心肺运动试验的临床应用——选择性β 1受体阻滞剂对运动耐力的影响

目的研究选择性β1受体阻滞剂对运动耐力的影响。方法24例服用倍他乐克（Metoprolol）的成年男性患者及20例健康男性进行运动试验,同步记录摄氧量（VO2）、二氧化碳产生量（VCO2）、心率（HR）等参数。结果倍他乐克组最大运动时的摄氧量和心率分别为VO2max=(18.96±3.82)ml/kg·min,HRmax=(117±19)beats/min,明显低于对照组VO2max=(24.71±5.15)ml/kg·min,HRmax=(147±12)beats/min。结论选择性β1阻滞剂通过抑制运动时心率的增加使运动耐力下降。     

康复运动对冠心病患者心脏自主神经功能的影响

摘要 目的：探讨有氧运动对冠心病患者心脏自主神经功能的影响。 方法：18例女性冠心病患者（实验组）,14例女性非冠心病患者（对照组）为本研究的受试者,在康复程序前、后,对她们进行了运动前（安静时）和运动后的心率变异性（HRV）指标的测定,其中包括极低频功率（VLF）、低频功率（LF）、高频功率（HF）、总功率（TP）和低高频比值（LF/HF）。 结果：①与对照组相比,实验组康复程序前安静时VLF、LF、HF和TP均显著降低,而LF/HF显著增高（P＜0.01）,运动后也有相似的趋势。②与康复程序前相比,12周心脏康复程序后,实验组安静时VLF、LF、HF和TP均有显著增高,LF/HF有所降低（P＜0.01和P＜0.05）;运动后HF显著增高,LF/HF显著降低（P＜0.05）。③与安静时相比,康复程序前实验组递增负荷运动后心率变异性指标均无显著性改变;康复程序后实验组递增负荷运动后VLF、LF、TP和LF/HF均有显著降低（P＜0.01和P＜0.05）;对照组递增负荷运动后VLF、LF、HF和TP均有显著降低（P＜0.01和P＜0.05）,LF/HF有显著增高（P＜0.01）。 结论：12周运动心脏康复程序不仅可以提高冠心病患者安静时自主神经的调节功能,而且对改善一次急性运动后自主神经的均衡性也有积极作用。     

高血压患者运动耐量的研究

目的通过对高血压患者心肺功能的评定,探讨高血压患者运动耐量的变化。方法选择符合入选标准的患者70例,按有无高血压分为高血压组(n=40),非高血压组(n=30),进行心肺运动试验,测定并比较两组在达最大摄氧量(VO2max)和无氧阈(AT)时的摄氧量(VO2)、二氧化碳排出量(VCO2),计算相应的代谢当量(METs)、每千克体质量摄氧量(VO2/kg);记录并比较两组的心率、血压和运动时间,计算最大心率血压乘积(RPP max)。结果高血压组与非高血压组各项指标的比较:运动时间(5.9±1.6)min vs(7.2±1.5)min,VO2max/kg(21.7±4.4)ml.min-1.kg-1vs(24.8±4.2)ml.min-1.kg-1,METs max(6.2±1.3)vs(7.1±1.2),最大心率(HR max)(141.6±14.9)次/min vs(156.5±29.1)次/min,RPP max(25.1±4.6)×103vs(28.1±6.7)×103,VO2AT/kg(19.2±3.5)ml.min-1.kg-1vs(21.5±3.7)ml.min-1.kg-1,METs AT 5....     

冠心病患者康复Ⅲ期运动处方的研制及效果观察

目的: 通过对冠心病康复Ⅲ期患者12周运动康复处方的实验和研究，为我国冠心病患者运动康复提供实验支持和参考依据。方法:对23例年龄为61—72岁冠心病患者进行改良Bruce递增负荷实验， 12导联心电监控及测量HR、血压、VO2、VE、RPE、SV、 CO、EF、 FS。结果：患者康复运动后,运动持续时间非常明显的提高，安静时SV及VO2pk明显增高并于Bruce第3级末开始VO2、RPP显著下降。结论：恢复Ⅲ期冠心病患者康复运动的靶心率可在94.3—117.4次/min;安静心率34.9±2.7次/min可以作为HRpk的估算值。     

