Though I don't know how efficacious it is, it's listed as a treatment for acute episodes of specific kinds of tachycardia (like Wolf Parkinson white syndrome -

Though I don't know how efficacious it is, it's listed as a treatment for acute episodes of specific kinds of tachycardia (like Wolf Parkinson white syndrome - http://emedicine.medscape.com/article/159222-overview#a1 http://emedicine.medscape.com/article/159222-overview#a1)