What is the difference between a heart palpitation, a murmur fibrillation, and arrhythmias?

Different conditions: Palpitation is the sensation that there is an abnormality in the heartbeat. It is a symptom. A murmur is something heard when listening to the heart. An arrhythmia is any abnormality of the heartbeat and is therefore nonspecific.

See full answer: A heart palpitation is a symptom--a layperson's term usually suggesting an abnormal heart beat. A murmur is a sound a doctor hears when listening to your heart. Fibrillation is usually a term for a specific abnormal heart rhythm. An arrhythmia is a broad term for an abnormal heart rhythm.