Arrhythmia is a change to the regular, rhythmic beating of your heart. A fluttering, heart palpitation, or "skipping a beat" sensation may be a symptom of arrhythmia. Do not panic; millions of Americans experience these sensations every year and have a harmless case of arrhythmia. If you experience other symptoms such as dizziness, unexplained fainting, shortness of breath, or chest pain you may have arrhythmia. Your doctor can determine what type of arrhythmia you might have and if you are at risk for any serious complications.