WCT Presumed VT Rule — EECC MCQ

Correct answer: D — Ventricular tachycardia until proven otherwise — in the presence of structural heart disease (prior MI), any WCT should be treated as VT; administering verapamil or diltiazem for a presumed SVT with aberrancy could be fatal in true VT

The fundamental rule of WCT management: in a patient with structural heart disease (especially prior MI, cardiomyopathy), WCT should be presumed to be VT until proven otherwise. Supporting statistics: ~80% of WCT in patients with structural heart disease is VT. The consequences of misdiagnosis are severe: administering IV verapamil or diltiazem to a patient with VT can cause haemodynamic collapse and death (these drugs have negative inotropy and vasodilation without meaningful anti-VT effect). Safe management: (1) haemodynamically stable WCT: IV amiodarone or procainamide (safe for both VT and SVT); (2) haemodynamically unstable: synchronised DC cardioversion regardless of mechanism. The Brugada algorithm and Vereckei algorithm help differentiate VT from SVT on ECG, but clinical management should not be delayed for definitive diagnosis.

Reference: ESC (2022): VA/SCD Guidelines