Evaluation of cardiovascular autonomic function tests in dialysis patients

Area of Science:

• Nephrology
• Cardiology
• Autonomic Neuroscience

Background:

• Autonomic dysfunction is a common complication in patients with chronic kidney disease.
• Cardiovascular autonomic neuropathy can lead to significant morbidity and mortality in dialysis patients.

Purpose of the Study:

• To investigate autonomic function in patients undergoing hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD).
• To compare autonomic function between dialysis modalities and healthy controls.
• To assess exercise tolerance in dialysis patients.

Main Methods:

• Noninvasive cardiovascular reflex tests were employed, including heart rate response to standing, Valsalva maneuver, deep breathing, and diving.
• Blood pressure responses to standing, cold pressor test, and sustained handgrip were measured.
• Master 2-step exercise test was performed in HD patients and controls.

Main Results:

• Hemodialysis patients exhibited significantly reduced R-R interval 30:15 ratio, Valsalva ratio, and heart rate change during diving compared to controls.
• CAPD patients also showed significantly lower 30:15 and Valsalva ratios than controls.
• Hemodialysis patients demonstrated a higher rate pressure product during exercise, indicating reduced exercise tolerance.

Conclusions:

• Dialysis patients, both HD and CAPD, display significant abnormalities in cardiovascular autonomic function tests.
• Parasympathetic function appears particularly impaired in these patient groups.
• Exercise intolerance is a notable finding in patients undergoing dialysis.