴左室肥厚和舒张功能不全患者血浆B型脑钠肽(BNP)水平变化以及BNP浓度与高血压分级的相关性。方法:使用微粒子酶免疫分析方法检测94例不同级别原发性高血压患者血浆BNP浓度,分析有无左室肥厚及左室舒张功能不全各组之间的差异及其关系。结果:原发性高血压患者BNP浓度显著高于正常对照组(P<0.01);高血压伴左室肥厚、舒张功能不全患者的BNP浓度也显著高于单纯高血压患者(P<0.01);血浆BNP浓度与原发性高血压分级呈正相关。结论:原发性高血压,尤其是伴有左室肥厚和舒张功能不全患者BNP浓度升高。检测血浆BNP水平的变化及其与原发性高血压的相关性有重要临床意义。     

超声心动图评价重度子痫前期孕妇左室形态和功能的临床意义

目的评价重度子痫前期患者左室形态及功能变化,并探讨二尖瓣舒张早期E波峰值流速与舒张早期二尖瓣环心肌运动峰值速度之比(E/Ea)、收缩期二尖瓣环心肌运动峰值速度(Sa)评价重度子痫前期患者早期左室功能异常的临床意义及其与N-端脑利钠肽前体(NT-pro BNP)的相关性。方法 36例重度子痫前期患者和51例血压正常孕妇(对照组)。运用超声心动图测量左室形态参数,包括舒张末期左室前后径(LVDd)、舒张末期室间隔厚度(IVSd)、舒张末期左室后壁厚度(LVPWd);运用超声心动图测量左室功能参数,包括射血分数(LVEF)、二尖瓣瓣口舒张早期E波峰值流速与舒张晚期A波峰值流速比值(E/A)、收缩期二尖瓣环左室侧壁处心肌运动峰值速度(Sa),舒张早期二尖瓣环左室侧壁处心肌运动峰值速度(Ea),计算E与Ea比值(E/Ea)。同时检测血浆N-端脑利钠肽前体浓度。结果与对照组比较,重度子痫前期组左室形态各参数均明显增加,差异有统计学意义(P0.01);重度子痫前期组Sa明显降低,E/Ea明显增大,差异有统计学意义(P0.01),E/A减小,差异有统计学意义(P0.05)。NT-pro BNP与E/Ea呈正相关(r值为0.58,P0.05);NT-pro BNP与Sa呈负相关(r值为-0.69,P0.05)。结论重度子痫前期患者可以导致左室形态和功能发生变化,应用超声心动图测量E/Ea、Sa与NT-pro BNP相关性良好,可以作为评价左室功能的早期指标,     

正常人颈动脉WI分析及其与左心室功能的关系

目的对正常人颈动脉应用无创性波强度(wave intensity,WI)技术进行分析,并探讨其与左心室功能关系。方法以34例健康人群为研究对象,行无创性WI检查,并将其与常规经胸超声心动图对比分析。结果左、右两侧颈动脉WI各项指标间无统计学差异(P0.05);收缩早期的WI(W1)与心脏射血分数(EF),与Simpson模式测得的舒张早期峰值速度(E)与舒张晚期峰值速度(A)的比值(E/A),与DTI模式获得的舒张早期峰值速度(E')与舒张晚期峰值速度(A')的比值(E'/A')均呈正相关;比值E/E'与E'/A'呈负相关;收缩晚期的WI(W2)与比值E/A、E'/A'、E/E'均无明显相关性。结论参数W1大小能反映左心室收缩功能,具有一定的临床应用价值;参数W2对于评价左室舒张功能具有局限性。应用无创WI技术评价左心室功能尤其是舒张功能方面有待更进一步的研究。     

超声心动图评价高血压患者血清脂联素水平与左心室心肌质量和舒张功能的关系

目的探讨高血压患者血清脂联素水平对左心室心肌质量(LVM)及舒张功能的影响。方法入选单纯高血压患者65例(其中男性36例,女性29例;年龄34～78岁,平均年龄53.78岁)和正常对照组33例(其中男性17例,女性16例;年龄32～65岁,平均年龄52岁)。采用酶联免疫吸附分析法测定血清脂联素水平。采用超声心动图测定LVM、左心室射血分数和代表左心室舒张功能的指标E/e比值、舒张早期左心室内血流传播速度(Vp)和左心室Tei指数。结果高血压组左心室心肌质量指数显著高于正常对照组[(123.58±45.40)g/m2 vs(87.29±17.40)g/m2;P<0.05]。高血压组Vp显著低于正常对照组[(41.25±9.86)cm/s vs(56.31±8.79)cm/s,P<0.01],而E/e比值和Tei指数显著高于正常对照组(8.28±1.96 vs 7.26±1.56,0.46±0.15 vs 0.39±0.12;P<0.05)。在高血压组中血清脂联素水平与左心室心肌质量指数、E/e比值和Tei指数均呈显著负相关(r分别为-0.36、-0.56、-0.58,P<0.05),而与Vp呈显著正相关(r为0.67,P=0.023)。多元逐步回归分析表明血清脂联素水平能分别进入以Vp和Tei指数为因变量的回归方程中。结论血清脂联素水平与左心室心肌质量指数呈显著负相关,血清脂联素水平降低是导致左心室舒张功能降低的危险因素之一。     

