When there is a midpoint combination of Node, Ascendant and Midheaven the family, nation or community put their marks on your situation and personality and define your destination. Or: the situation of a group of people (family, tribe, nation) depends on you. This combination occurs in the chart of John F. Kennedy and evil doctor Mengele. The Kennedy's of course influenced the career of JFK and Mengele was one of many Nazi's. The combination just means that you are associated with people who share your goals or that you share the goals of a group of persons.
Also visit: Astromarkt.net for example about Sun/Moon and AC/MC midpoint combinations. That is where I mentioned this midpoint combination as: 'the crucial importance of the people around you'.
There are various ways to link the Northern Node to Midheaven. Barack Obama for example has Node square Midheaven.