What is defined as sinus arrest?

What is defined as sinus arrest?

• A. Intermittent racing heartbeat
• B. Sudden ventricular tachycardia
• C. SA node ceases to pace
• D. Irregular heart rhythm

Answer: (C)

Sinus arrest refers specifically to a condition where the sinoatrial (SA) node, which is responsible for initiating the electrical impulses that stimulate heartbeats, fails to produce these impulses for a brief period. This results in a temporary cessation of the normal heartbeat rhythm, leading to an interruption in the pacing of the heart. When this occurs, the heart momentarily stops beating normally, which can lead to symptoms such as dizziness or fainting due to reduced blood flow.

Understanding sinus arrest is crucial, especially in the context of arrhythmias and other heart rhythm disturbances. It distinguishes itself from other types of cardiac events, such as tachycardia (abnormally rapid heart rate) or irregular rhythms, which do not inherently involve the failure of the SA node to generate impulses.