While minor, infrequent episodes of irregular heartbeat are usually nothing to worry about, it is important to know the signs and symptoms of palpitations in case the changes in your heartbeat become more frequent and seem to last longer and longer.

Symptoms of a Rapid Heart Rate:

An uncomfortable, persistent awareness of your heartbeat;
A fluttering, thumping, pounding, or racing beat in your chest;
Shortness of breath, chest pain, light-headedness, or fainting.

Symptoms of a Slow Heart Rate Fatigue, shortness of breath, light-headedness, or fainting.

Nausea.
Caution: If you experience frequent or severe palpitations, call your doctor for an immediate appointment.