A racing heart can occur from physical exertion, stress, sickness, menopause, a pre-existing heart condition or for no apparent reason at all. Sometimes, an electrical malfunction within the heart can cause a sporadic racing heart. Racing hearts can be treated with medication, physical manoeuvres (i.e., snapping the heart back into a normal rhythm, bearing down or vomiting) and a special diet to help prevent future incidences from occurring. The longer a racing heart takes place, the harder it can be to stop it.
Splash your face and neck with ice cold water. If the racing heart is severe, sometimes plunging the head into ice water (In a sink or tub) can control an erratic electrical pathway in the heart.
Place a rubberband on either wrist. Slowly snap it against the wrist in time to a regular heart beat. This should not only get your mind off the racing heart, which can help regulate it, but it can also send impulses to the brain and heart that can help slow the heart.
Bear down as if making a bowel movement. This is called the valsalva manoeuvre and puts enough strain and pressure into the chest region that the heart can sometimes regulate itself again.
Relax. Steady breathing, laying back and concentrating on remaining calm can be very effective in reducing a racing heart.
Seek medical attention if all other options have been exhausted and have not regulated the heartbeat. If a racing heart occurs for more than 10 minutes at a high rate of over 150 beats per minute, medical attention should be sought to prevent fainting or blood clots.