Sometime my heart beats really fast and cause problem in breathing and suddenly after sometime it become normal.. do i need a checkup??

Yes...soon.: Worst case scenario, this could be a heart rhythm disturbance. You need to be evaluated to be certain it's not.

Yes: More often than not occasional episodes of rapid heart beat turn out not to be of a dangerous type. However, since your are experiencing shortness ob breath with the episodes I think it is wise to consult with a physician. Often times a medication can be used to prevent these episodes. For more information on arrhythmia's see: http://www.patient.co.uk/health/abnormal-heart-rhythms-arrhythmias