What is the origin of paroxysmal atrial tachycardia (PAT)?

What is the origin of paroxysmal atrial tachycardia (PAT)?

• A. An irritable atrial automaticity focus
• B. An irregular ventricular focus
• C. Atrial hypoxia
• D. Atrial depolarization failure

Answer: (A)

The origin of paroxysmal atrial tachycardia (PAT) is associated with an irritable atrial automaticity focus. This occurs when a specific area within the atrial tissue begins to fire off electrical impulses at a rapid rate, overriding the normal pacemaker of the heart. The irritable focus can be a result of various factors such as structural heart changes, inflammation, or electrolyte imbalances, leading to enhanced automaticity in that region.

This focus behaves independently of the usual sinus rhythm, and since it is located within the atrium, it can result in rapid atrial contractions, contributing to the tachycardia seen in PAT episodes. Understanding this mechanism is crucial for comprehending how PAT develops and how it can be differentiated from other types of tachycardias, making it essential knowledge for those studying EKG interpretation and cardiac rhythms.