Ventricular and supraventricular ectopic beats

Ventricular and supraventricular ectopic beats

Isolated ventricular and supraventricular ectopic beats are quite common. Ventricular ectopic beats are recognized as wide bizarre QRS complexes which occur prematurely and are not usually preceded by a P wave. Sometimes a late diastolic ventricular ectopic can occur just after the P wave. If ventricular ectopics are very frequent or occur very prematurely so as to fall on the T wave of the previous beat, they can lead on to ventricular tachycardia or fibrillation. Isolated ventricular ectopic beats without any associated structural heart disease are usually left alone.

In the ECG shown here, ventricular premature complexes are occurring in a bigeminal pattern with each sinus beat followed by a VPC. When there are multiple VPC, they can be monomorphic, of same morphology or polymorphic, different morphologies. Monomorphic VPCs usually originate from same focus, unifocal VPC, while polymorphic VPCs may be originating from multiple foci, multifocal VPC. Rarely, different morphologies can be due to change in the conduction sequence of unifocal VPCs.

Isolated ventricular ectopics in bigeminy

Supraventricular ectopics are premature narrow QRS beats resembling the sinus beats. The P waves have a different morphology compared to the sinus beats or may be absent in case of junctional ectopics. P waves of supraventricular complexes may not always be visible as some of them may be overlapping a T wave. Supraventricular ectopy may indicate atrial dilatation as in left ventricular dysfunction and is a reason to suspect the latter in those with structural heart disease.

Isolated supraventricular ectopics