Original air date: 03/23/2016 Runtime: 42:16 min. When conjoined twins arrive at the hospital with a cancer diagnoses, Alex recommends a very risky surgery, resulting in a major ethical debate within the department. After spending time with the twins and observing their unique relationship, Alex also begins to question her relationship with Pierce.
Original air date: 04/06/2016 Runtime: 42:38 min. Alex (Melissa George) and Pierce (Dave Annable) disagree on whether an experimental treatment for those with advanced stage cancer is right for the hospital's patients. True to form, Alex takes matters into her own hands with a risky move to find volunteers. Meanwhile, Max (Joshua Leonard) looks to drastically change the family dynamic with Alex, and Ji-Sung (Maya Erskine) connects with Callahan (Jamie Kennedy).
Original air date: 04/20/2016 Runtime: 42:57 min. On the anniversary of her sister's death, Alex (Melissa George) performs state of the art heart surgery on a patient who doubts her ability to leave personal grief outside the OR. Meanwhile, Millicent (Shelley Conn) dates a sexy artist, and Pierce (Dave Annable) wants to be a bigger part of Alex's family.
Original air date: 04/27/2016 Runtime: 41:50 min. A case brings back memories for Alex (Melissa George), Jesse (Don Hany) and Millicent (Shelley Conn) as they fight to save a heart transplant patient when she sustains devastating injuries in a car crash. Also starring Dave Annable, Maya Erskine and Jamie Kennedy. Guest starring Rudy Martinez, Caitlyn Larimore, Sara Tomko, Makenzie Vega, Stephanie Nash and Rubén Garfias.
Original air date: 05/04/2016 Runtime: 42:57 min. When a transgender woman is diagnosed with breast cancer, Alex (Melissa George) and Ji-Sung (Maya Erskine) fight to save her life and her identity. Meanwhile, a beautiful consultant from another hospital forces Jesse (Don Hany) to confront his feelings for Alex. Also starring Dave Annable, Shelley Conn, Joshua Leonard and D.L. Hughley. Guest starring Candis Cayne, Brianne Davis, Andrew T. Lee, Caitlyn Larimore, Rudy Martinez, and Megan McNulty.
Original air date: 05/25/2016 Runtime: 42:43 min. In the season finale of "Heartbeat," Alex fights to save the lives of Jesse, Pierce and Ji-Sung when a mysterious and deadly illness sends the hospital into lockdown. Meanwhile, Millicent must pick up the pieces when Alex disobeys the orders of the CDC, and an elderly man searching for his missing wife leads Alex to make a drastic decision in her love life.