高血压、高胆固醇和吸烟对心肌梗死后患者运动负荷能力的影响

目的:定性并定量地分析高血压、高胆固醇和吸烟对心肌梗死后(PMI)患者运动时心脏负荷能力的影响。方法:46例未服用β-阻断剂的PMI患者根据其冠心病危险指数(Dundeerank,DR)(由血压、血胆固醇数值和吸烟状况得出)被分成三组:DR<60(1组,14例)、6070(3组,17例),然后在跑台上进行递增负荷实验(改良Bruce方案)。运动中每3min记录一次主观用力感觉和血压,每30s测量一次摄氧量(VO2)和心率,由VO2计算得出代谢当量(METs),并连续监测12导心电图。结果:运动时间、METs与DR之间存在高度正相关(P<0.01)。最大运动能力为7.5METs(运动"低危层")时DR的对应数值为70。在心脏康复早期只有部分患者(39.1%)可达到低危层的METs值。结论:DR与METs之间的高度相关意味着患者运动中的危险层次可以通过血压、血液胆固醇和吸烟状况被预测出来,这将有助于康复专业人员利用METs值为患者设定适宜的运动水平。     

心肺运动试验的临床应用—选择性β1受体阻滞剂对运动耐力的影响

目的 研究选择性β1受体阻滞剂对运动耐力的影响。方法 24蜉用倍他乐克（Metoprolol）的成年男性患者及20例健康男性进行运动试验,同步启示摄氧量（VO2）、二氧化碳产生量（VCO2）、心率（HR）等参数。结果 倍他乐克组最大运动时的摄氧量和心率分别为：VO2max＝（18．96&;#177;3．82）ml/kg.min,HRmax＝（117&;#177;19）beats/min,明显低于对照组VO2max＝（24．71&;#177;5．15）ml/kg.min,HRmax＝（147&;#177;12）beats/min。结论 选择性β1阻滞剂通过抑制运动时心率的增加使运动耐力下降。     

老年人24式简化太极拳能量消耗测定

目的:测定老年人24式简化太极拳的能量消耗范围,探讨其是否符合老年心血管患者的运动处方的要求。方法:采用实时气体采样,不限制太极拳练习的体位,测定老年人的耗氧量(VO2)、代谢当量(METs)、心率(HR)等指标(n=200);根据膝关节弯曲角度分为高位(150°)和低位(120°)两组,再测定其上述指标。结果:不限体位时,平均VO2为644.57±153.6ml/min,达47.90%±10.06%VO2max;平均METs为3.10±0.60,达47.74%±10.15%METsmax;平均HR为101.17±15.52bpm,达67.0%±10.25%HRmax;高位时平均VO2为541.66±96.13ml/min,达40.85%±6.57%VO2max,低位时739.95±134.44ml/min,达54.43%±8.15%VO2max;高位时平均METs为2.63±0.31,达40.86%±7.16%METsmax,低位时3.52±0.47,达54.12%±8.18%METsmax;高位时平均HR96.62±11.57bpm,达63.96%±7.72%HRmax,低位时105.37±17.56bpm,达69.82%±11.52%HRmax。两组间能量消耗差异有显著性(P0.05)。结论:简化24式太极拳运动强度、练习特点符合老年心血管患者运动处方的要求,是可调节的低-中强度的有氧运动。     

冠心病患者PTCA术前后及康复运动后的心肺功能评价

为比较冠心病患者PTCA术或PTCA加支架术前后和康复运动后的心肺功能指标，确定PTCA术或加支架术的急性效果，对15例急性心肌梗塞和不稳定型心绞痛患者于PTCA术或加支架术前后和康复运动训练后进行运动心肺功能评定。结果：PTCA术或加支架术后患者的运动时间和最大运动负荷量明显提高（P＜0．05），运动中的最大心率和心率增值非常显著提高（P＜0．05和0．01），运动诱发的心电图ST段压低显著改善（P＜0．002），最大代谢当量（METs）、每分通气量（VE）和最大氧耗量（VO2max）显著提高（P＜0．002、0．005和0．05）；康复运动训练8～12周后患者的运动时间非常显著延长（P＜0．01），METs、VO2max和VE进一步显著提高（P＜0．05）。提示PTCA术或加支架术配合康复运动训练可显著地提高患者的生活质量。     

