Dr. Usman's Cardiology Notes

VT vs SVT with Aberrancy – ECG Criteria for Accurate Diagnosis Wide complex tachycardia (WCT) is VT unless proven otherwise. Correct differentiation between ventricular tachycardia (VT) and supraventricular tachycardia (SVT) with aberrancy is critical because management differs significantly and misdiagnosis can be dangerous. --- 1. Basic Definitions Ventricular Tachycardia (VT) A tachycardia originating below the His bundle (ventricular myocardium or Purkinje system), usually with wide QRS ≥ 120 ms. SVT with Aberrancy A supraventricular rhythm conducted through abnormal ventricular conduction (e.g., bundle branch block or accessory pathway), producing a wide QRS. --- 2. Why It Matters Treating VT as SVT (e.g., giving AV nodal blockers in unstable VT) can cause hemodynamic collapse. Treating SVT as VT is generally safer (e.g., amiodarone). In structural heart disease, ischemic heart disease, or prior MI → assume VT. --- Stepwise ECG Approach to Wide Complex Tachycardia --- Step 1: Clin...