Stellate Ganglion Phototherapy Using a Portable Radiation Device, for Destination Therapy of Drug-Refractory Ventricular Tachycardia

Several studies have demonstrated the efficacy of stellate ganglion phototherapy (SGP) for drug-refractory ventricular arrhythmia (VA), primarily as a temporary or adjunctive measure prior to antiarrhythmic titration, ablation, surgical sympathectomy, and heart transplantation. ^{1 , 2} SGP employs near-infrared light to target the cervical region, presents a less-invasive alternative to surgical interventions, and is expected to become a destination therapy for outpatients. However, the long-term efficacy and frequency-dependent effects of portable SGP devices remain unclear. We present a case of a nonischemic cardiomyopathy patient with drug-refractory VA showing frequency-dependent suppression and sustained management for > 1 year using a portable SGP device.

A 72-year-old man with nonischemic cardiomyopathy, symptomatic heart failure, and reduced ejection fraction underwent cardiac resynchronization therapy with defibrillator implantation. During the follow-up period, the patient experienced multiple episodes of VA with an inferior axis, necessitating appropriate anti-tachycardia pacing and shocks, thus requiring catheter ablation. Catheter ablation was performed twice, including with an epicardial approach. The sustained ventricular tachycardia (VT) was terminated once during energy application beneath the aortic valve (Fig. 1A); however, VAs originating from the intramural region of the anterior ventricular septum persisted. Although nonsustained VA was observed frequently during the hospital stay, SGP using the EXCEL Glanz X2 device (KOKUSAI COMMERCE, Tokyo, Japan; wavelength, 800-1000 nm; Fig. 1B) was initiated in the bilateral cervical regions (10 minutes), showing a dramatic reduction in VA burden, especially during the daytime. The patient was discharged from the hospital, and the detection interval for VA was reprogrammed from 28 to 40 to mitigate unnecessary therapy in response to self-terminating episodes.

Figure 1.

(A) Twelve-lead electrocardiogram of ventricular tachycardia and catheter ablation sites during the initial procedure. Multiple energy applications were delivered, targeting ventricular arrhythmia originating from the anterior septum, but failed. (B) Features of stellate ganglion phototherapy devices. CS, coronary sinus; LAO, left anterior oblique; LV, left ventricle; RAO, right anterior oblique.

During the follow-up period, VTs requiring implantable cardioverter defibrillator therapies persisted, and nonsustained VT gradually increased while the patient was on sotalol. Consequently, amiodarone was added, and sotalol was then discontinued. Although VAs were controlled temporally using amiodarone, the number of VA episodes with 3 different cycle lengths requiring implantable cardioverter defibrillator therapy progressively increased (Fig. 2), particularly during a hospitalization for fever due to suspected cholangitis. The patient underwent testing to assess the feasibility of portable SGP, Superlizer mini device (Tokyo Iken, Tokyo, Japan; wavelength, 600-1800 nm; Fig. 1B), for drug-refractory VA. SGP was performed once daily in the morning by the patient for 2 months, resulting in a reduction in VA episodes, although VA was documented as occurring sporadically from evening to midnight. Surgical sympathectomy was proposed, but it was declined by the patient due to concerns about potential complications. While the SGP showed efficacy, bisoprolol was increased in the hope of suppressing the VAs, but it failed to do so.

Figure 2.

Frequency of appropriate ventricular tachycardia therapies, nonsustained ventricular tachycardia, and the timeline of anti-arrhythmic drug administration and frequency of stellate ganglion phototherapy. Of note, a prompt and frequency-dependent reduction of ventricular arrhythmia burden occurred, which was maintained over the course of a year. ABL, ablation; ATP, anti-tachycardia pacing; NSVT, nonsustained ventricular tachycardia; SGP, stellate ganglion phototherapy.

After discussions, the patient opted to purchase a Superlizer Mini (Tokyo Iken) for personal use. The frequency of SGP increased to twice daily (morning and evening), resulting in dramatic VA suppression for > 1 year despite de-escalation of amiodarone (Fig. 2). Only 2 VT episodes requiring appropriate therapies were recorded during this period—one associated with fever, and the other when SGP was interrupted once. No adverse events related to SGP occurred.

