Makindo Medical Notes

⚡ Introduction

• Electrical storm refers to the occurrence of recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF) within a short period (typically ≥3 episodes in 24 hours), requiring repeated cardioversion or defibrillation.
• It represents a state of electrical instability of the myocardium and is a true medical emergency with high mortality if untreated.

🔎 Causes

• Structural heart disease: Non-ischaemic cardiomyopathy, dilated cardiomyopathy, hypertrophic cardiomyopathy.
• Ischaemic causes: Acute myocardial infarction (especially first hours), post-MI scar tissue re-entry circuits.
• Inherited arrhythmia syndromes: Brugada syndrome, long QT syndrome, catecholaminergic polymorphic VT.
• Metabolic / iatrogenic: Hypokalaemia, hypomagnesaemia, digoxin toxicity, proarrhythmic drug effects.
• Post-cardiac device: Inappropriate shocks or lead malfunction in ICD patients can sometimes precipitate storm.

🩺 Clinical Features

• Recurrent episodes of cardiac arrest due to VT/VF.
• Chest pain or angina-equivalent symptoms if associated with ischaemia.
• Hypotension and haemodynamic collapse due to poor cardiac output.
• Dyspnoea and pulmonary oedema if left ventricular dysfunction is present.
• Psychological impact: Patients with ICDs may experience repeated shocks, causing severe distress or post-traumatic stress disorder.

🧪 Investigations

• Bloods: FBC (ensure Hb >90 g/L), U&Es (correct K⁺ >4.5 mmol/L, Mg²⁺ >1.0 mmol/L), Troponin (elevated if ischaemia).
• ECG: Document type of VT/VF; look for ischaemic changes or Brugada/long QT features.
• CXR: May show pulmonary oedema or cardiomegaly.
• Echo: Assess LV function and structural abnormalities.
• Coronary angiography: Consider if ACS suspected as trigger.

🚑 Management (Always involve senior cardiology / electrophysiology early)

• Immediate resuscitation: DC cardioversion/defibrillation as indicated by ALS protocol.
• Supportive measures: Oxygen, IV access, analgesia for chest pain, catheterisation if ACS suspected.
• Antiarrhythmics:
  • IV β-blockers (e.g., propranolol, metoprolol, or esmolol) — suppress sympathetic drive.
  • IV Amiodarone infusion (0.5–1.0 mg/min after bolus) — most widely used antiarrhythmic.
  • IV Lidocaine (2–4 mg/min) — useful in ischaemia-related VT, particularly post-MI.
• Revascularisation: Primary PCI or urgent CABG if storm triggered by acute coronary syndrome.
• Mechanical support: Intra-aortic balloon pump, LVAD, or ECMO in refractory cases with cardiogenic shock.
• Ablation: Catheter ablation of VT circuits is considered for refractory or recurrent cases despite optimal therapy.
• Long-term: Optimise heart failure therapy, correct metabolic triggers, and review device programming in ICD patients.

💡 Key teaching pearl: Electrical storm is often a reflection of an unstable myocardium — management requires both stabilising the rhythm acutely and addressing the underlying trigger (ischaemia, electrolytes, structural disease). Early input from an electrophysiologist is crucial.