彩色M型多普勒评价妊娠期高血压疾病左室舒张功能的研究

目的评价妊娠期高血压疾病左室形态及功能变化,并探讨彩色M型多普勒测量舒张早期左室内血流传播速度(FPV)评价妊娠期高血压疾病患者早期左室舒张功能异常的临床意义。方法 97例妊娠期高血压患者、94例轻度子痫前期患者、95例重度子痫前期患者和101例血压正常孕妇(对照组)。运用超声心动图测量左室形态和功能参数,包括左室前后径(LVDd)、室间隔厚度(IVSd)、左室后壁厚度(LVPWd)、相对室壁厚度(RWT)和左室质量指数(LVMI);射血分数(LVEF)、二尖瓣瓣口舒张早期E波峰值流速(VE)、舒张晚期A波峰值流速(VA)、E波与A波峰值流速比值(VE/VA);舒张早期左室血流传播速度。结果与对照组比较,重度子痫前期组左室形态各参数明显大于正常对照组,差异有统计学意义(P0.01)。左室功能参数与对照组比较,轻度子痫前期组FPV减低,差异有统计学意义(P0.05);重度子痫前期组VE/VA、FPV减低,VA增高,差异有统计学意义(P0.05)。结论妊娠期高血压疾病可以导致左室形态和舒张功能发生变化,并且左室舒张功能可先于左室形态发生改变,FPV可以作为评价左室舒张功能的早期敏感指标。     

加用β受体阻滞剂对高血压病左室舒张功能改善的评价

目的 评价美托洛尔+尼群地平联合治疗高血压病患者左室舒张功能改善.方法 选择60例心电图为窭性心律.有ST-T改变的高血压病患者,分为两组,每组30例,一组使用尼群地平(简称组Ⅰ),另一组使用美托洛尔联合尼群地平(简称组Ⅱ)抗高血压治疗.8周后复查心电图与心脏彩超比较两组治疗前后的左室舒张功能变化.结果 两组治疗后,血压均降至正常范围,心率变化:组Ⅰ t=2.96 P>0.05无差异,组Ⅱt=10.83 P<0.01有显著差异;两组心电图ST～T无变化,心脏彩超复查:心脏大小形态及左室射血分数(EF%)无变化,但两组多普勒频谱超声心动图左室舒张功能指标E/A比值有显著性差异,组1 t=10.83 p<0.01,组Ⅱt=17.74 P<0.001.且组Ⅰ E/A<1,组ⅡE/A>1.结论 联合应用β受体阻滞剂抗高血压治疗,能更有效的改善左室舒张功能,心脏彩超二尖瓣多普勒频谱E/A比值是简单有效的评价方法.心电图P/PR段指数短期内评价治疗后的左室舒张功能不敏感.     

脓毒症大鼠心肌功能障碍的常规超声心动图与组织多普勒成像分析

目的:利用脓毒症大鼠模型,比较常规超声和组织多普勒超声指标在早期诊断脓毒症大鼠心肌内在收缩与舒张功能障碍中的价值。方法:利用盲肠结扎穿孔(CLP)建立脓毒症大鼠模型,22只大鼠随机分成CLP组与假手术组,每组11只。利用ELISA和Western blot检测肿瘤坏死因子α(TNF-α)、细胞间黏附分子1(ICAM-1)和血管细胞黏附分子1(VCAM-1)的表达水平;离体心脏灌流、常规超声心动图和心脏组织多普勒成像测定心脏收缩与舒张功能。结果:与假手术组比较,CLP术后6 h,大鼠血清中TNF-α水平及左心室ICAM-1和VCAM-1表达显著升高,左心室±dp/dtmax显著降低,左心室每搏输出量与舒张末期容积显著降低,但左室射血分数的差异没有统计学显著性,二尖瓣血流速度E波峰值和A波峰值显著降低,二尖瓣环舒张早期运动速度E’波峰值和二尖瓣环舒张晚期运动速度A’波峰值显著降低,而E/E’比值的差异没有统计学显著性。相关分析显示,E’波峰值和A’波峰值分别与-dp/dtmax呈正相关(r分别为0. 460和0. 520,P<0. 05)。结论:组织多普勒成像可以有效评价脓毒症早期心...     

