Electrocardiographic predictive factors of long-term clinical improvement with multisite biventricular pacing in advanced heart failure

Biventricular pacing has recently been proposed for treating patients with drug refractory heart failure and intraventricular conduction delay. The purpose is to restore ventricular relaxation and contraction sequences as homogeneously as possible. The aim of this study was to determine if some factors could predict the long-term clinical effectiveness of that new treatment. This study included 26 patients, aged 66 ± 7 years, with drug refractory heart failure and wide QRS. Patients were implanted with a biventricular pacemaker. The left ventricle was paced through a coronary sinus tributary. New York Heart Association functional class, exercise tolerance, and left ventricular (LV) ejection fraction were collected at baseline and after pacemaker implantation. Patients were divided into 2 groups: group I = responders; group II = nonresponders. QRS duration and axis at baseline and during biventricular pacing, interventricular conduction time, and LV and right ventricular lead positions were compared between the 2 groups. Group I patients (n = 19) had a mean reduction of 1.3 in functional class and an increase in peak oxygen consumption rate by a mean of 50%. The only parameter that differed between the 2 groups was the QRS duration during biventricular pacing, with a significantly shorter value in group I than in group II (154 ± 17 vs 177 ± 26 ms; p = 0.016). Thus, a positive response to biventricular pacing is correlated with the quality of electrical resynchronization. The optimal positions of the right and LV leads would be those that could induce the greatest shortening of QRS duration.     

双心室起搏在严重心力衰竭病人中的应用

目的：探讨双心室心脏起搏在技术上的可行性及其在严重心力衰竭中的应用价值。方法：４例原发性扩张型心肌病,心功能Ⅲ或Ⅳ级,合并左束支传导阻滞,ＱＲＳ时间≥２０ｍｓ。经锁骨下静脉将左心室外膜起搏电极置于心脏后侧支静脉,按常规方法安置右心房和右心室电极。起搏器程控为ＤＤＤ工作方式,ＡＶ间期设置为１００ｍｓ。在１２个月随访中,观察临床、心电图、运动试验（６ｍｉｎ步行距离）和超声心动图指标的变化以评价疗效。结果：（１）４例均成功安置双心室心脏起搏器,术后心力衰竭症状明显缓解,并于手术后９～２０ｄ出院。出院前停用所有静脉用药,包括利尿剂、强心剂和扩血管药;（２）随访：４例心功能均改善一级,６ｍｉｎ步行距离增加７６～２８４ｍ。超声心动图显示：左心室和左心房前后径分别减小３～７ｍｍ和２～７ｍｍ,左心室射血分数增加４％～７％。结论     

Effect of biventricular pacing on heart rate variability in patients with chronic heart failure

BACKGROUND: Biventricular pacing is emerging as a long-term therapy for symptomatic heart failure. Analysis of heart rate variability (HRV) has become an important predictive tool in this syndrome. AIM OF THE STUDY: To assess whether chronic resynchronization therapy can affect HRV in patients with heart failure. METHODS AND RESULTS: Thirteen patients with heart failure were studied (mean age+/-1 S.E. 65+/-2.2 years, QRS 195+/-5.3 ms, NYHA class 3.2+/-0.1, LVEF 21+/-1.7%). The protocol included a preliminary no pacing period for 1 month following device implantation. Twenty-four hour Holter ECG recordings were performed at the end of this period (baseline) and after 3 months of biventricular stimulation (VDD mode). Prior to and following pacing patients underwent NYHA class evaluation, 6-min walk test, Quality of Life Assessment and a cardiopulmonary exercise test. Biventricular pacing improved functional class (P<0.0001) and Quality of life (P<0.0001), increased 6-min walk distance, (P=0.008) and exercise duration (P<0.0001) but had no significant effect on peak exercise VO(2). Resynchronization therapy increased mean 24-h RR (922+/-58 vs. 809+/-41 ms at baseline, P=0.006), SDNN (111+/-11 vs. 83+/-8 ms, P=0.003), SDNN-I (56+/-10 vs. 40+/-5 ms, P=0.02), rMSSD (66+/-14 vs. 41+/-8 ms, P=0.003), Total Power (5724+/-1875 vs. 2074+/-553 ms(2), P=0.03), Ultra Low Frequency Power (1969+/-789 vs. 653+/-405 ms(2), P=0.03) and Very Low Frequency Power (2407+/-561 vs. 902+/-155 ms(2), P=0.004). CONCLUSION: Biventricular pacing in heart failure improves autonomic function by increasing HRV. This may have important prognostic implications.     