The autonomic nervous system plays a critical role in VA development and maintenance. Various strategies, including stellate ganglion blockade,^3,4 cardiac sympathetic denervation (CSD),⁵ and SGP, have been developed to modulate the autonomic nervous system for VA management (Supplemental Fig. S1).^1,2 Stellate ganglion blockade (SGB) can be performed promptly by a trained physician without the need for a specialized facility. SGB is less invasive than CSD, and major complications are rare. A recent study demonstrated that SGB can be administered safely to patients receiving antiplatelet or anticoagulant therapy³; however, minor complications, such as hoarseness, light-headedness, brachial plexus blockade, and hematoma, have been reported.⁴ The effectiveness of SGB depends on the choice of pharmacologic agents and the infusion protocol, although it is generally employed as a temporary therapeutic measure. In contrast, CSD has demonstrated efficacy in patients with structural heart disease and refractory VAs. However, CSD carries a substantial risk of complications, including hemothorax, pneumothorax, and ptosis, even when it is performed at experienced centres.⁵ To date, no study has directly compared the efficacy and safety of different autonomic modulation techniques. SGP has emerged as a noninvasive alternative, with studies highlighting its potential role in managing drug-refractory VA, predominantly as a temporal therapy before definitive management.^1,2 SGP utilizes near-infrared light to irradiate the cervical region, offering a safer option for high-risk surgical candidates. An important aspect of SGP is that it can be utilized by patients themselves, without concern, thus having potential to become a destination therapy for outpatients. This case showed the sustained therapeutic efficacy of SGP for > 1 year in a patient with nonischemic cardiomyopathy. Notably, this case also highlights the fact that the efficacy of each SGP waned within 12 hours and was overcome by increasing the frequency of SGP (a frequency-dependent effect). Based on these findings, we recommend twice-daily SGP as the optimal protocol for in-home destination therapy.

The antiarrhythmic effects of SGP appear to extend beyond sympathetic activity inhibition by beta-blocker up-titration and may involve anti-inflammatory actions via neuroimmune regulation.⁶ In this case, beta-blocker up-titration yielded no additional benefit. Nevertheless, SGP showed a rapid reduction of VA burden. Although not all patients with drug-refractory VA showed positive responses to SGP,² dramatic and rapid improvements were observed in certain responders, as in our case. This dynamic, positive SGP effect may assist in the identification of suitable candidates for in-home SGP treatment using portable devices. Thus, in-home SGP using a portable device may be an alternative destination therapy for outpatients with drug-refractory VA. However, no definitive evidence exists, and a prospective study is warranted to confirm this finding.

Stereotactic radiotherapy also has been demonstrated to be a novel noninvasive treatment for refractory VA.⁷ However, SGP provides several advantages over radiotherapy. First, SGP is more cost-effective and can be implemented more readily, compared to radiotherapy, which requires specialized facilities and trained personnel. Second, SGP may be effective in patients with VAs, regardless of the extent of the arrhythmic substrate. In the present study, VAs with 3 distinct tachycardia cycle lengths were documented during follow-up, suggesting the presence of multiple VA circuits. In contrast, the efficacy of radiotherapy is highly dependent on accurately identifying the precise origin of the arrhythmia, and its clinical benefit may be limited in patients with an extensive arrhythmic substrate, due to concern regarding complications. Third, SGP is a completely noninvasive therapy, and no procedure-related complications have been reported to date. Conversely, radiotherapy carries risks, including pericardial effusion, myocardial injury, heart failure exacerbation, and mitral regurgitation.⁷ Additionally, data on long-term outcomes following radiotherapy remain limited. Fourth, the response to SGP appears to manifest early, allowing timely identification of responders. In cases in which patients do not exhibit a positive response to SGP, and radiotherapy is clinically available, radiotherapy may be considered as a last-resort therapeutic strategy for refractory VA.

Novel Teaching Points.

• •SGP is a noninvasive modality for autonomic modulation.
• •Clinically, SGP is utilized primarily as a temporary or adjunctive intervention prior to definitive treatment; its long-term efficacy remains largely unexplored.
• •In the presented case, SGP exhibited a frequency-dependent effect, with twice-daily radiation successfully suppressing VA for > 1 year.
• •In select patients, continuous autonomic modulation via a portable SGP device in an outpatient setting may serve as a destination therapeutic strategy for the management of refractory VA.