12周运动康复程序对急性期后心肌梗死患者身体机能的影响

目的:探讨康复运动对急性期后心肌梗死患者(PMIP)身体机能的影响。方法:101例男性PMIP参加了12周有氧多样化运动康复程序,程序前后通过递增负荷运动实验对其身体机能、运动能力等指标进行了测定分析。结果:受试者在康复训练后血胆固醇由5.9mmol/L降低到5.4mmol/L(P<0.01);对应跑台各级负荷时的摄氧量(VO2)、心率(HR)、心率-血压乘积(RPP)和主观用力感觉(RPE)在康复程序后有显著的下降(P<0.01或P<0.05);峰值HR、峰值%HRmax和峰值RPP分别增长了7.5%、8.5%和11.7%。结论:PMIP参加12周运动康复程序后,有氧工作能力有所增强、心血管机能有所改善。     

基于心肺运动试验的个体化运动康复疗法对老年稳定期慢性阻塞性肺疾病患者的影响

目的 探讨基于心肺运动试验的个体化运动康复疗法对老年稳定期慢性阻塞性肺疾病（COPD）患者的影响。 方法 选取老年稳定期COPD患者120例,按照随机数字表法将其分为试验组和对照组,每组60例。2组患者均给予药物和常规康复治疗,试验组增加基于心肺运动试验制订的个体化运动康复疗法。治疗前、治疗3个月后（治疗后）,采用Borg评分评估2组患者的呼吸困难程度,记录第1秒用力呼气容积（FEV1）、用力肺活量（FVC）、第1秒用力呼气容积与用力肺活量比值（FEV1/FVC）、最大摄氧量（VO2max）、无氧阈（AT）、心率（HR）、心脏指数（CI）,采用6 min步行距离（6MWD）测定患者的最大步行距离,评估康复疗效。 结果 治疗前,2组患者的Borg评分、心肺功能指标、6MWD比较,差异无统计学意义（P＞0.05）。治疗后,2组患者的Borg评分、心肺功能指标、6MWD均较组内治疗前改善（P＜0.05）。试验组治疗后Borg评分［(2.38±0.45)分］、FEV1［(3.65±1.31)%］、FVC［(64.09±12.10)%］、FEV1/FVC［(61.98±11.34)%］、VO2max［(19.62±4.06) ml/kg/min］、AT［(669.25±133.82) ml/min］、HR［(96.52±20.59)次/分］、CI［(3.98±1.17) L/min/m2］、6MWD［(315.25±60.12)m］、总有效率(58.33%)均高于对照组（P＜0.05）。 结论 基于心肺运动试验的个体化运动康复疗法,可以缓解老年稳定期COPD患者的呼吸困难症状,改善心肺功能,提高运动耐力和康复疗效。     

Estimating oxygen consumption from heart rate and heart rate variability without individual calibration

Heart rate (HR) as an estimator of oxygen consumption (VO(2) ) usually requires HR to be individually calibrated in a separate test. This study examined the validity of a new HR - and HR variability-based method (Firstbeat PRO heartbeat analysis software) in the estimation of VO(2) in real-life tasks. The method takes into account the respiration rate determined from HR variability and the differences in the on/off dynamics of HR and VO(2) , and no calibration tests are needed. Ten men and nine women performed 25 tasks representing different types of daily activities. Portable devices were used to measure R-to-R intervals (ECG), VO(2) and respiration rate. In pooled regression analysis, the estimated VO(2) accounted for 87% of the variability in the actual VO(2) , SEE 3·5 ml min(-1) kg(-1) (1 MET). At group level, the method underestimated slightly the measured VO(2) (mean difference - 1·5 ml min(-1) kg(-1) or - 0·4 METs). Some of the values at low exercise intensities were markedly underestimated, but the agreement was better during light and heavy activities. The limits of agreement for the data were from -8·4 to 5·4 ml min(-1) kg(-1) or from -2·4 to 1·5 METs. At individual level, the average deviations of the predicted VO(2) ranged from -1·0 to 0·6 METs and R(2) from 0·77 to 0·94, respectively. The present data indicate that the prediction method may be considered sufficiently accurate to determine the average VO(2) in field use, but it does not allow precise estimation of VO(2) .     

Effect of exercise on perfusion of collateral-dependent myocardium in dogs with chronic coronary artery occlusion.