A pilot experience with permanent biventricular pacing to treat advanced heart failure

BACKGROUND: The prognosis and quality of life of patients with advanced heart failure remain poor. The purpose of this study was to evaluate new nonpharmacologic approaches. Biventricular pacing was proposed in this indication, based on the encouraging results of acute hemodynamics studies. METHODS: Fifty patients with drug-resistant heart failure (New York Heart Association [NYHA] class III/IV, 16 of 34) were consecutively implanted with biventricular pacemakers. All patients had severe dilated cardiomyopathy and intraventricular conduction delay. Survival, NYHA class, electrocardiogram, echocardiographic data, and exercise tolerance were assessed over a mean follow-up period of 15.4 +/- 10. 2 months. RESULTS: At the end of follow-up, 55% of patients were alive without heart transplantation or left ventricular assistance device. The mortality rate was significantly lower in class III (12. 5%) than in class IV patients (52.5%). In survivors, biventricular pacing significantly improved symptoms (NYHA class 2.2 +/- 0.5 at follow-up vs 3.7 +/- 0.5 at baseline) and exercise tolerance ((. )VO(2) peak 15.5 +/- 3.4 mL/min per kilogram at follow-up vs 11.1 +/- 3 mL/min per kilogram at baseline). CONCLUSIONS: Biventricular pacing appears to improve the functional status of patients with dilated cardiomyopathy with advanced heart failure. The technique appears to be attractive as an additive treatment, especially in class III patients. Controlled randomized studies are needed to validate this novel concept.     

Acute hemodynamic effects of biventricular and left ventricular pacing in chronic pacemaker-dependent patients with advanced heart failure

The beneficial hemodynamic effects of cardiac resynchronization in patients with intraventricular conduction delay have been demonstrated. The potential hemodynamic effects of cardiac resynchronization to compensate the pacing-induced left ventricular conduction delay in chronically paced heart failure patients are not as well established. The aim of the study was to evaluate the acute hemodynamic effects of biventricular and left ventricular pacing in chronically paced patients with advanced heart failure.Fourteen consecutive pacemaker or defibrillator patients with permanent atrial fibrillation and AV block (11 male, 3 woman, mean age: 68 +/- 7 years) were enrolled in this study. There were 5 ischemic (36%) and 9 nonischemic (64%) patients (mean left ventricular ejection fraction: 19 +/- 5%; mean end-diastolic left ventricular diameter: 71 +/- 11 mm). In all patients a right ventricular and left ventricular (via coronary sinus) pacing lead was placed. The aortic and left ventricular hemodynamic measurements were performed using a two-channel micro-tip catheter. The measurements of the aortic pulse pressure (APP) and (dP/ dtmax) were performed during right ventricular apical pacing (RVP), left ventricular (LVP), and biventricular pacing (BVP) (70 bpm).Compared to RVP, LVP and BVP increased APP and dP/dtmax (35.8 +/- 4.2 vs 43.3 +/- 4.5 and 41.2 +/- 4 mmHg; p < 0.001) and (758 +/- 56 vs 967 +/- 60 and 961 +/- 62 mmHg/s; p < 0.001). LVP and BVP showed a comparable hemodynamic response. The hemodynamic effects were not related to the width of the paced QRS complex. Every patient showed improved hemodynamics during LVP and BVP unrelated to the underlying heart disease and to the baseline level of left ventricular dysfunction. BVP and LVP pacing acutely improve contractile left ventricular function in chronically paced patients with advanced heart failure.     

