Renal denervation as adjunctive therapy to cardiac sympathetic denervation for ablation refractory ventricular tachycardia.

BACKGROUND: Autonomic modulation is finding an increasing role in the treatment of ventricular arrhythmias. Renal denervation (RDN) has been described as a treatment modality for refractory ventricular tachycardia (VT) in case series. OBJECTIVE: The purpose of this study was to evaluate RDN as an adjunctive therapy to cardiac sympathetic denervation (CSD) for ablation refractory VT. METHODS: Patients who underwent RDN after radiofrequency ablation and CSD procedures at our center from 2012 to 2019 were evaluated. RESULTS: Ten patients underwent RDN after CSD (9 bilateral and 1 left-sided only) with a median follow-up of 23 months. The mean age was 59.9 ± 10.4 years, and 9/10 (90%) were men. All had cardiomyopathy with a mean ejection fraction of 33% ± 11% (20% ischemic). Four (40%) underwent CSD during the same hospitalization as that for RDN. Patients who underwent RDN as adjunctive therapy to CSD had a decrease in all implantable cardioverter-defibrillator therapies (shocks + antitachycardia pacing [ATP]) from 29.5 ± 25.2 to 7.1 ± 10.1 comparing 6 months pre-RDN to 6 months post-RDN (P = .028). Implantable cardioverter-defibrillator shocks were significantly decreased from 7.0 ± 6.1 to 1.7 ± 2.5 comparing 6 months pre-RDN to 6 months post-RDN (P = .026). This benefit was driven by a decrease in therapies for 6 patients who had a staged procedure, not performed during the same hospitalization (28.5 ± 24.3 to 1.0 ± 1.2; P = .043). CONCLUSION: RDN demonstrates the potential benefit when VT recurs after radiofrequency ablation and CSD. The benefit is seen in patients who undergo a staged procedure. The need for acute RDN after CSD portends a poor prognosis.

Autonomic Regulation and Ventricular Arrhythmias.

Autonomic nervous system (ANS) has a crucial role of regulating cardiac function in the physiological state and contributes to the pathogenesis of arrhythmias in the diseased state. The cardiac neuraxis consists of multiple feedback loops consisting of efferent and afferent limbs, mediating neurotransmission to and from the heart. Efferent parasympathetic neurotransmission is mediated by the vagus nerve, while paravertebral sympathetic ganglia relay efferent sympathetic neurotransmission to the heart. The association between autonomic activity and ventricular arrhythmias (VAs) has been studied extensively in both experimental models and humans. Efferent parasympathetic activity is felt to be antiarrhythmic, while the activation of efferent sympathetic signals is proarrhythmic. The cardiac neuraxis undergoes remodeling and becomes dysfunctional in the setting of myocardial infarction (MI), chronic cardiomyopathy (CMY), and structural heat disease. Altered ANS function has been shown to initiate and/or maintain VAs via various mechanisms. Interventions targeting the ANS have been used clinically to treat VAs, particularly in patients with hereditary heart rhythm disorders and structurally abnormal hearts. Clinical applications of cardiac neuraxial modulation at the level of spinal cord, stellate ganglion, and peripheral sympathetic and vagus nerve are being developed. In this review, the anatomy of cardiac autonomic innervation, the association between autonomic activity and ventricular arrhythmogenesis, and clinical applications of neuraxial modulation in the treatment of VAs are discussed.