Heart attacks can happen fast. One day you are living life and the next day you might be fighting for it. In the life-changing moments that require expert medical attention, turn to UnityPoint Health - St. Luke's Cardiology Services. With 24/7 immediate heart care, St. Luke's saves lives. Combining experienced care with the latest diagnostics and treatment, St. Luke's in Sioux City is saving your heart so you can follow it.