Which statement describes tachycardia?

Which statement describes tachycardia?

• A. Slow heart rate.
• B. No change in rate.
• C. Elevated heart rate.
• D. Decreased cardiac output.

Answer: (C)

Tachycardia means an abnormally fast heart rate. In adults, a resting heart rate above about 100 beats per minute defines tachycardia, so describing it as an elevated heart rate directly captures what tachycardia is. The other statements don’t fit: a slow heart rate is bradycardia, no change in rate is normal, and decreased cardiac output is a possible consequence in some cases but not the definition of tachycardia. Tachycardia can occur in response to exercise, fever, stress, or other stimuli, where the heart speeds up to meet metabolic demands.

Tachycardia means an abnormally fast heart rate. In adults, a resting heart rate above about 100 beats per minute defines tachycardia, so describing it as an elevated heart rate directly captures what tachycardia is. The other statements don’t fit: a slow heart rate is bradycardia, no change in rate is normal, and decreased cardiac output is a possible consequence in some cases but not the definition of tachycardia. Tachycardia can occur in response to exercise, fever, stress, or other stimuli, where the heart speeds up to meet metabolic demands.