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 also known as an 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.