急性冠脉综合征患者窦性心率震荡变化特点及其与心率变异性的相关性研究

目的分析急性冠脉综合征（ACS）患者窦性心率震荡（HRT）指标变化特点及其与心率变异性（HRV）的相关性。方法应用相应的分析软件对与59名健康体检者和161例确诊为ACS的患者24h动态心电图检查结果进行分析,检测HRT参数震荡初始（TO）、震荡斜率（TS）和HRV时域指标24h正常RR间期标准差（SDNN）、全程相邻窦性R—R间期之差的均方根值（rMSSD）、相邻正常RR间期差值〉50ms的心搏数占总RR间期数的百分比（PNN50）。将ACS组分为不稳定型心绞痛（UAP）组和急性心肌梗死（AMI）组,比较HRT、HRV指标和HRT异常的发生率在各组间的差异,进一步探讨ACS患者HRT和HRV指标相关性。结果与健康对照组比较,UAP组及AMI组TO明显增高,TS显著降低（均P〈0．01）;UAP组及AMI组间TO和TS无显著差异。UAP组及AMI组HRT异常率较对照组显著升高（X^2=5．385,P〈0．05;r=9．227,P=0．01）。UAP组及AMI组HRV指标SDNN、rMSSD、PNN50较对照组显著降低（均P〈0．01）,AMI组SDNN较UAP组降低（P〈0．05）,rMSSD、PNN50差异无统计学意义。ACS患者的TO与SDNN呈负相关（r=-0．26,P=0．031）,与rMSSD、PNN50不相关,TS与SDNN、PNN50、RMSSD呈正相关,其中和SDNN的相关性最强（r=0．301,P=0．047）。结论HRT可作为ACS危险分层的一项新的心电学筛选指标。ACS患者HRT、HRV变化从不同方面反映心脏迷走神经的功能受损,二者互相联系又相互独立。     

厄贝沙坦对原发性高血压患者心率变异性的影响

目的探讨厄贝沙坦对原发性高血压(EH)患者心率变异性(HRV)的影响。方法 76例原发高血压患者,每日口服厄贝沙坦治疗,分别测定患者治疗前、治疗6个月和治疗1年HRV。结果药物治疗6个月和治疗1年与治疗前相比,HRV有统计学意义,其中,相邻正常RR间期标准差(SDNN)、相邻正常RR间期差值的方差(rMSSD)、相邻正常RR间期差值大于50 ms的窦性心律占心搏总数的百分比(PNN50)、高频功率(HF)明显增加(P0.05),而低频功率(LF)及LF/HF则明显降低(P0.05)。药物治疗1年与治疗6个月比较,SDNNr、MSSD和PNN50继续增加(P0.05),LF和LF/HF无明显差异。结论厄贝沙坦对原发性高血压患者的HRV有显著改善作用。     

重组人脑利钠肽对心力衰竭患者心率变异性的影响

目的观察重组人脑利钠肽（rhBNP）对心力衰竭（ADHF）患者心率变异性（HRV）的影响。方法本院60例心力衰竭住院患者随机分为对照组和rhBNP组,对照组30例,进行基础抗心衰治疗;rhBNP组30例,在基础抗心衰的治疗上静脉注射重组人脑利钠肽,首先以1.5μg/kg弹丸式静脉冲击,随后以0.0075μg kg^-1min^-1连续静脉滴注72 h。所有患者治疗前后进行24小时动态心电图检查心率功率谱时域和频域分析。结果治疗后,rhBNP组全部窦性R-R间期的标准差（SDNN）、每5 min窦性R-R平均值的标准差（SDANNindex）、全部窦性R-R间期差值的均方根（rMSSD）、相邻两正常窦性R-R间期差值>50 ms的个数所占的百分率（PNN50）、低频功率（频率为0.04～0.15Hz,LF）、高频功率（频率为0.15～0.40Hz,HF）较对照组显著增加（P<0.05）。结论 rhBNP加心衰常规治疗,在改善心力衰竭患者心功能的同时显著改善HRV,从而改善自主神经的平衡性,改善患者的预后。     

