Premature Atrial Contractions — ECG Academy Lesson

Identify premature atrial contractions on a rhythm strip, recognize the different P wave morphology that indicates an ectopic atrial origin, classify PAC patterns, and understand their clinical significance as potential precursors to sustained atrial arrhythmias.

Learning Objectives

• Define a premature atrial contraction and explain its mechanism
• Identify the abnormal P wave morphology that distinguishes a PAC from a sinus beat
• Describe the incomplete compensatory pause and how it differs from a full compensatory pause
• Classify PAC patterns: isolated, couplets, bigeminy, trigeminy, and runs
• Explain non-conducted PACs and why they produce a pause without a QRS
• Describe when frequent PACs warrant clinical notification