Ventricular arrhythmia storm in the era of implantable cardioverter-defibrillator

Abstract

In the era of widespread use of implantable cardioverter-defibrillators (ICDs) for both primary and secondary prevention of sudden cardiac death, a significant proportion of patients experience episodes of multiple ventricular tachycardia/fibrillation over a short period of time requiring device interventions. The episodes are termed ventricular arrhythmia (VA) or electrical storms. VA storm is a tragic experience for patients, with many psychological consequences. Current management for VA storms remains complex. Acutely, administration of β-blockers, amiodarone and sedation or intubation is generally required to suppress sympathetic tone. Interventional treatment includes catheter ablation and sympathetic blockade by left cardiac sympathetic denervation. Strategies to modify autonomic tone to suppress VAs are the rationale of various novel interventions that have been published in recent studies. All patients with VA storm should be considered for transfer to an experienced high-volume tertiary centre for evaluation and treatment to prevent further recurrence of VA storm.

Beyond the Storm: Comparison of Clinical Factors, Arrhythmogenic Substrate, and Catheter Ablation Outcomes in Structural Heart Disease Patients With versus Those Without a History of Ventricular Tachycardia Storm

“…2 The mechanism is likely mediated by a complex interplay between neurohormonal changes, abnormalities in calcium-related signaling and protein phosphorylation abnormalities, 29 and a predisposing electrophysiological substrate. 1 We showed that storm patients have different extent and distribution of endocardial low voltage scar on intracardiac mapping, specific to cardiomyopathy type that may help explain their electrophysiologic vulnerability. Although abnormalities in electrophysiology properties have been speculated, no study prior to ours has compared the electroanatomic mapping features of storm versus nonstorm patients.…”

“…Storm is recognized as a distinctive clinical arrhythmia syndrome with specific management and prognostic implications portending an increased risk of death, heart transplantation, and heart failure hospitalization . The mechanism is likely mediated by a complex interplay between neurohormonal changes, abnormalities in calcium‐related signaling and protein phosphorylation abnormalities, and a predisposing electrophysiological substrate . We showed that storm patients have different extent and distribution of endocardial low voltage scar on intracardiac mapping, specific to cardiomyopathy type that may help explain their electrophysiologic vulnerability.…”

“…We do not have complete information on the impact of other factors such as the duration of arrhythmia history, infarct characteristics such as reperfusion and presence of persistent occlusion that would be of interest as potential markers of storm risk. However, the role of such factors has been evaluated in prior studies on ICD recipients in the nonablation setting …”

“…However, the role of such factors has been evaluated in prior studies on ICD recipients in the nonablation setting. 1,2,[5][6][7]28,[30][31][32] We did not examine the prevalence of electrophysiologic markers of substrate such as delayed, fractionated or isolated late potentials in storm versus nonstorm patients, nor did we collect information on the density of mapping points for each case. Given the long recruitment time period of this study, evolution in the patient population and technology, including mapping and ablation systems occurred and the impact of these factors cannot be completely addressed in a retrospective study.…”

“…Electrical storm, defined as 3 or more sustained episodes of ventricular arrhythmia or appropriate implantable cardioverter-defibrillator (ICD) shocks during a 24-hour period afflicts 3.5-4% of primary prevention and 10-40% of patients with a secondary prevention ICD. 1 It carries an ominous prognosis with an increased future risk of arrhythmic and cardiac death. 2 Percutaneous catheter ablation, as an adjunct to antiarrhythmic drugs (AADs), reduces the burden of ICD shocks 3 and can be lifesaving in ventricular tachycardia (VT) storm.…”