经胸超声心动图引导下行房间隔缺损封堵术治疗先天性房间隔缺损的临床研究

目的:探讨经胸超声心动图引导下行房间隔缺损封堵术治疗先天性房间隔缺损(Atrial septal defect,ASD)的临床疗效。方法:比较先天性ASD患者行超声心动图组(49例)或介入组(53例),患者的疗效及心脏功能的变化。结果:超声心动图组并发症发生率显著低于介入组(P0.05);术后4周,两组患者的心率、舒张期室间隔厚度(Interventricular septal thickness,IVST)、左室后壁厚度(Left ventricular posterior wall thickness,LVPWT)、左心室心肌重量(Left ventricular mass,LVM)和左心室心肌重量指数(Left ventricular mass index,LVMI)明显降低(P0.05),左心室射血分数(Left ventricular ejection fraction,LVEF)和左心室高峰充盈率(Left ventricular peak filling rate,LVPFR)均显著升高(P0.05),其余指标则无明显变化(P0.05);但术后1周超声心动图组的LVEF、IVST和LVMI即显著高于术前(P0.05)。结论:胸超声心动图引导下行ASD封堵术与X线介入封堵术疗效相当,但前者可能对ASD患者的心脏功能的改善更为显著。     

妊娠期高血压患者血清热休克蛋白70水平与心功能及免疫球蛋白的关系研究

目的:探究妊娠期高血压患者血清热休克蛋白70(HSP70)水平与心功能及免疫球蛋白的关系。方法:选择2017年4月至2018年4月在陕西省人民医院诊治的200例妊娠期高血压患者作为妊娠期高血压组,同时选择同期在我院进行孕检的200名健康孕妇作为对照组。采用酶联免疫吸附法检测血清HSP70水平,采用全自动生化分析仪检测免疫球蛋白G(Ig G)、免疫球蛋白M(Ig M)、免疫球蛋白A(Ig A)、免疫球蛋白D(Ig D)和免疫球蛋白E(Ig E)水平,采用多普勒超声心动图监测两组的左心室后壁厚度(LVPWT)、左心室舒张末期内径(LVEDD)和室间隔厚度(IVST)、左心室收缩末期内径(LVESD)、左心室射血分数(LVEF)和每搏指数(SVI),计算左心室质量(LVM)、二尖瓣舒张早期血流速度峰值与二尖瓣环侧壁舒张早期运动峰速度的比值(E/Em)、舒张早期与舒张晚期血流速度峰值的比值(E/A)。采用spearman相关性分析血清HSP70水平与血清免疫球蛋白水平及心功能指标的相关性。结果:与对照组相比,妊娠期高血压组的血清HSP70水平明显升高,而Ig G和Ig M水平明显下降,并且LVESD、LVEF、E/A也明显下降(P0.05)。血清HSP70水平与Ig G、Ig M、LVESD、LVEF、E/A均呈负相关性(P0.05)。结论:妊娠期高血压患者的血清HSP70水平明显升高,并且血清HSP70水平与妊娠期高血压患者免疫功能和心功能下降存在相关性,在妊娠期高血压患者的诊断和治疗中具有一定临床价值。     