Since the ability of mature intercoronary collateral channels to increase myocardial blood flow in response to drug-induced coronary vasodilation has been questioned, the present study was undertaken to evaluate the response of coronary collateral circulation to the stress of exercise. Studies were performed at rest and during two levels of treadmill exercise in six dogs a minimum of 6 mo after placement of an Ameroid constrictor on the left circumflex coronary artery. Regional myocardial blood flow was estimated in normally perfused anterior and predominantly collateral-dependent posterior left ventricular wall with left atrial injections of radio-nuclide-labeled microscheres 7-10 mum in diameter. At rest, heart rate was 87 +/- 7 beats/min and mean myocardial blood flow was comparable in control and collateral-dependent regions (0.96 +/- 0.13 and 0.97 +/- 0.14 ml/min-g, respectively). During exercise, heart rates increased to 180 +/- 13 and 228 +/- 14 beats/min and myocardial blood flow (MBF) in the anterior control region increased linearly with heart rate (HR), (MBF = 0.133 HR - 0.202, r = 0.88). MBF to the posterior collateral-dependent region was similarly augmented during exercise (MBF = 0.140 HR - 0.252, r = 0.89), so that the linear correlation between HR and MBF was similar for the control and collateral-dependent regions. In addition, the transmural distribution of MBF was uniform at rest and during exercise in both the anterior control and posterior collateral-dependent regions. Thus, not only could the mature intercoronary collateral vasculature supply adequate flow at rest, but when subjected to the natural stress of exercise, the increase in flow to the predominantly collateral-dependent area was similar to that in the normally perfused area.     

Regional myocardial blood flow during graded treadmill exercise in the dog.

Regional myocardial blood flow was measured in nine dogs at rest and during three levels of treadmill exercise by using left atrial injections of 7-10-mum radioactive microspheres. At rest, heart rate was 76 plus or minus 3 beats/min (mean plus or minus SEM), mean left ventricular myocardial flow was 0.94 plus or minus 0.09 ml/min/g and endocardial flow (endo) exceeded epicardial flow (epi) in all regions (endo/epi equals 1.12-1.33). When treadmill exercise was regulated to increase heart rates from 152 plus or minus 3 to 190 plus or minus 3 to 240 plus or minus 6 beats/min, myocardial blood flow (MBF) to all regions of the left ventricle increased linearly with heart rate (HR) from 1.83 plus or minus 0.11 to 2.75 plus or minus 0.22 to 3.90 plus or minus 0.26 ml/min/g (MBF EQUALs 0.0175 HR - 0.523 PLUS OR MINUS 0.614, R EQUALS 0.87). Exercise abolished the gradient of blood flow favoring the left ventricular endocardium at rest, so that the endo/epi flow ratios were not significantly different from 1.00. Right ventricular flows were consistently less than corresponding left ventricular flows, but showed a similar linear increase with heart rate. Right ventricular endo/epi ratios were not different from 1.00 either at rest or during exercise. Thus, exercise resulted in increased myocardial blood flow to all regions of the left and right ventricles with maintenance of subendocardial flow equal to subepicardial flow.     

Relationship Between Atrioventricular Delay and Oxygen Consumption in Patients with Sick Sinus Syndrome: Relevance to Rate Responsive Pacing

To develop a dromotropic-controlled rate adaptive algorithm for patients with sick sinus syndrome (SSS) and intact AV conduction, 14 pace-maker patients with SSS underwent cardiopulmonary exercise testing (CPX). During exercise, the pace-maker was programmed in an AAT mode without rate adaptation, whereby 3 patients developed supraventricular arrhythmia and 11 patients kept sinus rhythm. Chronotropic incompetence (CI) at heart rate (HR) < 95 beats/min at the anaerobic threshold (AT) was found in five patients. In patients with chronotropic competence (CC), the HR increase was significantly greater than in CI patients (rest: 73.2 +/- 12.6 vs. 64.2 +/- 4.0 beats/min;AT:101.2 +/- 6.2 vs. 82.0 +/- 5.1 beats/min;peak: 135.2 +/- 10.7 vs. 103.2 +/- 10.9 beats/min). There was no significant difference in the AVD between CC and CI patients (rest: 167.7 +/- 38.6 vs. 170.8 +/- 22.5 ms, AT: 156.2 +/- 30.7 vs. 163.6 +/- 21.6 ms, peak: 144.7 +/- 29.0 vs. 152.4 +/- 15.0 ms). The correlation coefficient between HR increase and VO2 was +1.0 and between AVD decrease and VO2 - 1.0 in both groups. An increase in pacing rate from 75 beats/min to 120 beats/min without exercise (overpacing) led to a prolongation of the AV interval of about 30.6 +/- 14.2 ms. Based on this closed loop control with negative feedback, a dromotropic rate adaptive algorithm for patients with SSS and intact AV conduction could be developed.     

