CPR chest compressions. Animation showing chest compressions being performed on a patient in cardiac arrest. To perform the compressions the hands are placed in the centre of the chest, with the fingers interlocked. Firm downward movements compress the ribcage and heart, pumping oxygenated blood around the body. To be effective the chest needs to be compressed by five centimetres at a rate of around 100 compressions per minute. The compressions will not restart the heart, but will prevent tissue death, most importantly in the brain, until further help can arrive. HD master supplied with transparent alpha channel. For a flat version on a black background, see clip K003 3705.