Ventricular Rhythms

Premature ventricular complexes (PVCs): Ectopic beat that originates in ventricles with no P wave, and a wide QRS; otherwise normal EKG with normal rate, rhythm, P wave, PR interval and QRS complexes

· PVC patterns:

o PVC every other beat → Ventricular bigeminy

o PVC every third beat → Ventricular trigeminy

o PVC every fourth beat → Ventricular quadrigeminy

o Two PVCs together → Couplets

o Three or more PVCs together → Runs of ventricular tachycardia

Ventricular tachycardia (VT): Three or more consecutive PVCs (Ventricular beats); HR > 100, regular rhythm, no P waves, wide QRS complexes. VT can be non-sustained (NSVT) if it lasts < 30 sec or sustained VT lasting > 30 sec

· Monomorphic VT: QRS complexes are identical

· Polymorphic VT: QRS complexes vary in shape and size

· Torsades de Pointes: QRS complexes appear to twist around the isoelectric baseline; prolonged QT

Ventricular fibrillation (VFib): Rapid irregular random waveforms, no identifiable QRS complexes.