Detection of autonomic dysfunction in hemodialysis patients using the exercise treadmill test: the role of the chronotropic index, heart rate recovery, and R-R variability

PLoS One. 2015 Jun 4;10(6):e0128123. doi: 10.1371/journal.pone.0128123. eCollection 2015.

Abstract

Objective: To evaluate the ability of different parameters of exercise treadmill test to detect autonomic dysfunction in hemodialysis patients.

Methods: Cross-sectional study involving hemodialysis patients and a control group. Clinical examination, blood sampling, echocardiogram, 24-hour Holter, and exercise treadmill test were performed. A ramp treadmill protocol symptom-limited with active recovery was employed.

Results: Forty-one hemodialysis patients and 41 controls concluded the study. There was significant difference between hemodialysis patients and controls in autonomic function parameters in 24h-Holter and exercise treadmill test. Probability of having autonomic dysfunction in hemodialysis patients compared to controls was 29.7 at the exercise treadmill test and 13.0 in the 24-hour Holter. Chronotropic index, heart rate recovery at the 1st min, and SDNN at exercise were used to develop an autonomic dysfunction score to grade autonomic dysfunction, in which, 83% of hemodialysis patients reached a scoring ≥2 in contrast to 20% of controls. Hemodialysis was independently associated with either altered chronotropic index or autonomic dysfunction scoring ≥2 in every tested model (OR=50.1, P=0.003; and OR=270.9, P=0.002, respectively, model 5).

Conclusion: The exercise treadmill test was feasible and useful to diagnose of the autonomic dysfunction in hemodialysis patients. Chronotropic index and autonomic dysfunction scoring ≥2 were the most effective parameters to differentiate between hemodialysis patients and controls suggesting that these variables portrays the best ability to detect autonomic dysfunction in this setting.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autonomic Nervous System Diseases / physiopathology*
  • Echocardiography*
  • Exercise Test*
  • Female
  • Heart Rate / physiology*
  • Humans
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Odds Ratio
  • Renal Dialysis*

Grants and funding

This research was all supported by Fundação de Apoio à Pesquisa do Estado do Rio de Janeiro (FAPERJ) in doctoral program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.