If the heart stops beating, blood flow to the brain and other vital organs ceases. With each heartbeat blood surges through the arteries, giving a pulse or throb which can be felt at various points on the body Normal pulse rate is 60-80 beats per minute in adults; in infants and young children it is faster, in elderly people and very fit people somewhat slower.
Taking the Pulse
You can hear a person’s heart by pressing your ear to his or her chest. The strongest pulse is usually just below the angle of the jaw, where the external carotid artery runs up beside the larynx. The radial pulse in the wrist at the base of the thumb is also easy to feel.
Feel for the pulse with the tips of your fingers (not your thumb, as it has a pulse itself). Count the number of beats per minute and note if it is fast or slow, full or weak.
If the heart is not beating, there will be no pulse and no detectable breathing, and the casualty will be unconscious, and either pale or blue, especially round the lips. As soon as you are sure the heart is not beating, give cardiac resuscitation.
Put the patient on his or her back and give a sharp thump to the chest, about half way down the breastbone and slightly to the left (this is where the heart lies, protected by the rib cage). This often starts the heart again. Follow up with 6-12 breaths of artificial respiration (see Breathing) and you should see the person’s colour return to normal
If this does not happen, press the heel of your on the breastbone, 2 fingers above the xiphisternum, the lump where the bottom ribs join in the midline, and place the heel of your other hand on your lower hand. Keeping your arms straight, rock backwards and forwards three times, springing the breastbone down by about 5 cm (2 in) each time. Do fifteen pushdowns and two breaths of artificial respiration, fifteen pushdowns and two breaths and so on, until you can detect the pulse or hear the heart.
If the casualty is a child, use less pressure or you may cause internal injury. Continue artificial respiration until the casualty is breathing again un-aided, then put him or her in the recovery position (see Unconsciousness).