Rapid heart beat is not always because of a bad cause. It may be because of a normal and healthy cause like physical exertion or from a bad one which can be from too much caffeine intake that be correted easily. An adults normal heart rate ranges from 60-100 beats per minute. If you have a faster than normal heart rate then you might have what we call in medical terms, tachycardia. If you have prolonged or sudden rapid heart rate with no reason to point at, you might to get medical opinion. But there are many ways to slow down a rapid heart and it would depend mostly on how it was caused.
Deep breathing helps. If you can sit or lie down, much better. Make sure you focus on the rise and fall of your abdomen. Doing this for several minutes can lower down your heart rate. This mostly effective if you have just reacted to stress as the rapid heart rate is a response from your sympathertic nervous system. This is to put in simple words, your turn off switch.
You can also try avoiding stimulants like caffeine and nicotine especially if you are on them while having a rapid heart rate. If you slowly cut down on your caffeine intakes like coffee, tea and caffeinated sodas, you might reduce recurrence. Diet pills should also be checked for possible stimulants.
If it hasn’t been stressed enough, eating a balanced diet with vegetables is the best way to reduce occurence of rapid heart rate. Some cases have been found to be caused by the lack of potassium and magnesium in their body and having green vegetables, nuts, meat and milk can be the best choices as source for such nutrients. Also, if it isn’t too redundant, exercise everyday. This reduces stress and strengthens the heart. But never go strong on your first try. Go slow by aiming for a 30 minutes aerobic workout each day and stick to that schedule. You can also ask your physician to recommend excercises appropriate for you.
Learn to also be do relaxation techniques like deep breathing and meditation. If you are relaxed, calm and collected, your body will slow down as well. It takes a lot of practice to effectively do this and make sure you apply it on episodes of rapid heart rate. Lastly, keep a record of when and where these occur. How fast they are during the episode, how long each one last and what you feel at that time is important to not. let you doctor see that record for it would help him diagnose the probable cause and treatment for it. Always know how to respond even in stressful situations.