Direct Proof of Endo-Epicardial Asynchrony of the Atrial Wall During Atrial Fibrillation in Humans.
BACKGROUND
The presence of focal fibrillation waves during atrial fibrillation (AF) can, besides ectopic activity, also be explained by asynchronous activation of the atrial endo- and epicardial layer and transmurally propagating fibrillation waves. To provide direct proof of endo-epicardial asynchrony, we performed simultaneous high-resolution mapping of the right atrial endo- and epicardial wall during AF in humans.


RESULTS
Intraoperative mapping of the endo- and epicardial right atrial wall was performed during (induced) AF in 10 patients with AF (paroxysmal: n=3; persistent: n=4; and longstanding persistent: n=3) and 4 patients without a history of AF. A clamp made of 2 rectangular 8×16 electrode arrays (interelectrode distance 2 mm) was inserted into the incision in the right atrial appendage. Recordings of 10 seconds of AF were analyzed to determine the incidence of asynchronous endo-epicardial activation times (≥15 ms) of opposite electrodes. Asynchronous endo-epicardial activation ranged between 0.9 and 55.9% without preference for either side. Focal waves appeared equally frequent at endocardium and epicardium (11% versus 13%; ITALIC! P=0.18). Using strict criteria for breakthrough (presence of an opposite wave within 4 mm and ≤14 ms before the origin of the focal wave), the majority (65%) of all focal fibrillation waves could be attributed to endo-epicardial excitation.


CONCLUSIONS
We provided the first evidence for asynchronous activation of the endo-epicardial wall during AF in humans. Endo-epicardial asynchrony may play a major role in the pathophysiology of AF and may offer an explanation why in some patients therapy fails.
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.). n.m.s.degroot@erasmusmc.nl.
Natasja
N
de Groot
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Lisette
L
van der Does
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Ameeta
A
Yaksh
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Eva
E
Lanters
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Christophe
C
Teuwen
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Paul
P
Knops
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Pieter
P
van de Woestijne
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Jos
J
Bekkers
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Charles
C
Kik
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Ad
A
Bogers
From the Department of Cardiology (N.d.G., L.v.d.D., A.Y., E.L., C.T., P.K.) and Department of Cardiothoracic Surgery (P.v.d.W., J.B., C.K., A.B.), Erasmus Medical Center, Rotterdam, The Netherlands; and Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands (M.A.).
Maurits
M
Allessie
D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D004699:Endocardium / Q000503:physiopathology*; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007089:Image Enhancement; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010496:Pericardium / Q000503:physiopathology*; D015203:Reproducibility of Results
atrial fibrillation; cardiac conduction defect; epicardial mapping; heart atria; humans