What is the usual heart rate range that defines tachycardia?

Tachycardia is characterized by an increased heart rate, typically defined as a resting heart rate exceeding 100 beats per minute. The normal resting heart rate for adults ranges from 60 to 100 beats per minute. When the heart rate rises above this threshold, it indicates a state of tachycardia.

The correct answer signifies that tachycardia is often discussed in the context of heart rates that can range from 150 to 250 beats per minute, especially in situations such as paroxysmal supraventricular tachycardia or ventricular tachycardia. This range reflects more severe or symptomatic presentations of tachycardia, where the rapid heart rate may lead to a decreased ability of the heart to pump effectively, potentially causing complications.

This understanding helps in identifying tachycardia during patient assessments and knowing when to intervene clinically. The other specified ranges do not accurately encapsulate the severity or the definition of tachycardia as outlined in cardiology practice.