Twenty-four-hour pattern of blood pressure and spectral analysis of heart rate variability in diabetic patients with various degrees of autonomic neuropathy. Comparison to standard cardiovascular tests.

We performed four cardiovascular tests of autonomic function (deep breathing, lying to standing, Valsalva manoeuvre, postural hypotension) and simultaneous 24h recordings of blood pressure (BP) and ECG in 35 normotensive diabetic subjects. Autoregressive power spectrum analysis of RR interval variability was applied to 24h ECG recordings to obtain for day and night periods power of low- (0.03-0.

Relationship between the circadian rhythms of blood pressure and sympathovagal balance in diabetic autonomic neuropathy.

In diabetic autonomic neuropathy, abnormal circadian patterns of blood pressure and sympathovagal balance with reduced fall of blood pressure and prevalence of sympathetic activity during the night have been described. To correlate the abnormalities of blood pressure to those of sympathovagal balance, we simultaneously performed 24-h noninvasive monitoring of blood pressure and ECG in 25 diabetic patients (45.6 +/- 13.

Impaired circadian modulation of sympathovagal activity in diabetes. A possible explanation for altered temporal onset of cardiovascular disease.

Background: Diabetic subjects have a high incidence of cardiovascular accidents, with an altered circadian distribution. Abnormalities in the circadian rhythm of autonomic tone may be responsible for this altered temporal onset of cardiovascular disease.

Methods And Results: To assess circadian changes of sympathovagal balance in diabetes, we performed 24-hour power spectral analysis of RR interval fluctuations in 54 diabetic subjects (age, 44 +/- 2 years) with either normal autonomic function or mild to severe autonomic neuropathy and in 54 age-matched control subjects.

[Transient cerebral ischemia and the risk factors].

A retrospective study was carried out in a general medicine ward of 100 male patients suffering from their first transient ischemic attack (TIA) in order to evaluate the incidence of different cerebrovascular risk factors. The results were then compared with those from another group of 100 patients suffering from initial cerebral ischemic softening (CIS) in order to identify a cerebrovascular risk population taking into account clinical similarities and common and divergent features. The study revealed that age is the prime risk factor in the genesis of TIA, followed by arterial hypertension and hypercholesterolemia.

Clinical assessment of respiratory sinus arrhythmia by computerized analysis of RR interval and respiration.

Heart rate variability (HRV) and respiratory sinus arrhythmia (RSA) are often considered as interchangeable terms. However, the application of power spectral analysis to describe spontaneous fluctuations in heart period has clearly shown that RSA is only a part of HRV, and that in specific situations their respective patterns may diverge. In order to quantify the RSA we have used a mathematical method based on combined spectral analysis of respiration and RR interval (cross-correlation function), and evaluated its performance in terms of reproducibility, sensitivity to parasympathetic withdrawal and in clinical evaluation of autonomic function.