Electrophysiologic and electroanatomic changes in the human atrium associated with age.
OBJECTIVE
The purpose of this study was to characterize the pattern of atrial remodeling seen with human aging.


BACKGROUND
Atrial fibrillation (AF) occurs in 3% to 4% of the population over 65 years of age. It is associated with thromboembolic complications, worsening heart failure, and increased mortality, yet the electrical and structural remodeling that occurs with human aging remains unknown.


METHODS
Thirteen patients (66.4 +/- 1.7 years) > or =60 years (group A), 13 patients (50 +/- 2.1 years) age 31 to 59 years (group B), and 15 patients (24.7 +/- 1.0 years) < or =30 years (group C) underwent conventional electrophysiologic studies and electroanatomic mapping. We measured atrial refractoriness (ERP) at the distal coronary sinus (CS); low and high lateral right atrium (LRA) and the high septal right atrium at 600, 500, and 400 ms; maximum corrected sinus node recovery time (CSNRT); P-wave duration (PWD); conduction time (CT) along the CS and LRA; and discrete double potentials (DP) along the crista.


RESULTS
Aging was associated with an increase in atrial ERP, prolonged CT along the CS, increased PWD and CSNRT. There was no significant change in dispersion of refractoriness or rate adaptation. Electroanatomic mapping revealed diffuse areas of low voltage with regional conduction slowing. Both techniques demonstrated a greater number of DPs and fractionated signals along the crista terminalis with aging.


CONCLUSIONS
Aging is associated with regional conduction slowing, anatomically determined conduction delay at the crista, and structural changes that include areas of low voltage. In addition, impairment of sinus node function and an increase in atrial ERP occurred with aging. This electrical and structural remodeling may explain the increased propensity to AF with aging.
Kistler
Peter M
PM
Department of Cardiology, Royal Melbourne Hospital, Australia.
Sanders
Prashanthan
P
Fynn
Simon P
SP
Stevenson
Irene H
IH
Spence
Steven J
SJ
Vohra
Jitendra K
JK
Sparks
Paul B
PB
Kalman
Jonathan M
JM
D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D001281:Atrial Fibrillation / Q000503:physiopathology; D016275:Atrial Function / Q000502:physiology; D018780:Body Surface Potential Mapping; D022062:Electrophysiologic Techniques, Cardiac; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000033:anatomy & histology / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D013223:Statistics as Topic