Exit block: a new technique for difficult side branch angioplasty.

Angioplasty of a stenosis at the origin of a diagonal branch was initially unsuccessful because of the straight course of the anterior descending artery and a sharp bend at the diagonal branch. Therefore, in a second attempt, the anterior descending artery was blocked by inflating a balloon distal to the diagonal branch, thereby facilitating the passage of guidewire and balloon into the diagonal branch.