Acute myocardial ischemia of rabbit was caused by Pituitrin (2. 5u/kg)intravenously. The effect of electroacupuncture (EA ) at Neiguan polnt on transmernbrane potential was observed with a suspension microelectrode technique in situ and under the condition of natural respiration; the blood pressure and electrocardiogram were recorded simultaneously- The results showed that during acute myocardial ischernia

the resting potential (RP)

action potentail amplitude (APA ) and maximurn velocity of depolarization (Vmax ) were all significantly decreased

but action potential duration (APD) was markedly prolonged and after depolarization potential appeared at the sarne time. All of the above mentioned changes of potentials could cause arrhythmia t while EA at Neiguan could weaken the changes of the potentials rnarkedly

prevent the ventricular cells from changing to slow reaction cells and reduce the incidence of after depolarization potential

That may be a reason why EA at Neiguan can prevent and cure arrhythmia complicated by acute myocardial ischemia