Study Reveals Shocking Connection Between Energy Drinks and Sudden Cardiac Arrest

Seven people survived sudden cardiac arrest, and the one thing they had in common was what they’d been drinking in the hours before it happened. Not a pre-existing medication. Not an extreme workout. An energy drink.

That finding came from a study of 144 cardiac arrest survivors conducted at the Mayo Clinic’s Windland Smith Rice Genetic Heart Rhythm Clinic. All of them had underlying genetic heart conditions. Of the 144 patients examined, seven – about 5% – had consumed one or more energy drinks in close proximity to their cardiac event. Dr. Michael J. Ackerman, the genetic cardiologist at Mayo Clinic who led the study, was careful not to call it causation. However, the pattern was troubling enough that cardiac electrophysiologists began reconsidering what they tell their highest-risk patients.

The thing about energy drinks is that they’re not just concentrated caffeine. That’s the part the “it’s just like coffee” argument gets wrong. These cans carry a cocktail of compounds – taurine, guarana, B vitamins, and proprietary blends – that interact with the heart in ways that plain caffeine does not. Energy drinks can potentially trigger life-threatening cardiac arrhythmias, with their highly stimulating and unregulated ingredients altering heart rate, blood pressure, cardiac contractility, and cardiac repolarization in a potentially proarrhythmic manner. That combination matters, and it’s the reason researchers are treating these drinks differently from a standard cup of coffee.

The market is enormous and growing fast. According to a 2025 systematic review in Current Cardiology Reports, energy drinks are widely marketed to enhance alertness and performance, making them a rapidly growing industry valued at $73.99 billion globally. They’re in gyms, gas stations, college libraries, and office break rooms. And the people drinking them the most are often the least likely to think of them as a health risk.

What’s Actually in an Energy Drink

These beverages typically contain caffeine and other stimulants, and their consumption has raised concerns about potential cardiovascular risks, including arrhythmias, tachycardia, and hypertension, particularly among young adults. What separates energy drinks from coffee isn’t just quantity – it’s the combination of active compounds and the fact that many consumers stack multiple cans in a single day.

Caffeine content alone varies dramatically. Energy drinks can contain caffeine ranging from 80 to 300 mg per serving, compared to roughly 100 mg in an 8-oz cup of brewed coffee. A single large can could already push a person to or past the daily ceiling that health agencies consider safe.

Taurine and guarana – two of the most common added ingredients – appear to amplify the cardiac effects of caffeine rather than simply adding to them. According to the Heart Rhythm journal study led by Dr. Ackerman and colleagues, including Dr. John R. Giudicessi and Dr. J. Martijn Bos, while low-dose taurine may have some antiarrhythmic properties, this beneficial effect appears to be overridden at higher concentrations by distinct hazardous electrophysiologic effects, including an abbreviation of cardiac repolarization and effective refractory periods that may increase ventricular vulnerability by facilitating re-entry. Re-entry, in plain terms, is when an electrical signal loops back through the heart instead of completing its normal pathway – a mechanism that can trigger dangerously fast or chaotic heart rhythms.

A 2025 review published in Cardiovascular Toxicology found consistent associations between energy drink consumption and QTc prolongation, atrial and ventricular arrhythmias, myocardial infarction, Takotsubo cardiomyopathy, and hypertensive episodes – even in young, healthy individuals. QTc prolongation refers to a delay in the heart’s electrical reset between beats. When that delay stretches too far, it creates a window where abnormal rhythms can start – rhythms that, in the worst cases, can cause sudden cardiac arrest.

The Blood Pressure and Heart Rate Picture

The 2025 systematic review by Mandato, Kola, Tyson, Laffin, and Bales, published in Current Cardiology Reports, analyzed 37 studies involving 1,597 participants and produced some of the most comprehensive data yet on energy drinks and heart function. Results showed significant cardiovascular effects, including increased heart rate in 60.9% of studies, systolic blood pressure elevation in 53.8%, diastolic blood pressure elevation in 61.5%, and QTc interval prolongation in 63.2%.

Other ECG changes, such as PR interval and T-wave alterations, were observed in 57.9% of studies. An ECG, or electrocardiogram, is the test that measures the electrical activity of the heart beat by beat. These aren’t theoretical changes – they’re measurable disturbances in the electrical signals that keep the heart beating in a regular, safe rhythm.

A 2025 review in Cardiovascular Toxicology confirmed that energy drinks, especially those with high caffeine content, can cause significant increases in systolic and diastolic blood pressure. Sustained blood pressure elevation is one of the primary drivers of long-term cardiovascular disease, and regular energy drink consumption could be quietly pushing that number up without the drinker realizing it.

The problem compounds with daily use. Research presented at the American College of Cardiology Asia 2024 conference in New Delhi found that chronic caffeine consumption exceeding 600 mg per day resulted in significantly elevated heart rates and blood pressure – and that even crossing the 400 mg daily mark showed measurable cardiovascular effects over time.

The National Center for Complementary and Integrative Health is explicit about the upper range: large amounts of caffeine may cause serious heart and blood vessel problems such as heart rhythm disturbances. That’s a direct warning from a federal health agency, not a hedged disclaimer.

When a Young Person With “No Risk Factors” Collapses

The case that put energy drinks back in the spotlight for cardiologists in 2025 involved a 24-year-old with no prior health conditions. Published in Case Reports in Cardiology by Ramcharan, Pereira, Maharaj, and colleagues, the report describes a 24-year-old Caribbean-Black male with no prior comorbidities who experienced aborted sudden cardiac death after a recent energy drink binge a few hours before his ventricular fibrillation cardiac arrest. Primary percutaneous coronary intervention was successfully performed for a widowmaker lesion, thought to have arisen as a sequela of his excessive energy drink intake.

