A premature P wave is referred to as which of the following?

A premature P wave is referred to as which of the following?

• A. PVC
• B. Second-degree AV block
• C. None of the above
• D. PAC

Answer: (D)

A premature atrial contraction occurs when an atrial ectopic focus fires early, producing a P wave that appears sooner than the normal one. On the ECG, that premature P wave may look different from the sinus P waves, and the following QRS is usually normal because ventricular conduction is intact. This is distinct from a premature ventricular contraction, which shows a premature QRS complex without a preceding P wave or with a wide QRS, and from second-degree AV block, where irregular timing is due to impaired conduction between atria and ventricles rather than an early atrial impulse. So the early P wave is best described as a premature atrial contraction.

A premature atrial contraction occurs when an atrial ectopic focus fires early, producing a P wave that appears sooner than the normal one. On the ECG, that premature P wave may look different from the sinus P waves, and the following QRS is usually normal because ventricular conduction is intact. This is distinct from a premature ventricular contraction, which shows a premature QRS complex without a preceding P wave or with a wide QRS, and from second-degree AV block, where irregular timing is due to impaired conduction between atria and ventricles rather than an early atrial impulse. So the early P wave is best described as a premature atrial contraction.