High-intensity inspiratory protocol increases heart rate variability in myocardial revascularization patients

Abstract

Objective:To evaluate heart rate variability during an inspiratory muscle endurance protocol at three different load levels [30%, 60% and 80% of maximal inspiratory pressure], in patients who had previously undergone coronary artery bypass grafting.Methods:Nineteen late postoperative myocardial revascularization patients participating in a cardiovascular rehabilitation program were studied. Maximal inspiratory pressure maneuvers were performed. An inspiratory muscle endurance protocol at 30%, 60% and 80% of maximal inspiratory pressure was applied for four minutes each, in random order. Heart rate and RR intervals were recorded and heart rate variability was analyzed by time (RMSSD-the mean of the standard deviations for all R-R intervals, and RMSM-root-mean square differences of successive R-R intervals) and frequency domains indices (high and low frequency) in normalized units. ANOVA for repeated measurements was used to compare heart rate variability indices and Student t-test was used to compare the maximal inspiratory pressure and maximal expiratory pressure values.Results:Heart rate increased during performance of maximal respiratory pressures maneuvers, and the maximal inspiratory pressure and maximal expiratory pressure mean values were significantly lower than predicted values (P<0.05). RMSSD increased significantly at 80% in relation to rest and 30% of maximal inspiratory pressure and RMSM decreased at 30% and 60% of maximal inspiratory pressure in relation to rest (P<0.05). Additionally, there was significant and progressive decrease in low frequency and increase in high frequency at 30%, 60% and 80% of maximal inspiratory pressure in relation to the resting condition.Conclusion:These results suggest that respiratory muscle training at high intensities can promote greater parasympathetic activity and it may confer important benefits during a rehabilitation program in post-coronary artery bypass grafting.

Physical Exercise Combined With CPAP in Subjects Who Underwent Surgical Myocardial Revascularization: A Randomized Clinical Trial

“…26 These findings, taken together, may indicate that ventilatory muscle relief, or even ventilatory muscle training, which aims to increase the strength of these muscles, may minimize the effects of intolerance to physical exercise in cardiac surgery patients during the postoperative period, 27 given that this procedure is closely associated with important losses in pulmonary function. 28 Although the 2 protocols presented in this study showed benefits to subjects, the intervention group protocol delivered additional improvements, mainly in the primary outcome variable. This shows that the interventions during the physical therapy sessions have clinical applicability and important functional outcomes that decrease the length of hospital stay, thus resulting in a reduction of the total hospital cost, even for short hospital stays.…”

Effects of inspiratory muscle training on respiratory muscle strength, lung function, functional capacity and cardiac autonomic function in Parkinson's disease: Randomized controlled clinical trial protocol

“…IMT has the function of enabling muscles to perform their functions more easily, increasing strength and endurance, promoting improved inspiratory muscle fatigue, dyspnoea, and ventilatory capacity, and consequently improving quality of life (Aznar‐Lain et al, ; Watsford & Murphy, ). There is evidence in the literature that IMT in different diseases can also improve thoracoabdominal mobility, increase the distance walking in the 6MWT, decrease dyspnoea during physical effort (Basso‐Vanelli et al, ) and improve cardiac autonomic function (Caruso et al, ; Mello et al, ).…”

“…The level of significance will be 5%. The effect size will be calculated using Cohen's d, and the results will be interpreted based on Cohen (1988) (Caruso et al, 2016;Mello et al, 2012).…”

“…There are some studies in the literature evaluating IMT in populations with other neurological diseases, such as ischaemic stroke (Menezes et al, 2016), amyotrophic lateral sclerosis (ALS; Ferreira, Costa, Plentz, Coronel, & Sbruzzi, 2016;Macpherson, Bassile, & Clare, 2016) and multiple sclerosis (MS; Ferreira et al, 2016;Fry, Pfalzer, Chokshi, Wagner, & Jackson, 2007;Klefbeck & Nedjad, 2003), which showed improvement in muscular strength and respiratory function. However, in addition to these, other benefits can be verified in other diseases, such as heart failure (Caruso et al, 2016;Mello et al, 2012) and chronic obstructive pulmonary disease (Basso-Vanelli et al, 2016), in which IMT was able to improve thoracic mobility, increase functional capacity, besides autonomic and peripheral controls, and quality of life.…”

Efficacy of POWERbreathe Medic Plus device on maximal inspiratory pressure, functional capacity and quality of life in coronary artery bypass graft patients: A randomized controlled trial protocol

“…4 Some degree of pulmonary impairment is unavoidable in the immediate postoperative period following CABG. 5 These effects may persist, resulting in 25-30% reductions in lung volume, 6 maximal inspiratory and expiratory pressure (MIP and MEP) relative to expected values), 7 and thoracic mobility. 8 The patient has a sternotomy and is then connected to a cardiorespiratory bypass machine during coronary artery bypass grafting (CABG), the usual treatment for CAD.…”