Cardiovascular autonomic reflex function after bilateral cardiac sympathetic denervation for ventricular arrhythmias

Outcomes following cardiac sympathetic denervation in patients with structural heart disease and refractory ventricular arrhythmia

Aim

Cardiac sympathetic denervation (CSD) has been introduced as a bailout therapy in patients with structural heart disease and refractory ventricular arrhythmias (VAs), but available data are scarce. Purpose of this study was to estimate immediate results, complications, and mid-term outcomes of CSD following recurrent VA after catheter ablation.

Methods and results

Adult patients who underwent CSD in the Heart Center Leipzig from March 2017 to February 2021 were retrospectively analysed. Follow-up (FU) was executed via implantable cardioverter defibrillator (ICD) interrogation, telephone interviews, and reviewing medical records. Twenty-one patients (age 63.7 ± 14.4 years, all men, 71.4% non-ischaemic cardiomyopathy, left ventricular ejection fraction 31.6 ± 12.6%) received CSD via video-assisted thoracoscopic surgery (90.5% bilateral, 9.5% left-sided only). Indication for CSD was monomorphic ventricular tachycardia in 76.2% and ventricular fibrillation in 23.8 with 71.4% of patients presenting with electrical storm before index hospitalization. Procedure-related major complications occurred in 9.5% of patients. In-hospital adverse events not related to surgery were common (28.6%) and two patients died during the index hospital stay. During FU (mean duration 9.1 ± 6.5 months), five more patients died. Of the remaining patients, 38.5 and 76.9% were free from any VA or ICD shocks, respectively.

Conclusions

The CSD showed additional moderate efficacy to suppress VAs, when performed as a bailout therapy after previously unsuccessful catheter ablation. At 9 months, it was associated with freedom of ICD shocks in two-thirds of patients. In a population with many comorbidities, the rate of CSD-related complications was acceptable, although there was an overall high risk of procedure unrelated adverse events and death.

Aorticorenal ganglion as a novel target for renal neuromodulation

BACKGROUND

Clinical trials for renal artery (RA) ablation have shown limited efficacy.

OBJECTIVE

The purpose of this study was to investigate whether the aorticorenal ganglion (ARG) can be targeted for renal denervation.

METHODS

Twenty-eight pigs were studied under isoflurane or alpha-chloralose to examine hemodynamic responses and catecholamine release in response to RA or ARG stimulation. To assess the efficacy of ARG ablation, we randomized 16 pigs to either sham, RA, or ARG ablation, followed by occlusion of the left anterior descending coronary artery (LAD). Hemodynamic responses, cardiac electrophysiological parameters, and arrhythmias/sudden cardiac death were assessed following LAD occlusion. Absent hemodynamic responses to stimulation confirmed ARG or RA ablation. In vivo stellate ganglion neural activity was recorded to assess cardiac sympathetic signaling. Cadaveric dissections were performed to localize the ARG in humans for comparison to swine.

RESULTS

The ARG is a purely sympathetic ganglion with cholinergic inputs and pass-through sensory afferent fibers. Compared to RA stimulation, ARG stimulation yielded greater hemodynamic responses during alpha-chloralose anesthesia. However, neither site yielded significant responses under isoflurane. Radiofrequency ablation of the ARG eliminated responses to both RA and ARG stimulation, whereas RA ablation did not eliminate responses to ARG stimulation. Ablation of the ARG did not impact the kidneys or adrenal glands. Compared to control and RA ablation, ARG ablation was protective against ventricular arrhythmias and sudden death. Human and swine ARG are similarly located in the aorticorenal region.

CONCLUSION

Our findings indicate that the ARG may be a novel target for renal neuromodulation. Further studies are warranted to validate these findings.

Cardiac sympathetic denervation and mental health

BACKGROUND

Bilateral cardiac sympathetic denervation (BCSD) is a surgical treatment for refractory ventricular arrhythmias. Although the procedure has shown efficacy at reducing cardiac arrhythmias, its impact on mental health is unknown. In the current study we examined associations between the BCSD procedure and mental health.

METHODS

10 ventricular arrhythmia patients undergoing BCSD completed assessments of anxiety, depression, and posttraumatic stress symptoms at pre- and post-BCSD time points. Wilcoxon signed rank and Mann-Whitney U tests were used to examine differences in mental health symptoms in the pre- and post-BSCD states. Point biserial correlations were used to explore associations between BCSD response and mental health symptoms.

RESULTS

A significant reduction of anxiety symptoms was observed from pre- to post-BCSD. At the post-BCSD assessment, participants who successfully responded to the BCSD procedure exhibited lower anxiety symptoms compared to non-responders. However, no significant relationships were identified for depressive or PTSD symptoms.

CONCLUSION

The BCSD procedure is associated with reduced anxiety shortly after successful treatment for refractory ventricular arrhythmias in a small sample. Longitudinal surveillance of mental health symptoms after BCSD may be warranted to monitor the impact of this procedure on mental health.