What defines tachycardia?

Tachycardia is defined specifically as a fast heart rate, which is characterized by a heart rate exceeding 100 beats per minute (bpm) in adults. This elevated heart rate can be a response to various factors, including physical activity, stress, fever, or underlying health conditions. It's essential to understand that while a normal resting heart rate ranges from 60 to 100 bpm, any sustained increase above this threshold can potentially indicate the presence of tachycardia.

The other options describe conditions unrelated to tachycardia: a slow heart rate is typically referred to as bradycardia, while a normal heart rate does not indicate tachycardia at all. An irregular heart rhythm is a different medical phenomenon known as arrhythmia, which may occur alongside tachycardia but is not synonymous with it. Recognizing the specific definition of tachycardia is crucial for properly diagnosing and managing cardiac health.