Time course of lysophosphatidylcholine release from ischemic human myocardium parallels the time course of early ischemic ventricular arrhythmia.
BACKGROUND
We determined the kinetics of the release of lysophosphatidylcholine (LPC) into the coronary sinus of patients undergoing stress tests after coronary artery bypass grafting. The kinetics were consistent with a role for this amphiphile in the pathogenesis of ischemic ventricular arrhythmia, a major cause of sudden death.


METHODS
Stress testing was initiated in the operating suite by pacing at a rate of 160 beats/min for 2 min. Ischemia was then induced by clamping the bypass grafts to the anterior wall for a maximal time of 4 min.


RESULTS
The pacing procedure induced a prompt but reversible increase in coronary sinus LPC concentration from a baseline of 60.9 +/- 2.5 to 83.8 +/- 5.0 mumol/l via pacing alone, and a further increase to 101.8 +/- 6.7 mumol/l when the grafts were clamped for 2 min (P < 0.01). Six minutes after the cessation of pacing, LPC concentration returned to 67.5 +/- 4.4 mumol/l.


CONCLUSIONS
These results demonstrate that severe myocardial ischemia is an agonist for rapid release of LPC from the myocardium. Kinetics of this release paralleled the time-course of early onset of electrophysiologic changes in isolated myocytes and perfused heart preparations in vitro. These results indicate that LPC may have an important role in the pathogenesis of ischemic ventricular arrhythmia in patients.
Sedlis
S P
SP
Division of Cardiology, New York Department of Veterans Affairs Medical Center, New York, USA.
Hom
M
M
Sequeira
J M
JM
Tritel
M
M
Gindea
A
A
Ladenson
J H
JH
Jaffe
A S
AS
Esposito
R
R
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology* / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000601:surgery; D006801:Humans; D008244:Lysophosphatidylcholines / Q000097:blood / Q000378:metabolism*; D008297:Male; D017202:Myocardial Ischemia / Q000150:complications* / Q000378:metabolism / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism*; D013997:Time Factors
D008244:Lysophosphatidylcholines