They're both about desperate mothers willing to do anything for their daughters. Both with the same leading actress: Kim Yunjin. Fortunately the situations are very different but with the same 'desperate mother thing'. While Heartbeat is more of a drama, 'Seven Days' is more of a thriller.
Both deal with lawyers who have to defend clients with shaky alibis and motives. Unexcepted twists that make both movies worth watching!