BACKGROUND: There is good evidence that power spectral analysis (PSA) of heart rate variability may provide an insight into the understanding of autonomic disorders. METHODS: We investigated 30 chronic uremic patients who were on periodic bicarbonate hemodialysis by a battery of six cardiovascular autonomic tests (beat-to-beat variations during quiet breathing and deep breathing, heart rate responses to the Valsalva maneuver and standing, blood pressure responses to standing and sustained handgrip) and PSA of heart rate variations. RESULTS: Eleven patients (37%) had an abnormal response to only one parasympathetic test. Twelve patients (40%) had a definite parasympathetic damage, as indicated by at least two abnormal heart rate tests, whereas four (13%) had combined parasympathetic and sympathetic damage. Multivariate analysis of the cardiovascular tests revealed that 19 patients (63%) had moderate-to-severe autonomic neuropathy (AN), and 11 patients exhibited normal autonomic function. Among the symptoms suggestive of autonomic dysfunction, only impotence in males was significantly associated with test-proven AN. The PSA of the heart rate variability demonstrated a good discrimination of low-frequency (LF) and high-frequency (HF) bands (LF, 0.03 to 0.15 Hz; HF, 0.15 to 0.33 Hz) among controls, uremic patients without test-proven AN, and uremic patients with test-proven AN. A significant reduction of the LF value on supine uremic patients without AN suggests that an early sympathetic involvement exists that traditional autonomic tests were unable to detect. CONCLUSIONS: Our study indicates that the current opinion of a major parasympathetic damage in chronic uremic patients on hemodialysis has to be modified in favor of a more widespread autonomic dysfunction involving both the sympathetic and parasympathetic pathways.
BACKGROUND: There is good evidence that power spectral analysis (PSA) of heart rate variability may provide an insight into the understanding of autonomic disorders. METHODS: We investigated 30 chronic uremicpatients who were on periodic bicarbonate hemodialysis by a battery of six cardiovascular autonomic tests (beat-to-beat variations during quiet breathing and deep breathing, heart rate responses to the Valsalva maneuver and standing, blood pressure responses to standing and sustained handgrip) and PSA of heart rate variations. RESULTS: Eleven patients (37%) had an abnormal response to only one parasympathetic test. Twelve patients (40%) had a definite parasympathetic damage, as indicated by at least two abnormal heart rate tests, whereas four (13%) had combined parasympathetic and sympathetic damage. Multivariate analysis of the cardiovascular tests revealed that 19 patients (63%) had moderate-to-severe autonomic neuropathy (AN), and 11 patients exhibited normal autonomic function. Among the symptoms suggestive of autonomic dysfunction, only impotence in males was significantly associated with test-proven AN. The PSA of the heart rate variability demonstrated a good discrimination of low-frequency (LF) and high-frequency (HF) bands (LF, 0.03 to 0.15 Hz; HF, 0.15 to 0.33 Hz) among controls, uremicpatients without test-proven AN, and uremicpatients with test-proven AN. A significant reduction of the LF value on supine uremicpatients without AN suggests that an early sympathetic involvement exists that traditional autonomic tests were unable to detect. CONCLUSIONS: Our study indicates that the current opinion of a major parasympathetic damage in chronic uremicpatients on hemodialysis has to be modified in favor of a more widespread autonomic dysfunction involving both the sympathetic and parasympathetic pathways.
Authors: Maggie Kam Man Ma; Ming Lang Zuo; Desmond Yat Hin Yap; Maggie Ming Yee Mok; Lorraine Pui Yuen Kwan; Gary Chi Wang Chan; David Chung Wah Siu; Tak Mao Chan Journal: J Nephrol Date: 2014-04-23 Impact factor: 3.902
Authors: Preeti Chandra; Robin L Sands; Brenda W Gillespie; Nathan W Levin; Peter Kotanko; Margaret Kiser; Fredric Finkelstein; Alan Hinderliter; Rodica Pop-Busui; Sanjay Rajagopalan; Rajiv Saran Journal: Nephrol Dial Transplant Date: 2011-09-12 Impact factor: 5.992
Authors: Kálmán Tory; Zsuzsanna Süveges; Erzsébet Horváth; Eva Bokor; Péter Sallay; Klára Berta; Attila Szabó; Tivadar Tulassay; György S Reusz Journal: Pediatr Nephrol Date: 2003-09-17 Impact factor: 3.714