Ventricular pacing improves exercise tolerance in patients with chronic heart block.

Exercise capacity was assessed by means of a simple six minute walking test in a group of 18 patients with heart block whose only presenting symptom was breathlessness. None was in overt cardiac failure. Patients were studied before and after implantation of a transvenous, ventricular, demand pacing system (study group). Eight patients with an implanted pacemaker admitted for elective generator replacement were assessed in the same manner (control group). Exercise capacity in the study group was significantly increased within 48 hours of pacing, and this improvement was maintained in most patients during the follow up period of up to 30 months. In contrast, exercise capacity was unaffected by generator replacement in the control group. Simple ventricular pacing produces symptomatic benefit in patients with heart block accompanied by breathlessness. This benefit is apparent within 48 hours of pacing and is maintained; it can be assessed objectively by a six minute walking test.     

Enhanced external counterpulsation improves exercise tolerance in patients with chronic heart failure.

OBJECTIVES: The PEECH (Prospective Evaluation of Enhanced External Counterpulsation in Congestive Heart Failure) study assessed the benefits of enhanced external counterpulsation (EECP) in the treatment of patients with mild-to-moderate heart failure (HF). BACKGROUND: Enhanced external counterpulsation reduced angina symptoms and extended time to exercise-induced ischemia in patients with coronary artery disease, angina, and normal left ventricular function. A small pilot study and registry analysis suggested benefits in patients with HF. METHODS: We randomized 187 subjects with mild-to-moderate symptoms of HF to either EECP and protocol-defined pharmacologic therapy (PT) or PT alone. Two co-primary end points were pre-defined: the percentage of subjects with a 60 s or more increase in exercise duration and the percentage of subjects with at least 1.25 ml/min/kg increase in peak volume of oxygen uptake (VO2) at 6 months. RESULTS: By the primary intent-to-treat analysis, 35% of subjects in the EECP group and 25% of control subjects increased exercise time by at least 60 s (p = 0.016) at 6 months. However, there was no between-group difference in peak VO2 changes. New York Heart Association (NYHA) functional class improved in the active treatment group at 1 week (p < 0.01), 3months (p < 0.02), and 6 months (p < 0.01). The Minnesota Living with Heart Failure score improved significantly 1 week (p < 0.02) and 3 months after treatment (p = 0.01). CONCLUSIONS: In this randomized, single-blinded study, EECP improved exercise tolerance, quality of life, and NYHA functional classification without an accompanying increase in peak VO2.     

Trimetazidine improves exercise tolerance in patients with ischemic heart disease

Aim

This study aimed to evaluate the effect of trimetazidine (TMZ) in addition to standard treatment on exercise tolerance in patients with ischemic heart disease (IHD).

Methods

Studies were identified via a systematic search of PubMed, Embase, Cochrane Library, and the Chinese CNKI databases from January 1978 to January 2015. Data extraction, synthesis, and statistical analysis were performed by standard meta-analysis methods. Random or fixed effects models were used to estimate pooled mean differences in total exercise duration (TED), peak oxygen uptake (pVO₂), metabolic equivalent system (METS), and 6-minute walking test (6-MWT).

Results

In all, 16 randomized controlled trials (RCTs) consisting of 2,004 participants were included. Pooled results showed that TMZ treatment significantly improved TED (WMD: 37.35, 95?% CI: 25.58–49.13, p?<?0.00001), pVO₂ (WMD: 2.41, 95?% CI: 1.76–3.06, p?<?0.00001), METS (WMD: 1.33, 95?% CI: 0.38–2.28, p?=?0.006), and 6-WMT (WMD: 62.46, 95?% CI: 35.86–89.05, p?<?0.001) in all patients with IHD. Subgroup analysis showed that TMZ significantly increased TED in nondiabetic participants (WMD 34.77, 95?% CI: 22.28–47.25, p?<?0.001), but not in diabetic participants (WMD: 40.36, 95?% CI: ??18.76–99.48, p?=?0.18). And, subgroup analysis of TED by intervention duration suggested that there is no statistically difference between the 3-month and 6-month periods (WMD: 35.47, 95?%CI: 18.35–52.60, p?<?0.0001 and WMD: 49.94, 95?%CI: 44.69–55.19, p?<?0.00001). In addition, TMZ improved TED (WMD: 50.01, 95?% CI: 44.77–55.25 and WMD: 24.20, 95?% CI: 12.72–35.68) in IHD patients with or without heart failure (HF), respectively.

Conclusion

Addition of TMZ to standard treatment significantly improved exercise tolerance in patients with IHD, and IHD patients with HF may experience even more benefits. However, there is insufficient evidence to show that TMZ has beneficial effects in participants with diabetes.

