The precordial thump is a medical procedure that may used by healthcare professionals, to respond to ventricular fibrillation or ventricular tachycardia under certain conditions. The procedure is outside the scope of first-aid treatment and requires, at minimum, training in advanced cardiac life support (ACLS). The precordial thump may be considered in those with witnessed, monitored, unstable ventricular tachycardia (including pulseless VT) if a defibrillator is not immediately ready for use, but it should not delay CPR and shock delivery or be used in those with unwitnessed out of hospital arrest.
In a precordial thump, a provider strikes with a single blow of the fist to the middle of a persons sternum. The intent is to interrupt a potentially life-threatening rhythm. The thump is thought to produce an electrical depolarization of 2 to 5 joules. However, it is effective only if used near the onset of ventricular fibrillation or pulseless ventricular tachycardia, and so should be used only when the arrest is witnessed or monitored. There is no evidence that the precordial thump improves recovery in unwitnessed cardiac arrest.
A precordial thump may be attempted only once during the onset of cardiac arrest. While the odds of success are poor, if the procedure is performed properly then little time is lost. The provider will immediately continue with other ACLS skills, including CPR, ACLS drugs, and defibrillation, as appropriate.
There are concerns that the precordial thump can result in worsening of a person heart rhythm more often than it improves it.
The use of the precordial thump technique has sometimes been shown in movies and television, usually in passing without any explanation. Untrained laypersons have been known to attempt it, and sometimes cause additional injury to the patient as the blow must be carefully aimed. If applied incorrectly it may cause further injury, for instance inducing Commotio cordis (cardiac arrest caused by blunt trauma) or breaking the tip of the sternum.
At one time, the technique was also taught as part of standard CPR training with the requirement that it must be administered within 60 seconds of the onset of symptoms. That time restriction, combined with a number of injuries caused by improper technique, resulted in the procedure being removed from CPR training.
Drs. James E. Pennington and Bernard Lown's cardiology group at Harvard University are credited with formalizing this technique in the medical literature. They published their report in the New England Journal of Medicine in the early 1970s. Drs. Richard S. Crampton and George Craddock, cardiologists at the University of Virginia helped to promote the paramedic use of chest thump through a curious accident. In 1970, the Charlottesville-Albemarle Rescue Squad (VA) was transporting a patient with an unstable cardiac rhythm in what was then called a Mobile Coronary Care Unit. When the vehicle inadvertently hit a speed bump in a shopping center parking lot, the patient's normal heart rhythm was restored. Further research confirmed that chest thumping patients with life-threatening arrhythmias could save lives .
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- Nehme, Z; Andrew, E; Bernard, SA; Smith, K (2013 Aug 27). "Treatment of monitored out-of-hospital ventricular fibrillation and pulseless ventricular tachycardia utilising the precordial thump.". Resuscitation 84 (12): 1691–6. doi:10.1016/j.resuscitation.2013.08.011. PMID 23994203.