• ventricular arrhythmia
• sudden cardiac death
• implantable cardioverter-defibrillator
• left ventricular impairment

Ventricular arrhythmia management can present a difficult clinical challenge. A proportion of the presenting population will be at high risk of sudden cardiac death (SCD). Little or no protection against SCD is afforded by simple prescription of drug treatment.^1,2 Antiarrhythmic drugs may be proarrhythmic and prescribed without secure understanding of drug effect. Though many ventricular arrhythmias are dangerous, the spectrum of risk ranges from the immediately life threatening to very benign (for example, from ventricular fibrillation through to true right ventricular outflow tract tachycardia). Generating the range of ventricular arrhythmias are diverse disease processes and understanding of the relation between witnessed arrhythmia and underlying disease process is often incomplete. There is debate over whether right ventricular outflow tract tachycardia overlaps with right ventricular cardiomyopathy—the one being a “benign” arrhythmia whose disease process is not understood, the other being a disease process whose principal manifestation is “malignant” arrhythmia.^3,4

A parallel management challenge to ventricular arrhythmia control is the prevention of SCD in patients with no previous symptomatic ventricular arrhythmia but who are at high risk. SCD may have non-arrhythmia causes, but evidence strongly suggests that many or even most patients suffering or rescued from SCD have ventricular arrhythmia as the index event.⁵ Depending on the clinical scenario, the approach to the management of the phenomenon of SCD includes risk stratification, family screening, genetic analysis, and prophylactic therapeutic strategies in addition to the management of an SCD survivor (fig 1).

The electrophysiology specialist has the …