Is applying the same exercise-based inpatient program to normal and reduced left ventricular function patients the best strategy after coronary surgery? A focus on autonomic cardiac response.

PURPOSE: To assess whether the same exercise-based inpatient program applied to patients with normal and reduced left ventricular function (LVF) evokes a similar cardiac autonomic response after coronary artery bypass graft (CABG). METHOD: Forty-four patients post-CABG, subgrouped according to normal LVF [LVFN: n = 23; left ventricular ejection fraction (LVEF) ≥ 55%] and reduced LVF (LVFR: n = 21; LVEF 35-54%), were included. All initiated the exercise protocol on post-operative day 1 (PO1), following a whole progressive program until discharge. Cardiac autonomic response was assessed by the indices of heart rate variability (HRV) at rest and during exercise (extremity range of motion and ambulation). RESULTS: During ambulation, lower values of HRV indices were found in the LVFR group compared with the LVFN group [standard deviation of all RR (STDRR; 6.1 ± 2.7 versus 8.9 ± 4.7 ms), baseline width of the RR histogram (TINN; 30.6 ± 14.8 versus 45.8 ± 24.9 ms), SD2 (14.8 ± 8.0 versus 21.3 ± 9.0 ms), Shannon entropy (3.6 ± 0.5 versus 3.9 ± 0.4) and correlation dimension (0.08 ± 0.2 versus 0.2 ± 0.2)]. Also, when comparing the ambulation to rest change, lower values were observed in the LVFR group for linear (STDRR, TINN, RR TRI, rMSSD) and non-linear (SD2 and correlation dimension) HRV indices (p < 0.05). On PO1, we observed only intra-group differences between rest and exercise (extremity range of motion), for mean intervals between heart beats and heart rate. CONCLUSION: For patients with LVFN, the same inpatient exercise protocol triggered a more attenuated autonomic response compared with patients with LVFR. These findings have implications as to how exercise should be prescribed according to LVF in the early stages following recovery from CABG. Implications for Rehabilitation Exercise-based inpatient program, performed by post-CABG patients who have normal left ventricular function, triggered a more attenuated cardiac autonomic response compared with patients with reduced left ventricular function. Volume of the inpatient exercises should be prescribed according to the left ventricular function in the early stages following recovery from CABG.

Left-ventricular function and autonomic cardiac adaptations after short-term inpatient cardiac rehabilitation: a prospective clinical trial.

OBJECTIVE: Cardiac rehabilitation is associated with cardiac autonomic and physiological benefits. However, it is unclear whether baseline left ventricular function (LVF) impacts on training-induced cardiac autonomic adaptations. The aim of this study was to assess the cardiac autonomic adaptations in patients with varying left ventricular function profiles undergoing coronary artery bypass grafting and cardiac rehabilitation. DESIGN: Assessor-blinded prospective trial. PATIENTS: Forty-four patients undergoing coronary artery bypass grafting, divided into normal LVFN (≥ 55%, n = 23) or reduced LVFR (35-54%, n = 21) were evaluated. METHOD: Cardiac autonomic function was evaluated by heart rate variability indexes obtained both pre- and post-cardiac rehabilitation. All patients participated in a short-term (approximately 5 days) supervised inpatient physiotherapy program. RESULTS: There were differences in heart rate variability indexes, correlation dimension and SD2 according to time and group (e.g. interaction time (effect of cardiac rehabilitation) vs group (LVFN vs LVFR), p = 0.04). Simple main effects analysis showed that the LVFR group benefited to a greater degree from cardiac rehabilitation compared with the LVFN group. Heart rate variability indexes increased significantly in the former group compared with the latter. CONCLUSION: Among post-coronary artery bypass grafting patients engaged in short-term inpatient rehabilitation, those with reduced left ventricular function are most likely to have better cardiac autonomic adaptations to exercise-based rehabilitation.

Short-term supervised inpatient physiotherapy exercise protocol improves cardiac autonomic function after coronary artery bypass graft surgery--a randomised controlled trial.

