There is a Heideggerian basis of OT, but it is a negative one (if you believe the thesis I was developing in my diss.). The structure of totalitarian ideology she outlines in OT resembles rather closely the structure of one of St. Augustine's interpretations of love she mapped out in her dissertation (and said was incapable of grounding social being, because it leads to viewing other people only as use-objects), which, in its turn, is suspiciously similar to certain aspects of the structure of Dasein given in Being and Time.
At the time she wrote OT, Arendt was completely and totally hostile on every level -- personal, philosophical, political, everything. Her 1946 Was ist Existenzphilosophie? is mostly one long slam of H's philosophy. This was when Arendt was in her "Heidegger is a potential murderer" phase. She was so foaming-at-the-mouth Jaspers had to talk her down.
OT has nada to do with Heidegger's theory of technology. As a matter of fact, it never influenced Arendt to any enormous extent.
Chris Doss The Russia Journal