What should I do if the heart has stopped?
Strike the chest smartly over the heart. This may be enough to start the beat. If not, quickly place the heel of one hand on the lower half of the breastbone and cover it with the heel of the other hand. Press down firmly on the lower part of the breastbone by rocking forward with your arms straight. Do this about once a second for an adult. For a child, use one hand only and press more rapidly—about 80 times a minute. For a baby, use finger tips only and press 100 times a minute. Meanwhile, you must continue giving mouth-to-mouth resuscitation. If you are alone, alternate two inflations of the lungs by mouth-to-mouth breathing with 15 heart compressions. Counting aloud will help you. If you have help, one person should do mouth-to-mouth breathing only; the other should do the heart compressions. The two of you should not act simultaneously, but alternate one air inflation with six heart compressions.