孤立性心房颤动患者心率变异与 P 波离散度的相关性研究

目的:探讨孤立性心房颤动患者心率变异性(HRV)与P波离散度(Pd)的关系.方法:在动态心电图上分析30例孤立性心房颤动患者(房颤组)的心率变异性指标,包括孤立性心房颤动发作前、后5分钟的时域、频域指标:RR间期的标准差、低频段功率、高频段功率以及低频段功率/高频段功率和24小时时域指标:全部RR间期的标准差、每5分钟平均RR间期的标准差、相邻RR间期差值的均方根和相邻RR间期差值大于50ms的心搏数占总心搏数的百分比,并计算P波最大宽度与P波离散度,再与30例正常对照组进行比较.结果:①对孤立性心房颤动患者发作前、后5分钟的时域、频域指标进行比较,可见孤立性心房颤动患者发作前5分钟RR间期的标准差、高频段功率较发作后5分钟增高(P＜0.05),而低频段功率/高频段功率降低(P＜0.05),差异有统计学意义,低频段功率无明显变化(P＞0.05).②24小时时域分析显示房颤组的全部RR间期的标准差、每5分钟平均RR间期的标准差、相邻RR间期差值的均方根和相邻RR间期差值大于50ms的心搏数占总心搏数的百分比高于正常对照组(P＜0.01),差异有统计学意义.③房颤组的P波最大宽度、P波离散度高于正常对照组(P＜0.01),差异有统计学意义.④房颤组的全部RR间期标准差、每5分钟平均RR间期的标准差、相邻RR间期差值的均方根和相邻RR间期差值大于50ms的心搏数占总心搏数的百分比与P波最大宽度、P波离散度呈正相关(P＜0.01),差异有统计学意义.结论:孤立性心房颤动患者迷走神经张力增高,特别在发作前迷走神经张力有明显增强,并且其P波最大宽度、P波离散度显著增高,两者之间有一定的相关性,可能是孤立性心房颤动的发病机制之一.     

心率变异性与冠状动脉病变的关系

目的探讨心率变异性(heartratevariability,HRV)与冠状动脉病变范围和程度的关系。方法回顾性分析我院冠心病患者186例的冠状动脉病变范围程度和HRV指标。用Logistic回归筛选冠状动脉病变的HRV预测指标。结果HRV时域指标和频域指标均随冠状动脉病变范围和程度的加重而降低,时域指标,包括正常窦性心搏间期标准差(standarddeviationofnormalnumberofintervals,SDNN),每5分钟平均正常窦性心搏间期标准差(standarddeviationofper5minaveragesnormalnumberofintervals,SDANN),正常窦性心搏间期标准差平均值(averageofstandarddeviationofnormalnumberofintervals,ASDNN),相邻正常窦性心搏间期差的平方根值(rootmeansquarevaluesofthestandarddeviationbetweenadjacentnormalnumberofintervals,rMSSD),相邻正常窦性心搏间期差超过50ms的个数占总窦性心搏数的百分率(percentageofdifferencesexceeding50msbetweenadjacentnormalnumberofintervalsPNN50),PNN50包括PNN50a(大于相邻心搏间期50ms)和PNN50b(小于相邻心搏间期50ms),频域指标包括低频带(lowfrequency,LF),极低频带(verylowfrequency,VLF),高频带(highfrequency,HF)都与冠状动脉病变范围和程度呈负相关(P<0.01或P<0.05);Logistic回归结果表明SDANN、LF/HF为冠状动脉病变范围和程度的保护因素。结论有冠状动脉病变的患者HRV降低,存在自主神经功能紊乱;HRV与冠状动脉病变范围和程度呈负相关。     

OSAHS病人心率变异性和心率减速力的相关性研究

目的探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)病人心率变异性(HRV)与心率减速力(DC)的相关性。方法收集经多导睡眠监测(PSG)确诊为OSAHS的病人127例,进行24h动态心电图监测,经人机对话,人工分析校正后,记录24h心率、心率变异性指标和心率减速力数值,观察DC和HRV时域指标之间的相关性。结果 DC值与HRV各时域指标呈显著正相关(P0.01),其中与相邻NN之差50ms的个数占总窦性心搏个数的百分比(PNN50)、三角指数、相邻RR间期差值的均方根(RMSSD)和全部窦性心搏RR间期的标准差(SDNN)相关性较强,与RR间期平均值标准差(SDANN)和24h相邻RR间期差值的均方根或标准差(SDSD)相关性较弱;DC与年龄和平均心率呈显著负相关(r值分别为-0.751、-0.774,P0.01)。结论 DC与HRV时域指标具有较好的相关性,可定量评估迷走神经张力对心率负性频率的调节作用。     