基于三维超声心动图对比分析扩张型心肌病与二尖瓣关闭不全左室构型和收缩功能的研究

摘要 目的：基于三维超声心动图对比分析扩张型心肌病（DCM）与二尖瓣关闭不全（MI）左室构型和收缩功能的研究。方法：收集我院2018年1月至2021年7月就诊患有左心室（LV）扩张的患者100例,其中DCM患者57例,MI患者43例。LV大小大致相仿,DCM组（43±5）mm/m²,MI组（42±5）mm/m²。另选取同时期50例健康受试者作为对照组。所有患者均进行常规超声心动图及三维超声心动图检查,测量指标主要包括左室大小（LVID）、左室后壁厚度（PWT）、左室舒张末期内径（LVEDD）、左室舒张末期室间间隔厚度（IVS）、左室舒张末期容积（LVEDV）、收缩末期容积（LVESV）、相对室壁厚度（RWT）、LV质量指数（LVMI）、三维左室射血分数（3D-LVEF）、三维舒张末期血流速度（3D-EDV）、二维或三维超声心动图球形指数（2D-SI/3D-SI）。结果：DCM组和MI组LVEDD均大于对照组,差异有统计学意义（P＜0.05）。DCM组比MI组患者心功能分级III/IV和心力衰竭的发生率更高,差异有统计学意义（P＜0.05）。DCM组和MI组患者的LVEDD、LVEDD指数、LVEDV、LVEDV指数、3D-EDV、3D-EDV指数均高于对照组,差异有统计学意义（P＜0.05）;但DCM组和MI组对比差异无统计学意义（P＞0.05）。DCM组和MI组患者的LV长度、LV长度指数、LVMI均高于对照组,差异有统计学意义（P＜0.05）;且MI组高于DCM组,差异有统计学意义（P＜0.05）。DCM组和MI组患者的LVESV、LVESV指数、2D-SI、3D-SI均高于对照组,差异有统计学意义（P＜0.05）;且DCM组高于MI组,差异有统计学意义（P＜0.05）。DCM组3D-LVEF、RWT均低于对照组和MI组,差异有统计学意义（P＜0.05）。ROC分析显示,3D-SI在评估左室扩大患者的左室重构方面优于其他变量,3D-SI的ROC曲线下面积为0.875,95%CI为0.816-0.920,3D-SI>0.62对于DCM和MI区分左室构型的特异性（81.66%）和敏感性（92.09%）较高。DCM和MI患者的3D-LVEF和3D-SI均呈线性负相关（r=-0.719,P=0.000;r=-0.682,P=0.000）。DCM和MI患者3D-SI检测心力衰竭的ROC曲线下面积均大于3D-LVEF的ROC曲线下面积,差异有统计学意义（P=0.000）。结论：与MI患者相比,尽管LV大小大致相仿,但DCM患者的左室几何形状更接近球形,且收缩功能更差。收缩功能与3D-SI显著相关,3D-SI较好地描述了左室重构,可能是LV扩张患者心力衰竭的较强指标。     

同型半胱氨酸与H型高血压左室肥厚的相关性及马来酸依那普利叶酸片的干预效果

目的:探讨同型半胱氨酸(Hcy)与H型高血压左室肥厚的相关性及马来酸依那普利叶酸片的干预效果。方法:选取达州市中心医院于2015年8月-2017年7月收治的450例原发性高血压患者,根据血浆Hcy水平将患者分为Hcy正常组(n=134)和H型高血压组(n=316),比较Hcy正常组、H型高血压组患者超声心动图检测指标的差异,并对Hcy水平与左心室结构改变进行相关性分析。同时将316例H型高血压患者随机分为观察组(n=158)和对照组(n=158),其中对照组患者给予马来酸依那普利片治疗,观察组给予马来酸依那普利叶酸片治疗。两组均连续治疗24个月。分别于治疗前、治疗后6个月、12个月、24个月检测血压、血浆Hcy和左心室质量指数(LVMI)水平,观察脑卒中及药物不良反应发生情况。结果:H型高血压组左室收缩末内径(LVESD)、左室舒张末内径(LVEDD)、左室后壁厚度(LVPWT)、室间隔厚度(IVST)、左心室质量(LVM)、LVMI均较Hcy正常组增大(P0.01)。血浆Hcy与LVPWT、IVST、LVM及LVMI呈正相关(r=0.652、0.526、0.736、0.786,均P0.05);治疗后6个月、12个月、24个月,观察组与对照组的H型高血压患者收缩压(SBP)、舒张压(DBP)水平及观察组Hcy、LVMI均较治疗前降低(P0.05),且观察组SBP、DBP、Hcy及LVMI均低于同时间点的对照组(P0.05)。两组均未见严重药物不良反应发生,观察组脑卒中发生4例(2.53%)较对照组12例(7.59%)明显减少,差异有统计学意义(P0.05)。结论:血浆Hcy水平是影响原发性高血压患者左心室肥厚的危险因素;马来酸依那普利叶酸片干预H型高血压患者后可显著降低血压、血浆Hcy水平,改善患者左心室肥厚程度,降低脑卒中发生率。     

