PubMed · 7220100
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
G N Kryzhanovskiĭ. [Pathological systems].. https://pubmed.ncbi.nlm.nih.gov/7220100/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Autonomic dysfunction seems to be involved in the progression and prognosis of congestive heart failure. Measurement of heart rate variability (HRV) provides a noninvasive method to obtain reliable and reproducible information on autonomic modulation of heart rate, but there is a difficulty in using HRV as a quantitative estimate of autonomic dysfunction in heart failure. This study was aimed at testing the hypothesis that abnormal modulation of heart rate assessed by power spectrum analysis may be present also in asymptomatic patients with left ventricular dysfunction and progress in patients with overt symptoms of congestive heart failure. HRV was measured in three groups of subjects: Group 1: 30 patients with chronic heart failure; Group 2: 21 patients with asymptomatic left ventricular dysfunction; and Group 3: 25 healthy volunteers as control group. HRV was evaluated by autoregressive spectral analysis with 600-beat ECG samples, while subjects were quietly recumbent (BSI), in conditions of controlled breathing (15 acts/min) (RSC) and passive orthostatism after tilting (80 degrees) (TLT). Patients in group 1 showed a reduction in the standard deviation of the R-R intervals (SDRR) (p<0.0003) and in the low frequency component (LF) (p<0.0001) compared to normal subjects. Low frequency component was not detectable in 11 patients of group I (p<0.0008). On RSC and TLT, group 1 failed to show any modification in the low frequency and high frequency components (HF) under any stimulation. Group 2 showed no modification at baseline evaluation, no increase in the high frequency component on RSC and in LF during TLT compared to controls (p<0.01 and p<0.0001 respectively). At baseline, group 1 had a lower SDRR (p<0.03) and LF (p<0.0001) vs. group 2, whereas during stimulation the two groups exhibited the same behaviour. In conclusion, reduced heart rate variability is specific for both asymptomatic and symptomatic post-ischemic left ventricular dysfunction. Our results suggest that frequency domain analysis of heart rate variability during a stimulation test allows a more accurate definition of the degree of autonomic control of heart rate.
To investigate the usefulness of the Composite Autonomic Scoring Scale (CASS) as an indication for autonomic dysfunction with Guillain-Barré syndrome, we quantitated autonomic deficits on follow-up using CASS in a patient with Guillain-Barré syndrome who did not have any autonomic symptoms and had good clinical recovery. Using the CASS we found the patient to have mild autonomic dysfunction but with a period of recovery. The scale showed that adrenergic deficits improved quickly, sudomotor deficits recovered moderately and cardiovagal deficits did not improve. These results suggested that the patient with Guillain-Barré syndrome might have dysautonomia although she did not have any autonomic symptoms. Results also suggest that there might be difference on the degree of improvement among adrenergic, sudomotor and cardiovagal deficits in Guillain-Barré syndrome. The CASS may be a sensitive tool for the detection of autonomic dysfunction in Guillain-Barre syndrome.
The autonomic nervous system is abnormal in patients with advanced Chagas' heart disease. Most researchers consider these autonomic abnormalities as primary, specific and irreversible. However, when and why these abnormalities appear in the natural history of Chagas' disease, is still the subject of intense controversy. Recent morphological and functional studies strongly suggest that the sympathetic and the parasympathetic abnormalities are preceded by myocardial damage and left ventricular dysfunction. Moreover, chagasic patients with cardiac failure benefit from drugs which antagonize neurohumoral activation. Consequently, the abnormalities of the autonomic nervous system of chagasic patients are very likely secondary and partially reversible.