Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients

• Main Authors: Maria Angela Magalhães de Queiroz Carreira, André Barros Nogueira, Felipe Montes Pena, Marcio Galindo Kiuchi, Ronaldo Campos Rodrigues, Rodrigo da Rocha Rodrigues, Jorge Paulo Strogoff de Matos, Jocemir Ronaldo Lugon
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Cardiologia (SBC) 2015-06-01
• Series: Arquivos Brasileiros de Cardiologia
• Subjects: Sistema Nervoso Simpático / fisiopatologia; Teste de Esforço; Diálise Renal; Mortalidade; Exercício
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0066-782X2015000600009&lng=en&tlng=en

Background: Autonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality. Objective: To 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. Methods: Cross-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. Results: Forty-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. Conclusion: No 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. (Arq Bras Cardiol. 2015; [online]. ahead print, PP.0-0)