To  determine  relationship between  blood    groups  and  myocardial

    infarction  we  studied  204  patients   who  admitted   in c.c.u  in  Ekbatan

    hospital    in  Hamadan .  The  patients   affected   by   acute   myocardial

    Infarction and they have elevated C.P.K and L.D.H enzymes and changes

    in  E.C.G   compatible    with   Q   wave  and  non   Q   wave   myocardial

    infarction . We   classified   the   patients  according  to age ,   sex ,  blood

    groups and different risk factors.

          In  this  study  with the aspect of frequency of blood groups in Iran and

    Hamadan the majority  of  blood  groups  were  group  A and the minority

    were group B. The most common risk factors among our patients was type

    A of personality which is similar to that mentioned  in  literature , and other

    risk factors were respectively as  below : cigarette  smoker ,  hypertension ,

    hyperlipidemia , diabetes  mellitus   and   family   history . The  age  of  the

    patients  with positive family history were less than 50 years.