A “widowmaker” refers to a total blockage of the left anterior descending artery – one of the most deadly types of coronary occlusion because it cuts blood supply to a large section of the heart muscle. Surviving it, especially in young adults, often requires immediate emergency intervention. This patient got that intervention in time. Many do not.

The authors concluded that the case illustrates the potentially lethal risks associated with excessive energy drink consumption, particularly in young adults without traditional risk factors for cardiovascular disease.

Dr. Ackerman’s team studying the 144 cardiac arrest survivors at Mayo Clinic noted that energy drink consumption likely combined with other variables – such as underlying genetic conditions – to create what they described as a “perfect storm” of risk. The team cautioned that their results reflect an association rather than proven causation, but that the findings were concerning enough to prompt further examination.

If you’re interested in how these ingredients affect people with underlying cardiac risk, this related article on energy drinks and heart disease from The Hearty Soul covers how daily consumption habits can add up over time.

Who’s Most at Risk

An editorial commentary published alongside the Heart Rhythm research by Ido Avivi and Ehud Chorin explored categorizing energy drinks as an “arrhythmogenic food” – meaning a food that might cause heart arrhythmia. That framing shifts the conversation from individual ingredient toxicity to something broader: the drink itself, in the context of how and how much it’s consumed, functioning as a cardiac trigger for susceptible people.

Susceptibility matters. The evidence is strongest for people with genetic heart conditions such as long QT syndrome, Brugada syndrome, or hypertrophic cardiomyopathy – inherited conditions that alter the heart’s electrical system. But the 2025 case report from Ramcharan et al. and the ACC 2024 data both show that even people without known diagnoses can face meaningful risk at high consumption levels.

Young adults are the primary consumers. A 2025 review in Cardiovascular Toxicology by researchers at Sapienza University of Rome found shared mechanisms between energy drinks and cocaine, including ion channel blockade, sympathetic overactivation, vasoconstriction, and prothrombotic states – and noted that chronic use of either substance can result in structural heart damage and remodeling. That comparison comes from peer-reviewed medical literature, not a public health warning campaign, and it reflects how seriously cardiologists are taking chronic high-volume energy drink use.

Emergency room visits tell their own story. Between 2005 and 2009, the number of emergency room visits due to energy drinks increased more than tenfold, from 1,128 to 13,114 visits, according to data from SAMHSA’s Drug Abuse Warning Network. The market – and the reported harms – have only grown since then.

The Regulation Gap

One of the more overlooked problems with energy drinks is how little oversight exists over what goes into them. Unlike pharmaceutical drugs or even some food additives, energy drink formulations are not subjected to the kind of pre-market safety testing that would be required of a product with equivalent cardiac effects.

The FDA does set a daily caffeine limit of 400 mg for healthy adults, but that guidance has no enforcement mechanism attached to it for beverages. The FDA also does not require manufacturers to disclose the exact amount of caffeine on conventional food and beverage labels – meaning a consumer can’t always know how much they’re actually consuming from a given can. And the agency has no specific regulatory category for energy drinks as a class, leaving them in a grey area between dietary supplement and conventional food depending on how the manufacturer chooses to market them.

The issue isn’t caffeine categorically. It’s the dose, the cocktail of co-ingredients, and the reality that most consumers have no reliable way of knowing how close they are to a dangerous threshold.

What to Do Now

The research on energy drinks and cardiac risk is observational in many places – that limitation is worth acknowledging. Studies in this area are often small, retrospective, or conducted in people who already had heart conditions. Causation hasn’t been proven definitively for otherwise healthy adults. But the accumulation of data across case reports, systematic reviews, and clinical studies points consistently in one direction: high consumption of energy drinks, especially in people with any cardiac vulnerability, carries real and measurable cardiovascular risk.

The most concrete guidance that emerges from the current evidence is this: if you have a known genetic heart condition, arrhythmia, high blood pressure, or a family history of sudden cardiac death, energy drinks are not a safe choice. Dr. Ackerman made that explicit in the Mayo Clinic study. If you have none of those risk factors, staying under 400 mg of total daily caffeine – from all sources combined – is the threshold the FDA considers the outer limit of reasonable safety. One large energy drink can already put you near that number. Two can push you past it.

The 2025 systematic review in Current Cardiology Reports – which screened 1,444 references and analyzed 37 studies – found that Red Bull and Monster were the most studied brands, and both produced significant cardiovascular effects across the studies analyzed. These aren’t obscure products. They’re in every gas station and grocery aisle in the country, consumed by tens of millions of people each week who have no idea their heart is registering the difference.

Checking a label before reaching for a second can isn’t overcaution. It’s the kind of information gap that, for a small but meaningful number of people, turns out to matter a great deal.

Disclaimer: The author is not a licensed medical professional. The information provided is for general informational and educational purposes only and is based on research from publicly available, reputable sources. It is not intended to constitute, and should not be relied upon as, medical advice, diagnosis, or treatment. Always consult a licensed physician or other qualified healthcare provider regarding any medical condition, symptoms, or medications. Do not disregard, avoid, or delay seeking professional medical advice or treatment because of information contained herein.

AI Disclaimer: This article was created with the assistance of AI tools and reviewed by a human editor.

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