We have previously reported that many of the cardiopathogenic effects described in patients and laboratory animal streated with one of the major anti-cancer agent Adriamycin could be stimulated in vitro. Among these effects is a dose-related arrhythmia which is demonstrated in vitro at 0.05 µg/ml of continuous exposure to adriamycin.

Using this procedure to induce arrhythmia we have found here that Crassostrea gigas extract (JCOE) at doses which have no effect on cardiac cell contractility in control cultures（100µg/ml）can reverse Adriamycin-induced arrhythmia.

Four general classes or anti-arrhythmic drugs are used clinically to treat a variety of cardiac conditions associated with arrhythmia：Class I via reduction of the fast inward sodium channel;Class II via the antisympathetic pathway（beta blockade);Class �V via prolongation of the action potential duration（APD）and class �Wvia the more recently discovered effects on the blockage of the slow inward calcium channel. Whether JCOE acts via one of the existing mechanisms remains to be investigated. However it could be of potential enormous benefit in offering a new approach to the treatment of cardiac dysfunction.