左西孟旦和米力农治疗难治性心力衰竭的疗效比较及对血清NT-proBNP、ET-1水平的影响

目的:观察和比较左西孟旦(LEV)与米力农(MIL)治疗难治性心力衰竭(RHF)的临床效果及对患者血清N末端B型利钠肽原(NT-proBNP)、内皮素(ET)-1水平的影响。方法:选取我院2015年1月~2017年4月收治的102例RHF患者,采取随机数字表法均分为两组。MIL组给予MIL治疗,LEV组予以LEV治疗。比较两组的临床疗效,治疗前后超声心动图指标[左室射血分数(LVEF)、二尖瓣舒张早期/舒张晚期峰值流速(E/A)、左室舒张末期内径(LVIDd)]、血清NT-proBNP、ET-1水平的变化及不良反应的发生情况。结果:治疗7 d后,LEV组总有效率较MIL组明显升高(P0.05)。与治疗前对比,两组治疗7 d后LVEF、E/A值均显著上升(P0.01),LVIDd值均显著下降(P0.01),且LEV组LVEF、E/A值均显著高于MIL组,LVIDd值均显著低于MIL组(P0.01)。两组治疗7 d后血清NT-proBNP、ET-1水平较治疗前均显著降低(P0.01),且LEV组血清NT-proBNP、ET-1水平均明显低于MIL组(P0.01)。LEV组不良反应的发生率较MIL组明显降低(P0.05)。结论:与米力农相比,左西孟旦治疗难治性心力衰竭能更有效缓解或消除患者症状体征、抑制心室重构、改善心功能,且安全性更高,可能与其显著降低血清NT-proBNP、ET-1水平有关。     

心脏彩超评估高血压左心室肥厚伴左心衰竭患者心功能的临床价值及与NYHA分级的关系研究

目的:探讨心脏彩超评估高血压左心室肥厚(LVH)伴左心衰竭患者心功能的临床价值,分析其超声指标与美国纽约心脏病协会(NYHA)分级的相关性。方法:选择2017年5月至2018年5月我院收治的127例高血压LVH伴左心衰竭患者为观察组,根据NYHA分级将其分为NYHAⅡ级组(41例)、Ⅲ级组(47例)、Ⅳ级组(39例),另选择100例体检的健康志愿者为对照组。所有受试者均接受心脏彩超获得相关参数[左心房内径(LAD)、左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心室短轴缩短率(LVFS)、左心室后壁厚度(LVPWT)、室间隔厚度(IVST)、左心室射血分数(LVEF)、左心室舒张早期充盈峰最大充盈速度/舒张晚期充盈峰最大峰值速度(E/A)比值、Tei指数],分析心脏彩超相关参数与NYHA分级之间相关性。结果:观察组患者LAD、LVEDD、LVESD、LVPWT、IVST、Tei指数高于对照组(P0.05),LVFS、LVEF、E/A比值低于对照组(P0.05)。Tei指数随着NYHA分级增高而增高(P0.05),LVFS、LVEF、E/A比值随着NYHA分级增高而降低(P0.05)。Spearman秩相关分析结果显示,Tei指数与NYHA分级呈正相关(rs=0.398,P0.05),LVFS、LVEF、E/A比值与NYHA分级呈负相关(rs=-0.285,-0.442,-0.305,P0.05)。结论:高血压LVH伴左心衰竭患者发生明显左室肥厚和左心功能降低,心脏彩超可准确评估高血压LVH伴左心衰竭患者的心功能和病情严重程度,且部分心脏彩超相关参数与NYHA分级相关。     

Regional metabolic rate of exogenous glucose in the isoprenaline and dobutamine stimulated canine myocardium as estimated by the 2-deoxy-d[1-14C]glucose method