单纯收缩期高血压患者的心率震荡与心率变异

目的:观察单纯收缩期高血压(ISH)患者的心率震荡(HRT)和心率变异(HRV)的变化。方法:记录24h动态心电图,计算窦性HRT的初始值(TO)和震荡斜率值(TS)以及HRV的SDNN、pNN50和LF/HF,比较ISH组(85例)、普通高血压组(80例),正常对照组(58例)3组之间的差别,分析HRT和HRV之间的相关性。结果:ISH组、普通高血压组的HRT和HRV与正常对照组的HRT和HRV比较差异均有统计学意义(P<0.05),ISH组的TS和LF/HF较普通高血压组明显降低(P<0.05);HRV的各项指标和HRT均有良好的相关性,其中pNN50与HRT相关系数最高。结论:原发性高血压患者有显著的HRT减弱及HRV的异常,其中ISH患者较普通高血压患者更加明显,且HRT与HRV的密切相关,表明心脏自主神经功能紊乱可能对于高血压的发生及预后均有重要影响。     

急性心梗患者心率减速力与心率变异性

目的:探讨急性心肌梗死(AMI)患者心率减速力(DC)与心率变异(HRV)、心率震荡(HRT)的相关性.方法62例窦性心律的AMI患者和51例非AMI对照组进行24h动态心电图检查,离线计算DC、HRV时域指标、HRT的两个参数震荡初始(TO)和震荡斜率(TS).结果:AMI患者的DC值、HRV降低;HRT减弱;且DC...     

原发性高血压患者窦性心率震荡与心率变异性

目的 检测单纯原发性高血压(EH)患者窦性心率震荡(HRT)及心率变异性(HRV).方法 EH患者60例和健康人50例分别为高血压组和对照组,亚组研究分析降压治疗 倍他洛克组和降压治疗组的HRT与HRV.根据24 h动态心电图记录资料,分别计算各组HRT的两个参数震荡初始值(TO)和震荡斜率值(TS)以及HRV的全部NN间期的标准差(SDNN)、全部相邻NN间期之差的均方根值(RMSSD)和低频/高频(LF/HF).结果 1)高血压组TO、TS、TO TS、SDNN、RMSSD及LF/HF分别为:52、48、46、42、41、38例;对照组分别为:2、3、0、5、1、3例;高血压组上述6种指标的阳性检出率均高于对照组(P<0.01);2)降压治疗 倍他洛克组及降压治疗组TO、TS、TO TS阳性检出率差异无统计学意义,降压治疗 倍他洛克组的SDNN、RMSSD及LF/HF分别为:12、13、9例;降压治疗组分别为:30、28、29例,降压治疗 倍他洛克组SDNN、RMSSD及LF/HF的阳性检出率明显低于降压治疗组(P<0.01).结论 单纯EH患者有显著的HRT减弱及HRV的异常,HRT现象不受β受体阻滞剂的影响.     

老年慢性阻塞性肺病患者窦性心率震荡及心率变异性的研究

目的 探讨慢性阻塞性肺病(COPD)患者窦性心率震荡(HRT)及心率变异性(HRV)变化及临床意义.方法 临床诊断为COPD老年患者59例,选择同期健康老年人30例为对照组.24 h动态心电图检测各组HRT参数:震荡初始(TO)和震荡斜率(TS)及HRV各项指标,肺功能检测,同时超声心动图测量左心室射血分数(LVEF)、右心房内径(RAD)、右心室内径(RVD)、右心室壁厚度(RVWT)等指标;组间比较且对HRT与HRV指标进行相关性分析.结果 与对照组比较,COPD患者TO值显著增高[(-0.2±1.1)%与(-3.8±2.8)%,t=6.830,P＜0.01],TS值显著下降[(7.0±3.6)与(11.7±6.1)ms/RR,t=3.866,P＜0.01];HRV指标正常R-R间期的标准差(SDNN)、正常R-R间期的标准差的平均值(SDNNI)、SDNNI的标准差(SDANN)、相邻R-R间期之差的均方根值(rMSSD)和正常R-R间期标准差≥50 ms的百分数(PNN50)增加,且随肺动脉压力的增高而恶化.TO与SDANN,rMSDD呈负相关(r=-0.369,P＜0.05;r=-0.472,P＜0.01),TS和SDNN,SDANN,PNN50呈正相关(P＜0.05),与rMSDD无相关性(P＞0.05).结论 COPD患者HRT现象减弱,HRT和HRV变化随患者肺动脉压力的增加而恶化,联合检测对评价COPD患者自主神经功能状态及预后有较高临床价值.

