Modulating the autonomic nervous system for the pur- pose of preventing arrhythmias is an emerging thera- peutic modality. For the prevention of VA, autonomic modulation can be done either through interruption of sympathetic outflow to the heart, pharmacological beta blockade, or through stimulation of the parasym- pathetic pathway (eg, vagal nerve stimulators, spinal cord stimulators). Although autonomic modulation has proven efficacy for certain conditions such as long QT syndrome and catecholaminergic polymorphic ventricu- lar tachycardia (see Section 7.9), evidence is limited for its applicability to the broader group of VA, but studies are ongoing. Currently, there are limited data on the role of vagal nerve stimulators and spinal cord stimula- tors for the prevention of VA/SCD in humans, and thus no formal recommendation could be supported.S5.6-5 Recommendation-Specific Supportive Text 1. Many patients with non life-threatening VA require only reassurance, but others have symp- toms that warrant therapy. A small RCT of patients with symptomatic VA demonstrated a significant reduction in the arrhythmic burden 2. VT/VF storm causes significant morbidity and is associated with increased mortality. For VT/ VF storm refractory to treatment (medications, catheter ablation), cardiac sympathetic denerva- tion has been shown in several small, observa- to reduce the arrhythmia burden. This has been shown for left or bilateral cardiac sympathetic denervation, and it has been suggested that bilateral cardiac sympathetic denervation may be superior.S5.6-3 Although data are limited, the significant morbid- ity and limited options in these patients make car- diac sympathetic denervation a reasonable option in selected patients. 6. Acute Management of Specific VA Recommendations for Management of Cardiac Arrest References that support the recommendations are summarized in Online Data Supplements 15 and 16. 