【Object ive】To study the inf luences of pirenzepine on heart rate variability

baroref lex sensitivity and cardiac elect rophysiologic characteristics in rabbit s af ter myocardial infarctio n .【Methods】Thirty-six rabbits w ere divided into three groups at random :the cont rol g roup

the myocardial infarction group and the pirenzepine group .Af ter tw o weeks

following parameters were measured :heart rate variability (HRV)

baroref lex sensitivity(BRS)

a dispersion of vent ricular ef fective ref racto ry period(VERP-D)and vent ricular fibrillation threshold(VFT).Correlation w as analyzed among these parameters .【Results】Af ter myocardial infarction

HRV and BRS w ere decreased

VERP-D was increased

and VFT w as decreased .In comparison w ith my ocardial infarction g roup

HRV

BRS and VFT were increased and VERP-D w as decreased in pirenzepine group . HRV and BRS had sig nificant ly correlation with VERP-D and VFT .【Conclusion】Pirenzepine has the effect of increasing parasympathetic activity and ventricular elect ric stability

so

it might prevent vent ricular fibrillation af ter myocardial infarction .