In this video, Dr Sanjay Gupta, consultant cardiologist explains a heart condition called atrial flutter. Atrial flutter is an abnormal heart rhythm which can cause symptoms of heart palpitations. In atrial flutter,the atria contract at 300 beats per minute and every other impulse goes down into the ventricles and therefore the ventricles beat at 150 beats per minute. In patients who are taking medications such as beta blockers or calcium blockers the impulses reaching the ventricles may be reduced even more so the heart rate can be even lower than 150/min but basically as doctors whenever we see a heart rate of about 150 in a patient complaining of heart palpitations, we think of atrial flutter as the likely underlying heart rhythm disturbance.