老年急性心肌梗死心率变异性的临床观察

目的 探讨老年急性心肌梗死患者的心率变异性(HRV)。方法 应用24小时动态心电图(Holter)检测36例老年急性心肌梗死(AMI)患者和30例正常人HRV的各项时域指标:总体标准差(SDNN)、均值标准差(SDANN)、标准差均值(SDNN IDX)、差值均方的平方根(rMSSD)和差值>50ms的百分比(PNN50)。结果 AMI组与正常对照组比较,SDNN、SDANN、SDNN IDX、rMSSD均显著降低(P<0.01)和PNN50明显降低(P<0.05)。结论 老年急性心肌梗死患者自主神经明显受损,迷走神经与交感神经平衡失调。且与AMI预后有关。     

肝豆状核变性患者心率变异性观察

目的探讨肝豆状核变性(HLD)患者自主神经功能变化。方法对未经正规治疗的90例HLD患者(观察组)和30例健康人(对照组)进行心率变异性(HRV)分析。结果观察组HLD肝型、脑—内脏型平均窦性R-R间期的标准差(SDNN)、每5 min正常R-R间距平均值的标准差(SDANN)、相邻窦性R-R间距差值的均方根(rMSSD)、窦性相邻R-R间距差值>50 ms的百分比(pNN50)与对照组比较,P均<0.01;HLD脑型SDNN、SDANN、rMSSD、pNN50与脑—内脏型比较,P均<0.05;HLD脑型SDNN、SDANN与肝型比较,P均<0.01。ChildB、C级患者的SDNN、SDANN、rMSSD、pNN50与Child A级患者及对照组比较,P均<0.01。结论肝型及脑—内脏型HLD患者HRV明显降低,且肝硬化病变程度越严重,HRV降低越明显。     

老年急性心肌梗死心率变异的临床观察

目的探讨老年急性心肌梗死患者心率变异(HRV)与急性心肌梗死(AMI)预后及死亡的关系。方法应用24h动态心电图(Holter)检测52例老年急性心肌梗死患者的HRV各项时阈指标,总体标准差SDNN、均值标准差SDANN、标准差均值SDNNIDX、差值均方的平方根rMSSD、差值>50ms的百分比(PNN50)。将AMI后2.5年内因心源性死亡人数与存活人数分为死亡组与存活组进行对比。结果死亡组与存活组比较,SDNN、SDANN、SDNNIDX、rMSSD均明显降低(P<0.05)。结论老年急性心梗患者心率变异性越大,AMI预后越差,死亡率越高。     

充血性心力衰竭心率变异性改变及其与心室重塑的关系

目的:检测充血性心力衰竭患者心率变异性(HRV)改变,探讨其与心室重塑的关系。方法:采用Holter检查系统检测了36例CHF患者HRV指标24h正常R-R间期标准差(SDNN)、24h内每5min平均正常R-R间期的标准差(SDANN)24h内每5min的正常R-R间期标准差的平均值(SDNNI),相邻正常R-R间期差值的均方根(rMSSD),相邻正常R-R间期差值≥50ms心搏数占总R-R间期数的百分数(PNN50)及超声心动图指标左心室舒张末期内径(LVEDD),收缩末期内径(LVESD),左心室后壁舒张末期厚度(LVPWT),心室间隔舒张末期厚度(IVST),左心室射血分数(LVEF),左心室舒张早期及舒张晚期充盈速度比值(E/A)及左心室重量指数(LVMI),并以20例健康体检者为对照。结果:CHF患者HRV各时域指标均下降,与对照组相比有显著差异(P<0.05～<0.01)。多元回归分析显示SDNN,SDNNI与LVEDD,LVPWT呈负相关(r=-0.337～-0.362,P<0.05);rMSSD,PNN50与LVEDD,LVESD呈负相关(r=-0.142～-0.433,P<0.05);rMSSD、PNN50与LVEF呈正相关(r=0.387～0.464,P<0.05～<0.001)。结论:CHF患者HRV下降,并与心室重塑有关。     

