Objective: To examined the effects of different training modalities on exercise capacity Vo(2peak)), systolic function, muscular strength and endurance and quality of life in heart failure patients.Design: Randomized controlled trial.Setting: Cardiac rehabilitation centre in Canada.Subjects: Forty-two individuals with heart failure (62 +/- 12 years; New York Heart Association (NYHA) classes I-III).Interventions: Aerobic training (n = 14), combined aerobic and resistance training (n = 15) or usual care (n = 13) three times per week for 12 weeks.Main measures: (1) Vo(2peak) measured by symptom-limited graded exercise test on cycle ergometer; (2) systolic function assessed by two-dimensional echocardiography; (3) muscular strength and muscular endurance measured by one-repetition maximum procedure,; and (4) quality of life assessed by questionnaires.Results: In the intention-to-treat analysis, neither aerobic nor combined aerobic and resistance training significantly improved Vo(2peak), systolic function or quality of life compared with usual care. However, combined aerobic and resistance training significantly improved upper extremity strength (40.7 (14.0)-48.5 (16.0) kg, P < 0.05) and muscular endurance (5.7 (2.7)-11.6 (7.6) reps, P < 0.05) compared with aerobic training or usual care. In compliant participants (exercise adherence 80%), Vo(2peak) increased in the aerobic group (16.9 (6.0)-19.0 (6.8), P = 0.026) and tended to increase in the combined training group (15.9 (5.0)-17.6 (5.6), P = 0.058) compared with usual care. Quality of life was improved in the aerobic group only.Conclusions: Both aerobic and combined aerobic and resistance training are effective interventions to improve Vo(2peak) in compliant heart failure patients. Combined training may be more effective in improving muscle strength and endurance.

Heart transplant recipients (HTR) have impaired pulmonary oxygen uptake (VO2p) kinetics. Exercise training has been shown to improve VO2p kinetics in healthy individuals, however the effect that combined aerobic and strength training has on VO2p kinetics in HTR has not been studied. PURPOSE: This investigation examined the effect of combined aerobic and strength training on phase II VO2p kinetics in HTR. METHODS: Thirty-three clinically stable HTR were randomly assigned to 12 weeks of aerobic and strength training (HTR-T, n = 18; mean ± SEM, age: 57 ± 2years; 14 males, 4 females) or usual care (HTR-UC, n = 15; age: 58 ± 3 years; 14 males, 1 female). Constant work rate exercise was performed from rest to the VO2p at ∼75% of the ventilatory threshold. Aerobic training was completed 5 days/week on a cycle ergometer and treadmill at 60 to 100% VO2peak. Upper and lower extremity strength training (1–2 sets of 10–15 repetitions at 50% one-repetition maximum) was performed 2 days/week. Usual care participants continued with their normal activities of daily living. VO2p kinetics was determined using first-order non-linear regression. Measurements were made prior to randomization at baseline and after the 12-week intervention or usual care period. ANO VA was used for between group comparisons on the delta change (follow-up - baseline) in outcomes and the alpha level was set at p < 0.05. RESULTS: Exercise training was not associated with a significant change in the phase I amplitude response (HTR-T: −0.01 ± 0.04 vs. HTR-UC: −0.07 ± 0.04 L/min), phase II amplitude response (HTR-T: 0.02 ± 0.05 vs. HTR-UC: 0.05 ± 0.03 L/min), phase II time delay (HTR-T: −5 ± 5 vs. HTR-UC: −14 ± 5 seconds), or steady-state VO2 (HTR-T: 0.01 ± 0.06 vs. HTR-UC: −0.01 ± 0.05 L/min). However, the phase II VO2 time constant significantly improved in HTR-T (−14 ± 4 seconds) vs. HTR-UC (−2 ± 3 seconds; p < 0.05). CONCLUSION: Twelve weeks of combined aerobic training is an effective intervention to improve pulmonary oxygen uptake kinetics in HTR. Funded by the Heart and Stroke Foundation of Canada and the Canadian Institutes of Health Research (CIHR) (M.J. Haykowsky). C.R. Tomczak is a CIHR Strategic Training Fellow in TORCH (Tomorrow's Research Cardiovascular Health Professionals) and is supported by the Natural Sciences and Engineering Research Council of Canada.

