What is a premature ventricular contraction (PVC)?

What is a premature ventricular contraction (PVC)?

• A. A contraction that occurs too late in the cycle
• B. A late atrial contraction
• C. A premature ventricular beat causing a giant complex on EKG
• D. A normal QRS complex

Answer: (C)

A premature ventricular contraction (PVC) represents a specific type of heartbeat that originates from the ventricles instead of the normal conduction system. This abnormal contraction occurs earlier than the next expected heartbeat, which can lead to a visible and significant alteration in the electrocardiogram (EKG) reading. The characteristic feature of a PVC is the presence of a wide and bizarre QRS complex, which appears different from the normal rhythm.

On the EKG, the PVC causes a "giant complex" appearance because the ventricular depolarization is not following the usual pathway through the His-Purkinje system. As a result, the QRS duration is often prolonged, and it may also be associated with compensatory pauses before returning to the normal rhythm. This electrical disturbance highlights the nature of PVCs as they disrupt the regular cardiac cycle, effectively showcasing why option C accurately describes a PVC.

Understanding PVCs is essential as they can be benign in healthy individuals but may indicate underlying heart disease when occurring frequently or in the presence of symptoms. Therefore, recognizing their significance on an EKG is crucial for proper assessment and management of a patient's cardiac health.