Dr. Ahamed Idris of the University of Texas Southwestern Medical Center, in conjunction with the Resuscitation Outcomes Consortium, said one administering CPR should perform between 100 and 120 chest compressions per minute for the best chance to restore a pulse.
Compressions to the chest performed to the repeatable beat of "Row, Row, Row Your Boat" [Gently down the stream, Merrily, merrily, merrily, merrily, Life is but a dream] fall right in that crucial range, Idris said.
"More or less compressions have a substantially lower chance of restoring a heartbeat," Idris, an emergency medicine expert, said in a statement.
Idris said three steps can significantly improve the chance of saving the life of someone who suffers cardiac arrest -- call 9-1-1; use both palms to press hard on the center of the chest, and repeatedly hum the "row, row, row your boat" tune while maintaining the compressions; do not stop until first responders arrive.
The findings were published in the journal Circulation.