29-year-old twins Naomi and Joëlle Karfich are active, have healthy diets and feel fit. But when it comes to their hearts, they don't have much to go on. They're unaware of any potential genetic risks or how their heart health has been measured up to now. That's why they've come to see Conchita Ruiz-Mohné, in Cologne. The cardiologist is an expert in female cardiovascular medicine, a field that has long been neglected. Women's hearts differ from men's, and often present subtler heart attack symptoms. This can lead to dangerously late diagnoses. Every minute counts in a heart attack: as soon as the blood supply stops, heart tissue begins to die, irretrievably.

Paramedic Celine Kilian shows how to respond quickly and correctly in the event of a heart attack. This is knowledge that may very well come in handy one day: Heart attacks are the most common cause of death in Germany. Younger people are increasingly affected — especially younger men, under 40. Ferruccio Labita, who had a heart attack at the age of 38, is one of them. Today, he trusts his heart again — and is a passionate competitive cyclist. But he's learned never to exceed his own physical limits.

One major risk factor is stress. Chronic interpersonal stress can cause heart disease — even leading to what's known as "broken heart syndrome". Christiane Waller explains why the hormone oxytocin can play a protective role here. Freediver Anna Karina Schmitt shows how to combat stress with breathing. She uses specific exercises to prepare her heart for dives to depths of up to 80 meters — using just one breath.

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