Caffeine.
It slightly speeds up your metabolism meaning your body needs more oxygen and glucose to be circulated through your blood, thus an increased heart rate.
The heart beat can increase due to stress and exercise. There are many other factors that can increase heart rate.
I hope you mean that you're drinking the coffee and breastfeeding the baby. Yes, it is harmful for a baby, by whatever means the baby gets the coffee. There are ingredients in coffee besides caffeine that are dangerous to a baby, causing dehydration, stomach problems. The caffeine can increase the baby's heart beat, damaging an already small and fragile heart.
moving around, emotion and what not
The only way I can think that music would affect the heart beat! is by increasing the amount of the hormone adrenalin secreted by the pituitary gland. Andrenalin control the pacemaker cells of the heart and regulates the heart beat. So if there is more adrenalin, the heart beat would go faster. The same would occur with Coffee/Caffeine.
check you tube :P
The heart would more than LIKELY not beat again (unable to make it beat again) and he or she will die.
Sometimes you can get scared,frustarated or upset and your heart rate will increase.
Cycling, swimming, running are three exercises that will increase the heart beat, open up the lungs, and increase the endurance and stamina.
Because the heart has to pump more oxygen than usual to your muscles
You can drastically increase your heart rate by smoking a bunch of crystal meth.
doing any excersice for 20 minutes or more, no less should increase your heart beat to the max. eg, jogging then sprinting.
Most video games will increase someone's heart rate. The main games that increase heart rate are racing (especially off-road or street racing) games, horror games, fast paced shooters, etc. Racing games like Need for Speed Series, Burnout Series, Flatout Series, Midnight Club Series, Motorstorm Series, etc increase it the most. Though if you play horror games like Alien vs. Predator 2, F.E.A.R, Doom Series, etc you can increase your heart rate considerably because of the constant spooks from bad guys or monsters or whatever jumping out the darkness at you suddenly. Violent shooters actually increase heart rate the least. Only a few shooters increase the heart rate significantly. An example would be the Brothers in Arms series.