Catecholaminergic polymorphic ventricular tachycardia
Catecholaminergic polymorphic ventricular tachycardia is an inherited disorder of calcium handling causing exercise- or emotion-induced bidirectional or polymorphic ventricular tachycardia in structurally normal hearts with a normal resting ECG. Management is high-dose beta-blockade, flecainide, exercise restriction, and an ICD for high-risk patients.
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What this article covers
- Overview
Definition: catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited disorder of intracellular calcium handling causing adrenergically triggered bidirectional or polymorphic…
- Epidemiology
Typically presents in childhood or adolescence.
- Risk factors
RYR2 (autosomal dominant) and CASQ2 (autosomal recessive) mutations and family history.
- Pathophysiology
Abnormal calcium release: mutations in the ryanodine receptor (RYR2) or calsequestrin (CASQ2) cause excessive diastolic calcium leak from the sarcoplasmic reticulum under adrenergic stimulation.
- Clinical features
Exertional or emotional syncope. Palpitations with exercise.
- Differential diagnosis
Long QT syndrome (especially LQT1): exertional syncope, distinguished by a prolonged corrected QT interval on the resting ECG, which is normal in CPVT (Long QT syndrome).
- Diagnosis
Establish by reproducible adrenergically induced bidirectional or polymorphic VT with a normal resting ECG and structurally normal heart: the diagnostic basis is exercise or catecholamine provocation…
- Management
First-line, start high-dose beta-blockade and restrict triggers: give a non-selective beta-blocker (nadolol 1 to 2 mg/kg/day, continued indefinitely) and restrict competitive and strenuous exercise.
- Complications
Bidirectional and polymorphic VT and ventricular fibrillation.
- Prognosis
Good with adherent high-dose beta-blockade and flecainide.
- Prevention
High-dose beta-blockade (nadolol 1 to 2 mg/kg/day) and exercise restriction.
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