Left ventricular volumes with ventricular inhibited and atrial triggered ventricular pacing

Left ventricular (LV) volumes were assessed with equilibrium radionuclide angiocardiography at rest and during exercise in nine patients with high-degree AV block treated with ventricular inhibited (VVI), which was subsequently changed to atrial triggered ventricular pacing (VAT). The ventricular rates were similar at rest but higher on exercise during treatment with VAT (102 ppm) than with VVI (71 bpm). The LV end-diastolic volume tended to be larger with VAT than with VVI pacing, both at rest (185 vs. 145 ml) and during exercise (220 vs. 162 ml). The LV end-systolic volume also tended to be larger at rest (110 vs. 81 ml) and during exercise (149 vs. 83 ml). The LV ejection fractions were similar at rest but on exercise they decreased to significantly lower levels with VAT (0.35), while remaining unchanged with VVI (0.47). One mechanism for this difference could be an enhanced contractile state in VVI pacing compared with VAT pacing.     

Multifractal analysis of ventricular fibrillation and ventricular tachycardia

A study of ventricular fibrillation and ventricular tachycardia was undertaken using multifractal analysis. By applying the method of direct determination of the f(alpha) singularity spectrum, the value of the area of the VF and VT singularity spectrum was calculated. The comparison between the results showed that the value of the area of the VF singularity spectrum tended to be larger than that of the value of the area of the VT singularity spectrum. This makes the multifractal singularity spectrum a powerful criterion for discriminating between VF and VT.     

Hypoplasia of the right ventricular myocardium with ventricular tachycardia

A 20-year-old woman died suddenly after having had recurrent ventricular tachycardia for five years. An ECG showed two distinct varieties of ventricular tachycardia, both characterized by left bundle-branch block. Pathologic examination showed what we considered to be a type of Uhl's anomaly. Most of the compact layer of the right ventricle was replaced by fat, with the trabeculated areas intact but showing severe fibrosis and chronic inflammation. Patches of such degeneration were also found in the septum and the left ventricle. The conduction system disclosed a septated bundle of His.     

Left ventricular function after long-term treatment with ventricular inhibited compared to atrial triggered ventricular pacing

The long-term effect of ventricular inhibited (VVI) and atrial triggered ventricular (VAT) pacing on cardiac performance was determined by cardiac catheterization at rest and during exercise in 9 patients with high-degree AV block. Cardiac output (Q) increased at rest by 22% during VAT vs. VVI (5.5 vs. 4.5 l/min, p less than 0.01). An increased stroke volume constituted the difference (75 vs. 63 ml, p less than 0.05). Mean working capacity increased by 12% in the supine position with VAT vs. VVI (p less than 0.05). During exercise Q increased by 40% with VAT vs. VVI (10.2 vs. 7.3 l/min, p less than 0.01) due to an increase in heart rate. Most pressures were largely unchanged. Stroke work and atrial rate decreased during VAT vs. VVI, which may indicate a lower sympathetic activity with VAT vs. VVI. The study demonstrated that hemodynamics advantages of VAT are still obtainable after several years of VVI pacing.     

Catch 22: a case of incessant ventricular tachycardia post-left ventricular assist device resulting in right ventricular failure,left ventricular cavity obliteration and failure of endocardial ventricular tachycardia ablation

Ventricular tachycardia (VT) in the setting of left ventricular assist device (LVAD) therapy has been well described. We present a case of incessant ventricular tachycardia resulting in severe right ventricular (RV) failure and subsequent left ventricular (LV) cavity obliteration, which in turn diminished the feasibility of initial attempt at VT ablation.     

Regenerating a ventricular cavity during left ventricular assist device implantation

Journal of Artificial Organs - Ten months after an ineffective percutaneous coronary stent placement, a 53-year-old patient was rehospitalized with NYHA functional class IV congestive heart...     

Cow ventricular muscle

1. The effect of [K]₀ on the current-voltage relationship is described. In the negative potential range the curves cross over as [K]₀ is increased. At positive potentials the curves re-cross so that in low [K]₀ there is more outward current than in high [K]₀
2. Chord conductance has been calculated from the current-voltage relationship and this is taken as a measure ofg _K. It is shown thatg _K is a function of both the potassium driving force (E _M?E _K) and [K]₀.
3. Current-voltage relationships obtained by the voltage clamp technique have been compared to net current-voltage relationships obtained by phase plane analysis of the action potential. [K]₀ is shown to have similar effects on both.
4. The effect of [K]₀ at positive potentials suggests that delayed outward current during large depolarizing voltage clamp steps is due to an activation of a time-dependent outward current and not to potassium accumulation. An analysis of current tails also suggests the presence of a time-dependent outward current.
5. In contrast delayed outward current changes during small depolarizing voltage clamp steps are probably due to potassium accumulation.
6. Evidence is presented which indicates that inward current tails following depolarizing voltage clamp steps are due to potassium accumulation.