冠心病患者心率变异性特点分析

目的了解冠状动脉粥样硬化性心脏病(冠心病)患者心率变异性(HRV)特点。方法入选156例冠心病患者及128例正常体检人员,进行24小时动态心电图监测。冠心病组通过彩色多普勒超声显像仪测量心功能(LVEF)并分组为射血分数正常组(LVEF≥50%)和射血分数下降组(LVEF50%),同时对冠心病组进行不同年龄段的分组,计算各组的心率变异性参数:NN间期标准差(SDNN)、NN间期平均值的标准差(SDANN)、相邻NN间期差的均方根(RMSSD)、相邻NN间期的差值超过50 ms的心搏数占NN间期总心搏数的百分比(pNN50)、5分钟总功率(TP)、低频功率(LF)、高频功率(HF),通过组间比较分析,分析比较各组间HRV参数的特点。结果与正常对照组比较,冠心病组患者SDNN(96.2±28.8 ms vs.138.1±27.7 ms)、SDANN(79.4±27.1 ms vs.130.4±28.2ms)、RMSSD(24.3±9.8 ms vs.31.2±9.3 ms)、pNN50(8.5±3.2 ms vs.12.3±3.9 ms)及HF(233.6±95.5 ms2 vs.292.3±100.2 ms2)均明显下降,差异均有统计学意义(P均0.05)。冠心病患者中,射血分数下降组患者SDNN、SDANN、RMSSD、pNN50、TP、HF均较射血分数正常组患者降低,差异均有统计学意义(P均0.05),在不同年龄段冠心病组间SDNN、TP以及RMSSD、pNN50、LF、HF水平比较,差异无统计学意义(P0.05);35～45岁组SDANN高于55～65岁组,差异有统计学意义(P0.05)。结论冠心病患者心率变异性降低,射血分数下降会进一步加重自主神经的损害。     

心肌梗死与心肌梗死伴糖尿病患者的心率变异性分析

应用24小时全信息动态心电监测仪,分别测定单纯MI组(39例),MI合并T2DM组(20)例,正常对照组(24例)HRV的时域指标:总体标准差(SDNN),均值标准差(SDANN),差值均方的平方根(rMSSD)和爱丁堡指数(pNN50);频域指标:低频(LF)反应交感神经张力,高频(HF)反应迷走神经能力,低/高比率(LF/HF)反应交感神经与迷走神经均衡性。结果与对照组比较,单纯MI组SDNN、HF显著降低(P0.05),rMSSD、PNN50差异无显著意义。MI伴DM组与对照组比较,HRV时域指标SDNN、SDANN、PNN50显著降低,HF降低、LF/HF升高有显著意义。与单纯MI组比较,SDNN、HF差异有统计学意义,其余指标比较无显著意义。结论心肌梗死伴糖尿病患者HRV降低可能与糖尿病性神经系统损害及心肌缺血程度较单纯心肌梗死严重有关。     

原发性高血压患者动态脉压与心率减速力和心率变异性的相关性

目的探讨原发性高血压患者动态脉压(PP)与心率减速力(DC)和心率变异性(HRV)的相关关系。方法就诊我科的原发性高血压患者180例均给予动态血压检查,根据动态血压检测结果,按照动态PP水平分为三组:将24h平均PP40mmHg的患者作为PP1组(n=60)、将24h平均PP在40～60mmHg之间的患者作为PP2组(n=60)、将24h平均PP60mmHg的患者作为PP3组(n=60)。同时选取60例健康人作为健康对照组。分析计算所有研究对象DC值和HRV时域指标总体标准差(SDNN)、差值均方根(rMSSD)和大于50ms百分比(pNN50),比较各组患者DC和HRV时域指标并进行各指标之间相关性分析。结果原发性高血压患者DC值和HRV时域指标SDNN、rMSSD、pNN50数值水平均较健康对照组降低(P0.01),且随着PP增高而出现降低趋势(P0.05); DC和HRV时域指标SDNN、rMSSD、pNN50呈正相关(r=0.25～0.48,P0.05);动态PP与DC和HRV时域指标SDNN、rMSSD、pNN50均呈负相关(r=-0.15～-0.68,P0.05)。结论原发性高血压患者动态PP与DC和HRV时域指标呈负相关,DC和HRV时域指标呈正相关;原发性高血压患者自主神经功能受损程度与动态PP正相关。     

