Ventricular arrhythmia storm in ischaemic heart disease

When a patient with coronary artery disease develops recurrent ventricular tachycardia or ventricular fibrillation within a short window, the clinical trajectory can deteriorate in minutes. This pattern, often called electrical storm or ventricular arrhythmia storm, is one of the most time-critical presentations in modern cardiology. Treating teams must terminate the arrhythmia, recognise the underlying ischaemic substrate, prevent recurrence, and coordinate the cascade of interventions that follow.

In Australia, where distances between tertiary cardiac centres stretch across vast regions and where many patients first present to non-specialist hospitals, a structured multidisciplinary response has become essential. The interplay between emergency physicians, interventional cardiologists, cardiac electrophysiologists, intensive care specialists, and heart failure teams shapes whether a patient survives the index event and whether secondary prevention succeeds in the months that follow. The sections below examine each layer of that response, with attention to local realities and the evidence base published in the journal's themed journal collections.

Defining the syndrome and identifying the substrate

Ventricular arrhythmia storm is generally defined as three or more sustained episodes of ventricular tachycardia, ventricular fibrillation, or appropriate implantable cardioverter-defibrillator therapies within 24 hours. The threshold is somewhat arbitrary, but it captures the clinical reality of a myocardium generating repetitive lethal rhythms that resist conventional suppression. In patients with ischaemic heart disease, the substrate is most often heterogeneous scar from prior myocardial infarction, where surviving myocyte bundles within fibrotic tissue create the slow-conduction corridors that sustain re-entry.

The distinction matters because it dictates therapy. Acute ischaemia from a new coronary occlusion produces a fundamentally different arrhythmogenic milieu than chronic infarct scar, which determines whether the patient needs emergent revascularisation, substrate-based catheter ablation, or both. Cardiac MRI with late gadolinium enhancement has transformed our ability to characterise scar burden before ablation, and emerging prognostic data are reviewed in an imaging biomarker analysis archived within the journal.

Acute coronary syndromes as the triggering event

When ventricular arrhythmia storm arises during the early hours or days of an acute myocardial infarction, reperfusion is the priority. Australian centres participating in state-based registries such as the Victorian Cardiac Outcomes Registry have emphasised door-to-balloon targets, but electrical storm complicates these pathways because the patient may be too unstable for the catheter lab without preliminary stabilisation. Antiarrhythmic therapy, typically intravenous amiodarone combined with a beta-blocker, runs in parallel with activation of the catheterisation team.

In regional settings, where patients may first reach a non-PCI-capable hospital in towns such as Broken Hill or Mount Isa, early liaison with retrieval services becomes a critical decision point. The Royal Flying Doctor Service and state-based aeromedical retrieval teams are routinely mobilised to transfer patients to tertiary centres, although the decision must be weighed against the risk of arrhythmia during transport. Some services now deploy temporary mechanical support or perform thrombolysis before retrieval, particularly when weather windows are narrow, and protocolised triage remains a continuing focus of quality improvement across the country.

Pharmacological stabilisation in the critical phase

Antiarrhythmic drugs remain the cornerstone of early management while definitive therapy is arranged. Amiodarone, given as a loading infusion, is widely used in Australian emergency departments and coronary care units, often combined with a beta-blocker such as metoprolol or esmolol to blunt sympathetic surge. Where beta-blockade is insufficient, lidocaine is sometimes added, particularly when ischaemia is felt to dominate. Sedation with propofol or dexmedetomidine is often required to reduce the catecholamine-driven substrate for recurrent VT.

Where pharmacological measures fail, ultrasound-guided stellate ganglion block has emerged as a viable intermediate step before catheter ablation, and several Australian centres now maintain protocols for its rapid deployment. The goal during this phase is rhythm control combined with preservation of end-organ perfusion, and clinicians frequently titrate therapy against markers such as lactate clearance and mean arterial pressure. Drug availability is governed by the Pharmaceutical Benefits Scheme for outpatient use and by individual hospital formulary committees for inpatient indications, with newer agents sometimes accessed through the Therapeutic Goods Administration's special access pathway.

Catheter ablation and device-based interventions

When pharmacological measures fail to suppress the storm, catheter ablation becomes the next step. Contemporary Australian practice favours early referral rather than ablation as a last resort, particularly when recurrent VT storms continue despite maximally tolerated antiarrhythmic therapy. The electrophysiologist will typically target the clinical VT alongside all inducible VTs, using a combination of substrate mapping and activation mapping to identify critical isthmi within the infarct scar. Outcomes from high-volume centres such as Royal Melbourne Hospital and Westmead are broadly consistent with international series, with acute procedural success typically reported in the 80–90 per cent range.

Device therapy is central to both bridge and destination treatment. Patients who survive electrical storm without an implantable cardioverter-defibrillator should generally receive one once stabilised, often with a period of inpatient telemetry to ensure the device is not simply delivering recurrent shocks without rhythm control. Some patients require temporary mechanical support during ablation, particularly those with cardiogenic shock or refractory VT. ECMO and Impella devices are increasingly available in major Australian centres, and their use is captured in the ANZICS registry for ongoing quality surveillance.

Building a multidisciplinary response across Australian centres

A functioning pathway typically includes a cardiology admitting team, an on-call electrophysiologist, an interventional cardiologist when ischaemia is suspected, an intensivist, a heart failure physician, and often a cardiac surgeon for mechanical support decisions. Regular case conferences, modelled on the VT rounds used at hospitals such as The Alfred and Royal Prince Alfred, allow the team to align on substrate characterisation, ablation timing, and device strategy. Standardised handover tools reduce the risk of information loss when patients transfer between teams.

Equally important is the network of care extending beyond the quaternary centre. General cardiologists, rural generalists, and Aboriginal Community Controlled Health Organisations often provide long-term follow-up, and cardiogenetics services at major centres can be engaged where hereditary arrhythmia syndromes coexist with coronary disease. TGA-approved remote monitoring platforms now allow device interrogation from remote communities, although patchy telecommunications in outback regions continue to challenge equitable follow-up. Embedding these links into formal referral pathways reduces the likelihood of patients slipping between services once the storm has passed.

Long-term surveillance and secondary prevention strategies

Survivors of ventricular arrhythmia storm face substantial risk of recurrence, particularly in the first 12 months. Secondary prevention therefore extends well beyond the index admission. Optimal medical therapy for the underlying ischaemic substrate—high-intensity statins, antiplatelet agents where indicated, beta-blockade, and renin-angiotensin system inhibition—forms the foundation. Cardiac rehabilitation, which is publicly subsidised through Medicare for eligible patients, provides both exercise training and an opportunity to address the psychological sequelae of repeated ICD shocks.

Arrhythmia-specific surveillance includes regular device interrogation, often via remote monitoring, and a low threshold for re-referral to the electrophysiology team if VT recurs. The role of repeat ablation, escalation of antiarrhythmic therapy, and consideration of adjunctive neuromodulation are all part of the shared decision-making conversation. Clinicians interested in how these themes are evolving across the Asia-Pacific region can explore a storm risk commentary published within the journal, which frames electrical storm within broader questions about probabilistic risk and patient communication.

Researchers and clinicians across Australia and New Zealand are invited to submit case series, original research, and review articles on this topic to the Journal of Arrhythmia, where multidisciplinary work on ventricular arrhythmia storm has become a recurring theme. Sharing local protocols, registry data, and ablation outcomes allows the regional electrophysiology community to keep refining its response to one of cardiology's most demanding presentations, while readers can access related work through the journal's online portal.