The American Heart Association (2010) suggests a ratio of 30 chest compressions followed by 2 ventilations for an adult for each cycle of cardiopulmonary resuscitation. The same ratio is used for infants and children when a single rescuer is working alone. Two rescuers working together with an infant or child should use a ratio of 15:2. The breaths and compressions do not need to be synchronized. The breaths and compressions do not need to be synchronized.