July 25, 2024
Patients prone to cardiac arrhythmias due to genetic heart disease could be at a higher risk of arrhythmia when consuming energy drinks. The event rate is low, yet sudden cardiac arrest (SCA) could occur.
The stimulating ingredients in energy drinks may lead to a potentially proarrhythmic state by altering:
- Heart rate.
- Blood pressure.
- Cardiac contractility.
- Cardiac repolarization.
In a study published in Heart Rhythm in June 2024, Mayo Clinic cardiac researchers looked at the level of risk for patients who consume energy drinks. The retrospective review of more than 5,000 patients identified patients who survived sudden cardiac arrest with proven arrhythmias requiring resuscitation, defibrillation or both. The patients were referred to the Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic for evaluation between July 2000 and January 2023.
Take caution
While consuming energy drinks may not directly cause sudden cardiac arrest, caution is advised. "The heart reacts to the high caffeine and other chemicals. It's the magnitude and the combination of the chemicals in energy drinks that can catch the vulnerable heart off guard and send it into a potentially lethal heart rhythm that leads to sudden cardiac arrest and sudden cardiac death," says the study's lead investigator, Michael J. Ackerman, M.D., Ph.D. Dr. Ackerman is a genetic cardiologist at Mayo Clinic in Rochester, Minnesota, and director of the Mayo Clinic Windland Smith Rice Genetic Heart Rhythm Clinic. "It's more concerning than we thought, and we need to take some prudent steps to make people aware so that they're not moving things past their safety margin into cardiac danger."
What you need to know:
- Energy drinks are not monitored by the Food and Drug Administration (FDA). Most of the beverages claim to have natural ingredients and are classified as dietary supplements and not as medications.
- The beverages contain caffeine ranging from 80 to 300 mg per serving. An 8-ounce cup of brewed coffee has 100 mg of caffeine. Previous studies have shown a link between caffeine and sudden cardiac death.
- Most of the drinks contain additional stimulating ingredients that are unregulated by the FDA, such as guarana and taurine. Many beverage brands are targeting adolescents.
- There is a concern that the lack of dose information listed can contribute to accidental overdoses of caffeine. Though such overdoses are rare, the potential harmful effects of the other unregulated ingredients are unknown.
High-energy effect
The study found that of 144 survivors of SCA, seven patients (5%) experienced an unexplained SCA following energy drink consumption. Two patients had long QT syndrome. Two had catecholaminergic polymorphic ventricular tachycardia. And three were diagnosed with idiopathic ventricular fibrillation. The mean age of the survivors (six females and one male) was 29 ± 8 years.
Three patients consumed energy drinks regularly. Six patients (86%) required a rescue shock, and one was resuscitated manually. All survivors stopped consuming energy drinks and have since been event-free.
"There's no discernible health benefit of consuming energy drinks," says Dr. Ackerman. "The absolute risk of danger is very low. The relative risk in the fragile heart is higher. So, for my patients with long QT syndrome or any genetic heart disease that is associated with sudden cardiac death, the appropriate dose of a highly caffeinated energy drink is 0. It's not worth the relative risk exposure when there's no upside to be gained from the product."
Next steps
More awareness and larger studies are needed. "About 1 in 200 humans has one of these genetic heart diseases and most of them don't know about it," says Dr. Ackerman. "For which hearts would consumption be a bridge too far where the risk equation is not worth it? And which hearts have more than enough bandwidth so you can consume a drink without fear that it may detonate your heart?"
Educate patients on the chemicals in energy drinks and the potential risks. "We need to ask our patients about their supplement use and energy drink consumption. We don't necessarily take inventory of that, and it makes sense that we need to," says Dr. Ackerman. "We should at least have an awareness and help patients decide whether we think their heart is healthy enough to handle the effects of these chemicals."
For more information
Martinez KA, et al. Sudden cardiac arrest occurring in temporal proximity to consumption of energy drinks. Heart Rhythm. 2024;21:1083.
Refer a patient to Mayo Clinic.