The precordial thump has largely fallen out of mainstream resuscitation practice. Major international guidelines now recommend against it for cardiac arrest, and the 2025 European Resuscitation Council guidelines dropped it entirely. The only scenario where it still has a narrow foothold is a very specific one: a witnessed, monitored case of unstable ventricular tachycardia when no defibrillator is immediately available.
What a Precordial Thump Actually Is
A precordial thump is a sharp strike delivered with a closed fist to the lower half of the breastbone. The idea is that the mechanical force generates a small electrical impulse in the heart, potentially enough to reset a dangerously fast or chaotic rhythm. Think of it as a crude, low-energy alternative to a defibrillator shock. The energy it delivers is a tiny fraction of what a defibrillator produces, which is both its appeal (it requires no equipment) and its limitation (it rarely works).
Where Guidelines Stand Today
The trajectory over the past two decades has been a steady retreat. The International Liaison Committee on Resuscitation (ILCOR), which coordinates global resuscitation science, issued a strong recommendation against using the precordial thump for cardiac arrest. That recommendation, first formalized in 2010, was reaffirmed in the 2020 international consensus statement and remains unchanged. ILCOR groups the thump alongside cough CPR and fist pacing as “alternative techniques” that are not supported by evidence for out-of-hospital cardiac arrest.
The European Resuscitation Council went a step further in 2025, removing the precordial thump from its advanced life support guidelines altogether. It is simply no longer mentioned as an option.
The American Heart Association takes a slightly more permissive but still very cautious position. It considers the thump an optional technique, not a recommended one. The only scenario where it carries even a weak endorsement is when a healthcare professional witnesses a patient go into unstable ventricular tachycardia on a monitor and no defibrillator is within reach. Outside that narrow window, the AHA does not support its use.
Why It Fell Out of Favor
The short answer: it doesn’t work often enough, and it can make things worse. One study of 27 patients who received a precordial thump during ventricular tachycardia found that only 3 (11%) converted to a normal rhythm. Nearly half stayed in the same dangerous rhythm. The remaining 12 patients, a full 44%, were thumped into something worse: 8 went into ventricular fibrillation (a more chaotic and immediately life-threatening rhythm), 3 went into asystole (no heartbeat at all), and 1 deteriorated into a rhythm with no effective blood flow.
Those numbers paint a grim picture. In roughly equal measure, the thump either did nothing or caused harm. Researchers who studied it in prehospital settings concluded that the precordial thump “is usually not beneficial, and may be detrimental.” Animal studies have shown higher success rates (up to 95% in one pig study), but those results have never translated to real-world human outcomes in a meaningful way.
The other factor working against the thump is practical: defibrillators are now widely available. Automated external defibrillators (AEDs) sit in airports, gyms, office buildings, and ambulances. The scenario where a trained provider witnesses a monitored arrest and genuinely cannot access a defibrillator has become exceedingly rare. When the thump was first introduced, defibrillators were large, expensive, and confined to hospitals. That world no longer exists.
The One Remaining Use Case
The only situation where the precordial thump retains any clinical relevance is highly specific. All of the following must be true simultaneously:
- The arrest is witnessed by a healthcare professional, not discovered after the fact
- The patient is on a cardiac monitor showing unstable ventricular tachycardia
- No defibrillator is immediately available
In practice, this combination almost never occurs in modern healthcare settings. Hospital rooms, emergency departments, and ambulances all have defibrillators at hand. The scenario essentially describes a gap of seconds between recognizing the rhythm and grabbing the defibrillator, during which a provider might attempt one thump before moving on to standard resuscitation.
Even in this narrow window, the thump should never delay CPR or defibrillation. It is a single attempt, not a repeated intervention. If it doesn’t work immediately, the provider moves straight to chest compressions and defibrillation.
Use in Children
There are no studies on the precordial thump in pediatric cardiac arrest. The 2025 AHA guidelines note that any position on children is extrapolated entirely from adult data, which itself is unfavorable. Case reports have documented serious complications from the thump in children. Given the lack of evidence for benefit and the documented risk of harm, the technique has no established role in pediatric resuscitation.
What Bystanders Should Know
If you’ve seen a precordial thump in a movie or TV show and wondered whether you should try it on someone in cardiac arrest, the answer is no. The technique is not part of bystander CPR training and never has been. For a layperson who witnesses a cardiac arrest, the correct steps remain calling emergency services, starting chest compressions, and using an AED if one is available. These interventions have strong evidence behind them. The precordial thump does not, and attempting it without cardiac monitoring means you have no way of knowing whether you’re helping or pushing the heart into a worse rhythm.