There is indeed a practice of piety called the Heroic Act. It has been encouraged by the Theatine Order. It is called heroic because of the complete selflessness involved in the practice.
According to T.C. O’Brien in the Encyclopedic Dictionary of Religion, persons who make the heroic act offer to God any and all indulgences they might gain, as well as all expiatory works and all prayers offered for them after death.
The Heroic Act should not be confused with St. Louis Marie de Montfort’s act of total consecration to Mary or the offering made by “victim souls.”
O’Brien remarks that this offering is not to be made lightly or easily permitted by a spiritual director. I would say the same of the Heroic Act and total consecration. They should not be spur-of-the-moment actions but thoughtful and mature acts.