The effects of atropine on respiratory sinus arrhythmia in asthma.
Heart rate is rhythmically related to respiratory rate, in a phenomenon known as respiratory sinus arrhythmia (RSA). Amplitude of RSA has been found to be an accurate noninvasive measure of vagal tone in the normal population. The purpose of this study was to examine the relationship between RSA and cardiac vagal tone among asthmatics, a group which has been described as having elevated RSA. This was accomplished by examining the effects of atropine on RSA in asthmatics, and comparing the results to those obtained elsewhere among normal subjects. Atropine at a dose of 1 mg/75 kg body weight was administered to 18 asthmatics, and produced decreases in RSA, equivalent to those previously found among normal subjects. The results suggest that the relationship between cardiac vagal tone and RSA is unaffected by the presence of asthma.
Lehrer
P M
PM
UMDNJ-Robert Wood Johnson Medical School, Piscataway 08854.
Hochron
S M
SM
Rausch
L
L
Carr
R
R
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D001285:Atropine / Q000494:pharmacology*; D004311:Double-Blind Method; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D005540:Forced Expiratory Flow Rates / Q000187:drug effects; D005541:Forced Expiratory Volume / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D012119:Respiration / Q000502:physiology; D015656:Respiratory Mechanics / Q000187:drug effects*; D014630:Vagus Nerve / Q000187:drug effects*; D014797:Vital Capacity / Q000187:drug effects
D001285:Atropine