AIVR/VT or Aberrancy?

Pt admitted due to SOB due to CHF. Is this accelerated idioventricular rhythm/ventricular tachycardia (AIVR/VT) or aberrancy?

QRS #3 is the "giveaway"

Figure 1

This atrial fibrillation as seen by the fibrillatory waves. After QRS 1-3 are wide QRS complexes at regular intervals with a rate of about 60 bpm. Are these aberrant QRS complexes or ventricular ectopics (acceleated idioventricular rhythm or AIVR)?

QRS #3 is the "giveaway" in this case. This QRS complex  is intermediate in morphology between the sinus beat and the ectopic ventricular beat. This is because the ventricles are depolarized both by the ectopic ventricular impulse and a supraventricular impulse.  QRS#3 is a "fusion" beat. Thus, this wide QRS rhythm is AIVR.  

The Fusion is the Clue

A 30 yo with no known significant PMHx is c/o of SOB. This telemetry strip is:

Image 1 -  Fusion beat is marked with a red arrow which means the wide QRS complexes are ventricular ectopics (VT)

There are 3 QRS morphologies on this rhythm strip. QRS #4 is a sinus beat. QRS #5 is a fusion beat and the rest are VT in morphology. A fusion beat (aka "Dressler beat") is a QRS that has a morphology that is INTERMEDIATE between a sinus QRS and that of a ventricular complex. This intermediate QRS morphology is due to the simultaneous ventricular myocardial activation by a supraventricular impulse (sinus) and a ventricular ectopic.

Thus, this telemetry strip is SR with ventricular tachycardia (VT).

#709

VT or SVT with aberrancy?

Image 1

A pt c/o of SOB and treated for pneumonia.

Is this VT or SVT with aberrancy?

Image 2

The QRS complex (#5) at the beginning of the tachycardia is called a FUSION beat. In this strip, the morphology or shape looked in-between the normal-looking QRS and the wide QRS complex.

A fusion beat is happens when the ventricle is being activated by 2 impulse (supraventricular and ventricular). The likelihood ratio (LR) for VT is high if you see a fusion beat (diagnostic for VT).

#521

Do we have the same ladder diagram?

 What is your interpretation?

Figure 1 - 2 leads

Multiple beats in one strip (+ T wave memory)

Figure 1 - Paced beat, Fusion, pseudofusion, cardiac memory

#426

Fusion Beats

What is the name of QRS complexes # 5 and 6 and its significance?

Figure 1 - ECG case

Accelerated Idioventricular Rhythm with Fusion beats

This ECG is from a 65 yo patient with h/o HTN c/o chest pain s/p intervention for  a mid-LAD lesion.

Figure 1 - ECG case