Which of the following is a sign of tachycardia?

Tachycardia is characterized by an elevated heart rate, specifically defined as a heart rate that exceeds 100 beats per minute (bpm) in adults. This condition can result from various factors such as physical stress, anxiety, fever, or underlying medical conditions.

A heart rate above 100 bpm indicates that the heart is beating faster than normal, which aligns with the definition of tachycardia. The other options do not describe tachycardia: a heart rate below 60 bpm identifies bradycardia, an irregular heart rhythm can occur in different arrhythmias but does not specifically denote tachycardia, and no heart activity suggests asystole, which is a state of cardiac arrest rather than an increased heart rate.

Understanding the specifics of heart rates and their classifications is essential in identifying various cardiac conditions, making it critical to recognize that a heart rate above 100 bpm confirms the presence of tachycardia.