The Interrupt Flow is a connection used to define the two UML concepts of connectors for Exception Handler and Interruptible Activity Region. An Interrupt Flow is a type of activity edge. It is typically used in an Activity diagram.
OMG UML Specification:
The OMG UML specification (UML Superstructure Specification, v2.1.1, p. 327) states:
An activity edge is an abstract class for directed connections between two activity nodes.