Researchers say a 31-year-old woman’s case shows that doctors should ask about soda consumption during medical screenings.

A Monaco woman who drank nothing but soda for 16 years developed heart problems and a fainting disorder by age 31, according to the European Society of Cardiology.

Researchers say that kind of excessive soda consumption may have caused to woman to suffer from a potassium deficiency and a life-threatening arrhythmia, or irregular heartbeat.

Dr. Naima Zarqane and Prof. Nadir Saoudi from the Princess Grace Hospital Centre in Monaco say a 31-year-old woman was admitted to the hospital for a traumatic form of fainting.

After excluding other possible causes—including a family history of heart problems, digestive symptoms, and possible hormonal abnormalities—blood tests showed the woman had low levels of potassium and abnormally high heart muscle sensitivity, which can lead to a host of problems.

Doctors found the likely cause when they took her medical history—the woman had replaced her water intake with 2 liters of soda a day. After being instructed to stop drinking soda for one week, the woman’s potassium levels returned to healthy levels and her heart muscle sensitivity ceased.

Potassium is important for the body because it helps regulate the heartbeat. It can be lost during bouts of diarrhea, which excessive soda consumption can cause by increasing the amount of fluid in the intestines. Researchers say the caffeine in the cola may affect the way the kidneys absorb potassium.

Reviewing other literature on excessive soda drinking, the Monoco researchers found proof that too much soda can lead to damage in skeletal muscle tissue and to irregular heart rates. One death was attributed to Torsades des pointes, a heart condition that can lead to ventricular fibrillation or a “heart flutter.”

After their experience with the 31-year-old women, Zarquane and Saoudi said doctors need to ask people showing irregular heartbeats on EKG tests about their soda drinking habits.

“It’s also important that the people are made aware of the potential health dangers of excessive consumption of sugary drinks. There are important political messages for governments to ensure that bottled water is cheaper than sugary drinks, which is not always the case,” Saoudi said in a press release.

The researchers said additional studies are needed to compare the blood potassium levels of chronic soda drinkers to those of non-soda drinkers.

Until then, they warn of some of the other dangers of chugging too much bubbly sugar water.

“Due to the high calorie intake it’s likely to result in weight gain, which increases the risk of developing metabolic syndrome,” Saoudi said.