Irregular or extra heartbeats happen when an electrical signal starts some place other than the sinus node and causes the heart to beat out of rhythm. Depending on the precise timing of the extra heartbeat, patients may experience an “extra beat,” a “skipped beat,” a “forceful beat” or a “fluttering” sensation. Many patients are completely unaware that they are experiencing extra heartbeats. Even completely healthy people have irregular or extra heartbeats once in a while. Usually, they are nothing to worry about. In some cases, however, irregular or extra beats can cause bothersome symptoms or may lead to other types of sustained rapid heart rhythms.