Premature complexes, with QRS similar to that of conducted complexes but not preceded by a P-wave. Retrograde P waves (negative in II, III, aVF, positive in aVR and aVL may be seen immediately after the QRS or may be absent.

Premature complexes, with QRS similar to that of conducted complexes but not preceded by a P-wave. Retrograde P waves (negative in II, III, aVF, positive in aVR and aVL may be seen immediately after the QRS or may be absent.