Cardiovascular Autonomic Neuropathy (cardiovascular + autonomic_neuropathy)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Early Detection Of Diminished Baroreflex Sensitivity In Diabetic Patients Without Evidence Of Cardiovascular Autonomic Neuropathy

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2000
D Ziegler
Diabetic cardiovascular autonomic neuropathy (CAN) carries an increased risk of mortality. Decreased baroreflex sensitivity (BRS) has been identified as a predictor of increased mortality following myocardial infarction. We evaluated spontaneous BRS in 39 healthy control subjects (C: age (mean ± SEM): 41.5 ± 1.9 years) and 116 diabetic patients (64% Type 1, 36% Type 2; age: 45.8 ± 1.4 years; diabetes duration: 16.9 ± 1.0 years; HbA1c: 9.2 ± 0.2%) using cross-spectral analysis between systolic blood pressure and heart rate in the low-frequency (LF) and high-frequency (HF) bands as well as time domain (sequence) analysis in the supine and standing positions over 10 min. According to previously suggested definitions based on autonomic function tests (AFTs), 36 patients had definite CAN (CAN+: 3 of 7 indices abnormal), 13 had borderline CAN (CAN[+]: 2 of 7 indices abnormal), and 64 had no evidence of CAN (CAN,: 1 of 7 indices abnormal). Maximum gain in cross-spectral LF band (standing) was significantly reduced in CAN, as compared with C (5.2 ± 0.4 vs. 7.2 ± 0.8 ms/mmHg, p < 0.05). Moreover, maximum gain in cross-spectral HF band was significantly lower in CAN, than in C (supine: 12.0 ± 1.2 vs. 17.9 ± 2.5 ms/mmHg, p < 0.05; standing: 4.9 ± 0.5 vs. 8.7 ± 1.0 ms/mmHg, p < 0.05). The slope of the regression line between defined increases or reductions in systolic blood pressure and R-R intervals was significantly reduced in CAN, compared to C (supine: 10.6 ± 0.7 vs. 14.2 ± 1.6 ms/mmHg, p < 0.05; standing: 5.6 ± 0.4 vs. 8.1 ± 0.7 ms/mmHg, p < 0.05). Similar differences were obtained when comparing the CAN, and CAN[+] groups, the latter showing significantly reduced BRS by both techniques (p < 0.05). In contrast, no such differences were noted when comparing the CAN[+] and CAN+ groups. In conclusion, reduced spontaneous baroreflex sensitivity is an early marker of autonomic dysfunction at a stage when autonomic function tests do not yet indicate the presence of CAN, while cases with borderline CAN show a degree of BRS abnormality that is comparable to the level seen in definite CAN. Prospective studies are needed to evaluate whether reduced BRS is a predictor of mortality in diabetic patients. [source]

Impairment of cerebral autoregulation in diabetic patients with cardiovascular autonomic neuropathy and orthostatic hypotension

DIABETIC MEDICINE, Issue 2 2003
B. N. Mankovsky
Abstract Aims Impaired cerebrovascular reactivity and autoregulation has been previously reported in patients with diabetes mellitus. However, the contribution of cardiovascular diabetic autonomic neuropathy and orthostatic hypotension to the pathogenesis of such disturbances is not known. The purpose of this study was to evaluate cerebral blood flow velocity in response to standing in patients with diabetes and cardiovascular autonomic neuropathy with or without orthostatic hypotension. Methods We studied 27 patients with diabetes,eight had cardiovascular autonomic neuropathy and orthostatic hypotension (age 46.4 ± 13.5 years, diabetes duration 25.0 ± 11.0 years), seven had autonomic neuropathy without hypotension (age 47.3 ± 12.7 years, diabetes duration 26.4 ± 12.1 years), and 12 had no evidence of autonomic neuropathy (age 44.1 ± 13.8 years, diabetes duration 17.1 ± 10.2 years),and 12 control subjects (age 42.6 ± 9.7 years). Flow velocity was recorded in the right middle cerebral artery using transcranial Doppler sonography in the supine position and after active standing. Results Cerebral flow velocity in the supine position was not different between the groups studied. Active standing resulted in a significant drop of mean and diastolic flow velocities in autonomic neuropathy patients with orthostatic hypotension, while there were no such changes in the other groups. The relative changes in mean flow velocity 1 min after standing up were ,22.7 ± 16.25% in patients with neuropathy and orthostatic hypotension, +0.02 ± 9.8% in those with neuropathy without hypotension, ,2.8 ± 14.05% in patients without neuropathy, and ,9.2 ± 15.1% in controls. Conclusions Patients with diabetes and cardiovascular autonomic neuropathy with orthostatic hypotension show instability in cerebral blood flow upon active standing, which suggests impaired cerebral autoregulation. [source]

Early Detection Of Diminished Baroreflex Sensitivity In Diabetic Patients Without Evidence Of Cardiovascular Autonomic Neuropathy

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2000
D Ziegler
Diabetic cardiovascular autonomic neuropathy (CAN) carries an increased risk of mortality. Decreased baroreflex sensitivity (BRS) has been identified as a predictor of increased mortality following myocardial infarction. We evaluated spontaneous BRS in 39 healthy control subjects (C: age (mean ± SEM): 41.5 ± 1.9 years) and 116 diabetic patients (64% Type 1, 36% Type 2; age: 45.8 ± 1.4 years; diabetes duration: 16.9 ± 1.0 years; HbA1c: 9.2 ± 0.2%) using cross-spectral analysis between systolic blood pressure and heart rate in the low-frequency (LF) and high-frequency (HF) bands as well as time domain (sequence) analysis in the supine and standing positions over 10 min. According to previously suggested definitions based on autonomic function tests (AFTs), 36 patients had definite CAN (CAN+: 3 of 7 indices abnormal), 13 had borderline CAN (CAN[+]: 2 of 7 indices abnormal), and 64 had no evidence of CAN (CAN,: 1 of 7 indices abnormal). Maximum gain in cross-spectral LF band (standing) was significantly reduced in CAN, as compared with C (5.2 ± 0.4 vs. 7.2 ± 0.8 ms/mmHg, p < 0.05). Moreover, maximum gain in cross-spectral HF band was significantly lower in CAN, than in C (supine: 12.0 ± 1.2 vs. 17.9 ± 2.5 ms/mmHg, p < 0.05; standing: 4.9 ± 0.5 vs. 8.7 ± 1.0 ms/mmHg, p < 0.05). The slope of the regression line between defined increases or reductions in systolic blood pressure and R-R intervals was significantly reduced in CAN, compared to C (supine: 10.6 ± 0.7 vs. 14.2 ± 1.6 ms/mmHg, p < 0.05; standing: 5.6 ± 0.4 vs. 8.1 ± 0.7 ms/mmHg, p < 0.05). Similar differences were obtained when comparing the CAN, and CAN[+] groups, the latter showing significantly reduced BRS by both techniques (p < 0.05). In contrast, no such differences were noted when comparing the CAN[+] and CAN+ groups. In conclusion, reduced spontaneous baroreflex sensitivity is an early marker of autonomic dysfunction at a stage when autonomic function tests do not yet indicate the presence of CAN, while cases with borderline CAN show a degree of BRS abnormality that is comparable to the level seen in definite CAN. Prospective studies are needed to evaluate whether reduced BRS is a predictor of mortality in diabetic patients. [source]