Transcatheter aortic valve implantation (TAVI) has been performed at Waikato Hospital for high-risk severe symptomatic aortic stenosis patients who are considered unsuitable for conventional cardiac surgery for the last 3 years. The Medtronic CoreValve (MCV) is a self-expandable device, while the Edwards SAPIEN valve (EV) requires the use of a balloon to expand the device. This observational study reports and compares the incidence of heart block in both Medtronic and Edwards transcatheter valves.