The groin first approach for transcatheter aortic valve implantation: are we pushing the limits for transapical implantation? - Beller, Carsten J.; Schmack, Bastian; Seppelt, Philipp; Arif, Rawa; Bekeredjian, Raffi; Krumsdorf, Ulrike; Katus, Hugo; Karck, Matthias; Kallenbach, Klaus (Clinical research in cardiology, 2013)