Butterfly and reverse butterfly: usefulness of a resistance band to provoke exercise-induced arrhythmias during catheter ablation in a patient refractory to pharmacological stimulation - Xynogalos, Panagiotis; Lugenbiel, Patrick; Schweizer, Patrick Alexander; Katus, Hugo; Thomas, Dierk; Scholz, Eberhard P. (Clinical research in cardiology, 2019)