     

Biventricular pacing improves quality of life and exercise tolerance in patients with heart failure and intraventricular conduction delay

Background: Biventricular pacing improves left ventricular dysynchrony, leading to improvement in congestive heart failure symptoms. The extent of placebo effect, the predictors of response and the long term benefits are unknown. Patients and Methods: Forty-five patients with symptomatic congestive heart failure underwent implantation of a biventricular pacing system over a 30-month period (age 65 10 years, 37 men). Patients underwent implantation of a biventricular pacemaker or implantable defibrillator one month or longer after stabilization of congestive heart failure on maximal medical therapy, including angiotensin-converting enzyme inhibitors in 84% of patients and beta-blockers in 56% of patients. Three patients had New York Heart Association (NYHA) class II heart failure, 34 had NYHA class III and eight had NYHA class IV. Cardiomyopathy was ischemic in 31 patients, dilated in 12 and the result of other causes in two. The left ventricular ejection fraction was 19 5%. Results: Implantation of the biventricular pacing system was successful in 38 of 45 patients (84%). Two patients had successful implantation with a second attempt, and one patient had an epicardial lead implant. Lead dislodgement occurred in four patients, with successful repositioning in all. During a mean follow-up of 10 7 months, the Minnesota Living with Heart Failure Questionnaire quality of life index score improved from 62 16 to 42 22 at one month (P<0.001), but subsequently returned to intermediate levels (55 26 at three months, 48 26 at six months and 56 34 at one year, P=0.50). In seven patients with deferred device activation, quality of life scores also improved by 10 15 points from baseline to one month with VDI 35 pacing, and improved a further 15 20 points with left ventricular lead activation. The mean NYHA class fell from 3.1 0.5 at baseline to 2.7 0.7 at one month (P=0.006) and remained stable thereafter (2.8 0.9 at three months, 2.8 0.9 at six months). Six patients died during follow-up, one patient had a cardiac transplantation and subsequently died, one patient had a successful cardiac transplantation and one patient underwent insertion of a left ventricular assist device. Death occurred due to progressive heart failure in five patients, sudden death occurred in one patient and a noncardiovascular cause resulted in the death of one patient. An analysis of NYHA responders (NYHA class improvement of 1 or more at last follow-up, 44% of patients) and quality of life responders (score improvement of 10 or more at last follow-up, 57% patients) did not show any difference in age, sex, heart failure etiology, QRS width, ejection fraction or baseline NYHA class. Conclusions: Biventricular pacing improves quality of life and NYHA class in patients with advanced heart failure and intraventricular conduction delay. The attenuated benefit seen over time may be related to initial placebo effect or simple dual- chamber pacing, or the natural history of the underlying disease. Identification of patients most likely to respond to biventricular pacing was not possible.     

Rate-responsive pacing improves exercise tolerance in heart transplant recipients: a pilot study

BACKGROUND: Chronotropic incompetence is one cause of diminished exercise capacity in heart transplant recipients. If reinnervation occurs, it often is late after transplantation and is not always accompanied by functional improvements in peak heart rate and appropriate tachycardia during exercise. To determine the efficacy of rate-responsive pacing on peak heart rate and exercise capacity, the authors studied eight male heart transplant recipients (age 57 +/- 12 years; 23 +/- 9 months after transplantation) that had either atrial or dual-chambered pacemakers. METHODS: All subjects completed two maximal graded exercise tests (GXT) using the Naughton treadmill protocol. During the first GXT, pacemakers were programmed for bradycardia support only and without rate responsiveness (unpaced). After a 14-day regimen of beta blockade with metoprolol to nullify the influence of circulating catecholamines on heart rate, subjects performed the second GXT with pacemakers programmed to respond optimally in the rate-responsive mode (paced). RESULTS: Peak heart rate (149 versus 129 bpm), peak oxygen uptake (18.9 versus 15.4 mL/kg/min), treadmill time to exhaustion (14.6 versus 12.4 min), and minute ventilation (76.7 versus 66.2 L/min) were significantly increased (P < or = 0.05) during the paced versus unpaced GXT. CONCLUSIONS: The results of this study demonstrate that chronotropic support of the transplanted heart using a rate-responsive pacemaker, with activity-based sensors programmed for maximal sensitivity, improves both peak heart rate and exercise capacity in heart transplant recipients significantly more than circulating catecholamines alone.     

