Coronary sinus lysophosphatidylcholine accumulation during rapid atrial pacing.

The purpose of this study was to determine whether lysophosphatidylcholine (LPC) release from the myocardium could be detected in patients with pacing-induced ischemia. We measured LPC levels in plasma obtained from the coronary sinus in 20 patients undergoing diagnostic atrial pacing stress tests. In 14 patients with pacing-induced ischemia, coronary sinus LPC concentration rose from 69.1 +/- 5.3 microM at baseline to 101.7 +/- 9.0 microM at 4 minutes and to 178.0 +/- 18.0 microM at peak pacing (p less than 0.01). LPC did not increase significantly in 6 nonischemic patients (from 60.8 +/- 7.8 microM at baseline to 70.2 +/- 7.6 microM at peak pacing, difference not significant). LPC did not increase in mixed venous or arterial blood from ischemic patients. Thus, coronary sinus LPC accumulation may be an early marker of ischemia.