Patients with ventricular arrhythmias: who should be referred to an electrophysiologist?

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. 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. 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. 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 choice of sophisticated device therapies or interventional ablation techniques, and their combination, for the management of symptomatic ventricular arrhythmias and SCD risk. However, the optimal way to deliver ventricular arrhythmia and SCD management strategies to appropriate patient populations is debatable. There is a tension between the need to make treatments available to appropriate populations, by delegation of clinical services to general cardiologists who express subspecialty interest, and the need to ensure that patients are offered optimal clinical care, which often can only be provided by experts in the field. Most patients with or at risk of ventricular arrhythmias will benefit from specialist electrophysiological assessment. Generally, SCD prophylaxis, management of SCD syndromes, and management of patients in whom symptomatic ventricular arrhythmias carry a significant burden of morbidity with or without SCD risk is best provided by shared care rather than in electrophysiological exclusivity. Table 1 lists those patients who do not require referral to an electrophysiologist, and those who do.