"Meditation in the life of the Prophet (sawa) predated the divinely revealed instruction on canonical prayer. The Prophet (sawa) underwent long periods of spiritual retreats known as tahannuth on mount Hira. As we have seen given the fact that His daughter used a black knotted prayer rope used in the hesychast tradition indicates that he himself most probably engaged in body-breath-mind meditative practices BEFORE the command of performing Salah was given through divine revelation." (Dr. Francisco Luis).
The field of the transmission of practices from the Imamiyya to what later became Sufi groups and then orders is one of the most neglected in Islamic Studies, although it is slowly developing. Mohammad Ali Amir-Moezzi mentions possible links between the muraqaba techniques practiced by the Naqshbandiyya-Mujadidiyya and the Imamiyya (pps 50-51, The Divine Guide in Early Shi'ism) - although this does not involve breathing techniques, but rather connection through intention to subtle centres called 'lata'if'. It is interesting that the Naqshbandiyya arose in Khorasan where there were many Imamiyya. It is a general rule that with the democratisation of a religious/spiritual movement, there can be a watering down of its teachings. Similarly, we have almost no extant texts from the early period of Islam - and that can't be just because all of the texts were burned or destroyed; so the question remains with regard to the full extent of what has been lost, and why.