What is the diagnosis? What will be the clinical findings?

ECG Quiz 6

Ventricular ectopic bigeminy
Ventricular ectopic bigeminy

What is the diagnosis? What will be the clinical findings?

ECG shows ventricular ectopic bigeminy. Clinical findings will be pulsus bigeminus and intermittent cannon waves as alternate P waves are falling on the T waves. When P waves fall on the latter part of QRS, ST segment or T waves, cannon waves can be expected as QT interval roughly represents the electrical systole of the ventricle. Diastole ends and systole starts at the peak of R wave. In the tracing, P waves are seen as distortions in the contour of the T wave of the ectopic beat. The distortion is exactly midway between the preceding and succeeding P waves of the sinus beats with narrow QRS.

Ventricular ectopics are characterised by wide bizarre QRS complexes which are premature and not preceded by a P wave. The ventricular ectopic beats are followed by a full compensatory pause meaning that the sum of the coupling interval or interval from the onset of the previous QRS to the onset of the ectopic QRS and the compensatory pause, which is the next RR interval will be exactly twice that of the RR interval of sinus beats. The exact compensatory pause is because the sinus cycle is not reset by the ventricular beat as it finds the retrograde path to the sinus node refractory. Sometimes the retrograde conduction to the AV node produces a prolongation of conduction of the next sinus beat manifesting as a prolongation of the next PR interval. That will be a manifestation of concealed retrograde conduction.

Add a Comment

Your email address will not be published. Required fields are marked *