OBJECTIVE: Coronary artery bypass grafting (CABG) is accompanied by severe impairment of cardiac autonomous regulation (CAR). This study aimed to determine whether a short-term physiotherapy exercise protocol post-CABG, during inpatient cardiac rehabilitation (CR), might improve CAR. DESIGN: Seventy-four patients eligible for CABG were recruited and randomised into physiotherapy exercise group (EG) or physiotherapy usual care group (UCG). EG patients underwent a short-term supervised inpatient physiotherapy exercise protocol consisting of an early mobilisation with progressive exercises plus usual care (respiratory exercises). UCG only received respiratory exercises. Forty-seven patients (24 EG and 23 UGC) completed the study. Outcome measures of CAR included linear and non-linear measures of heart rate variability (HRV) assessed before discharge. RESULTS: By hospital discharge, EG presented significantly higher parasympathetic HRV values [rMSSD, high frequency (HF), SD1)], global power (STD RR, SD2), non-linear HRV indexes [detrended fluctuation analysis (DFA)alpha1, DFAalpha2, approximate entropy (ApEn)] and mean RR compared to UCG (p<0.05). Conversely, higher values of mean HR, low frequency (LF) (sympathetic activity) and the LF/HF (global sympatho-vagal balance) were found in the UCG. CONCLUSIONS: A short-term supervised physiotherapy exercise protocol during inpatient CR improves CAR at the time of discharge. Thus, exercise-based inpatient CR might be an effective non-pharmacological tool to improve autonomic cardiac tone in patient's post-CABG.

Efeitos fisiológicos da fisioterapia respiratória convencional associada à aplicação de BiPAP no pós-operatório de cirurgia cardíaca / Physiological effects of the conventional respiratory physical therapy associated to BiPAP in post cardiac surgery

O objetivo deste estudo foi avaliar as alterações da função pulmonar pela Força Muscular Respiratória (FMR-PImax e PEmax), Capacidade Vital (CV), Freqüência Respiratória (FR) e Oxigenação (SpO2) do pré-operatório ao 1º pós-operatório (PO) e deste à pré-alta; e verificar a eficácia da Fisioterapia Respiratória Convencional (FRC) associada à Ventilação não-invasiva (BiPAP) no PO de cirurgia cardíaca. Incluiu-se 27 pacientes, 12 tratados com FRC associada à BiPAP (Grupo1-G1) e 15 com FRC (Grupo2- G2), com avaliação das variáveis citadas no pré-operatório, 1ºPO, 3ºPO e pré-alta. Para a análise utilizou-se Friedman ANOVA e Mann-Whitney (p ≤ 0,05). Quanto a FMR, apenas G1 aumentou significativamente do 1ºPO para pré-alta, e os valores de PImax apresentaram-se significativamente maiores que G2. Em ambos os grupos, a CV aumentou significativamente do 1º para o 3ºPO, mas apenas G1 mostrou valores da pré-alta próximos ao pré-operatório. A oxigenação aumentou do 3ºPO à pré-alta para ambos, mas apenas o G1 aproximou-se dos valores do pré-operatório. Quanto à FR, apenas o G1 reduziu significativamente no PO. A FRC associada à BiPAP mostrou-se mais eficiente do que a FRC isolada, no aumento da FMR, CV e oxigenação, e na reversão da FR, apesar dos valores não terem sido recuperados completamente até a pré-alta.

The aim of this study was to evaluate the pulmonary function alterations by the Respiratory Muscular Force (RMF- MIP and MEP), Vital Capacity (VC), Breathing Frequency (BF) and Oxigenation (SpO2) from the Pre-operation to the 1st post-operation (PO) and from that one to the pre-discharge; and to verify the efficiency of the Conventional Respiratory Physical Therapy (CRP) associated to the Non-invasive ventilation (BiPAP) in the cardiac surgery PO. 27 patients were included; 12 of them were treated with FRC associated to the BiPAP (Group 1-G1) and 15 with FRC (Group 2-G2). These patients were evaluated in the pre-operation ,1st PO, 3rd PO and pre-discharge as for the mentioned variables. To the analysis were used Friedman ANOVA and Mann-Whitney (p ≤ 0,05). As for the RMF, only G1 increased significantly from the first PO to the pre-discharge, and the values of MIP were significantly bigger than G2. In both groups, the VC increased significantly from the 1st to the 3rd PO, but only G1 presented pre-discharge values near to the pre-operation. The oxigenation increased from the 3rd PO to the pre-discharge for both, but only the G1 came near to the preoperation values. As for RF, only the G1 decreased significantly in the PO. In conclusion, the CRF associated to the BiPAP seemed be more efficient than the isolated CRF, in the RMF increasing, VC and oxigenation, and in the RF reversion, despite of the values have not been completely recuperated until the pre-discharge.

