An assessment of the partial agonist activity of Ro 31‐1118, flusoxolol and pindolol in man.

McCaffrey, P. M.; Riddell, J. G.; Shanks, R. G.

doi:10.1111/j.1365-2125.1987.tb03215.x

Cited by 20 publications

(9 citation statements)

References 44 publications

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“…It is well known that in humans, the autonomic activity shows a circadian rhythm with an increase in parasympathetic activity during the night and a prevalence of sympathetic activity during the day. Therefore, the sleep period is characterized by a low level of sympathetic dominance, and the parasympathetic influence could reduce the heart rate, which reaches its lowest point after 5–6 hours of sleep (53,54). Thus, it is possible that HRV indices collected at evening/nighttime while sleeping may not be representative of day‐time HRV.…”

Section: Discussionmentioning

confidence: 99%

Obesity is associated with impaired cardiac autonomic modulation in children

Rodríguez-Colón

Bixler

et al. 2011

International Journal of Pediatric Obesity

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Objective To examine the cross-sectional association between measurements of obesity and subclinical impairment of cardiac autonomic modulation (CAM) in a population-based sample of children. Methods Data from 616 grade K-5 children randomly selected from Central Pennsylvania were utilized. Obesity was defined using the International Obesity Task Force (IOTF) age and sex specific cut off criteria and classified as normal weight, overweight, and obese. CAM was measured by heart rate variability (HRV) analysis of beat-to-beat RR intervals, including time domain measures i.e., the standard deviation of all RR intervals (SDNN), the square root of the mean of the sum of squares of differences between adjacent RR intervals (RMSSD), and mean heart rate (HR); and frequency domain measures i.e., high frequency power (HF), low frequency power (LF), and LF/HF ratio. Results The prevalence of obesity and overweight in children was 12.3%, and 16.5%, respectively. Age, race, sex, and sleep disorder breathing (SDB) adjusted means (SE) of SDNN were 98(1.24), 90.2(2.58), and 81.9(3.03) milliseconds (ms) in normal weight, overweight, and obese groups, respectively; and that for (log) HF were 6.83(0.04), 6.56(0.08), and 6.35(0.09) ms2, respectively. Comparing the magnitude of effects from BMI, weight, and height percentiles, and waist circumference on HRV indices revealed that body weight was the strongest correlate of HRV indices. Conclusion Childhood obesity is significantly associated with lower HRV, indicative of sympathetic overflow unopposed by parasympathetic modulation. These findings support the need to target childhood-obesity, before traditional “high risk age” for cardiac events.

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Section: Discussionmentioning

confidence: 99%

Obesity is associated with impaired cardiac autonomic modulation in children

Rodríguez-Colón

Bixler

et al. 2011

International Journal of Pediatric Obesity

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“…The HRV parameters were compared between the two doses of celiprolol alone, and when celiprolol was co-administered with propranolol 160 mg or atenolol 50 rag. The selectivity and dose-dependence of the partial agonist activity of agents acting at the/3a-or #2-adrenoceptor can be assessed from the sleeping heart rate, due to the low level of prevailing sympathetic drive at night [21,22].…”

Section: Methodsmentioning

confidence: 99%

“…The long-term timedomain variable SDNN (representing total power in frequency domain) correlated best with scatterplot length and area (overall variation), while the short-term variables (rmsSD, pNNs0) strongly correlated with the scatterplot width (p90%) suggesting that this measure of variance should prove useful in assessing parasympathetic nervous activity [16]. These studies were undertaken during sleep; due to the low level of prevailing sympathetic drive at night, the agonist or antagonist activity of agents acting at the /31-or 32-adrenoceptor can be assessed from the sleeping heart rate [21,22]. Our study demonstrated that atenolol and propranolol did not increase scatterplot length or width, although this may have been due to the minimal sympathetic drive present during the night.…”

Section: Non-linear Analysis Of Heart Rate Variabil#y During Beta-adrmentioning

confidence: 98%

Heart rate variability effects of an agonist or antagonists of the β-adrenoceptor assessed with scatterplot and sequence analysis

Silke

Riddell

1998

Clinical Autonomic Research

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There is evidence that the processes regulating heart rate variations reflect non-linear complexity and show 'chaotic' determinism. Data analyses using non-linear methods may therefore reveal patterns not apparent with conventional statistical approaches. We have consequently investigated two non-linear methods, the Poincaré plot (scatterplot) and cardiac sequence (quadrant) analysis, and compared these with standard time-domain summary statistics, during a normal volunteer investigation of an agonist and antagonists of the cardiac beta-adrenoceptor. Under double-blind and randomized conditions (Latin square design), 12 normal volunteers received placebo, celiprolol (beta 1- and beta 2-adrenoceptor partial agonist), propranolol (beta 1- and beta 2-adrenoceptor antagonist), atenolol (beta 1-adrenoceptor antagonist) and combinations of these agents. Single oral doses of medication (at weekly intervals) were administered at 22:30 hours with sleeping heart rates recorded overnight. The long (SDNN, SDANN) and short-term (rmsSD) time-domain summary statistics were reduced by celiprolol--effects different from the unchanged or small increases after atenolol and propranolol alone. The Poincaré plot was constructed by plotting each RR interval against the preceding RR interval, but unlike previous descriptions of the method, an automated computer method, with a high level of reproducibility, was employed. Scatterplot length and area were reduced following celiprolol and different from the small increases after propranolol and atenolol. The geometric analysis of the scatterplots allowed width assessment (i.e. dispersion) at fixed RR intervals. Differences between the drugs were confined to the higher percentiles (i.e. 75% and 90% of scatterplot length: low heart rate). The long-term time-domain statistics (SDNN, SDANN) correlated best with scatterplot length and area whereas the short-term heart rate variability (HRV) indices (rmsSD), pNN50) correlated strongly with scatterplot width. Cardiac sequence analysis (differences between three adjacent beats; delta RR vs delta RRn+1) assessed the short-term patterns of cardiac acceleration and deceleration, four patterns are identified: +/+ (a lengthening sequencing), +/- or -/+ (balanced sequences), and finally -/- (a shortening sequence). A running count of events by quadrant, together with the average magnitude of the differences was computed. The beta-adrenoceptor partial agonist celiprolol increased acceleration sequences. The duration of beat-to-beat difference shortened after celiprolol; this contrasted with increased duration of beat-to-beat difference after propranolol and atenolol. These results demonstrated a shift towards sympathetic dominance after the beta-adrenoceptor partial agonist celiprolol contrasting in parasympathetic dominance after the beta-adrenoceptor antagonists propranolol and atenolol. These non-linear methods appear to be valuable tools to investigate HRV in health and in cardiovascular disease and to study the implications of alterations in autonomi...

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“…Previous studies in vivo have evaluated the P, and P2 components of PAA by measuring effects of single doses on resting parameters of heart rate, systolic blood pressure, tremor and forearm blood flow (McCaffrey et al, 1987(McCaffrey et al, ,1988. Such studies have not however, evaluated the effects of dose on the selectivity of PAA in vivo.…”

Section: Introductionmentioning

confidence: 99%