Monomorphic ventricular tachycardia (MMVT)
- All beats look similar; predominantly upward in V1 = RBBB-type vs. downward = LBBB-type
- In obviously structurally abnormal heart: prior MI (scar); CMP
- In apparently nl heart that is actually diseased: subtle HCM, infiltrative CMP, myocarditis, arrhythmogenic CMP (ACM): incomplete RBBB, ε wave (terminal notch in QRS) & TWI in V1–V3 on resting ECG LBBB-type VT, dx w/ MRI (Lancet 2009;373:1289)
- In structurally normal heart w/ normal resting ECG & cardiac MRI:
RVOT VT: LBBB-type VT or PVCs w/ inferior axis; typically ablate
LVOT VT: RBBB-type VT or PVCs w/ superior axis; responds to verapamil