双心室起搏对慢性心力衰竭患者心肺功能和生活质量的影响

目的:观察双心室起搏对慢性心力衰竭患者心肺功能和生活质量的影响。方法:慢性心力衰竭伴室内传导阻滞患者9例,植入三腔双心室起搏器,比较双心室起搏前、后患者超声心动图检查、心肺功能和生活质量的变化。结果:双心室同步起搏后.患者左室射血分数(%)由术前(21.6±6.7)%增加到(27.3±5.2)%(术后3月,P< 0.05)。(29.5±5.4)%(术后6月,P<0.05);6 min步行距离,由术前(320±97)m增加到(384±103)m(术后3月.P<0.01).(413±110)m(术后6月.P<0.01);峰值氧耗量、氧通气当量(VE/VO2)、二氧化碳通气当量(VE/VCO2)较术前均有显著增加(P<0.05～<0.01);生活质量评分分别改善30%(术后3月,P<0.01),28% (术后6月,P<0.01)。结论:双心室起搏能有效改善慢性心衰患者心肺功能,增加运动贮量,提高生活质量。     

双心室起搏对慢性心力衰竭患者心肺功能和生活质量的影响

目的观察双心室起搏对慢性心力衰竭患者心肺功能和生活质量的影响.方法慢性心力衰竭伴室内传导阻滞患者9例,比较双心室起搏前后患者超声心动图、心肺功能以及生活质量的变化.结果双心室同步起搏后,患者左心室射血分数(%)由术前21.6±6.7增加到27.3±5.2(术后3个月,P<0.05)、29.5±5.4(术后6个月,P<0.05),6分钟步行距离(m),由术前320±97增加到384±103(术后3个月,P<0.01)、413±110(术后6个月,P<0.01),峰值氧耗量、摄氧效率斜率及每分通气量/每分二氧化碳产生量斜率较术前均有显著增加.生活质量评分分别改善30%(术后3个月,P<0.01)、28%(术后6个月,P<0.01).结论双心室起搏能有效改善慢性心衰患者心肺功能,增加运动能量,提高生活质量.     

双室再同步起搏治疗充血性心力衰竭近期疗效

目的本研究旨在观察双室再同步起搏治疗严重的充血性心力衰竭疗效. 方法2001年4月～2002年11月在我科住院病人10例,男8例,女2例,年龄42～74岁,其中缺血性心肌病5例,扩张型心肌病4例,酒精性心肌病1例.     

双心室同步起搏治疗顽固性心力衰竭的疗效

目的观察双心室同步起搏对扩张型或缺血性心肌病出现顽固性心力衰竭(心衰)时的治疗效果.方法 7例患者,男性6例,女性1例.NYHA 心功能分级Ⅲ～Ⅳ级, QRS 间期>0.12 s, 左室射血分数(LVEF)< 35%, 左室舒张末直径≥60 mm,患者均为药物治疗效果不佳的顽固性心衰.分别植入右心房、右心室和冠状静脉左室分支电极导线,行房室顺序双心室同步起搏.起搏前后跟踪随访患者,观察LVEF,NYHA心功能分级和6 min步行的变化.结果右心房、右心室和左心室导线感知和起搏参数均符合起搏要求,随访中亦未发现导线移位和功能障碍.起搏后QRS时间明显缩短,起搏前(188±40)ms、左心室起搏(212±42)ms、右心室起搏(222±34)ms、双心室起搏(169±26)ms.随访(430±136)d.心功能分级(NYHA)术前(3.28±0.45)级,术后1周(1.86±0.64)级,随访中未见进一步改善;LVEF术前(28.30±3.94)%, 术后1周(37.80±3.98)%, 随访时(41.67±6.77)%;6 min步行起搏前(398±168)m,术后1周(478±126)m,随访时增加到(506±134)m.结论双心室同步起搏治疗顽固性心衰可以缓解患者的症状,改善心功能,增加LVEF,提高运动耐量,这些变化可能与心室间电活动以及机械活动的再同步化有关.     

