Precordial Thump

Precordial Thump

The precordial thump is a medical intervention that may be employed by healthcare professionals in response to specific cardiac arrhythmias like ventricular fibrillation or ventricular tachycardia. This procedure falls outside the realm of basic first-aid and necessitates training in advanced cardiac life support (ACLS) at a minimum.

It may be considered in cases of witnessed, monitored, unstable ventricular tachycardia (including pulseless VT) when a defibrillator is not readily available. However, it should not impede the delivery of CPR and defibrillation or be utilized in instances of unwitnessed out-of-hospital cardiac arrest.

Performed by a highly trained provider, the precordial thump involves delivering a single, precisely aimed blow with the fist to a specific area on the patient's sternum. The goal is to disrupt a potentially life-threatening heart rhythm. The thump is believed to generate an electrical depolarization of 2 to 5 joules.

Nonetheless, its efficacy is contingent upon its use near the onset of ventricular fibrillation or pulseless ventricular tachycardia, thus it should only be administered when the arrest is witnessed or monitored. Approximately 25% of cardiac arrest patients who received a precordial thump regained cardiac function (Scherf and Bornemann, 1960); however, there is no evidence indicating its effectiveness in cases of unwitnessed cardiac arrest.

A precordial thump should only be attempted once during the onset of cardiac arrest. Despite its low success rate, if executed correctly, minimal time is lost. Subsequently, the provider must promptly proceed with other ACLS interventions, including CPR, administration of ACLS drugs, and defibrillation as necessary.

Portrayals of the precordial thump in movies and television often lack context and explanation, leading untrained individuals to attempt it. Unfortunately, improper execution may result in additional harm to the patient, as the blow must be accurately aimed. Incorrect application may lead to further injury, such as inducing Commotio cordis (cardiac arrest due to blunt trauma) or fracturing the sternum.

Historically, the technique was included in standard CPR training, with the stipulation that it must be administered within 60 seconds of symptom onset. However, due to limitations in efficacy and instances of injury caused by improper execution, the procedure was eventually removed from CPR training protocols.

As the precordial thump can potentially worsen arrhythmias or induce more lethal ones, it is no longer taught as a standard treatment. Percussion pacing or fist pacing, proposed as an alternative method for mechanical pacing during cardiac arrest, lacks substantial evidence to support its use.