Vacillate pulse is a term used to describe an irregular heartbeat. Synonyms for this term include arrhythmia, irregular heartbeat, abnormal heart rhythm, and cardiac dysrhythmia. These terms refer to a condition where the heart beats either too fast, too slow, or irregularly, which affects the flow of blood through the body. Other synonyms for vacillate pulse include atrial fibrillation, tachycardia, and bradycardia. Atrial fibrillation is a specific type of arrhythmia that occurs when the heart's upper chambers beat irregularly. Tachycardia is a condition where the heart beats too fast, while bradycardia is a condition where the heart beats too slowly. It is important to seek medical attention if you experience any symptoms of an irregular heartbeat.