Effects of levosimendan on coronary artery flow and cardiac performance in patients with advanced heart failure

BACKGROUND: Levosimendan has inotropic and vasodilatory effects. We investigated the effects of levosimendan on coronary flow and associated changes in neurohormonal activation and cardiac performance in patients with advanced heart failure. METHODS: Forty-two patients with NYHA III-IV and a left ventricular ejection fraction (EF) 25+/-6%, were randomised to levosimendan 0.1 microg/kg/min (n=21) or placebo for 24 h. Before and 24 h after each treatment, we assessed: the maximal velocity (Vmax), time integral (VTI) and deceleration time (DT) of the diastolic coronary flow wave (CF) in LAD using transthoracic Doppler echocardiography, pulmonary artery systolic pressure by Doppler echocardiography, E/E' ratio using Doppler imaging of mitral inflow velocity, tissue Doppler imaging of the mitral annulus and B-type natriuretic peptide (BNP) levels. RESULTS: By ANOVA, there was a greater increase in CF-Vmax (43+/-23 vs.25+/-8 cm/s), CF-DT (904+/-250 vs. 667+/-151 ms), and EF and a greater decrease in BNP, pulmonary artery systolic pressure and E/E? after levosimendan than after placebo (p<0.05). Compared to baseline, the percent changes in CF-VTI were related to the concomitant changes in EF, E/E?, and BNP after treatment with levosimendan (r=0.69, r=?0.51 and r=?0.80, p<0.05 respectively). CONCLUSION: Treatment with levosimendan improves coronary flow and microcirculation in parallel with an improvement in cardiac performance and neurohormonal activation in patients with advanced heart failure.     

Improvement in cardiac adrenergic function post biventricular pacing for heart failure.

AIMS: We investigated whether biventricular (BiV) pacing favourably affects cardiac sympathetic activity in heart failure (HF). METHODS AND RESULTS: In 10 HF patients treated with BiV pacing, we assessed cardiac sympathetic activity by metaiodobenzylguanidine ((123)I-MIBG) imaging. Patients were randomized in a double-blinded crossover fashion, for two weeks of either inactivation of BiV pacing or BiV pacing, with crossover to the alternate group for a further two weeks. After randomization blocks, cardiac (123)I-MIBG imaging and a 6 min walk test were performed. BiV pacing was associated with significant improvements in cardiac (123)I-MIBG uptake reflected by increases in early (BiV 1.71 +/- 0.09 vs. non-BiV 1.63 +/- 0.06, P = 0.03) and late (at 4 h) heart to mediastinal ratio of uptake (BiV 1.54 +/- 0.08 vs. non-BiV 1.45 +/- 0.06, P = 0.03). Additionally, pulmonary (123)I-MIBG uptake, measured as lung to mediastinal ratio, significantly improved (P = 0.009). Six-minute walk and systolic blood pressure tended to improve with BiV vs. non-BiV pacing (P = 0.09). CONCLUSION: In patients with stable HF, BiV pacing is associated with long-term improvements in cardiac sympathetic nerve activity, as reflected by improvements in cardiac (123)I-MIBG uptake. This is a potential mechanism for morbidity and mortality benefits observed in larger studies.     

Acute hemodynamic effects of biventricular DDD pacing in patients with end-stage heart failure

Objectives. The aim of this study was to assess the potential acute benefit of multisite cardiac pacing with optimized atrioventricular synchrony and simultaneous biventricular pacing in patients with drug-refractory congestive heart failure (CHF).

Background. Prognosis and quality of life in severe CHF are poor. Various nonpharmacological therapies have been evaluated but are restricted in their effectiveness and applications. In the early 1990s, dual chamber pacing (DDD) pacing was proposed as primary treatment of refractory CHF but results were controversial. Recently, tests to evaluate the effect of simultaneous pacing of both ventricles have elicited a significant improvement of cardiac performance.