具备独立步行能力的脑卒中患者运动所需代谢当量的初步研究

目的：观察具备独立步行能力的脑卒中患者常规运动疗法所需的代谢当量。方法：18例脑卒中患者参加了实验。用K4b2便携式运动心肺功能仪记录受试者在静息坐位、坐站转换、靠墙挺髋、患腿负重、患腿上下、上下楼梯、60m行走和连续完成上述动作过程中的耗氧量，计算上述各项运动所需代谢当量。结果：静息坐位代谢当量值为1.024±0.162METs，各项活动代谢当量值分别为：坐站转换2.854±0.907METs、靠墙挺髋2.079±0.397METs、患腿负重2.159±0.418METs、患腿上下2.247±0.515METs、上下楼梯2.865±0.558METs、60m行走2.590±0.603METs、连续动作为2.999±0.590METs。结论：各项训练代谢当量值的确定为合并心血管疾病的脑卒中患者的安全运动强度提供了依据。     

心脏冠状动脉旁路术后的康复方案

目的　探讨心脏冠状动脉旁路术 (CABG)后的康复特点及方案。方法　对 3 5例CABG术后患者进行以运动疗法为主的综合性康复 ,并对出院后患者实施有指导的家庭康复。结果　术后住院日平均 16.66d ,出院时亚极量运动试验测得的代谢当量 (METs)平均为 3 .64 ( 2 .5～ 5 )。追踪问卷调查及 7例在术后 1、3、6月复查结果表明 :患者功能储量明显提高 ,生活质量得以改善。结论　以运动疗法为主的综合性康复使CABG术后患者早日恢复体能 ,提高手术疗效。指导性的家庭康复可以预防复发 ,改善生活质量 ,提高手术的远期疗效     

Benefits and Limitations of Rate Adaptive Pacing Under Laboratory and Daily Life Conditions in Patients with Minute Ventilation Single Chamber Pacemakers

Rate adaptive pacing has been shown to improve hemodynamic performance and exercise tolerance during acute testing. However, there remain concerns about its benefit in daily life and possible complications incurred by unnecessary pacing. This double-blind crossover study compared the benefit of rate adaptive (SSIR) versus fixed rate (SSI) pacing under laboratory and daily life conditions in 20 rate incompetent patients with minute ventilation single chamber pacemakers (META II). The heart rate (HR) response during three different exercise tests (treadmill, bicycle ergomctry, walking test) was correlated with the Holler findings during daily life in either pacing mode. The maximal HR was significantly higher in the SSIR-mode compared to the SSI-mode, both during laboratory testing (treadmill: 123 ± 15 vs 93 ± 29 beats/min: ergometry: 118 ± 15 vs 89 ± 27 beats/min; walking test: 127 ± 9 vs 95 ± 26 beats/min, all P values < 0.01) as well as during daily life (Holter: 126 ± 13 vs 103 ± 24 beats/min, P < 0.01). On Holter, the average HR (71 ± 14 vs 71 ± 8 beats/min) and the percentage of paced rhythm (54 % vs 62%, SSI- vs SSIR-mode, P = NS) were not different in either mode. However, despite a 30% rate gain in the SSIR-mode, the exercise capacity remained unchanged, and only 38% of patients preferred the SSIR-mode. Minute ventilation pacemakers provide a physiological rate response to exercise. Irrespective of the protocol used, the findings of laboratory testing are comparable to those during daily life. However, patient selection for rate adaptive single chamber pacing should be made with caution, since the objective benefit of restoring normal chronotropy may subjectively be negligible for most patients.     

