Ventricular Arrhythmia Identification Flashcards

A rhythm analysis technician observes a wide, bizarre QRS complex measuring 0.14 seconds on a patient's EKG. The beat occurs earlier than the next expected sinus beat, is not preceded by a P wave, and is followed by a pause. What is this single beat best described as?

Answer: Premature Ventricular Contraction (PVC)

This describes a Premature Ventricular Contraction (PVC). The key features are its premature nature, a wide QRS complex (≥0.12 seconds) due to its ventricular origin, the absence of a preceding P wave, and a subsequent compensatory pause.

A patient's rhythm strip shows a regular rhythm with a rate of 35 bpm. The QRS complexes are wide (0.16 seconds) and there are no discernible P waves associated with the QRS complexes. Which rhythm is most likely present?

Answer: Idioventricular Rhythm

Idioventricular Rhythm (IVR), also known as a ventricular escape rhythm, is characterized by a rate of 20-40 bpm, wide QRS complexes, and the absence of P waves. It occurs when higher pacemakers fail and the ventricles must pace the heart.

Which of the following ECG characteristics is the most definitive feature of Ventricular Fibrillation (VF)?

Answer: Chaotic, disorganized electrical activity with no identifiable P, QRS, or T waves.

Ventricular Fibrillation is defined by its chaotic and disorganized nature. On the ECG, there are no discernible waves (P, QRS, T); instead, the baseline is wavy and chaotic, reflecting the quivering, uncoordinated contraction of the ventricles.

A technician is analyzing a rhythm strip and notes a run of three or more consecutive wide-complex beats at a rate of 140 bpm. The rhythm is regular. This finding is best classified as:

Answer: Ventricular Tachycardia (VT)

Ventricular Tachycardia (VT) is defined as a rhythm with three or more consecutive beats of ventricular origin at a rate greater than 100 bpm. AIVR has a rate of 41-100 bpm, and while SVT with aberrancy has a wide QRS, the description points directly to the definition of VT.

A patient with a known prolonged QT interval develops a rapid, polymorphic ventricular tachycardia. On the monitor, the technician notes that the QRS complexes appear to be twisting around the isoelectric baseline. What is this specific arrhythmia called?

Answer: Torsades de Pointes

Torsades de Pointes, which means "twisting of the points," is a specific type of polymorphic ventricular tachycardia that occurs in the setting of a prolonged QT interval. Its hallmark feature on the ECG is the QRS axis swinging from one direction to another, creating a twisting appearance.

When analyzing a wide-complex tachycardia, which of the following findings would most strongly suggest a diagnosis of Ventricular Tachycardia over SVT with aberrancy?

Answer: A regular R-R interval

AV dissociation, where the atria and ventricles beat independently of each other, is a classic sign of Ventricular Tachycardia. It is demonstrated on the ECG by P waves that are not associated with the QRS complexes. While other features can be present in both VT and SVT with aberrancy, AV dissociation is highly specific for VT.