Fusion Beats

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

Figure 1 - ECG case

Fusion Beat/Dressler Beat

ECG Recognition: It has the morphology that is INTERMEDIATE between a sinus QRS complex and a ventricular complex.

Figure 2 - Fusion complexes

Reason: Occurs when a ventricular ectopic beat and a supraventricular beat simultaneously activate the ventricular myocardium. 

Figure 3- Laddergram

Fusion beats are infrequently seen but can be observed if the rate is slower.

Significance: Presence of a Fusion Beat is highly diagnostic of VT.

Reference:

Issa et al. 2012. Clinical Arrhythmology and Electrophysiology: A Companion to Braunwad's Heart Disease. Elsevier Health

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