Abstract：

Objective To explore the clinical significance of sinus heart rate turbulence (HRT)and heart rate variability (HRV) in patients with chronic obstructive pulmonary disease(COPD).Methods The 59 moderate to severe COPD patients and 30 healthy subjects were enrolled in this study. The 24-hour holter monitor was used to screen the HRT onset (TO), turbulence slope (TS)and HRV. Pulmonary function tests and echocardiographic examination were performed for measuring left ventricular ejection fraction (LVEF), right atrial dimension (RAD), right ventricular dimension (RVD), right ventricular wall thickness (RVWT). Then all the parameters were compared between NC group and COPD group, and the relationship between HRT and HRV was investigated. Results Compared with control group, TO was significantly increased [(-0.2±1.1) % vs.(-3.8±2.8) %, t=6. 830,P＜0.01] and TS was decreased [(7.0±3.6) ms/RR vs. (11.7±6.1) ms/RR, t =3. 866, P＜0.01] in COPD group. In time domain HRV parameters, normal RR intervallerinin standart deviation(SDNN), standard deviation of normal-to-normal beats index (SDNNi), standard deviation of the averages of normal sinus to normal sinus (SDANN), mean squared differences of the successive RR intervals (rMSDD), fraction of consecutive normal sinus intervals that differ by more than 50 ms (PNN50) were significantly lower in COPD group than in control group(P＜0. 05). TO was negatively correlated with SDANN and rMSDD (r=-0. 369, P＜0. 05; r=-0.472, P＜0.01).TS was positively correlated with SDNN, SDANN and PNN50 (all P＜0.05), but had no correlation with rMSDD (P＞0. 05). Conclusions HRT and HRV are dramatically blunted in COPD patients.Combination of HRV and prognosis. and HRT may be simple and elegant ways for evaluating cardiac autonomic functions.     

Restoration of heart rate turbulence by titrated beta-blocker therapy in patients with advanced congestive heart failure: positive correlation with enhanced vagal modulation of heart rate

INTRODUCTION: Heart rate turbulence (HRT) is a powerful novel predictor for cardiovascular mortality. Chronic congestive heart failure is associated with abnormal HRT. Whether antiadrenergic beta-blocker therapy can restore control of HRT in patients with chronic congestive heart failure is unknown. METHODS AND RESULTS: A 24-hour Holter ECG recording was obtained before and 1 and 3 months after titrated addition of atenolol therapy in 10 consecutive patients with advanced congestive heart failure. Two parameters derived from HRT, turbulence slope (TS) and turbulence onset (TO), and time- and frequency-domain heart rate variability (HRV) parameters (SDNN, RMSSD, VLF, LF, HF) from 24-hour ECG were compared before and after beta-blocker therapy, together with the same parameters in age-matched normal control. Results showed that TS (3.1 +/- 2.2 vs 6.2 +/- 3.0; P = 0.001) and all HRV parameters were increased after 3 months of atenolol treatment. No changes in TO were evident (0.6 +/- 0.5 vs -0.2 +/- 1.3; P = 0.13). The improvement of TS and the vagally mediated parameters of mean R-R interval, RMSSD, and the HF component of HRV were positively correlated. CONCLUSION: Abnormal HRT caused by chronic congestive heart failure can be restored by beta-blocker therapy. The evolution of TS was positively correlated with measures of vagal modulation of heart rate.     

