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BACKGROUND Aiming to establish an effective tool in new cardiac rehabilitation programs, we investigated the use of a lumbar-type hybrid assistive limb (HAL) in patients with heart failure (HF) who had difficulty in walking at the usual speed of healthy subjects (≈80 m/min).Methods and Results:We randomly assigned 28 HF patients (age, 73.1±13.8 years) to perform a sit-to-stand exercise with or without HAL. The sit-to-stand exercise was repeated as many times as possible as cardiac rehabilitation therapy over a period of 6-10 days. We measured 5 parameters before and after the completion of cardiac rehabilitation: B-type natriuretic peptide, Short Physical Performance Battery (SPPB), 6-min walking distance (6MWD), 30-s chair-stand test (CS-30), and isometric knee extensor muscle strength. The SPPB and 6MWD were significantly improved, and the CS-30 score was somewhat improved, after the exercise therapy in both the HAL and non-HAL groups. The knee extensor muscle strength improved significantly in the HAL group (0.29±0.11 to 0.35±0.11 kgf/kg, P

The lumbar-type Hybrid Assistive Limb (HAL) is expected to expand the possibilities of exercise therapy for severe cardiac patients who have difficulty in moving on their own legs. We investigated whether motion assistance from HAL during squat exercise could effectively reduce the cardiopulmonary burden in healthy subjects. Twelve healthy subjects (33 ± 11 years) performed squat exercise for 3 consecutive minutes at a repetition rate of 20 squats per minute with and without assistance from a lumbar-type HAL. The oxygen uptake (VO2), carbon dioxide output (VCO2), minute ventilation (VE), and the Borg Scale were monitored during exercise. VO2 (930 ± 207 vs 992 ± 169 mL/min, p 0.05) and the Borg Scale rating (12.8 ± 1.1 vs 13.7 ± 0.8, p 0.05) at the end of exercise were significantly lower when HAL was used. When 2 subjects who regularly perform high-intensity exercise for more than 10 h per week were excluded from the analyses, VO2, VCO2, VE, and the Borg Scale were significantly lower when HAL was used. Our results demonstrate that the lumbar-type HAL significantly reduces cardiopulmonary burden during squat exercise in healthy subjects. The effects were especially striking in sedentary subjects. Further studies on cardiac patients are expected to establish a new cardiac rehabilitation program using HAL.

Background Recent Cochrane Systematic Review suggested that the participation in cardiac rehabilitation is associated with approximately 20% lower cardiovascular mortality and morbidity. Exercise therapy is the key component of cardiac rehabilitation programs. In recent years, innovative technologies have been introduced into the field of rehabilitation, and a typical example is the wearable cyborg Hybrid Assistive Limb (HAL). The wearable cyborg HAL provides motion assistance based on detection of bioelectrical signals on the skin surface when muscle forces are generated. The lumbar-type HAL is expected to expand the therapeutic options for severe cardiac patients who have difficulty in performing usual cardiac rehabilitation programs, such as bicycle pedaling or walking. Purpose We aim to compare the efficacy of exercise therapy performed with motion assistance from a lumbar-type HAL versus conventional training (sit-to-stand exercise without HAL) in patients with chronic heart failure. Methods This clinical trial is a randomized, non-blinded, and controlled study. Twenty-eight heart failure patients (73.1±13.8 years) who have difficulty in walking at the usual walking speed of healthy subjects were randomly assigned to 2 groups (HAL group or control group) with a 1:1 allocation ratio and performed sit-to stand exercise either with HAL or without HAL for 5 to 30 minutes once a day, and 6 to 10 days during the study period. The brain natriuretic peptide (BNP), isometric knee extensor strength, standing ability (30-seconds chair-stand test: CS-30), short physical performance battery (SPPB) and 6-minute walking distance (6MWD) were measured before and after the completion of cardiac rehabilitation. Cardiac events such as death, re-hospitalization, myocardial infarction and worsening of angina pectoris and heart failure during 1 year after discharge were evaluated. Results There was no significant difference in the number of days of exercise therapy between the two groups. BNP, SPPB and 6MWD were improved in both groups. In the HAL group, the isometric knee extensor strength (0.29±0.11 vs 0.35±0.11 kgf/kg, p=0.003) significantly improved and CS-30 (5.5±5.1 vs 8.2±5.3, p=0.054) tended to improve. However, in the control group, either the isometric knee extensor strength (0.35±0.11 vs 0.36±0.14 kgf/kg, p=0.424) or CS-30 (6.0±4.3 vs 9.2±6.2, p=0.075) did not significantly change. HAL group showed significantly more improvement in the isometric knee extensor strength than control group (p=0.045). Cardiac events occurred in 20% in the HAL group and 43% in the control group. Conclusion The improvement in isometric knee extensor strength with the assistance from lumbar-type HAL suggests that exercise therapy using this device may be useful in chronic heart failure patients with flail or sarcopenia, a strong poor prognostic factor in these patients. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (JSPS KAKENHI grant number JP17K09485) and funded by the ImPACT Program of the Council for Science, Technology and Innovation (Cabinet Office, Government of Japan) (grant number 2017-PM05-03-01).

Background Exercise-based in-hospital rehabilitation for patients with electrical storm (ventricular tachycardia/ventricular fibrillation, VT/VF) following antiarrhythmic therapy may prevent the deleterious outcomes of prolonged immobility, but the safety and efficacy of this strategy are still uncertain. We retrospectively investigated the rate of electrical storm recurrence in patients receiving rehabilitation. Methods Sixty-seven patients receiving therapy for electrical storm were included in this study. After treatment, patients were divided into rehabilitation (n = 39) and non-rehabilitation (n = 28) groups. Results Incidences of electrical storm recurrence and VT/VF requiring anti-tachycardia pacing or electrical defibrillation did not differ significantly between the rehabilitation and non-rehabilitation groups (13% vs. 21% and 28% vs. 25%, respectively). However, early mobilization initiated ≤2 days after primary therapy was disadvantageous for electrical storm and VT/VF recurrence compared to later mobilization (21% vs. 6% and 34% vs. 19%, respectively). Although the activities of daily living (ADL) at admission were significantly lower in the rehabilitation group, the scores were restored to the level of the non-rehabilitation group at the time of discharge. Univariate analysis revealed that high B-type natriuretic peptide (hazard ratio [HR]: 3.2; 95% confidence interval [CI]: 1.1–11), decreased left ventricular ejection fraction, and elevated E/E′ (HR: 3.4; 95% CI: 1.1–11) were associated with VT/VF recurrence. Conclusions The incidence of electrical storm relapse is substantial following antiarrhythmic therapy, but it is not increased by in-hospital rehabilitation. Although caution is urged for early mobilization, sustaining mobility to resume activity is recommended because ADL levels tend to deteriorate as a result of prolonged bed rest.

HAL, which assists voluntary control of joint motion, has been reported to improve walking function in patients with muscular dystrophy. Aiming to establish an effective tool in new cardiac rehabilitation programs, we investigated the effects of using a lumbar-type HAL in patients with heart failure