The effect of β-adrenoceptor stimulation by isoprenaline and dobutamine on the transmural distribution pattern of regional myocardial metabolic rate of exogenous glucose (RMMRGlc) was studied in the anesthetized closed chest dog using the 2-deoxy-d[1-¹⁴C]glucose method. In a previous series a lumped constant (LC) value of 0.93 ± 0.47 (1 SD) was measured for [¹⁴C]2-deoxyglucose in the canine myocardium. In the control group (N = 12) RMMRGlc was significantly higher in the subendocardial layer of the left ventricular free wall than in both the middle and subepicardial layer, where it was quite evenly distributed (P ⩽ 0.05). With i.v. dobutamine (N = 8) RMMRGlc was significantly lower in the midportion of left ventricular free wall than in the subepicardial layer (P ⩽ 0.05), but it was not different from the inner wall section. Significant differences between the subepicardial and subendocardial portions of the left ventricular free wall could not be found, either. In the isoprenaline group (N = 9) no transmural gradients of RMMRGlc were observed in the left ventricular myocardium. In all groups, both the interventricular septum and the right ventricular free wall exhibited homogeneous distribution patterns of RMMRGlc.It is concluded that transmural distribution patterns of exogenous glucose utilization probably reflect corresponding gradients in energy demands of the left ventricular wall. Redistribution of RMMRGlc in the isoprenaline and dobutamine groups may result from altered working conditions, a change in local inotropic state of the left ventricular myocardium, or from regional differences in the proportions of substrate utilization, and from regional differences in adrenoceptor density.     

拉西地平对内质网应激导致左室重塑的保护作用

目的:研究在高温高湿应激状态下拉西地平对葡萄糖调节蛋白(glucose-regulated protein78,GRP78)和C/EBP环磷酸腺苷反应元件结合转录因子同源蛋白(C/EBP-homologous protein,CHOP)在大鼠心肌中表达及对心室重塑的影响。方法:将30只雄性Sprague-Dawly(SD)大鼠随机分为对照组、高温高湿组、拉西地平干预组,每组10只。喂养6周后颈动脉插管测定平均动脉压及心率。B超检测左室形态结构。免疫组化法检测大鼠心肌GRP78及CHOP蛋白及表达水平。结果:高温高湿组的大鼠平均动脉压(MBP)、隔厚度(IVST)、左室后壁厚度(LPWT)、左室重量指数(LVWI),GRP78及CHOP蛋白表达水平与对照组相比均有显著升高(p<0.01),拉西地平干预组能显著降低大鼠平均动脉压(MBP)、室间隔厚度(IVST)、左室重量指数(LVWI),GRP78及CHOP蛋白的表达水平(p<0.05)。结论:内质网应激可能参与了高温高湿诱导的左室重构;拉西地平可能通过降低GRP78及CHOP的表达干预了ERS介导的心肌肥厚通路,从而改善心脏功能。     

Effect of endurance training on cardiac morphology in Alaskan sled dogs

The cardiac morphology of 77 consciousAlaskan sled dogs before and after 5 mo of endurance training (20 km/day team pulling a sled and musher) was studied usingtwo-dimensional and M-mode echocardiography. Subgroups included dogswith at least one season of previous training ("veterans") anddogs undergoing their first season of training ("rookies").Training resulted in a significant (P < 0.05) decrease in resting heart rate (15%) and significant increases in interventricular septal thickness (systole, 15%; diastole, 13%), left ventricular (LV) internal dimension in diastole (LVIDd, 4%), LV free wall thickness in systole (9%) and diastole (LVWd, 9%), and left atrial diameter (5%) in all dogs, but the increase in LVWd was greater in rookies (16%) than in veterans (7%).Training increased end-diastolic volume index (8%), LV mass index(24%), and heart weight index (24%) and decreased the LVIDd-to-LVWd ratio (6%) but did not alter cardiac index. We conclude that increased LV mass attributable to LV dilation and hypertrophy isassociated with endurance training in Alaskan sled dogs.Disproportionate LV wall thickening accompanying LV dilation suggeststhat cardiac morphological changes are due to volume and pressureloading. These training-induced changes are similar to those documented in human athletes undergoing combined isometric and isotonic training and differ from studies of dogs trained on treadmills.

     