The influences of positive end expiratory pressure (PEEP) associated with physiotherapy intervention in phase I cardiac rehabilitation.

PURPOSE: To evaluate the effects of positive end expiratory pressure and physiotherapy intervention during Phase I of cardiac rehabilitation on the behavior of pulmonary function and inspiratory muscle strength in postoperative cardiac surgery. METHODS: A prospective randomized study, in which 24 patients were divided in 2 groups: a group that performed respiratory exercises with positive airway expiratory pressure associated with physiotherapy intervention (GEP, n = 8) and a group that received only the physiotherapy intervention (GPI, n = 16). Pulmonary function was evaluated by spirometry on the preoperative and on the fifth postoperative days; inspiratory muscle strength was measured by maximal inspiratory pressure on the same days. RESULTS: Spirometric variables were significantly reduced from the preoperative to the fifth postoperative day for the GPI, while the GEP had a significant reduction only for vital capacity (P < .05). When the treatments were compared, smaller values were observed in the GPI for peak flow on the fifth postoperative day. Significant reductions of maximal inspiratory pressure from preoperative to the first postoperative day were found in both groups. However, the reduction in maximal inspiratory pressure from the preoperative to the fifth postoperative day was significant only in the GPI (P < .05). CONCLUSIONS: These data suggest that cardiac surgery produces a reduction in inspiratory muscle strength, pulmonary volume, and flow. The association of positive expiratory pressure with physiotherapy intervention was more efficient in minimizing these changes, in comparison to the physiotherapy intervention alone. However, in both groups, the pulmonary volumes were not completely reestablished by the fifth postoperative day, and it was necessary to continue the treatment after hospital convalescence.

The influences of positive end expiratory pressure (PEEP) associated with physiotherapy intervention in phase I cardiac rehabilitation

OBJETIVO: Avaliar os efeitos da pressão positiva expiratória final e da intervenção fisioterápica na fase I da reabilitação cardiovascular sobre o comportamento da função pulmonar e da força muscular inspiratória e sobre o pós-operatório de cirurgia cardíaca. MÉTODO: Estudo prospectivo, randomizado, com 24 pacientes, separados em 2 grupos: GEP (n=8), que realizaram exercícios respiratórios com pressão positiva expiratória nas vias aéreas associados à intervenção fisioterápica; e GFI (n=16), que realizaram somente a intervenção fisioterápica. A função pulmonar foi avaliada pela espirometria no pré e 5º dia pós-operatório; a força muscular inspiratória pela pressão inspiratória máxima no pré, 1º e 5º dias pós-operatório. RESULTADOS: As variáveis espirométricas mostraram reduções significativas do pré para o 5º dia pós-operatório no GFI, porém no GEP, observou-se redução apenas para capacidade vital (p<0,05). Com relação às diferenças entre os tratamentos, foram observados menores valores no GFI para o pico de fluxo no 5º dia pós-operatório. Foram observadas reduções significativas da pressão inspiratória máxima do pré para 1º dia pós-operatório em ambos os grupos. A pressão inspiratória máxima mostrou reduções significativas da situação pré para o 5º pós-operatório somente no GFI (p<0,05). CONCLUSÕES: Estes dados sugerem que a cirurgia cardíaca produz reduções da força muscular inspiratória, dos volumes e fluxos pulmonares e que a pressão positiva associada à intervenção fisioterápica foi mais eficiente em minimizar essas alterações do que quando a fisioterapia foi realizada de forma isolada. Entretanto, os volumes pulmo nares não foram completamente restabelecidos até o 5º dia pós-operatório em ambos os grupos, sendo necessária a continuidade dos tratamentos após a convalescença hospitalar.