Very similar to internal medicine interviews in my experience. Most all of the ones I went on were about 2/3 of the day with 4-8 interviews of 30-60 minutes each. Many people had not read about me until moments before the interview, but some had read my application and had a good idea of who I was. Expect to be asked about "why cardiology?" and some questions about your background. More so than in residency, I got questions about any connections to the geographic area (ie: "are you committed to moving here") and also questions about my research projects. Mine were overall, benign.
