When your heart isn't pumping correctly, blood isn't getting to the parts of your body that need it, such as your brain. That's why you might feel dizzy, faint, or even have blurry vision during an atrial flutter episode.  Atrial flutter happens when the atria start beating faster, and the ventricles can't keep up. The heart rate during episodes of atrial fibrillation may reach over 150 a minute. Lightheadedness, shortness of breath, and heart palpitations are some obvious signs, along with increased heart rate.