Atrioventricular nodal reentrant tachycardia (AVNRT) is a mouthful of a medical term that refers to a type of supraventricular tachycardia. This condition is characterized by a rapid and irregular heartbeat that originates in the atrioventricular nodal region of the heart. While there are no true synonyms for AVNRT, there are a few related terms that may help clarify the condition. These include supraventricular tachycardia (SVT), atrial tachycardia, and even heart palpitations. No matter how you describe it, AVNRT can be a serious condition that requires prompt medical attention to avoid potential complications.