Predictors of Long‐Term Risk for Heart Failure Hospitalization after Acute Myocardial Infarction

Background: Data on the value of baseline brain natriuretic peptide (BNP) and autonomic markers in predicting heart failure (HF) hospitalization after an acute myocardial infarction (AMI) are limited. Methods: A consecutive series of patients with AMI without a previous history of HF (n = 569) were followed up for 8 years. At baseline, the patients had a blood sample for determination of BNP, a 24‐hour Holter recording for evaluating heart rate variability (HRV) and heart rate turbulence (HRT), and an assessment of baroreflex sensitivity (BRS) using phenylephrine test. Results: During the follow‐up, 79 (14%) patients were hospitalized due to HF. Increased baseline BNP, decreased HRV, HRT, and BRS had a significant association with HF hospitalization in univariate comparisons (P < 0.001 for all). After adjusting with all the relevant clinical parameters, BNP, HRV, and HRT still significantly predicted HF hospitalization (P < 0.001 for BNP and for the short‐term scaling exponent α₁, P < 0.01 for turbulence slope). In the receiver operator characteristics curve analysis, the area under the curve for BNP was 0.77, for the short‐term scaling exponent α₁ 0.69, for turbulence slope 0.71, and for BNP/standard deviation of all N‐N intervals ratio 0.80. Conclusion: Baseline increased BNP and impaired autonomic function after AMI yield significant information on the long‐term risk for HF hospitalization. Ann Noninvasive Electrocardiol 2010;15(3):250–258     

慢性心力衰竭患者动态心率震荡分析

目的：探讨窦性心率震荡（HRT）的新测量指标动态心率震荡（TD）及HRT测量指标震荡初始（TO）、震荡斜率（TS）在慢性心力衰竭（CHF）患者中的变化,分析其与传统高危预测指标的相关性及预测CHF患者价值。方法纳入2011年9月~2013年6月在天津市胸科医院就诊的CHF患者120例作为CHF组,同期纳入非器质性心脏病患者30例作为对照组,将CHF组按NYHA分级分为轻度CHF组（心功能Ⅰ~Ⅱ级,n=72）和中重度CHF组（心功能Ⅲ~Ⅳ级,n=48）。所有患者行放射免疫法检测B型脑钠肽（BNP）水平,超声心动图检查左房内径（LAD）、左室舒张末径（LVEDD）、左室射血分数（LVEF）;24 h动态心电图检查记录心率变异性时域（SDNN）、平均心率、室性早搏前心率（HRVPC）以及RR间期,计算HRT指标（包括TO、TS和TD）。比较各组之间的差异,分析HRT各指标与年龄、性别、LAD、LVEDD、LVEF、BNP的相关性。结果与对照组相比,CHF组SDNN缩短[（95.67±30.22） msvs.（131.65±20.71）ms],TO和TD更高[TO：（-1.50±2.71）%vs.（0.61±1.95）%;TD：（0.012±0.004）mm/RRIvs.（0.063±0.031）mm/RRI],LAD和LVEDD更高[LAD：（36.11±2.24）mmvs.（47.65±2.13）mm;LVEDD：（43.65±7.33）mmvs.（62.13±8.70）mm],BNP明显升高[（80.05±32.30）pg/ml vs.（941.00±139.17）pg/ml],TS和LVEF更低[TS：（12.13±3.67）vs.（6.80±5.33）;LVEF：（67.30±5.21）% vs.（38.22±12.75）%],而且随着CHF程度的加重,上述改变更加明显。CHF组TO与TS、LVEF、SDNN负相关（P＜0.05）;TS与SDNN正相关（P＜0.05）,与HRVPC、BNP负相关（P＜0.05）。结论 CHF患者HRT明显减弱,其中TO和TS均受到SDNN的影响,而TD与HRVPC、SDNN、LVEF、BNP指标无关。     

冠心病患者窦性心率震荡与心率变异性和室性早搏关系的探讨

目的探讨冠心病患者的窦性心率震荡(HRT)及其与心率变异性(HRV)和室性早搏之间的关系。方法86例冠心病患者行24h动态心电图检查,计算机自动测定HRT的两个参数震荡初始(TO)和震荡斜率(TS)、HRV时域和频域指标及室性早搏数目。结果冠心病患者的HRT减弱,HRV降低,且TO与时域指标SDNN和SDANN及频域指标LF和LF/HF明显相关(p<0.05),TS与时域指标SDNN和RMSSD及频域指标HF和LF/HF及室性早搏数目明显相关(p<0.05)。结论冠心病患者的HRT现象减弱,且HRT与HRV及室性早搏数目明显相关。HRT应当是一种较HRV更好预测高危冠心病患者的无创性检查方法。     

Heart rate turbulence and left ventricular ejection fraction in Chagas disease.