低血钾对心率变异的影响

目的 探讨低血钾对心率变异(HRV)的影响,将16例低血钾患者和15例健康受试者分成A、B2组,分别接受24h动态心电图(DCG)检查,并对2组检得的HRV时域指标(SDNN、SDANN、SDNNi、rMSSD、pNN50)进行比较分析。结果 低血钾组(A组)的SDNN、SDANN、SDNNi、rMSSD、pNN50均显著低于对照组(B组)(P<0.01)。结论 低血钾时HRV减小,心脏自主神经对心脏的调节功能下降。     

2型糖尿病下肢神经病变心率变异性时域指标的昼夜节律

目的 了解糖尿病合并周围神经病变患者的自主神经功能.方法 2008年1月至2009年3月按随机数字表法抽取天津医科大学代谢病医院的117例2型糖尿病患者,分为2型糖尿病不伴下肢神经病变组(糖1组)59例和2型糖尿病伴下肢神经病变组(糖2组)58例.无糖尿病的对照组50例来源于我院健康体检者.受试对象均接受体重指数、收缩压、舒张压、甘油三酯、总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、空腹血糖、餐后2 h血糖、糖化血红蛋白、空腹胰岛素、稳态模型胰岛素抵抗指数、24 h动态心电图心率变异性(HRV)、乏式动作反应指数、30/15比值、呼吸差的检测.统计学处理采用卡方检验、方差分析、配对秩和检验.结果 (1)糖1组、糖2组患者心动周期标准差(SDNN)、每5 min R-R均值的标准差(SDANN)、每5 min R-R均值的标准差指数(SDNNIDX)、相邻R-R差值的均方根(rMSSD)、24 h内相邻R-R间期相差＞50 ms的个数占总心跳次数的百分比(pNN50),与对照组比较差异有统计学意义(F值分别为94.702、77.786、55.422、56.175、49.110,均P＜0.01);(2)对照组SDNN、rMSSD、pNN50日间节律分别为(113±20)ms、(31±15)ms、4%(0～45%),夜间节律分别为(104±25)ms、(38±18)ms、11%(0～45%),日夜间比较差异有统计学意义(t=2.472、4.629、5.007,均P＜0.05);糖1组SDNN Et间节律为(81±16)ms,夜间节律为(77±19)ms,日夜间节律比较差异无统计学意义(t=1.952,P＞0.05),糖2组SDNN、rMSSD、pNN50日间节律分别为(64±15)ms、(21±19)ms、1%(0～30%),夜间节律分别为(64±20)ms、18(7～97)ms、1%(0～28%),日夜间节律比较差异无统计学意义(t值分别为0.155、1.103、1.328,均P＞0.05).结论 2型糖尿病不伴及伴下肢神经病变组均存在自主神经功能受损,但后者的自主神经功能更明显受损.心率变异性时域指标的昼夜节律可有效判断自主神经损害.     