Methods. Acute hemodynamic study was conducted in 18 patients with severe CHF (New York Heart Association class III and IV) and major intraventricular conduction block (IVCB) (QRS duration = 170 ± 37 ms). Using a Swan-Ganz catheter, pulmonary artery pressure, pulmonary capillary wedge pressure (PCWP) and cardiac index (CI) were measured in different pacing configurations: atrial pacing (AAI) mode, used as reference, single-site right ventricular DDD pacing and biventricular pacing with the right ventricular lead placed either at the apex or at the outflow tract.

Results. The CI was significantly increased by biventricular pacing in comparison with AAI or right ventricular (RV). DDD pacing (2.7 ± 0.7 vs. 2 ± 0.5 and 2.4 ± 0.6 l/min/m², p < 0.001). The PCWP also decreased significantly during biventricular pacing, compared with AAI (22 ± 8 vs. 27 ± 9 mm Hg; p < 0.001).

Conclusions. This acute hemodynamic study demonstrated that biventricular DDD pacing may significantly improve cardiac performance in patients with IVCB and with severe heart failure, in comparison with intrinsic conduction and single-site RV DDD pacing.     

Variability in the clinical status of patients with advanced heart failure

BACKGROUND: The importance of repeated clinical assessments of patients with heart failure is widely accepted. The frequency of such follow-up is not established and is likely to depend on the natural history and variability of patients' health status and the availability and use of appropriate treatments. METHODS AND RESULTS: We analyzed data from a multicenter prospective cohort study of heart failure outpatients comparing baseline variables including New York Heart Association (NYHA) class, summary score on the Kansas City Cardiomyopathy Questionnaire (KCCQ), and performance on a 6-minute walk test with results of a repeat evaluation at 6 weeks. We also compared patient and physician assessment of change in disease status among patients with advanced symptoms (NYHA class III with a recent antecedent hospitalization or class IV) and those with milder degrees of limitation (NYHA classes I, II, and stable III). Patients with advanced symptoms had greater short-term variability in health status as reflected by the KCCQ summary score and a visual analog scale. A greater proportion of patients with advanced heart failure experienced moderate or greater clinical change. Patient and physician global assessments were congruent with more direct measures of health status. CONCLUSION: Patients with advanced heart failure have greater short-term variability in status, supporting the need for frequent clinical follow-up and appropriate power calculations for clinical trials that are designed to measure meaningful changes over a short period.     

三腔双心室起搏治疗20例充血性心力衰竭患者的近期临床效果

目的 观察三腔双心室同步起搏治疗充血性心力衰竭的临床效果。方法 充血性心力衰竭伴心室内阻滞患者20例,男性16例,女性4例,平均年龄54.7岁。心功能均在Ⅲ-Ⅳ（NYHA分级）,体表心电图平均QRS时限为142.6ms。患者均进行了三腔双心室同步起搏,起搏电极导线分别置于右心房、右心室以及经由冠状静脉窦置于一支心脏静脉起搏左心室。观察双心室起搏前后左心室射血分数变化以及体表心电图QRS波变化。结果 双心室同步起搏后,患者心功能得到明显改善,左心室射血分数（left ventricular ejection fraction,LVETF)从24.4%提高至32.1%,左心室充盈时间延长,二尖瓣返流量减少,心功能从Ⅲ-Ⅳ级改善至Ⅱ-Ⅲ级,QRS时限由术前的142.6ms缩短至124.8ms。结论 初步临床观察提示,三腔双心室同步起搏可有效改善充血性心力衰竭伴心室内阻滞患者的心功能。     

Effects of left ventricular pacing on cardiac performance and on quality of life in patients with drug refractory heart failure

We assessed the effects of left ventricular pacing on echocardiographic and clinical parameters in 13 consecutive patients with heart failure and bundle branch block by means of a controlled acute and medium-term evaluation. Left ventricular pacing induced a significant improvement in left ventricular ejection fraction, Minnesota Living with Heart Failure Questionnaire score, New York Heart Association class, and 6-minute walking test compared with sinus rhythm or right ventricular pacing.