関連ワード:  is a flutter an arrhythmia    is a heart flutter an arrhythmia    is a flutter an irregular heartbeat    is atrial flutter an arrhythmia    is ventricular flutter an arrhythmia    is a flutter a supraventricular arrhythmia    is a flutter afib    what type of arrhythmia is atrial flutter    which is more dangerous afib or a flutter    can afib turn into a flutter