Which rhythm disturbance is suggested by an early beat with a normal PQRS complex followed by a brief pause and continued normal rhythm?

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Multiple Choice

Which rhythm disturbance is suggested by an early beat with a normal PQRS complex followed by a brief pause and continued normal rhythm?

Premature atrial contraction occurs when an atrial impulse fires early. This produces a premature P wave that may look different from the normal ones, but the ventricles still conduct normally, so the QRS complex is normal in width and shape. After the premature beat, there's a brief pause as the SA node timing resets, and then the rhythm resumes normally. This combination—an early beat with a normal P wave preceding a normal, narrow QRS, followed by a short pause—is the hallmark of a PAC. If you look at the other patterns: a ventricular ectopic beat would have a wide, abnormal QRS and often no preceding P wave; atrial flutter shows rapid, sawtooth atrial activity; sinus arrhythmia involves varying RR intervals with breathing, not a single premature beat followed by a pause.

Premature atrial contraction occurs when an atrial impulse fires early. This produces a premature P wave that may look different from the normal ones, but the ventricles still conduct normally, so the QRS complex is normal in width and shape. After the premature beat, there's a brief pause as the SA node timing resets, and then the rhythm resumes normally. This combination—an early beat with a normal P wave preceding a normal, narrow QRS, followed by a short pause—is the hallmark of a PAC.

If you look at the other patterns: a ventricular ectopic beat would have a wide, abnormal QRS and often no preceding P wave; atrial flutter shows rapid, sawtooth atrial activity; sinus arrhythmia involves varying RR intervals with breathing, not a single premature beat followed by a pause.

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