Correlation of electrotonic monophasic action potential shortening with short-term memory in human atrium.
To determine the presence of memory in human atria, we recorded monophasic action potential (MAP) at the high right atrium (HRA) in 21 patients. After reaching a steady state at 600 ms, HRA pacing was switched to the coronary sinus (CS) pacing to alter the activation sequence. After 20 minutes of CS pacing, pacing was continued at HRA to record the memory effect of CS pacing. Atrial memory was defined as the change in HRA MAP duration (MAPd) after 20 minutes of altered activation sequence. Baseline MAPd was 229 +/- 31 ms, which was shortened to 226 +/- 24 ms immediately after CS pacing. After 20 minutes of CS pacing, HRA MAPd during HRA pacing was 220 +/- 28 ms, which was significantly shorter than the baseline MAPd (P = 0.003). The degree of atrial memory was associated with the degree of initial electrotonic MAPd changes caused by the altered activation sequence. These results suggest that memory phenomenon exists in human atria, and it can be expressed as a change in MAPd.
Nam
Gi-Byoung
GB
Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Korea.
Choi
Kee-Joon
KJ
Kim
Jun
J
Rhee
Kyoung-Suk
KS
Kim
You-Ho
YH
Lee
Jong-Min
JM
D000200:Action Potentials; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D013223:Statistics as Topic