ECG of sustained monomorphic ventricular tachycardia

Shown are the six precordial electrocardiogram (ECG) leads (V1-V6). The QRS complex is wide and bizarre and the rhythm is ventricular tachycardia (VT). The sixth (+) and seventh (*) QRS complexes show a change in morphology, resembling a normal QRS complex; these represent fusion beats, with partial (+) or complete (*) normalization of the QRS complex. The seventh QRS complex (*) is preceded by a distinct P wave, which is probably conducted, capturing the ventricle for one beat, but not terminating the VT; this is also known as a Dressler beat.