High-Yield Arrhythmia Recognition Part 2: Master Wide QRS Patterns

Here are the 5 high-yield wide QRS patterns every acute care provider and nursing student must master.

1. Premature Ventricular Contraction (PVC)

• Definition: An early, ectopic impulse originating from an irritable focus within the ventricular myocardium.
• Key EKG Features:
  • Premature Timing: Appears earlier than the next expected sinus beat
  • Wide & Bizarre Morphology: QRS > 0.12s, often with T-wave discordance
  • Compensatory Pause: Usually followed by a full compensatory pause

2. Ventricular Tachycardia (V-Tach)

• Definition: A run of 3 or more consecutive PVCs at a rate > 100 bpm.
• Key EKG Features:
  • Rate: Fast (typically 100–250 bpm)
  • Rhythm: Regular (Monomorphic V-Tach)
  • QRS: Monomorphic, wide, and uniform
  • P Waves: Absent or AV dissociation

3. Torsades de Pointes

• Definition: Polymorphic VT associated with prolonged QTc.
• Key EKG Features:
  • Morphology: QRS complexes twist around the isoelectric baseline
  • Pattern: Spindle-like waxing and waning appearance
  • Triggers: Hypomagnesemia, hypokalemia, QTc-prolonging drugs

4. Idioventricular Rhythm (IVR)

• Definition: Slow ventricular escape rhythm when higher pacemakers fail.
• Key EKG Features:
  • Rate: 20–40 bpm (40–100 bpm = Accelerated IVR)
  • QRS: Wide (> 0.12s), slurred or bizarre
  • P Waves: Absent or dissociated

5. Bundle Branch Block (BBB)

• Definition: Conduction delay in the right or left bundle branch.
• Key EKG Features:
  • Underlying rhythm usually sinus (P waves present)
  • QRS: Wide (> 0.12s)
  • Morphology: Notched “bunny ears” (rsR′ in V1 for RBBB)

Quick Differentiation Summary