血清胱抑素C 水平与糖尿病心室重构关系的临床研究

目的:研究血清胱抑素C水平与糖尿病心室重构的关系。方法:选择2013年10月~2015年10月在我院进行诊治的糖尿病患者90例,检测血清胱抑素C水平,按照糖尿病患者血清胱抑素C水平的中位数,分为正常组(胱抑素C水平1.65mg/L)和升高组(胱抑素C水平1.65mg/L)。行超声心动图检测左室舒张末内径、左房内径、左室舒张末容积、室间隔厚度和左室后壁厚度,并计算出左室质量指数。对两组的这些指标进行比较,并分析血清胱抑素C与糖尿病心室重构的相关性。结果:与正常组相比,升高组的胱抑素C、左室舒张末内径、左房内径、室间隔厚度、左室后壁厚度、左室质量指数和脑钠肽水平均明显增高(P0.05);经过相关性分析,血清胱抑素C水平与左室舒张末内径、左房内径、室间隔厚度、左室后壁厚度、左室质量指数和脑钠肽均呈正相关(P0.05);Logistic回归分析显示左室舒张末内径、左房内径、室间隔厚度、左室后壁厚度、左室质量指数和脑钠肽等是胱抑素C水平升高的危险因素。结论:血清胱抑素C水平与糖尿病患者的心功能和心室重构具有明显相关性,可作为衡量糖尿病患者心室重构程度的一项参考指标。     

Concentric adaptation of the left ventricle in response to controlled upper body exercise training.

Upper body exercise has many applications to the rehabilitation and maintenance of cardiovascular health of individuals who are unable to exercise their lower body. The hemodynamic loads of upper body aerobic exercise are characterized by relatively high blood pressure and relatively low venous return. It is not clear how the left ventricle adapts to the specific hemodynamic loads associated with this form of exercise training. The purpose of this study was to measure left ventricular structure and function in previously sedentary men by using echocardiography before and after 12 wk of aerobic arm-crank exercise training (n = 22) or a time control period (n = 22). Arm-crank peak oxygen consumption (in ml x kg(-1) x min(-1)) increased by 16% (P < 0.05) after training, and significant differences (P < 0.05) were found in wall thickness (from 0.86 to 0.99 cm) but not in left ventricular internal dimension in diastole or systole. This suggested a concentric pattern of left ventricular hypertrophy that persisted after scaling to changes in anthropometric characteristics. No differences (P < 0.05) were found for any measurements of resting left ventricular function. We conclude that upper body aerobic exercise training results in a specific left ventricular adaptation that is characterized by increased left ventricular wall thickness but no change in chamber dimension.     

原发性高血压患者血压昼夜节律与靶器官损害的关系研究

目的:研究原发性高血压患者血压昼夜节律异常是否与靶器官损害存在关联。方法:将2015年2~11月份在我院治疗的94例原发性高血压病人按照血压昼夜节律是否正常分为节律正常组52例和异常组42例。比较两组患者的24h、白天、夜间的收缩压(SBP)与舒张压(DBP)及血压负荷,并且比较两组患者心脏、脑、肾损伤相关指标。结果:异常组全天24h、白天、夜间SBP及DBP,血压负荷均高于正常组,差异具有统计学意义(P0.05)。异常组患者左室重量(LVM)和左室重量指数(LVMI)、发生心肌缺血次数及持续时间、发生脑梗死几率均明显高于正常组,差异有统计学意义(P0.05)。异常组尿微量白蛋白(MAU)、尿酸(UA)水平均高于正常组,差异有统计学意义(P0.05)。结论:原发性高血压患者出现昼夜节律异常,可能对相关靶器官造成损伤。     

超声造影与B型超声对人颈动脉内膜-中层厚度及斑块的诊断价值分析

摘要 目的：探讨超声造影（CEUS）与B型超声在诊断人颈动脉内膜-中层厚度（CIMT）及斑块中的临床应用价值。方法：选取2018年10月至2022年12月内蒙古自治区人民医院健康体检者142例,均行颈动脉B型超声和CEUS成像检查。记录左右侧颈动脉各分段点CIMT近壁和远壁值,然后取平均值。采用半定量的方法进行评分,以确定在B型超声和CEUS成像过程中的CIMT可视化。比较B型超声和CEUS成像技术对斑块检出的差异。根据CIMT平均值进行进一步分组,分析CIMT与亚临床左心功能障碍之间的关系。结果：在B型超声成像上,左右侧颈动脉CIMT远壁的可视化评分均明显高于CIMT近壁,差异有统计学意义（P＜0.05）;在CEUS成像上,左右侧颈动脉CIMT远壁的可视化评分均高于CIMT近壁,差异有统计学意义（P＜0.05）。与B型超声成像模式对比,在CEUS成像模式中左右侧颈动脉CIMT远壁和近壁的可视化评分均得到显著提高,差异有统计学意义（P＜0.05）。142例健康体检者中,B型超声总共检测出271个斑块,CEUS总共检测出293个斑块,斑块检出率组间比较差异有统计学意义（P＜0.05）。随着CIMT平均值的逐渐增大,LVM逐渐减小,LVGLS逐渐增大,差异有统计学意义（P＜0.05）。CIMT平均值的大小与LVEDD、LVESD和LVEF差异无统计学意义（P＞0.05）。结论：CEUS改善了CIMT的可视化,并能更好地检测出颈动脉斑块（主要为低回声斑块）,对预测心血管疾病的发生有一定临床价值。     