Atriobiventricular pacing improves exercise capacity in patients with heart failure and intraventricular conduction delay

OBJECTIVES: We sought to assess the efficacy of biventricular pacing with respect to both peak and submaximal measures of exercise in patients with New York Heart Association class III heart failure (HF) and intraventricular conduction delay in a randomized, blinded study. BACKGROUND: Submaximal and maximal changes in exercise capacity need evaluating in this patient population with this novel therapy. METHODS: Graded exercise and 6-min walk tests were performed in patients randomized to three months each of active (atrio-biventricular) and inactive pacing. Minute ventilation (VE), oxygen uptake (VO(2)), ventilated carbon dioxide (VCO(2)) and heart rate were measured in patients achieving a respiratory quotient >1 (n = 30). Oxygen pulse, anaerobic threshold (AT) and ventilatory efficiency (VE/VCO(2)) were calculated. RESULTS: Active biventricular pacing increased peak VO(2) (15.8 +/- 4.3 vs. 14.4 +/- 4.6 ml/kg/min, p = 0.02), exercise time (501 +/- 223 s vs. 437 +/- 233 s, p < 0.001) and oxygen pulse (9.3 +/- 2.8 vs. 8.1 +/- 3.1 ml/beat, p < 0.01) compared with inactive pacing. The submaximal measures of exercise capacity significantly increased with active pacing: AT (11.2 +/- 4.1 ml/kg/min vs. 9.5 +/- 2.3 ml/kg/min, p = 0.02) and 6-min walk (414 +/- 94 m vs. 359 +/- 94 m, p = 0.001). Minute ventilation/ventilated carbon dioxide improved (32 +/- 9 vs. 36 +/- 11, p = 0.03) with normalization of the VE/VCO(2) slope in 59% of patients (chi-square test, p = 0.002) with active pacing. CONCLUSIONS: Biventricular pacing may improve maximal and submaximal exercise capacity in patients with advanced HF and intraventricular conduction delay.     

Noninvasive ventilation during exercise training improves exercise tolerance in patients with chronic obstructive pulmonary disease

PURPOSE: In patients with chronic obstructive pulmonary disease, pulmonary rehabilitation has been demonstrated to increase exercise capacity and reduce dyspnea. In the most disabled patients, the intensity of exercise during the training sessions is limited by ventilatory pump capacity. This study therefore evaluated the beneficial effect of noninvasive ventilation (NIV) support during the rehabilitation sessions on exercise tolerance. METHODS: This study included 14 patients with stabilized chronic obstructive pulmonary disease, ages 63 +/- 7 years, with a forced expiratory volume in 1 second (FEV(1)) 31.5% +/- 9.2% of predicted value. All 14 patients participated in an outpatient pulmonary rehabilitation program. Seven of the patients trained with NIV during the exercise sessions (NIV group), whereas the remaining seven patients breathed spontaneously (control group). Exercise tolerance was evaluated during an incremental exercise test and during constant work rate exercise at 75% of peak oxygen consumption (VO(2)) before and after the training program. RESULTS: The application of noninvasive ventilation increased exercise tolerance, reduced dyspnea, and prevented exercise-induced oxygen desaturation both before and after training. The pressure support was well tolerated by all the patients during the course of the training program. In the NIV group, training induced a greater improvement in peak VO(2) (18% vs 2%; P <.05) and a reduced ventilatory requirement for maximal exercise, as compared with the control group. The constant work rate exercise duration increased similarly in both groups (116% vs 81%, nonsignificant difference), and posttraining blood lactate was decreased at isotime (P <.05 in both groups), but not at the end of the exercise. CONCLUSION: In this pilot study, exercise training with noninvasive ventilation support was well tolerated and yielded further improvement in the increased exercise tolerance brought about by pulmonary rehabilitation in patients with chronic obstructive pulmonary disease. This improved exercise tolerance is partly explained by a better ventilatory adaptation during exercise.     

培哚普利联合左卡尼汀对心力衰竭患者运动耐量的影响

目的 探讨培哚普利联合左卡尼汀对心力衰竭患者运动耐量的影响.方法 选择2018年1月至2019年10月于广东省普宁市人民医院药学部进行治疗的心力衰竭患者96例,按照接受药物治疗不同分为2组,每组患者48例.对照组给予培哚普利治疗,观察组给予培哚普利联合左卡尼汀治疗,其余抗心力衰竭治疗措施完全相同.用药结束后3 d,比较...     