健康人心率变异时域法正常值分析

为了解国人心率变异(HRV)时域法指标正常值,检测1524例17—94岁健康人24h动态心电图,分析HRV时域法5项指标。结果显示:(1)SDNN、SDANN、SDNN_(Index),rMSSD和PNN_(50)均值分别为127±33、116±32、49±14、29±12(ms)和8±9％,与国内研究一致。(2)HRV时域法各指标随年龄增加而降低(r=0.30——0.48,P<0.01),中青年组与老年组HRV差异有显著意义(P<0.01)。(3)男性SDNN、SDANN和SDNN_Index大于女性(P<0.05),而rMSSD和PNN_(50)小于女性(P<0.05)。SnNN、SDANN、SDNN_(Index)和rMSSD单侧下限值分别为73、64、26和9ms,PNN_(50)呈偏态分布,临床意义有待探讨。     

窦性心率震荡对老年人慢性心功能不全预后的预测价值

目的 探讨窦性心率震荡(HRT)对老年慢性心功能不全(CHF)患者预后的预测价值.方法 选择本院2006年10月至2009年5月住院的老年CHF患者96例,记录其相关临床资料,并进行超声心动图、动态心电图检查.应用相应的分析软件对动态心电图检查结果进行分析,比较不同心功能分级患者窦性HRT指标变化的差异;随访9～28个月,终点事件为患者心源性死亡,采用Logisitc回归法分析窦性HRT、年龄、高血压、糖尿病、心肌梗死、左室射血分数(LVEF)、血管紧张素转换酶抑制剂(ACEI)、β受体阻滞剂对CHF患者死亡的预测能力. 结果 按照震荡初始和震荡斜率结果进行HRT分类,HRT的主要参数正常在心功能Ⅱ级(60.0%)与Ⅲ级(45.0%)者比较差异无统计学意义(χ~2=1.60,P>0.05);心功能Ⅲ级与Ⅳ级者(16.7%)比较差异无统计学意义(χ~2=1.43,P>0.05);但心功能Ⅱ级与Ⅳ级者比较差异有统计学意义(χ~2=9.84,P<0.05),HRT在心功能Ⅳ级组明显减弱.平均随访(18.0±9.6)个月,96例患者中,心源性死亡34例,分析显示CHF患者死亡与HRT、低LVEF(≤45%)、年龄(≥65岁)、糖尿病、心肌梗死及心功能分级相关. 结论 窦性HRT指标对老年人CHF预后有良好的预测能力.     

Surgical treatment of advanced heart failure: alternatives to heart transplantation and mechanical circulatory assist devices

Although orthotopic heart transplantation is the gold standard for definitive surgical treatment of end-stage heart failure, other operative therapies exist for dealing with severe systolic left ventricular dysfunction. The choice of surgical intervention depends on the etiology and functional characteristics of the patient's ventricular dysfunction. In patients with ischemic cardiomyopathy, surgical revascularization improves survival. Patients with mitral regurgitation experience significant functional improvement from mitral valve repair and replacement. In patients with aortic valve dysfunction, aortic valve replacement results in improved survival and functional status. Although surgical ventricular reconstruction is controversial, significant data exist suggesting that it is an effective therapy in a subset of patients with left ventricular dysfunction. Finally, passive restraint devices are effective at halting further ventricular dilation. Although cardiac surgery in patients with severe ventricular dysfunction can be complicated by significant morbidity and mortality, experienced centers have demonstrated acceptable outcomes in carefully selected patients.     

Radionuclide angiography in congenital heart disease

Cardiac nuclear imaging (radionuclide angiography, electrocardiographic gated ventriculography and myocardial scintigraphy) provides structural and functional information simultaneously. This method extracts accurate quantitation of cardiovascular hemodynamics and unique information regarding myocardial perfusion. It is a reliable and relatively simple and atraumatic technique because the only discomfort to the patient is a simple intravenous injection. These studies are carried out rapidly in out-or inpatients. Radionuclide angiography is ideal also to assess the effect of exercise, oxygen or drugs on cardiac function. The radiation exposure associated with current nuclear imaging is within the range of common radiographic procedures and many times lower than that of cardiac catheterization. The use of newer radionuclides such as iridium-191m with a physical half-life of 4.96 seconds will result in a dramatic decrease in the radiation exposure to patients undergoing radionuclide angiography. Also, newer and smaller computerized gamma cameras will provide studies of improved spatial resolution and accuracy. The future of pediatric applications of cardiac nuclear imaging is bright.     