The effect that pretransplantation heart failure cause has on pulmonary oxygen uptake (VO2p) kinetics and peak aerobic. power (VO2peak) in heart transplant recipients (HTRs) has not been studied. We examined VO2p kinetics and VO2peak in HTRs with previous ischemic heart failure (I-HTRs; n = 16, mean age 64 +/- 6 years) or nonischemic heart failure (NI-HTRs; n = 13, mean age 50 +/- 12 years). HTRs performed an incremental exercise (VO2peak) test and a constant work rate submaximal exercise (VO2P kinetics) test. A monoexponential model was used to determine the phase II VO2p time constant (tau). Phase II VO2p T was slower in I-HTRs (49 +/- 10 seconds) than in NI-HTRs (34 +/- 10 seconds) (p < 0.001). No significant difference was found between I-HTRs and NI-HTRs for VO2peak (19.0 +/- 6.4 vs 23.0 +/- 8.2 ml . kg(-1) min(-1), respectively), change in heart rate from rest to steady-state exercise (11 +/- 8 vs 9 +/- 9 beats. min-1, respectively), or peak exercise heart rate (140 +/- 22 vs 144 +/- 22 beats . min(-1), respectively). In conclusion, the prolonged phase II VO2p tau in I-HTRs compared with NI-HTRs suggests that the magnitude of alteration in VO2p kinetics after heart transplantation may be dependent on previous heart failure cause. (c) 2007 Elsevier Inc. All rights reserved.

Patients with congestive heart failure (CHF) are characterized by low levels of aerobic fitness (peak oxygen consumption, VO2peak) that may be secondary to reductions in oxygen transport capacity and peripheral oxygen extraction (Belardinelli et al., 1995). Near infrared spectroscopy (NIRS) is a valid and reliable non-invasive technique for evaluating localized muscle oxygenation and blood volume during exercise in situ in CHF patients (Watanabe et al., 2005). PURPOSE: To investigative the relationship between VO2peak and selected cardiorespiratory responses and muscle oxygenatioin/blood volume changes in patients with CHF. METHODS: Twelve CHF patients (ischemic/non-ischemic:4/8, age (mean±SD): 63 ±11.5 yrs, VO2peak: 1.19±0.52 L/min, 14.3±5.2 ml/kg/min) gave written informed consent to participate in a step-wise symptom-limited incremental cycle exercise test to voluntary fatigue. Cardiorespiratory variables were recorded using a metabolic measurement cart. Localized muscle oxygenation and blood volume were recorded continuously from the right vastus lateralis using a dual wave NIRS device for 2 mins at rest (baseline) and throughout exercise. The difference between the baseline and the highest values recorded during exercise were used for statistical analysis. RESULTS: Oxygen uptake, heart rate and ventilation rate increased systematically during incremental exercise. In most patients, muscle blood volume increased up to 50% to 60% of VO2peak and then leveled off or decreased until the termination of exercise. Muscle oxygenation decreased (implying greater oxygen extraction) with increasing work rate and leveled off prior to the attainment of VO2peak. In a forward stepwise multiple regression analysis, only the peak exercise oxygen pulse and heart rate were selected into the regression equation to predict VO2peak. These two variables explained 71% and 28% of the variance respectively in VO2peak. The ventilation rate, muscle oxygenation and blood volume changes were not included into the predictive model. CONCUSIONS: The findings on this small sample of CHF patients suggest that VO2peak is determined primarily by the ability of the central circulation to transport oxygen and not by the capacity of the exercising muscles to extract oxygen.

Aim Female cardiac transplant recipients' aerobic capacity is 60% lower than sex and age-predicted values. The effect of exercise training on restoring the impaired aerobic endurance and muscle strength in female cardiac transplant recipients is not known. This study examined the effect that aerobic and strength training have on improving aerobic endurance and muscle strength in female cardiac transplant recipients. Methods 20 female cardiac transplant recipients (51 ± 11 years) participated in this investigation. The subjects performed a baseline six-minute walk test and a leg-press strength test when they were discharged following cardiac transplantation. The subjects then participated in a 12-week exercise program consisting of aerobic and lower extremity strength training. Baseline assessments were repeated following completion of the exercise intervention. Results At baseline, the cardiac transplant recipients' aerobic endurance was 50% lower than age-matched predicted values. The training program resulted in a significant increase in aerobic endurance (pre-training: 322 ± 104 m vs. post-training: 501 ± 99 m, p < 0.05) and leg-press strength (pre-training: 48 ± 16 kg. vs. post-training: 78 ± 27 kg, p < 0.05). Conclusion Aerobic and strength training are effective interventions that can partially restore the impaired aerobic endurance and strength found in female cardiac transplant recipients.

2005 CACR Abstracts: Canadian Association of Cardiac Rehabilitation Association Canadienne de Re´adaptation Cardiaque: 15th Annual Meeting and Symposium October 22 & 23, 2005 Montreal, Quebec