What characterizes tachycardia?

Tachycardia is characterized specifically by a fast heart rate that typically falls within the range of 101 to 160 beats per minute (bpm). This condition can arise due to various factors, including stress, anxiety, heart conditions, or other physiological responses. A heart rate above 100 bpm is a common clinical threshold used to define tachycardia, as it indicates that the heart is beating faster than the normal resting rate.

In contrast, a heart rate under 60 bpm is classified as bradycardia, while a heart rate between 61 to 100 bpm is considered to be within the normal or slightly elevated range. An irregular heart rate does not specifically define tachycardia, as it can occur with different types of arrhythmias where the rhythm may vary but not necessarily indicate an increased rate. Therefore, the definition of tachycardia focuses primarily on the elevated heart rate itself.