Spectral analysis of blood pressure and heart rate, catecholamine and neuropeptide Y plasma levels in a new model of neurogenic orthostatic hypotension in dog

1996 ◽  
Vol 6 (2) ◽  
pp. 75-82 ◽  
Author(s):  
P. Verwaerde ◽  
J. -M. Senard ◽  
M. Mazerolles ◽  
M. -A. Tran ◽  
C. Damase-Michel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Spectral Analysis ◽  
Orthostatic Hypotension ◽  
Neuropeptide Y ◽  
Plasma Levels ◽  
Neurogenic Orthostatic Hypotension ◽  
New Model

Abstract P393: Orthostatic Heart Rate-Blood Pressure Relationship Identifies Neurogenic Orthostatic Hypotension

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Alejandro Velasco ◽  
Luis E Okamoto ◽  
Emily M Garland ◽  
Chang Yu ◽  
Italo Biaggioni
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Orthostatic Hypotension ◽  
Roc Analysis ◽  
Valsalva Maneuver ◽  
Characteristic Curve ◽  
Receiver Operator Characteristic Curve ◽  
Neurogenic Orthostatic Hypotension ◽  
Autonomic Reflexes ◽  
Simple Ratio

Background: Neurogenic orthostatic hypotension (nOH) is a chronic disabling condition associated with significant morbidity and mortality. Currently, the diagnosis of nOH relies on impaired autonomic reflexes as determined by testing available only in specialized centers. Our objective was to test the hypothesis that a blunted heart rate (HR) increase in response to a given systolic blood pressure (SBP) fall will correctly diagnose nOH. Methods: We performed a retrospective study of nOH patients (studied in an inpatient environment off medications that can interfere with autonomic function) and control subjects. nOH was diagnosed on the basis of SBP fall ≥20 mmHg on standing associated with a decrease in SBP≥ 20 mmHg during phase 2 of the Valsalva maneuver and absence of phase 4 SBP overshoot. Controls had any SBP fall on standing but intact autonomic reflexes. Receiver operator characteristic curve (ROC) analysis was performed on the ratio of the changes from supine to 3 min standing in HR and SBP (ΔHR/ΔSBP). Results: We studied 171 nOH patients (66±1 years, males 61%, multiple system atrophy 42%, Parkinson disease 14%, pure autonomic failure 32% and undetermined 12%) and 53 controls (51±3 years, males 28%). nOH patients had a greater drop in standing SBP (-63±2 vs. -16±4 mmHg in controls; p<0.01) but a smaller increase in HR (13±1 vs. 18±1 bpm in controls; p<0.01). The ROC analysis at 95% Confidence Interval showed that a ΔHR/ΔSBP ratio <0.445 had a 81% specificity and 79% sensitivity in identifying nOH (AUC=0.86, p<0.01. Figure). Conclusions: Our study suggests that a simple ratio of ΔSBP/ΔHR <0.445 during a posture test in clinic can reliably identify patients with nOH.

The Involvement of Platelets and the Coronary Vasculature in Collagen-Induced Sudden Death in Rabbits

1985 ◽  
Vol 53 (01) ◽  
pp. 070-074 ◽  
Author(s):  
G Mallarkey ◽  
G M Smith
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Platelet Count ◽  
Sudden Death ◽  
Myocardial Ischaemia ◽  
Plasma Levels ◽  
Sodium Citrate ◽  
Plasma Samples ◽  
Calcium Entry Blockers

SummaryThe mechanism of collagen-induced sudden death in rabbits was studied by measuring blood pressure (BP), heart rate, ECG, the continuous platelet count and the plasma levels of thromboxane B2 (TxB2) and 6-keto prostaglandin Fia (6-keto PGF1α). Death was preceded by myocardial ischaemia and a sharp fall in BP which occurred before any fall in platelet count was observed. The calcium entry blockers (CEBs), verapamil, nifedipine and PY 108-068 protected the rabbits from sudden death without any significant effect on the decrease in the platelet count or increase in plasma TxB2 levels. 6-keto PGF1α could not be detected in any plasma samples. Indomethacin and tri-sodium citrate also protected the rabbits but significantly reduced the fall in platelet count and plasma TxB2. In vitro studies on isolated aortae indicated that verapamil non-specifically inhibited vasoconstriction induced by KC1, adrenaline and U46619 (a thromboxane agonist). It is concluded that CEBs physiologically antagonize the vasoconstricting actions of platelet-derived substances and that it is coronary vasoconstriction that is primarily the cause of death.

