Renal Sympathetic Denervation For Electrical Storm(2 Cases Report)

Electrical storm(ES)refers to a state of cardiac electrical instability that is defined by ≥3 episodes of sustained VT,VF or appropriate shocks from an implantable cardioverter defibrillator(ICD)within 24 h.Clinical presentation can be dramatic in most cases and triggering mechanism are not clear at all yet,but electrical storm is associated with high mortality rates and low quality of life,both in the acute phase and in the long term.At present,the first line therapy is based on anti-arrhythmic drugs and catheter ablation to suppress ES,but in refractory patients,interventions such as cardiac sympathetic denervation might be helpful.The main way of cardiac sympathetic denervation reducing the occurrence of ES is to decrease the excitability of sympathetic nerve.However,there are multiple complications in this surgery,which limit its application.Similarly to cardiac sympathetic denervation,renal sympathetic denervation(RSD),which specifically blocking renal efferent and afferent nerves,can also reduce the excitability of sympathetic nerve.At present,many studies have shown that RSD can effectively reduce the occurrence of ES,and there are no complications such as renal dysfunction,renal artery stenosis and so on.Two patients with repeated ES had poor response to drug therapy or cardiac catheter ablation.The first patient,a 60-year-old female with idiopathic ventricular aneurysm,presented ES repeatedly after the use of a variety of anti-arrhythmic drugs and twice endocardial ablation.The patient was treated with RSD in July 17,2015.Although the patient presented ES time after time during the first 3 months after RSD as before,there were no more ES since then.When we followed up to 30 months,only one ventricular tachycardia occurred,that was terminated by one antitachycardia pacing therapy.The second patient with hypertrophic cardiomyopathy arose three ESs during the last 3 months before RSD.However,the patient had only one ventricular tachycardia event without ES during 42 months post-RSD.No significant changes were observed in renal function,average heart rate and glycosylated hemoglobin of the two patients after RSD.Our finds suggest that RSD could decrease the occurrence of ES effectively and safety.Randomized controlled clinical trials are needed to study the effects of RSD in patients with ES.