Morphological and functional differences in cardiac parameters between power and endurance athletes: a magnetic resonance imaging study

The present study compared morphological and functional parameters of the left ventricle by magnetic resonance imaging (MRI) in competitive athletes engaged in endurance and power activities and sedentary control subjects. Twenty male subjects, 7 endurance-trained athletes (ETA) (age 23.8+/-3.5 yr), 7 strength-trained athletes (STA) (age 22.8+/-4.0 yr), and 6 sedentary controls (age 24.1+/-2.2 yr) were studied by MRI. In the ETA group body size related left ventricular mass (rel.LVM) was significantly higher than that in the STA group (71.0+/-9.2 vs 57.4+/-15.7 g/m3). The difference between their size related left ventricular wall thickness (rel.LVWT) values (9.37+/-1.0 vs 8.37+/-1.8 mm/m) was near to the level of significance (p=0.057). Relative left ventricular internal diameter (rel.LVID) was significantly higher in the ETA group compared to the STA group (42.3+/-1.0 vs 40.1+/-2.5 mm/m, p<0.05). The muscular quotient (MQ=LVWT/LVID) of the ETA group was not significantly higher compared to the strength athletes. Relative left ventricular end-diastolic volume (LVEDV) was also higher in the ETA group than in the STA group (69.5+/-6.7 vs 59.9+/-8.2 ml/m3, p<0.05) and the controls (53.6+/-3.7, p<0.001). Significantly higher relative stroke volume (SV) was measured in the ETA group compared to the STA group and the controls (41.0+/-5.7; 32.6+/-6.9; 32.0+/-3.2 ml/m3). According to the present data, the strongest impact on LV cavity size and wall thickness is caused by long-term high intensity endurance training. Intense strength training does not necessarily induce wall thickening.     

The influence of body composition, fat distribution, and sustained weight loss on left ventricular mass and geometry in obesity

Alterations in left ventricular mass and geometry vary along with the degree of obesity, but mechanisms underlying such covariation are not clear. In a case–control study, we examined how body composition and fat distribution relate to left ventricular structure and examine how sustained weight loss affects left ventricular mass and geometry. At the 10‐year follow‐up of the Swedish obese subjects (SOS) study cohort, we identified 44 patients with sustained weight losses after bariatric surgery (surgery group) and 44 matched obese control patients who remained weight stable (obese group). We also recruited 44 matched normal weight subjects (lean group). Dual‐energy X‐ray absorptiometry, computed tomography, and echocardiography were performed to evaluate body composition, fat distribution, and left ventricular structure. BMI was 42.5 kg/m², 31.5 kg/m², and 24.4 kg/m² for the obese, surgery, and lean groups, respectively. Corresponding values for left ventricular mass were 201.4 g, 157.7 g, and 133.9 g (P < 0.001). In multivariate analyses, left ventricular diastolic dimension was predicted by lean body mass (β = 0.03, P < 0.001); left ventricular wall thickness by visceral adipose tissue (β = 0.11, P < 0.001) and systolic blood pressure (β = 0.02, P = 0.019); left ventricular mass by lean body mass (β = 1.23, P < 0.001), total body fat (β = 1.15, P < 0.001) and systolic blood pressure (β = 2.72, P = 0.047); and relative wall thickness by visceral adipose tissue (β = 0.02, P < 0.001). Left ventricular adjustment to body size is dependent on body composition and fat distribution, regardless of blood pressure levels. Obesity is associated with concentric left ventricular remodeling and sustained 10‐year weight loss results in lower cavity size, wall thickness and mass.     

