This is an excellent Russian movie about an ambulance unit and the paramedic that leads it. 

His long-time relationship starts suffering from a combination of alcoholism and his devotion to his work, which are also linked together. This is set in a country where ambulances are underfunded and the health-care system is frail. 

As a consequence, the story of Arrhythmia is one of a worker dedicated to saving their patients' lives in a system that seems not to care. This is portrayed in the ambulance's everyday missions, but also in the paramedic's decaying relationship. It's Blue Valentine meets an Andrey Zvyagintsev movie like Elena. Sadly, it might be more realistic than both those movies, and added to the fact that it's Russian, it has stayed severely under-watched since it came out.