Beta blockers in ischemic heart disease

Many trials have reported that beta blockers increase survival after myocardial infarction; these trials are reviewed. The timolol trial was randomized and showed that mortality was reduced for all patients randomized to beta blockers. Similar findings have been found in both the metoprolol trial in Göteburg and the Beta-Blocker Heart Attack Trial in the U.S. Chronic beta-blockade therapy appears to reduce mortality in patients who survive acute myocardial infarction. The mechanism is as yet unknown.     

The cardiorenal syndrome in heart failure

The frequently occurring condition of renal failure in heart failure (HF) has been termed the cardiorenal syndrome. However, the importance of renal insufficiency in HF has only been embraced in the last decade, and therefore, the pathophysiology of cardiorenal failure is still poorly understood. The main driving force of renal failure in HF is probably hemodynamic derangement, with both reduced renal perfusion and increased venous pressure as the most important driving forces. Different cardiorenal connectors may modulate this relationship. Furthermore, renal failure is not only limited to reduced filtration but also includes glomerular hypertension and tubulointerstitial hypoxia, leading to loss of glomerular integrity and tubular damage. Recognition of these key pathophysiologic pathways in the concept of the cardiorenal syndrome is needed to value the interrelationship and incremental contribution of different risk markers and possible new treatments to improve renal function and outcome in this complex and bidirectional interplay between the heart and the kidney.     

The monostrut Björk-Shiley heart valve

To avoid the possibility of a fracture of the welded two-armed outflow strut of the Bj?rk-Shiley heart valve, since 1982 it has been machined from one piece of Haynes 25 in the form of a monostrut valve without welds. Of the first 864 patients with a monostrut Bj?rk-Shiley valve implanted, 268 have now been followed up to 3 years. The clinical findings, as well as absence of hemolysis, excellent hemodynamics even with a narrow aortic root as demonstrated by transseptal cardiac catheterization and excellent functional improvement are reported. No valve thrombosis in patients receiving anticoagulant therapy was observed with valves in either the aortic or the mitral position and there was no case of mechanical failure.     

Serum lipoproteins and coronary heart disease

It is necessary to examine lipid abnormalities at a macromolecular level, with emphasis on the transport lipoproteins rather than on cholesterol and triglyceride values alone. Methods for determining serum lipoproteins, which can be adapted for a small laboratory, are now available and are recommended for general clinical use. It is becoming increasingly apparent that the process of atherosclerosis has a long natural history that begins in childhood, and that it is now possible to study children for potential risk.     

老年慢性心力衰竭患者N末端钠尿肽前体与心脏功能的相关性研究

目的探讨老年慢性心力衰竭(CHF)患者N末端钠尿肽前体(NT-proBNP)与心脏功能的相关性。方法选择老年CHF患者133例为CHF组,另选正常体检者116例为对照组。2组均行超声进行心脏功能检测;采用ELISA法检测NT-proBNP水平。结果与对照组比较,CHF组患者左心室舒张末内径(LVEDD)、左心室收缩末内径(LVESD)、Tei指数及NT-proBNP明显升高,LVEF、左心室短轴缩短率(LVFS)及二尖瓣舒张早期血流峰值(E)和舒张晚期血流峰值(A)均明显降低(P<0.05)。随着心功能分级的上升,LVEDD、LVESD、Tei指数以及NT-proBNP明显升高(P<0.05),LVEF、LVFS及E/A比值明显降低(P<0.05)。NT-proBNP与LVEF、LVFS、E/A比值呈负相关,与Tei指数、LVEDD、LVESD呈正相关。多因素回归分析显示,LVEF、LVFS、心功能分级和Tei指数是影响NT-proBNP的主要因素。结论 NT-proBNP升高与老年CHF患者心脏功能损害程度相关。