Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients

Abstract

BackgroundAutonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality.ObjectiveTo correlate heart rate variability (HRV) during exercise treadmill test (ETT) with the values obtained when measuring functional aerobic impairment (FAI) in HD patients and controls.MethodsCross-sectional study involving HD patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, 24-hour Holter, and ETT were performed. A symptom-limited ramp treadmill protocol with active recovery was employed. Heart rate variability was evaluated in time domain at exercise and recovery periods.ResultsForty-one HD patients and 41 controls concluded the study. HD patients had higher FAI and lower HRV than controls (p<0.001 for both). A correlation was found between exercise HRV (SDNN) and FAI in both groups. This association was independent of age, sex, smoking, body mass index, diabetes, and clonidine or beta-blocker use, but not of hemoglobin levels.ConclusionNo association was found between FAI and HRV on 24-hour Holter or at the recovery period of ETT. Of note, exercise HRV was inversely correlated with FAI in HD patients and controls.

<p>Is aerobic exercise training during hemodialysis a reliable intervention for autonomic dysfunction in individuals with chronic kidney disease? A prospective longitudinal clinical trial</p>

“…Unregulated ANS is present in hemodialysis patients because it directly targets several vital organs, and can even lead to death in cardiac compromise 8,9. One of the main causes of ANS imbalance in renal patients is related to cardiovascular problems 8,9,12. HRV is greatly impaired in its normal functioning when it is related to cardiac arrhythmias associated with these patients 8,9,12.…”

“…Reduced HRV is an increased risk of death in several populations, but its prognostic value in patients with hemodialysis remains uncertain 9. Literature has investigated the existing relationship between HRV in patients carriers of CKD who undergo hemodialysis, and observed that high mortality is related to an erroneous functioning of cardiac autonomic regulation 12…”

Evaluation of the effects of aerobic training during hemodialysis on autonomic heart rate modulation in patients with chronic renal disease

“…[7,8] Dysfunction of the ANS has been related to cardiovascular events in patients with CRD. [7–9] Several studies have shown the relationship between HRV reduction and the development of complex arrhythmias in these patients. [7–9] Generally, in the most advanced stage of this pathology, there are changes that are noticed in almost all systems of the body: nervous, cardiovascular, respiratory, musculoskeletal, immunologic, and endocrine/metabolic.…”

“…[7–9] Generally, in the most advanced stage of this pathology, there are changes that are noticed in almost all systems of the body: nervous, cardiovascular, respiratory, musculoskeletal, immunologic, and endocrine/metabolic. [7–9]…”

“…[7,8] Cardiac autonomic dysregulation, shown by a reduced HRV, contributes to the high mortality observed in patients with CRD undergoing hemodialysis. [9]…”