Prejuízo na recuperação da frequência cardíaca após exercício físico em pacientes com cirrose hepática

Abstract

Introduction: The decrease in heart rate after ending a physical exercise is used as an indirect measure of cardiac autonomic control, associated to cardiovascular prognosis. As patients with hepatic cirrhosis have resting cardiac autonomic dysfunction, it is possible that these same patients also present this recovery phenomenon after exercising. Objective: To assess heart rate recovery after the 6-minute walk test in patients with liver cirrhosis. Also, correlate the biochemical markers of the cirrhosis group with heart rate recovery in the three minutes evaluated. Methodology: 24 patients with hepatic cirrhosis were analyzed (cirrhotic group, 21 child A and 3 child B) and 24 individuals without liver disease (control group) paired by age (57±10 vs. 53±11 years, p=0,21, respectively) and gender/sex (7 women and 17 men in the cirrhotic group and 13 women and 11 men in the control group, p=0,07). The electrocardiogram was analyzed to exclude patients with any disorders of cardiovascular origin. The physical exercise was carried out via TC6min, in which the individual must walk the longest distance in a 6 minute period. The cardiac frequency was registered (Polar RS800CX) for 10 minutes with the volunteer at rest, along the TC6min and for 3 min in recovery. The TC6min was conducted twice, with a 10-minute interval between attempts. The reported data are regarding the test in which the volunteer covered the greatest distance. The descent of cardiac frequency was calculated by the absolute delta (Δ) between the first three minutes of recovery and the registered peak by the end of the TC6min. Two factor ANOVA and the Student t-test were conducted, considered substantial p≤0,05. Results: The cirrhotic group covered an inferior distance in the TC6min when compared to the control group (435±100 vs. 560±92 m; p=0,01, respectively). In both groups, the cardiac frequency during peak and the three-minute recovery remained significantly higher compared to the resting period (cirrhotic group: Rest=68±12bpm, Peak=100±11bpm, REC1=79±13bpm, REC2=74±13bpm and REC3= 71±13bpm vs. control group: Rest=71±11, Peak=113±20bpm, REC1=85±16bpm, REC2=79±15bpm and REC3=77± 15bpm)(time effect, p<0,01) and behaved in a similar manner in these moments (group effect, p=0,09). However, the cirrhotic group presented an inferior descent of cardiac frequency during the first minute of recovery (Δ= 20±8 vs. 27±10 bpm), the second minute of recovery (Δ = 26±12 vs. 34±13 bpm) and during the third minute of recovery (Δ = 29±12 vs. 35±14 bpm), with the effect of time of p=0,01 and group p=0,05. Moreover, it was observed the positive correlation between the distance covered in the walk test and the values of albumin in the three-minute recovery of cardiac frequency (1st MIN: R=0,50; P=0,01; 2nd MIN: R=0,47;P=0,01;3rd MIN: R=0,43;P=0,03). It was also observed the positive correlation of the delta in the three-minute cardiac frequency recovery and albumin rates (1st MIN: R=-0,48;P=0,01; 2nd MIN: R=- 0,44;P=0,02; 3rd MIN: R=-0,42;P=0,03). Conclusion: Patients with hepatic cirrhosis present an inferior decline in cardiac frequency during recovery after TC6min. Furthermore, the cardiac frequency recovery was associated with biochemical markers of liver function and liver disease.