AIMS: Chagas disease patients often present premature ventricular complexes (PVCs), depression of left ventricular ejection fraction (LVEF) and autonomic dysfunction, which is generally evaluated by heart rate variability (HRV) analysis. As frequent PVCs may complicate HRV computation, we measured heart rate turbulence (HRT) and evaluated the correlation between ejection fraction and HRT or HRV in Chagas disease. METHODS: We studied 30 patients (47+/-11 years, 20 men) with Chagas cardiomyopathy and left ventricular dilatation who underwent clinical evaluation, ejection fraction (EF: 45+/-14%) determination and 24-h Holter monitoring (median PVC=1781). In all patients, the standard deviation of normal RR intervals (SDNN), the square root of the mean square differences of successive RR intervals (RMSSD) and values of turbulence onset (TO) and turbulence slope (TS) were calculated. RESULTS: HRT indices were independent of mean RR interval and presented high correlation with EF: TO (-0.11+/-0.01%, r=-0.60, P<0.001) and TS (5.8+/-3.7 ms/RR-interval, r=0.73, P<0.001). Of HRV parameters, only SDNN, corrected for mean RR interval, showed a weak but not significant correlation with EF (r=0.41). The comparison of HRT/EF and HRV/EF correlation coefficients, indicated the presence of a significant difference (P=0.017). CONCLUSIONS: HRT indices appear to correlate better with EF than SDNN in Chagas disease. Thus, an analysis based on heart rate transient adaptation seems to perform better than HRV in detecting the autonomic alterations that parallel left ventricular dysfunction in Chagas disease patients. The high number of PVCs observed in these patients further support the use of HRT methodology.     

心率震荡在慢性充血性心力衰竭患者中的变化规律及预测价值

目的研究心率震荡(HRT)在慢性充血性心力衰竭(CHF)患者中的变化规律及对其预后的预测价值,比较正常人与CHF患者以及不同心功能级别、病因、危险度CHF患者的HRT变化。方法72例CHF患者和50例正常对照均接受动态心电图(Holter)、超声心动图等检查,记录临床资料,分别计算HRT的两个参数震荡初始(TO)和震荡斜率(TS),并进行6~30个月的随访。结果CHF患者TO明显高于对照组,TS明显低于对照组(P<0.05);重度CHF患者TS明显低于轻度CHF患者(P<0.05);各种病因所致CHF之间HRT变化无明显差异;TS在高危组和低危组差异显著(P<0.05),前者低于后者;TS和心率变异性(HRV)、左心室射血分数(LVEF)呈正相关;多变量分析结果显示LVEF、TS、以及TO、TS值联合作为一个指标对终点事件的预测有显著性意义(P<0.05),TO和TS联合成为预测价值最高的指标(相对危险度为4.157),远远高于LVEF(相对危险度为0.955)及其他指标。结论CHF患者HRT现象明显减弱,HRT不仅可以作为判断CHF严重程度的指标,而且可以作为预测CHF患者预后的敏感指标之一。     

糖尿病患者窦性心率震荡与心率变异性关系的初步探讨

目的 探讨糖尿病患者的窦性心率震荡(HRT)与心率变异性(HRV)的关系.方法 糖尿病患者和健康体检者各50例行24h动态心电图(Holter)检查,计算并比较2组患者心率震荡初始(TO)、震荡斜率(TS)与HRV各指标的相关性.结果 糖尿病组的HRT减弱,HRV降低,且震荡初始与SDNN、SDANN及低频成分具有明显相关性(P＜0.05),震荡斜率与SDNN、RMSSD及高频成分具有明显相关性(P＜0.05).结论 糖尿病患者的HRT现象减弱,且与HRV明显相关.HRT对诊断糖尿病自主神经功能损伤更有价值.     

Relationship between heart rate turbulence and heart rate, heart rate variability, and number of ventricular premature beats in coronary patients

