Autonomic dysfunction in vasovagal syncope occurs during head-up tilt test: results of heart rate variability analysis.
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
BACKGROUND: Because dipyridamole is used to assess heart rate (HR) variability, we investigated whether a low HR response during dipyridamole single photon emission computed tomography (SPECT) in patients with diabetes indicates the presence of cardiac autonomic neuropathy (CAN). METHODS AND RESULTS: Subjects were 61 non-insulin-dependent diabetes patients without perfusion defects, myocardial infarction, or arrhythmia who underwent thallium 201 SPECT imaging. The control group comprised 28 subjects without diabetes. HR was measured during infusion of dipyridamole at a rate of 0.14 mg/kg/min, and peak-baseline ratios of 1.20 or less were defined as low. CAN severity was classified by standard autonomic function tests as severe (n = 22), mild (n = 19), or none (n = 20). HR ratios were significantly attenuated in patients with diabetes compared with those in control subjects (1.22 +/- 0.12 vs 1.32 +/- 0.12, P <.001). Among the patients with diabetes, HR ratios decreased as CAN severity increased from none (1.32 +/- 0.10) to mild (1.23 +/- 0.12, P <.05) to severe (1.13 +/- 0.08, P <.005). There was good correlation between HR ratio and R-R interval ratio to deep breathing and to Valsalva, and patients with low HR ratios showed an attenuated response to both tests (all P <.001). The sensitivity and specificity of HR ratios in the detection of CAN were 77% and 74% for severe CAN and 63% and 90% for mild-to-severe CAN, respectively. CONCLUSIONS: In patients with diabetes who have normal dipyridamole SPECT results, an attenuated HR response observed during stress indicates a high likelihood of CAN. Further work that assesses these results in diabetes patients with coronary artery disease is warranted.
A cross-sectional study was designed to identify a relationship between the presence of symptoms usually related to nervous system involvement as well as other chronic complications of diabetes with three objectively defined degrees of autonomic neuropathy (AN). Symptoms usually related to peripheral sensitive neuropathy and AN were assessed using a questionnaire applied to 132 diabetics (38 IDDM and 94 NIDDM), 65 without and 67 with AN. AN was classified as follows according to 5 cardiovascular autonomic tests described by Ewing: 1) early involvement-1 abnormal test (N = 27); 2) definite involvement-2 or 3 abnormal tests (N = 26); 3) severe involvement-4 or 5 abnormal tests (N = 14). A statistically significant association was observed between degree of autonomic involvement and the presence of the following symptoms: dizziness on standing, dysphagia, vomiting, diarrhea, fecal incontinence, gustatory sweating, urinary retention, numbness and hyperesthesia of the feet or legs. Constipation and cystitis were not significantly related to cardiovascular AN. Only 3% of the patients without neuropathy and with early involvement had four or more than four of the symptoms. The prevalence of proliferative retinopathy and nephropathy was increased among patients with more severe degrees of AN. For IDDM patients there was a positive correlation between the degree of cardiovascular AN and the duration of diabetes. We conclude that: 1) severe cardiovascular AN is usually related to 4 or more of the evaluated symptoms and those patients usually have the other complications of diabetes; 2) severe AN could be a risk factor or an indicator of the same underlying process that determines the beginning of proliferative retinopathy and/or nephropathy.
BACKGROUND/AIMS: It was previously shown that sertraline hydrochloride treatment improved hemodynamic parameters of patients with dialysis induced hypotension (DIH). The aim of this study was to examine the effect of sertraline on the autonomic functions of patients with DIH. METHODS: Ten patients with DIH, 10 hemodialysis patients without DIH and 10 healthy control subjects were included into the study. All of the patients were treated with sertraline 50 mg per day for 4 weeks. Pre-treatment and post-treatment heart rate variability (HRV) in supine and tilt position was evaluated. In order to evaluate the autonomic response to tilt position, gap values were calculated by subtracting the HRV in supine position from the HRV in tilt position. RESULTS: Analysis of the HRV response to tilt, demonstrated a paradoxical reduction in the indices of sympathetic modulation and sympathovagal balance in the patients with DIH while there was an increase in normalized powers of low frequency components (LFNU) and low frequency to high frequency components ratio (LFP/HFP) in the patients without DIH and control group. The number of therapeutic interventions for restoration of DIH decreased significantly in the sertraline period (p < 0.001). The gap values of the patients with DIH in LFNU (sympathetic modulation) (p < 0.05) and LFP/HFP (sympathovagal balance) increased in the sertraline period (p < 0.01). The decrease in gap value of normalized powers of high frequency components (parasympathetic modulation) was pronounced in the sertraline period in the patients with DIH (p < 0.05). CONCLUSION: The preventive effect of sertraline on DIH might be related to the improvement of regulation of autonomic response to hypovolemia.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The study have been conducted using a tetrapolar impedance plethysmography technique (RA5-01 rheoanalyser). Reliable differences of some amplitude-time rheogram parameters of cerebral hemispheres and shins in hypertensive patients with vegetative dysfunctions manifested somatically and who had suffered from harmful consequences of Chernobyl accident have been established.
FINDINGS: This case involves a 56-year-old man with a 3-year case history, starting with vertigo, cerebellar symptoms, followed by inspiratory stridor, especially during the night, and autonomic failure with recurrent syncopes. Magnetic resonance imaging confirmed the diagnosis of olivopontocerebellar atrophy and tilting table tests with plasma catecholamine measurement revealed an extensive drop of blood pressure with no adequate change in the heart rate or plasma catecholamine, leading to the diagnosis of multiple system atrophy (MSA). In addition, bronchoscopy revealed that the inspiratory stridor was caused by paradoxical movement of the vocal cords (sometimes known as Gerhardt's syndrome). TREATMENT AND COURSE: The patient needed a tracheotomy and treatment of the autonomic symptoms. He could be discharged in better psychic condition, without syncopes or respiratory problems.
Dizziness resulting from inner ear or CNS disease has been well described. However, there is a large number of patients for whom dizziness does not seem to be related to either the ears or the CNS. We postulate an abnormality in the autonomic nervous system of such patients and have used standard tilt testing and Valsalva methods to assess the abnormality. Based on the results of these tests, we can suggest therapeutic options.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.