Electrical storm management in structural heart disease

Abstract

Electrical storm (ES) is a life-threatening condition characterized by at least three separate episodes of ventricular arrhythmias (VAs) over 24 h, each requiring therapeutic intervention, including implantable cardioverter defibrillator (ICD) therapies. Patients with ICDs in secondary prevention are at higher risk of ES and the most common presentation is that of scar-related monomorphic VAs. Electrical storm represents a major unfavourable prognostic marker in the history of patients with structural heart disease, with an associated two- to five-fold increase in mortality, heart transplant, and heart failure hospitalization. Early recognition and prompt treatment are crucial to improve the outcome. Yet, ES management is complex and requires a multidisciplinary approach and well-defined protocols and networks to guarantee a proper patient care. Acute phase stabilization should include a comprehensive clinical assessment, resuscitation and sedation management skills, ICD reprogramming, and acute sympathetic modulation, while the sub-acute/chronic phase requires a comprehensive heart team evaluation to define the better treatment option according to the haemodynamic and overall patient’s condition and the type of VAs. Advanced anti-arrhythmic strategies, not mutually exclusive, include invasive ablation, cardiac sympathetic denervation, and, for very selected cases, stereotactic ablation. Each of these aspects, as well as the new European Society of Cardiology guidelines recommendations, will be discussed in the present review.

Electrical storm treatment by percutaneous stellate ganglion block: the STAR study

“…The strong connection between the autonomic nervous system and ventricular arrhythmias was elegantly demonstrated in the 1970s 7 , 8 and recently reviewed. 5 , 17 , 21 Neuronal sympathetic activation decreases the VF threshold and ventricular refractoriness. 7 , 8 Neuronal sympathetic activation increases spatial dispersion of repolarization and, in the setting of structurally abnormal hearts, even paradoxically prolongs activation time, 22 making it more likely for all types of ventricular arrhythmias to occur and perpetuate.…”

“…ES is a relatively common condition, occurring in ∼5% of patients with an implantable cardioverter defibrillator (ICD) implanted for primary prevention and in 25% of patients implanted for secondary prevention. 3 , 4 Traditional treatments, either pharmacological or non-pharmacological, 5 , 6 are few and often not rapidly effective or available at all hospitals. Therefore, there is an unmet need for additional therapeutic options.…”

The Intrinsic Cardiac Nervous System: From Pathophysiology to Therapeutic Implications

“…As already mentioned, sympato-vagal balance is of pivotal importance for ventricular electrical stability, both in structurally normal hearts [26,126] as well as in cardiac pathology [127,128], independently from the etiology. As a general concept, at the ventricular level, sympathetic activation is pro-arrhythmic while the parasympathetic one is antiarrhythmic, with extremely rare exceptions.…”

Etiologies, Mechanisms, Management, and Outcomes of Electrical Storm

“…Outcomes of catheter ablation of ES are excellent with resolution of storm in up to ∼90% of patients at 1 year 2,107 with a low complication rate (∼2%). 2 Despite its undeniable efficacy, RF ablation in patients presenting with ES is challenging, even when performed in high-volume centers, and is associated with an increased risk of peri-procedural morbidity and mortality compared with VT ablation in patients without ES.…”

“…108 A comprehensive overview of management of patients with ES and structural heart disease proposed by Dusi and colleagues is summarized in figure 6. 107…”