A baby’s heart rate of 170 beats is obviously not normal, but of course it also depends on how old the child is. Generally, the younger the child, the faster the heart rate. If a newborn baby has a heart rate of 170 beats, especially if the child is crying vigorously or after activity, the heart rate will increase due to increased sympathetic excitement. After a while or after a quiet period, the child’s heart rate will gradually return to normal, this situation does not require special treatment, and can be observed for the time being. If a child is over 6 weeks old or over 4 weeks old and has a heart rate of 170 beats, this is definitely not normal. The rapid heart rate is a manifestation of myocardial injury and should be further examined at the hospital. ECG, cardiac enzymes, cardiac ultrasound, etc. should be examined and the possibility of myocardial injury and myocarditis is very high. If it is a myocardial injury, you need to apply drugs that nourish the myocardium for treatment, which should take about 10-14 days at the very least.