title: Persistent sympathoexcitation long after submaximal exercise in subjects with and without coronary artery disease.
abstract: There is an increased risk of cardiac events after exercise, which may, in part, be mediated by the sympathoexcitation that accompanies exercise. The duration and extent of this sympathoexcitation following moderate exercise is unknown, particularly in those with coronary artery disease (CAD). Twenty control subjects (mean age, 51 years) and 89 subjects with CAD (mean age, 58 years) underwent two 16-min bicycle exercise sessions followed by 30-45 min of recovery. Session 1 was performed under physiological conditions to peak workloads of 50-100 W. In session 2, parasympathetic blockade with atropine (0.04 mg/kg) was achieved at end exercise at the same workload as session 1. RR interval was continually recorded, and plasma catecholamines were measured at rest and selected times during exercise and recovery. Parasympathetic effect, measured as the difference in RR interval with and without atropine, did not differ between controls and CAD subjects in recovery. At 30 and 45 min of recovery, RR intervals were 12% and 9%, respectively, shorter than at rest. At 30 and 45 min of recovery, plasma norepinephrine levels were 15% and 12%, respectively, higher than at rest. A brief period of moderate exercise is associated with a prolonged period of sympathoexcitation extending >45 min into recovery and is quantitatively similar among control subjects and subjects with CAD, with or without left ventricular dysfunction. Parasympathetic reactivation occurs early after exercise and is also surprisingly quantitatively similar in controls and subjects with CAD. The role of these autonomic changes in precipitating cardiac events requires further evaluation.
authors.affiliation: Division of Cardiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
authors.forename: Norman C
authors.initials: NC
authors.lastname: Wang
authors.forename: Alexandru
authors.initials: A
authors.lastname: Chicos
authors.forename: Smriti
authors.initials: S
authors.lastname: Banthia
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Bergner
authors.forename: Marc K
authors.initials: MK
authors.lastname: Lahiri
authors.forename: Jason
authors.initials: J
authors.lastname: Ng
authors.forename: Haris
authors.initials: H
authors.lastname: Subacius
authors.forename: Alan H
authors.initials: AH
authors.lastname: Kadish
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Goldberger
mesh_terms: D000704:Analysis of Variance; D001285:Atropine / Q000008:administration & dosage; D016022:Case-Control Studies; D002395:Catecholamines / Q000097:blood; D016009:Chi-Square Distribution; D003324:Coronary Artery Disease / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D004562:Electrocardiography; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D008875:Middle Aged; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000503:physiopathology; D010276:Parasympatholytics / Q000008:administration & dosage; D020127:Recovery of Function; D018570:Risk Assessment; D012307:Risk Factors; D013318:Stroke Volume; D013564:Sympathetic Nervous System / Q000378:metabolism / Q000503:physiopathology*; D013997:Time Factors; D016277:Ventricular Function, Left
chemical_list: D002395:Catecholamines; D010276:Parasympatholytics; D001285:Atropine