Mine

block load
{
  es_xsetinfo myhealth 0
}


event player_hurt
{
  if (event_var(health) <= 50) do
  { 
    es_setinfo myid event_var(userid)
    es_xdoblock heartbeat/firstbeat
  }
}

block firstbeat
{
   es_getplayerprop myhealth server_var(myid) "CCSPlayer.baseclass.m_iHealth"
   if (server_var(myhealth) > 30) do
   {
     es_emitsound player server_var(myid) hb/hb21.mp3 1.0 1.0
     es_delayed 5.5 es_xdoblock heartbeat/firstbeat
   }
   else do 
   {
      es_xdoblock heartbeat/secondbeat
   }
}   

block secondbeat
{
  es_getplayerprop myhealth server_var(myid) "CCSPlayer.baseclass.m_iHealth "
  if (server_var(myhealth) > 0) do
  {
   es_emitsound player server_var(myid) hb/hb22.mp3 1.0 1.0
   es_delayed 5 es_xdoblock heartbeat/secondbeat
  }
}