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ClearRounds Health · Cardiology · Quick Reference

Ventricular Tachycardia / Ventricular Fibrillation

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Arrhythmias & DevicesAdvancedIn progressOne-page PDF

Stable vs unstable VT, reversible causes, ischemic evaluation, amiodarone/lidocaine concepts, ICD considerations, and escalation.

Covers both VT and VF.

Last reviewed

Pending initial clinical review

Sources / guidelines to verify

  • 2017 AHA/ACC/HRS Ventricular Arrhythmias & SCD Guideline
  • Current ACLS algorithms
Disclaimer: Educational reference only. Not a substitute for clinician judgment, local protocols, or current guideline review.

One-page reference

Draft content pending the site owner’s clinical review. Verify against the sources above and local protocol before clinical use.

1

What it is / why it matters

  • VT = ≥3 consecutive ventricular beats >100 bpm; "sustained" if ≥30 s or causing hemodynamic compromise.
  • VF = disorganized ventricular activity with no effective output → cardiac arrest.
  • A wide-complex tachycardia is VT until proven otherwise — especially with prior MI or reduced EF.
2

Key diagnostic clues

  • QRS >120 ms, AV dissociation, capture or fusion beats, very wide/bizarre QRS.
  • Known structural heart disease, prior MI, or low EF strongly favors VT.
  • Pulseless and unresponsive with VT/VF morphology = cardiac arrest.
3

Initial workup / reversible causes

  • 12-lead ECG; continuous monitoring; electrolytes (K⁺, Mg²⁺, Ca²⁺).
  • Ischemia evaluation (troponin; consider urgent coronary angiography).
  • Review QT-prolonging and proarrhythmic drugs; echo for EF/structure.
  • Address the H’s and T’s (hypoxia, hypovolemia, H⁺, hypo/hyperkalemia, hypothermia; tension pneumothorax, tamponade, toxins, thrombosis).
4

Management framework

Unstable / pulseless

  • Pulseless VT or VF → immediate defibrillation + ACLS (CPR, epinephrine, antiarrhythmic).
  • VT WITH a pulse but unstable (hypotension, ischemia, shock, altered mentation) → synchronized cardioversion.

Stable monomorphic VT

  • IV antiarrhythmic (procainamide is often preferred for stable monomorphic VT; amiodarone is an alternative) or elective cardioversion.
  • Do NOT give AV-nodal blockers when the wide-complex rhythm could be VT.

Polymorphic VT

  • With long QT (torsades): IV magnesium, correct K⁺/Mg²⁺, stop offending drugs, overdrive pacing or isoproterenol.
  • With normal QT: treat ischemia — it is often ischemic in origin.

After the event

  • Correct reversible causes; an ICD is indicated for secondary prevention when VT/VF is not due to a fully reversible cause.
5

Red flags / escalate now

  • Pulselessness → call the code and defibrillate immediately.
  • Sustained VT, recurrent shocks, or electrical storm (≥3 episodes/24 h) → emergent escalation (antiarrhythmic, sedation, ischemia work-up, EP).
6

Clinic pearls

  • The dangerous error is calling a wide-complex tachycardia "SVT with aberrancy" and undertreating — assume VT.
  • Magnesium is first-line for torsades; verapamil/diltiazem can be lethal in VT.
7

Sources to verify

  • 2017 AHA/ACC/HRS Ventricular Arrhythmias & Sudden Cardiac Death Guideline
  • Current AHA ACLS algorithms

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ClearRounds Health · Cardiology — Ventricular Tachycardia / Ventricular Fibrillation Quick Reference · Last reviewed: Pending initial clinical review · Educational reference only. Not a substitute for clinician judgment, local protocols, or current guideline review.