INTRODUCTION: Heart rate variability (HRV) illustrates regulation of the heart by the autonomic nervous system whereas heart rate turbulence (HRT) is believed to reflect baroreflex sensitivity. The aim of this study was to determine the association between HRT and HRV parameters and the relationship between HRT parameters and heart rate and number of ventricular premature beats (VPBs) used to calculate HRT parameters. METHODS AND RESULTS: In 146 patients (117 males and 29 females; mean age 62 years) with coronary artery disease, a 24-hour ECG Holter monitoring was performed to calculate mean heart rate (RR interval), number of VPBs, time- and frequency-domain HRV parameters and two HRT parameters: turbulence onset (TO) and turbulence slope (TS). Univariate and multivariate regression analyses were performed to evaluate the association between tested parameters. Significant correlation between TS and mean RR interval was observed (r = 0.42; p < 0.001), while no association for TO vs. RR interval was found. TS values were significantly higher in patients with less than 10 VPBs/24 hours than in patients with more frequent VPBs. Significant associations between HRT and HRV parameters were found with TS showing stronger correlation with HRV parameters than TO (r value ranging from 0.35 to 0.62 for TS vs. -0.16 to -0.38 for TO). CONCLUSION: HRT parameters correlate strongly with HRV parameters indicating that HRT should be considered as a reflection of both baroreceptors response and overall autonomic tone. Heart rate dependence of turbulence slope indicates the need to adjust this parameter for heart rate.     

Depressed Heart Rate Variability as an Independent Predictor of Death in Chronic Congestive Heart Failure Secondary to Ischemic or Idiopathic Dilated Cardiomyopathy

After acute myocardial infarction, depressed heart rate variability (HRV) has been proven to be a powerful independent predictor of a poor outcome. Although patients with chronic congestive heart failure (CHF) have also markedly impaired HRV, the prognostic value of HRV analysis in these patients remains unknown. The aim of this study was to investigate whether HRV parameters could predict survival in 102 consecutive patients with moderate to severe CHF (90 men, mean age 58 years, New York Heart Association [NYHA] class II to IV, CHF due to idiopathic dilated cardiomyopathy in 24 patients and ischemic heart disease in 78 patients, ejection fraction [EF], 26%; peak oxygen consumption, 16.9 ml/kg/min) after exclusion of patients in atrial fibrilation with diabetes or with chronic renal failure. In the prognostic analysis (Cox proportional-hazards model, Kaplan-Meier survival analysis), the following factors were investigated: age, CHF etiology, NYHA class, EF, peak oxygen consumption, presence of ventricular tachycardia on Holter monitoring, and HRV measures derived from 24-hour electrocardiography monitoring, calculated in the time (standard deviation of all normal RR intervals [SDNN], standard deviation of 5-minute RR intervals [SDANN], mean of all 5-minute standard deviations of RR intervals [SD], root-mean-square of difference of successive RR intervals [rMSSD], and percentage of adjacent RR intervals >50 ms different [pNN50]) and frequency domain (total power [TP], power within low-frequency band [LF], and power within high-frequency band [HF]). During follow-up of 584 ± 405 days (365 days in all who survived), 19 patients (19%) died (mean time to death: 307 ± 315 days, range 3 to 989). Cox's univariate analysis identified the following factors to be predictors of death: NYHA (p = 0.003), peak oxygen consumption (p = 0.01), EF (p = 0.02), ventricular tachycardia on Holter monitoring (p = 0.05), and among HRV measures: SDNN (p = 0.004), SDANN (p = 0.003), SD (p = 0.02), and LF (p = 0.003). In multivariate analysis, HRV parameters (SDNN, SDANN, LF) were found to predict survival independently of NYHA functional class, EF, peak oxygen consumption, and ventricular tachycardia on Holter monitoring. The Kaplan-Meier survival curves revealed SDNN <100 ms to be a useful risk factor; 1-year survival in patients with SDNN <100 ms was 78% when compared with 95% in those with SDNN >100 ms (p = 0.008). The coexistence of SDNN <100 ms and a peak oxygen consumption <14 ml/kg/min allowed identification of a group of 18 patients with a particularly poor prognosis (1-year survival 63% vs 94% in the remaining patients, p <0.001). We conclude that depressed HRV on 24-hour ambulatory electrocardiography monitoring is an independent risk factor for a poor prognosis in patients with CHF. Whether analysis of HRV could be recommended in the risk stratification for better management of patients with CHF needs further investigation.

In 102 consecutive patients with stable chronic congestive heart failure and sinus rhythm, several heart rate variability measures derived from 24-hour electrocardiographic recording were significant prognostic risk markers, independent of clinical variables (New York Heart Association class, peak oxygen consumption, left ventricular ejection fraction). The coexistence of the standard deviation of all normal RR intervals <100 ms and peak oxygen consumption <14 ml/kg/min had the worst prognosis, and it is concluded that heart rate variability analysis is useful for noninvasive heart transplant assessment.