Very premature ventricular complex and risk of ventricular fibrillation

Patient

39-year-old man with no particular prior history; hospitalization following the occurrence of a traumatic syncopal episode; recording of this tracing;

Trace

Sinus rhythm (positive P wave in leads I, II, V5, V6 and negative in aVR); narrow QRS with no particular abnormality; very premature ventricular complexes since occurring in the initial ascending phase of the T wave; left delay pattern, left axis, with very likely right ventricular origin due to delayed transition (in V4); ventricular trigeminy (succession of 2 QRS complexes of sinus origin and one premature ventricular complex);

Exergue

The coupling interval between the premature ventricular complex and the preceding QRS complex is generally fixed; when the coupling interval is short, the premature ventricular complex occurs on the ascending branch of the T wave or at the peak of the T wave, i.e. the vulnerable period (certain ventricular cells are excitable and others are still in refractory period), with an increased risk of induction of a polymorphic ventricular rhythm disorder.