All of the options listed are types of arrhythmias. However, "ventricular flutter" is less commonly recognized as a distinct category compared to the others. The more widely used term is "ventricular fibrillation," which is a serious condition.
So, while "ventricular flutter" is not commonly referenced in the same way as the others, it does not mean it doesn't exist. If there is a need to identify the least common or least recognizable, it would be "ventricular flutter." However, please clarify whether you need a specific answer based on context or definitions.