Prevalence and upper limit of cardiac hypertrophy in professional cyclists

The term athlete's heart refers to an increased left ventricular mass. Few studies have assessed the prevalence and normal upper limit of cardiac hypertrophy in highly trained cyclists and this was the aim of this study. A group of 40 professional road cyclists [mean age 26 (SD 3) years] who had participated in European competitions for 3–10 years, were evaluated at the beginning of the 1992–93 season. Evaluation included a clinical history and physical examination, one and two-dimensional echocardiography, 12-lead resting electrocardiogram and a graded exercise test. Determination of the left ventricular mass index (LVMI) was performed using Devereux's formula with correction for the body surface area. Systolic and diastolic blood pressure were measured at rest and at peak exercise. Of the group 23 cyclists (58%) presented a LVMI greater than 130 g · m^–2, 21 cyclists presented a diastolic ventricular thickness equal to or greater than 13 mm, with a superior limit of 19 mm; 3 cyclists presented asymmetrical septum hypertrophy; and the relationship between posterior wall and left ventricular diastolic radius was equal to or greater than 0.45 in 14 cases (35%). Electrocardiographic abnormalities of ST-T segment were seen in only 1 subject. No correlation was found between the degree of ventricular hypertrophy and arterial blood pressure. We concluded that these professional cyclists showed a high prevalence of cardiac hypertrophy (58%). The distribution of this hypertrophy was concentric in 20/33 and asymmetric in 3/23 of the subjects with left ventricular hypertrophy. The electrocardiograms were normal in 98% of the subjects.     

右室间隔部起搏患者起搏QRS 波时限与心功能的关系

目的:探讨右室间隔部起搏患者起搏QRS波时限与心功能的关系。方法:回顾性分析植入右室间隔部起搏的双腔起搏器患者(111例),起搏器平均植入时间(4.52±3.65)年,通过常规体表心电图测得完全起搏时QRS波时限分为四组:A组为QRS≤120ms(21例);B组为120ms180ms(26例),行心脏彩色多普勒检查获取左房内径(LAD)、收缩末期左室内径(LVESD)、舒张末期左室内径(LVEDD)、室间隔厚度(IVST)、左室后壁厚度(LVPWT)及LVEF,同时检测患者的血清氨基末端脑肭肽前体(NT-proBNP),分析起搏QRS波时限与以上各指标的关系。结果:D组患者LAD、LVEDD、LVESD、IVST及IVPWT较其他三组明显增大,同时LVEF显著下降,NT-proBNP明显升高,有统计学意义(P<0.05)。同时发现随起搏QRS时限的不断增宽,不同组别的LVEF是依次降低(中位值分别为66.5%、60.3%、52.7%和45.8%),而血清NT-proBNP水平是依次增大(中位值分别为143.7 pg/ml、261.8 pg/ml、599.4 pg/m和971.2 pg/ml)。直线相关性分析示起搏QRS波时限与LAD(r=0.141,P<0.05)、LVEDd(r=0.678,P<0.05)、LVEDs(r=0.439,P<0.05)、IVST(r=0.165,P<0.05)及LVPWT(r=0.189,P<0.05)有显著线性关系,呈正相关。起搏QRS波时限与LVEF负相关(r=-0.684,P<0.05),起搏QRS波时限与NT-proBNP的对数正相关(r=0.368,P=0.029)。结论:对于右室间隔部起搏的双腔起搏患者,起搏QRS波时限是一个可初步判断心脏结构和功能的指标,其起搏QRS波时限延长可能会恶化患者的心脏结构及功能,可结合NT-proBNP进行动态观察,对起搏器植入患者的心功能恶化和心衰的预防有一定的临床实用价值。     

Echocardiographic characteristics in adolescent junior male athletes of different sport events

The purpose of this study was to examine the effects of different sport activities on cardiac adaptation. Echocardiographic data of 137 athletes and 21 non-athletes were measured and compared in two age groups 15-16 and 17-18 years of age. Athletes belonged into three groups according to their sports activity (endurance events, power athletes, ball game players). The observed variables were related to body size by indices in which the exponents of the numerator and the denominator were matched. Left ventricular hypertrophy was manifest in all athletic groups. Power athletes had the largest mean left ventricular wall thickness (LVWTd) in both age groups. In the older age group differences between the athletic groups were smaller, but the endurance and power athletes had significantly higher wall thickness. Left ventricular internal diameter (LVIDd) was the largest in the endurance athletes, while mean relative muscle mass (LVMM) was the largest in the power athletes. LVMM of the older endurance athletes was significantly larger. Muscular quotient (MQ) was the highest in the endurance athletes; in the 17-18-year group there was no inter-event difference. Bradycardia was most manifest in the endurance athletes and ball game players, power athletes had higher resting heart rates than non-athletic subjects. It can be inferred that endurance training induces firstly an enlargement of the left ventricle what is then followed by an increase of muscle mass. In the studied functional and regulatory parameters no difference was found between the athletic and non-athletic groups.     

