Watch Heartbeat Online at Couchtuner. Based on the real life and achievements of Dr. Kathy Magliato, this unique character-driven medical drama follows Dr. Alex Panttiere, an outspoken, world-renowned heart transplant surgeon, one of the few women in her field. Stubborn and fearless, Alex always operates on her own terms. She revels in a racy personal life that’s a full-time job in itself, manages the daily demands of skeptical faculty and dutiful interns, and pushes the boundaries of medical science to impressive new heights.