Exercise-induced polymorphic, broad complex tachycardia?

![Figure][1] A 56-year-old man presented with a 4-month history of exercise-induced palpitations and pre-syncope. Resting electrocardiogram and echocardiogram were normal. Treadmill testing provoked a polymorphic, broad complex tachycardia (A) . During recovery, atrial flutter with 2:1