key: cord-0907707-hegk7m0e authors: Pillai, Ajay; Koneru, Jayanthi N.; Ellenbogen, Kenneth A.; Padala, Santosh K. title: Autonomic Modulation for Treatment of Repolarization Alternans and Refractory Ventricular Electrical Storm date: 2021-09-15 journal: JACC Case Rep DOI: 10.1016/j.jaccas.2021.06.040 sha: 91de38ebc2ee950d69d4096383bd676de3454f0a doc_id: 907707 cord_uid: hegk7m0e Macroscopic T-wave alternans (TWA) is a rare finding on surface electrocardiogram and has been associated with an increased risk of impending sudden cardiac death. We highlight a case of macroscopic TWA in a patient with markedly prolonged QTc interval preceding ventricular electrical storm, which was refractory to medical management. Autonomic modulation of the stellate ganglion resulted in improvement in both TWA and QTc interval. (Level of Difficulty: Advanced.) To identify macroscopic T-wave alternans as a rare but grave sign of ventricular electrical instability. To review the role of sympathetic nervous system modulation through stellate ganglion blockade as a useful adjunct for treatment of medically refractory ventricular electrical storm. To understand the role of stellate ganglion blockade in attenuating T-wave alternans. The patient had a history of recurrent syncope thought to be caused by seizures. She was medicated chronically with levetiracetam. Her daughter had a history of sudden cardiac death (SCD) and implantable cardioverter-defibrillator (ICD) insertion at 30 years of age. The differential diagnosis included congenital vs ac- To perform SGB, ultrasound is utilized to visualize the longus colli muscle, hyoid and thyroid cartilages, internal jugular vein, carotid artery, and occasionally the stellate ganglion itself ( Figure 6 ). The anterior QTc interval 597 ms and T-wave alternans has resolved, although increased heart rate must be considered compared to prior electrocardiogram. Table 1 . The patient had no ICD shocks at 6-month follow-up. Genotyping revealed VUS in the CACNAIC, KCNA1, and KCNQ1 genes. Family member screening is being pursued. The 12-lead ECG at time of outpatient follow-up was unavailable for analysis. Macroscopic TWA is a grave marker of electrophysiological instability. Autonomic modulation of the Twitter: @AjayPMD, @santosh_padala, @KennethEllenbo1, @jaykoneru. T-wave alternans and the susceptibility to ventricular arrhythmias Cardiac alternans: mechanisms and clinical utility in arrhythmia prevention Repolarization alternans: implications for the mechanism and prevention of sudden cardiac death Mechanisms linking T-wave alternans to spontaneous initiation of ventricular arrhythmias in rabbit models of long QT syndrome Comparison of symptomatic and functional responses to vagus nerve stimulation in ANTHEM-HF, INO-VATE-HF, and NECTAR-HF Autonomic regulation therapy via left or right cervical vagus nerve stimulation in patients with chronic heart failure: results of the ANTHEM-HF trial Neuromodulation for the treatment of heart rhythm disorders Stellate ganglion blockade and bilateral cardiac sympathetic denervation in patients with life-threatening ventricular arrhythmias Effective use of percutaneous stellate ganglion blockade in patients with electrical storm Cardiac sympathetic denervation in patients with refractory ventricular arrhythmias or electrical storm: Intermediate and long-term follow-up Stellate ganglion blockade for the treatment of refractory ventricular arrhythmias Beyond the one gene-one disease paradigm complex genetics and pleiotropy in inheritable cardiac disorders