Ventilatory capacity and exercise tolerance in patients with chronic stable heart failure

BACKGROUND: Patients with chronic heart failure complain of breathlessness. This is associated with an increase in the ventilatory response to carbon dioxide production (VE/VCO(2) slope), yet a reduction in the maximal ventilation achieved at peak exercise. We analysed ventilatory capacity in heart failure in relation to exercise capacity. METHODS: We analysed data from 74 patients with chronic stable heart failure [age (S.D.) 50.6 (8.8) years; left ventricular ejection fraction 30 (15)%] and 36 controls [48.9 (11.5) years]. Subjects undertook maximal incremental exercise testing with metabolic gas exchange measurements to derive peak oxygen consumption (VO(2)), the VE/VCO(2) slope and ventilation. Spirometry was used to measure FEV(1) and FVC. Maximal voluntary ventilation (MVV) was calculated as FEV(1)x 35. RESULTS: Peak VO(2) was lower in patients [20.9 (7.5) ml min(-1) kg(-1) vs. 34.5 (10.1); P<0.001] and VE/VCO(2) greater [33.4 (10.7) vs. 26.0 (4.7); P<0.001]. Ventilation at peak exercise was lower in patients [63.5 (20.4) l/min vs. 86.9 (29.5); P<0.001], as was MVV [110.1 (37.9) l/min vs. 136.2 (53.1); P<0.001], but ventilation at peak as a proportion of MVV was the same in patients [60.0 (19.0)%] as controls [65.7 (12.4)%)]. There was an inverse relation between peak VO(2) and VE/VCO(2) slope (r=-0. 62; P<0.001). Percentage predicted FEV(1) correlated with ventilation at peak (r=0.62; P<0.001) and inversely with VE/VCO(2) slope (r=-0.32; P<0.001). There was no relation between percentage of MVV achieved and peak VO(2), or VE/VCO(2) slope. CONCLUSIONS: Although ventilation at peak exercise is lower in patients with heart failure than normal subjects, ventilation is the same proportion of maximal voluntary ventilation. These findings suggest that ventilatory capacity does not limit exercise capacity in heart failure.     

运动康复改善老年慢性心衰患者心功能和生活质量的研究

目的:观察老年慢性心衰患者运动康复后心功能和生活质量的改变。方法:对60例老年慢性心衰病人在常规药物治疗的基础上,实施运动康复疗法,并与58例非康复组进行对照比较;观察出院时病人6min步行距离、运动耐量、平均住院日和心功能变化,同时测定血浆脑钠肽(BNP)含量,对其生活质量进行评定;观察随访一年时病人的心功能、再住院率和死亡率。结果:出院时康复组运动贮量、生活质量明显提高,NYHA心功能级别显著改善(P<0.05或<0.01),BNP水平和心室重量指数(LVMI)则显著降低(P<0.05);较之对照组除上述指标显著改善(P<0.05~<0.01)外,6min步行距离增加非常显著(P<0.01)平均住院日显著减少(P<0.05);随访一年时康复组病人的心功能、6min步行距离、运动贮量、生活质量、左室射血分数(LVEF)和E/A比值均明显增加,NYHA心功能级别显著改善(P<0.01),左房内径(LAd)、LVMI以及再入院率和死亡率明显低于对照组(P<0.01或P<0.05)。结论:运动康复可以改善心功能,提高运动耐量和生活质量,缩短住院时间,降低再入院率和死亡率;长期运动康复可能有改善心肌的重构的作用。     

Blood flow redistribution during exercise contributes to exercise tolerance in patients with chronic heart failure.

BACKGROUND: It is widely known that blood flow redistribution is impaired in patients with chronic heart failure (CHF). However, the relationship between exercise tolerance and the degree of blood flow redistribution is not fully understood. Whole-body thallium-201 chloride ((201)Tl) scintigraphy can estimate blood flow distribution. This study will evaluate the relationship between exercise tolerance and blood flow redistribution using whole-body scintigraphy in patients with CHF. METHODS AND RESULTS: Exercise stress whole-body thallium scintigraphy was performed in 19 patients with CHF (mean ejection fraction: 33.0%; peak oxygen uptake: 15.5 ml x min(-1) x kg(-1)). Blood flow redistribution was quantified by comparing the regional thallium count (count/pixel) in the thigh and arm. We then assessed the relationship between these parameters and parameters obtained from cardiopulmonary exercise testing. (201)Thallium-chloride uptake in the thigh increased during exercise compared to rest (p<0.05), while its uptake in the arm was not different between exercise and rest. Increased (201)Tl uptake in the thigh during exercise was positively correlated with exercise tolerance (r=0.689). In contrast, (201)Tl uptake in the arm was not correlated with exercise tolerance. CONCLUSIONS: By using this method, it is concluded that blood flow redistribution to the exercising muscle increases as the exercise tolerance increases in patients with CHF.     

