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