Which EKG reading indicates a heart rate greater than 100?

• A. Sinus tachycardia
• B. Supraventricular tachycardia
• C. Premature ventricular contraction
• D. Sinus bradycardia

Answer: (A)

The correct answer is sinus tachycardia, which is characterized by a heart rate exceeding 100 beats per minute while still maintaining a normal sinus rhythm. In sinus tachycardia, the electrical impulses originate from the sinoatrial node (the heart's natural pacemaker), but they occur at a faster rate due to various physiological or pathological triggers, such as exercise, fever, anxiety, or anemia.

Understanding sinus tachycardia is important as it reflects the heart's response to a need for increased blood flow and oxygen delivery to the tissues. Recognizing this EKG pattern is crucial for emergency department practitioners as it aids in determining the potential underlying cause of the elevated heart rate and guiding appropriate management.

In contrast, supraventricular tachycardia also indicates a heart rate over 100 but involves different mechanisms relating to abnormal electrical pathways in the heart. While it also signifies a rapid heart rate, recognizing it as separate from sinus tachycardia is fundamental for targeted treatment. Premature ventricular contractions do not typically result in a sustained heart rate above 100 and are abnormal beats that can occur in a normal heart rhythm. Sinus bradycardia, on the other hand, is defined by a heart rate below 60