What is Premature Ectopic Beat and Supraventricular Ectopic Beat?

Ectopic heartbeat is associated with the abnormal electrical conduction or activity of the heart. It is a light variation in the heart beat and causes irregular pulse. The patient feels a thump or a flutter in the chest as if the heart missed a beat. 

Premature ectopic beat is the most common type of arrhythmia which is most often harmless. The premature ectopic beat can be of atrial origin or of ventricular origin. 
Supraventricular ectopic beat originates either from the atria or from the atrioventricular node which is called as the junctional premature beat. It may indicate an atrial dilation and shows premature and narrow QRS complex on the ECG. 
Very often the symptoms are aggravated due to stress or factors like alcohol, caffeine, exercise emotion