Which of the following describes an increase in heart rate?

Tachycardia refers specifically to an increase in heart rate, generally defined as a resting heart rate exceeding 100 beats per minute. This condition can occur in response to various factors, including exercise, stress, fever, or medical conditions that affect heart function. Understanding tachycardia is crucial in clinical settings, as it can indicate underlying health issues that may require monitoring or treatment.

Bradycardia denotes a slower than normal heart rate, usually considered to be fewer than 60 beats per minute. Arrhythmia describes any irregularity in heart rhythm, which can encompass both fast and slow heart rates. Stenosis refers to the narrowing of a blood vessel, often implicating the flow of blood but unrelated to the specific measurement of heart rate. Each of these terms denotes a specific cardiovascular condition, distinguishing them from tachycardia, which directly addresses an elevated heart rate.