Predominance of Intrinsic Mechanism of Resting Heart Rate Control and Preserved Baroreflex Sensitivity in Professional Cyclists after Competitive Training

Different season trainings may influence autonomic and non-autonomic cardiac control of heart rate and provokes specific adaptations on heart’s structure in athletes. We investigated the influence of transition training (TT) and competitive training (CT) on resting heart rate, its mechanisms of control, spontaneous baroreflex sensitivity (BRS) and relationships between heart rate mechanisms and cardiac structure in professional cyclists (N = 10). Heart rate (ECG) and arterial blood pressure (Pulse Tonometry) were recorded continuously. Autonomic blockade was performed (atropine—0.04 mg.kg^-1; esmolol—500 μg.kg^-1 = 0.5 mg). Vagal effect, intrinsic heart rate, parasympathetic (n) and sympathetic (m) modulations, autonomic influence, autonomic balance and BRS were calculated. Plasma norepinephrine (high-pressure liquid chromatography) and cardiac structure (echocardiography) were evaluated. Resting heart rate was similar in TT and CT. However, vagal effect, intrinsic heart rate, autonomic influence and parasympathetic modulation (higher n value) decreased in CT (P≤0.05). Sympathetic modulation was similar in both trainings. The autonomic balance increased in CT but still showed parasympathetic predominance. Cardiac diameter, septum and posterior wall thickness and left ventricular mass also increased in CT (P<0.05) as well as diastolic function. We observed an inverse correlation between left ventricular diastolic diameter, septum and posterior wall thickness and left ventricular mass with intrinsic heart rate. Blood pressure and BRS were similar in both trainings. Intrinsic heart rate mechanism is predominant over vagal effect during CT, despite similar resting heart rate. Preserved blood pressure levels and BRS during CT are probably due to similar sympathetic modulation in both trainings.     

Sex differences in physiological cardiac hypertrophy are associated with exercise-mediated changes in energy substrate availability

Exercise-induced cardiac hypertrophy has been recently identified to be regulated in a sex-specific manner. In parallel, women exhibit enhanced exercise-mediated lipolysis compared with men, which might be linked to cardiac responses. The aim of the present study was to assess if previously reported sex-dependent differences in the cardiac hypertrophic response during exercise are associated with differences in cardiac energy substrate availability/utilization. Female and male C57BL/6J mice were challenged with active treadmill running for 1.5 h/day (0.25 m/s) over 4 wk. Mice underwent cardiac and metabolic phenotyping including echocardiography, small-animal PET, peri-exercise indirect calorimetry, and analysis of adipose tissue (AT) lipolysis and cardiac gene expression. Female mice exhibited increased cardiac hypertrophic responses to exercise compared with male mice, measured by echocardiography [percent increase in left ventricular mass (LVM): female: 22.2 ± 0.8%, male: 9.0 ± 0.2%; P < 0.05]. This was associated with increased plasma free fatty acid (FFA) levels and augmented AT lipolysis in female mice after training, whereas FFA levels from male mice decreased. The respiratory quotient during exercise was significantly lower in female mice indicative for preferential utilization of fatty acids. In parallel, myocardial glucose uptake was reduced in female mice after exercise, analyzed by PET {injection dose (ID)/LVM [%ID/g]: 36.8 ± 3.5 female sedentary vs. 28.3 ± 4.3 female training; P < 0.05}, whereas cardiac glucose uptake was unaltered after exercise in male counterparts. Cardiac genes involved in fatty acid uptake/oxidation in females were increased compared with male mice. Collectively, our data demonstrate that sex differences in exercise-induced cardiac hypertrophy are associated with changes in cardiac substrate availability and utilization.