Power spectral analysis of heart rate and blood pressure variability in anaesthetized dogs

1992 ◽  
Vol 146 (2) ◽  
pp. 155-164 ◽  
Author(s):  
A. E. HEDMAN ◽  
J. E. K. HARTIKAINEN ◽  
K. U. O. TAHVANAINEN ◽  
M. O. K. HAKUMÄKI
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Spectral Analysis ◽  
Blood Pressure Variability ◽  
Power Spectral Analysis ◽  
Power Spectral

Effects of spinal cord transection on sympathetic discharge in decerebrate-unanesthetized cats

1989 ◽  
Vol 257 (6) ◽  
pp. R1506-R1511 ◽  
Author(s):  
L. C. Weaver ◽  
R. D. Stein
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Heart Rate ◽  
Spectral Analysis ◽  
Spinal Cord Transection ◽  
Renal Nerves ◽  
Frequency Range ◽  
Renal Nerve ◽  
Sympathetic Discharge ◽  
Nerve Discharge

Previous experiments in our laboratory have shown that discharge of splenic, mesenteric, and splanchnic nerves is well maintained after spinal cord transection in chloralose-anesthetized cats (8, 9, 11). The primary purpose of this investigation was to determine if maintained sympathetic discharge could be observed after spinal transection in the absence of chloralose anesthesia. In cats anesthetized with alphaxalone-alphadolone, changes in splanchnic discharge, blood pressure, and heart rate caused by decerebration and removal of the forebrain were observed. This procedure decreased blood pressure, increased heart rate, and had no immediate effect on sympathetic discharge or its rhythm (assessed by power density spectral analysis). One hour after decerebration and termination of anesthesia, splanchnic discharge had increased by approximately 36%. Next, effects of spinal cord transection on discharge of splanchnic, mesenteric, and renal nerves were observed in the decerebrate-unanesthetized cats. Splanchnic discharge decreased by 50%, mesenteric nerve discharge was unchanged, and renal nerve discharge decreased by 97%. Therefore, splanchnic nerve discharge was not as well maintained in decerebrate-unanesthetized cats as it had been in chloralose-anesthetized animals, and the remaining splanchnic discharge appeared to affect mesenteric nerves preferentially. Finally, spectral analysis of the splanchnic discharge demonstrated that before cord transection, most of the signal was in the 0- to 6-Hz frequency range, whereas after transection the proportion of signal in this frequency range was significantly reduced and the proportion in higher frequencies (7-25 Hz) was significantly increased. This loss of low-frequency rhythmicity is consistent with findings in our previous studies in chloralose-anesthetized cats.

Standing and Supine Blood Pressure Outcomes Associated With Droxidopa and Midodrine in Patients With Neurogenic Orthostatic Hypotension: A Bayesian Meta-analysis and Mixed Treatment Comparison of Randomized Trials

2018 ◽  
Vol 52 (12) ◽  
pp. 1182-1194 ◽  
Author(s):  
Jack J. Chen ◽  
Yi Han ◽  
Jonathan Tang ◽  
Ivan Portillo ◽  
Robert A. Hauser ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Orthostatic Hypotension ◽  
Fixed Effects ◽  
Randomized Trials ◽  
Meta Analysis ◽  
Mixed Treatment Comparison ◽  
Neurogenic Orthostatic Hypotension ◽  
Supine Hypertension ◽  
Treatment Comparison ◽  
Mixed Treatment

Background: The comparative effects of droxidopa and midodrine on standing systolic blood pressure (sSBP) and risk of supine hypertension in patients with neurogenic orthostatic hypotension (NOH) are unknown. Objective: To perform a Bayesian mixed-treatment comparison meta-analysis of droxidopa and midodrine in the treatment of NOH. Methods: The PubMed, CENTRAL, and EMBASE databases were searched up to November 16, 2016. Study selection consisted of randomized trials comparing droxidopa or midodrine with placebo and reporting on changes in sSBP and supine hypertension events. Data were pooled to perform a comparison among interventions in a Bayesian fixed-effects model using vague priors and Markov chain Monte Carlo simulation with Gibbs sampling, calculating pooled mean changes in sSBP and risk ratios (RRs) for supine hypertension with associated 95% credible intervals (CrIs). Results: Six studies (4 administering droxidopa and 2 administering midodrine) enrolling a total of 783 patients were included for analysis. The mean change from baseline in sSBP was significantly greater for both drugs when compared with placebo (droxidopa 6.2 mm Hg [95% CrI = 2.4-10] and midodrine 17 mm Hg [95% CrI = 11.4-23]). Comparative analysis revealed a significant credible difference between droxidopa and midodrine. The RR for supine hypertension was significantly greater for midodrine, but not droxidopa, when compared with placebo (droxidopa RR = 1.4 [95% CrI = 0.7-2.7] and midodrine RR = 5.1 [95% CrI = 1.6-24]). Conclusion and Relevance: In patients with NOH, both droxidopa and midodrine significantly increase sSBP, the latter to a greater extent. However, midodrine, but not droxidopa, significantly increases risk of supine hypertension.

scholarly journals Power Spectral Analysis of Spontaneous Blood Pressure and Heart Rate Variability in Elderly Hypertensives.

1996 ◽  
Vol 19 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Tadashi Aono ◽  
Takayuki Sato ◽  
Masanori Nishinaga ◽  
Akiko Kawamoto ◽  
Toshio Ozawa
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Spectral Analysis ◽  
Power Spectral Analysis ◽  
Power Spectral ◽  
Elderly Hypertensives
Sign in / Sign up

Export Citation Format

Share Document