She was 23 years old and a rising tennis star. Last week, she died suddenly.

This week, the tennis world has been celebrating big victories and stunning performances during the Australian Open. But today it’s been shaken by some unexpected sad news: the sudden death of up-and-coming player Violetta Degtiareva.

The Russian sportswoman, who was ranked 1084 in the world and apparently one of the highest earning tennis players, reportedly collapsed during a training session on January 12.

It’s not known whether she died on the court or en route to the hospital, but according to current reports her death was caused by heart failure. It’s believed the news broke on Facebook when one of Degtiareva’s tennis player friends, Anastasia Vdovenco, wrote: “I can hardly believe it. Rest in peace.”

What makes this story even more tragic is the fact Degtiareva, who had reportedly been nicknamed 'the next Anna Kournikova', was just 23.

Although this is undeniably shocking news, it isn't the first time a young person has suddenly died while playing sport. Just last year here in Australia, a 27-year-old City to Surf competitor and a 39-year-old Ironman died of heart complications at their respective events. And those are just the incidences that received media coverage.

"[W]e believe that up to five young people under the age of 35 pass away each week in Australia from this type of sudden cardiac death – it happens a few times a week in otherwise healthy, fit young people,” Professor Chris Semsarian, a cardiologist from Sydney’s Royal Prince Alfred Hospital, explained to The Glow at the time.

While coronary heart disease generally causes sudden death in people older than 35, among younger people it's attributable to inherited or genetic heart conditions which affect the heart's muscles. Sudden death is considered a rare complication, but it can happen - and in about 50 per cent of cases, it occurs without any warning signs beforehand.

It's worth knowing the symptoms that can signal an underlying heart problem - these include blackouts, unusual chest pains and heart palpitations, along with dizziness or a noticeable higher-than-usual heart rate during exercise.

Professor Semsarian also recommends that if you have a family history of heart diseases, you should visit a doctor so you can be properly checked through an electrocardiogram and heart ultrasound.

If you want to know more, you can read our full report on cardiac arrest in young adults here, which includes additional information about what to look out for and what to do if symptoms present.