运动康复改善老年慢性心衰患者心功能和生活质量的研究

目的:观察老年慢性心衰患者运动康复后心功能和生活质量的改变.方法:对60例老年慢性心衰病人在常规药物治疗的基础上,实施运动康复疗法,并与58例非康复组进行对照比较;观察出院时病人 6 min步行距离、运动耐量、平均住院日和心功能变化,同时测定血浆脑钠肽(BNP)含量,对其生活质量进行评定;观察随访一年时病人的心功能、再住院率和死亡率.结果:出院时康复组运动贮量、生活质量明显提高,NYHA心功能级别显著改善(P＜0.05或＜0.01),BNP水平和心室重量指数(LVMI)则显著降低(P＜0.05);较之对照组除上述指标显著改善(P＜0.05～＜0.01)外,6 min步行距离增加非常显著(P＜0.01)平均住院日显著减少(P＜0.05);随访一年时康复组病人的心功能、6 min步行距离、运动贮量、生活质量、左室射血分数(LVEF)和E/A比值均明显增加,NYHA心功能级别显著改善(P＜0.01),左房内径(LAd)、LVMI以及再入院率和死亡率明显低于对照组(P＜0.01或P＜0.05).结论:运动康复可以改善心功能,提高运动耐量和生活质量,缩短住院时间,降低再入院率和死亡率;长期运动康复可能有改善心肌的重构的作用.     

步行试验对老年慢性心力衰竭患者运动耐量的评估

目的探讨6 min步行试验(6MWT)对老年慢性心力衰竭(CHF)患者运动耐量的评价.方法将54例CHF患者随机分为常规治疗组(n=25)和卡维地洛组(n=29),治疗前后进行步行试验,监测肿瘤坏死因子(TNF-α)、白细胞介素6(IL-6)、去甲肾上腺素(NE)和左室射血分数(LVEF).结果心功能Ⅳ级患者较Ⅱ级患者步行距离明显下降(P<0.01),Ⅲ级与Ⅱ级、Ⅳ级与Ⅲ级患者之间步行距离的差异无显著性意义(P>0.05);卡维地洛组6 min步行距离治疗前后差异有显著性意义(P<0.01), 而常规治疗组差异无显著性意义(P>0.05),两组患者步行距离与TNF-α、IL-6、NE呈显著负相关(P<0.05),与LVEF呈正相关(P<0.05).结论6MWT具有简单、易行、安全、可靠的特点,可作为评估CHF患者运动耐量的临床工具,尤其适用于老年患者,同时可提供一定的判断CHF预后及治疗效果的信息.     

Impaired glucose tolerance worsens exercise capacity and ventilatory response to exercise in patients with chronic heart failure

BACKGROUND: There is increasing evidence for the importance of peripheral abnormalities in the pathogenesis and progression of heart failure (HF). Recently, glucose and insulin metabolism abnormalities have been intensively investigated in patients with HF. AIM: To investigate whether coexistence of impaired glucose tolerance (IGT) may decrease exercise tolerance and influence ventilatory response to exercise in patients with systolic HF. METHODS: Maximal cardiopulmonary exercise test with evaluation of peak VO2 and VE/VCO2 slope and oral glucose tolerance test were performed in 64 clinically stable patients with HF and LVEF <45%. RESULTS: Impaired glucose tolerance was diagnosed in 26 (41%) patients and normal glucose tolerance (NGT) in 38 (59%) patients. There were no significant differences in baseline clinical characteristics or LVEF between groups. There were significant differences in peak VO2 between IGT and NGT (15.4+/-4.1 vs. 18.7+/-4.2 ml/kg/min respectively; p=0.003) and VE/VCO2 slope (35.7+/-7.3 vs. 31.8+/-5.7 respectively; p=0.02). The IGT was independently related to peak VO2 and VE/VCO2 slope in multivariate regression analysis. CONCLUSION: The IGT is associated with worse exercise capacity and ventilatory response to exercise in patients with HF.     

左旋卡尼汀能有效提高稳定型心绞痛患者的运动耐量

目的观察国产左旋卡尼汀（L-CN）对稳定型心绞痛患者临床症状和运动耐量的影响。方法在常规治疗的基础上使用L-CN辅助治疗稳定型心绞痛患者80例,40例患者作为对照。记录两组患者治疗前后临床症状、心电图、心功能、运动试验心电图。结果L-CN可以明显缓解患者心绞痛临床症状,改善心功能,并显著提高运动耐量和心绞痛负荷阈值。结论L-CN是心绞痛代谢治疗的有效药物之一。