O treinamento muscular inspiratório não altera a arritmia sinusal respiratória de pacientes com infarto agudo do miocárdio
Abstract
Introduction: Respiratory sinus arrhythmia (RSA) has been used for assessment the cardiac modulation autonomic and measured by ratio expiration/inspiratory (E/I) and inspiration/expiration heart rate variation (∆IE). The RSA is lower in patients with acute myocardial infarction. Objective: To evaluate the effect of inspiratory muscle training (IMT) on the RSA magnitude and maximal inspiratory pressure (PImax) in patients with AMI after 6 days of physiotherapeutic intervention during hospitalized period. Methodology: Thirty three patients were divided in two groups: 19 patients of treatment group (TG) (14 males, 5 females, aged 50±9 years) who underwent the cardiovascular physiotherapy and 14 patients of control group (CG) (11 males, 3 females, aged 52±11 years) without physiotherapy. The intervals RR of electrocardiogram were obtained by Polar S810i during the RSA test on the 1st and 6th days. It was used to calculate the heart rate variability in the time (TD) and in the frequency domain and the RSA index. The PImax was obtained by manovacuometer on the 2nd and 6th days. The IMT (3x, 10 forced inspiration, 40% PImax, for 3 seconds each) was done from the 2nd to 6th days. Two-way ANOVA, Paired-t Test, Chi-square test and Pearson s correlation (p<0.05) were used. Results: In the TD, the TG showed higher values than the CG for the SDNN (1st day 58±37 and 33±23ms; 6th day 49±20 and 32±17ms, respectively) and for the RMSSD (1st day 40±32 e 21±18 ms; 6th day 33±18 and 22±14ms, respectively). The ∆IE decreased significantly for the TG (12,8±7,5 to 9,9±4,8 bpm) and for the CG (10,8±5,3 to7,5±3,4 bpm). For the TG, the PImax increased (p<0,05) from 78±25 to 101±25. Conclusion: The IMT increased the PImax, although it did not modify the ASR magnitude in patients with acute myocardial infarction.