有氧运动对维持性血液透析患者生理功能、心肺耐力及生活质量的影响

目的探讨12周有氧运动对维持性血液透析(maintenance hemodialysis,MHD)患者生理功能、心肺耐力、健康相关生活质量的影响。方法入选在北京博爱医院就诊的MHD患者14例,所有患者运动前应用Bruce方案平板运动测定最大摄氧量(peak oxygen uptake,VO2peak)、代谢当量(metabolic equivalents,METs)、负荷运动时间等,记录血压和心率。生理功能的评估采用6min步行试验(six-minute walking test,6MWT);心肺耐力的评定采用VO2peak、METs和负荷运动时间;健康相关生活质量的评估采用美国慢性肾脏病临床实践指南(Kidney Disease Outcomes Quality Initiative,K/DOQI)推荐的简易健康相关生活质量评分表(SF-36,the Health-Related Short Form)。有氧运动定义为中等运动强度(50%～80%VO2peak)的平板运动,运动训练在透析间期进行,每周3次,每次30min,共持续12周,运动前15min热身运动,运动结束后5min放松训练,12周运动结束后再次评价上述指标,比较其前后结果有无统计学差异。结果 12周有氧运动后6MWT结果有所改善(Z=-1.132,P=0.241);VO2peak明显提高(Z=-2.226,P=0.028)、负荷运动时间显著延长(Z=-2.701,P=0.007),代谢当量有所提高(Z=-1.632,P=0.103);SF-36评分明显改善(Z=-2.701,P=0.007)。结论 12周有氧运动训练对MHD患者生理功能、心肺耐力、健康相关生活质量有部分改善作用。     

Activity-Sensing, Rate-Responsive Pacing: Improvement in Myocardial Performance with Exercise

A sensor that detects body activity by low frequency sonic impulses has been incorporated in a pacemaker so that body activity may be translated to an increased pacing rate in response to exercise. The pacemaker is designed for patients who may benefit from an increased cardiac output mediated by an increased heart rate during exercise. Following permanent pacemaker implantation, six patients (mean age 69 years) entered a single blind, randomized, crossover trial for comparison of activity-sensing, rate-responsive pacing (A) to fixed rate demand pacing (D). Ventricular function was assessed by gated radionuclide ventriculography at rest and at exercise, while exercise capacity was assessed by treadmill performance, along with measurements of oxygen consumption and carbon dioxide production. Total treadmill duration and maximum oxygen consumption were similar in the two pacing modes (A = 284 +/- 244 s, 13.4 +/- 3.4 ml O2/min/kg; D = 256 +/- 250 s, 11.7 +/- 3.7 ml O2/min/kg). Anaerobic threshold, however, was significantly improved (A = 266 +/- 199 s, (p less than .05), 13.0 +/- 2.2 ml O2/min/kg (p less than .01); D = 231 +/- 208 s, 10.8 +/- 2.3 ml O2/min/kg).(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical Study of a New Activity Sensor for Rate Adaptive Pacing Controlled by Electrical Signals Generated by the Kinetic Energy of a Moving Magnetic Ball

A new rate adaptive pacemaker (Sensorithm) controlled by an activity sensor providing electrical signals induced by a magnetic ball moving freely in an elliptical cavity surrounded by two copper coils, was implanted in ten patients; mean age of 75 years (range 64–89). Six patients had atrioventricular block and four had sinus node disease. In auto-set testing procedure during a 1-minute walk in the corridor, a slope resulting in a maximum rate of 95 beats/min was selected in every patient, and a medium reaction time was programmed. During graded treadmill exercise tests the heart rate increased 63 ± 7 beats/min to 135 ± 6 beats/min in rate adaptive pacing mode (VVIR), and 15 ± 6 beats/min (P < 0.0001) in ventricular pacing mode (VVI). The symptom-limited exercise time was 9.1 ± 1.1 minutes and 8.2 ±1.2 minutes (P = NS), and the exercise distance was 501 ± 95 meters and 428 ± 92 meters (P < 0.05) in VVIR and VVI pacing mode, respectively. The maximum oxygen uptake was 20.6 ± 2.6 mL/kg per minute in VVIR pacing and 18.1 ± 2.1 mL/kg per minute (P < 0.05) in VVI pacing. The delay time until the pacing rate increased 10% of the total rate increase at onset of treadmill exercise was 4.4 ± 0.7 seconds. Assuming a linear relation between metabolic workload and heart rate response from rest to the age predicted maximum heart rate, a deviation of heart rate ranging from 13.5 ± 11.2% to –1.6 ± 5.2% from the expected heart rate at mid-point and endpoint of each quartile of workload was observed during treadmill testing. Conclusions : By using a 1 -minute walk test for selecting an appropriate slope setting, Sensorithm provided a significant and proportional heart rate increase during exercise resulting in an improvement of exercise capacity during VVIR pacing compared to VVI pacing.