Intra-atrial block requiring dual-site atrial pacing through a femoral approach in a univentricular heart oleh Alessio Marinelli, MD, Jonathan M. Behar, MBBS, PhD, MRCP, FEHRA, Pablo Meras Colunga, MD, Samuel Griffiths, BSc, MSc, Michael A. Gatzoulis, MD, PhD, FACC, FESC, Tom Wong, MD, FRCP