Ranal Denervation For Ventricular Arrhythmia

Aims: Sudden cardiac death is the leading cause of death among patients with cardiovascular disease.About half of sudden cardiac death are due to VT(Ventricular Tachycardia)or VF(Ventricular Fibrillation).Most VT/VF of structural heart disease are lack of reliable therapies,therefore ICD(Implantable Cardioverter Defibrillator)plus anti-arrhythmia drug are the preferred treatments.Cardiac RFCA(Radiofrequency Catheter Ablation)can also be used to reduce VT/VF episodes and improve symptoms.Even though,some VT/VF patients with structural heart disease still remains difficult to control,and it is need to explore more effective treatment methods.The sympathetic nervous system plays an important role in the occurrence,maintenance and termination of ventricular arrhythmia.Even mild changes of sympathetic nerve activity can deteriorate or improve ventricular arrhythmia.Focusing on adjusting the sympathetic nervous system by ablation of the afferent and efferent nerves around the outer membrane of renal artery,RDN(Renal Denervation)has been used for the related diseases,like hypertension,heart failure and atrial fibrillation for several years.The aim of this study is to investigate the efficacy of RDN on the recurrence of ventricular arrhythmia in Chinese patients with ICD.Methods: From April 2012 to February 2015,patients with structural heart disease and ICD were consecutively recruited in this study.Inclusion criteria were that patients between 18-75 years old and documented recurrent ventricular arrhythmia(including electrical storm)in ICD.Exclusion criteria were that patients showed allergic reaction to contrast agent,active infection,systolic blood pressure ≤ 80 mmHg or vascular vasopressors(such as dopamine)were used,history of renal artery stenosis or stent,prior renal artery CTA showed unsuitable conditions for ablation and declination of participation in this study.Eligible patients then underwent RDN and were followed up for at least 6 months.The before and after procedure ventricular arrhythmia episodes were counted via ICD interrogation.All statistical analyses were performed using SPSS 13.0.Continuous variables were represented as mean ± SD or median and range.Dichotomous variables were described as numbers and percentages.N-terminal pro-brain natriuretic peptide,ceatinine,heart rate,blood pressure,VT/VF burden,ICD shock and ATP(antitachycardia pacing)were assessed using the nonparametric wilcoxon signed rank test.All tests were two tailed and statistical significance was accepted at p value of 0.05.Results: Eight structural heart disease patients with ICD and recurrent ventricular arrhythmia episodes were enrolled in this study.The mean age and left ventricular ejection fraction were 51.4 ± 14.3 years and 48.3 ± 17.1% respectively.Among these patients,seven were male,one was ischemic cardiomyopathy and seven were non-ischemic cardiomyopathy(1 hypertrophic cardiomyopathy,5 dilated cardiomyopathy,1 idiopathic cardiomyopathy with left ventricular aneurysm).ES occurred in five cases and two patients underwent a previous unsuccessful cardiac RFCA.Finally,all of these patients underwent bilateral RDN successfully without any complications.The median follow-up before and after RDN was 16 months(range 3 to 44)and 15 months(range 6 to 30)respectively.The median ventricular arrhythmia episodes per month were significantly reduced from 3.17(range 0.33 to 15.33)before RDN to 0.11(range 0 to 5.83)after RDN(P < 0.05).The median ATP/month and Shock/month before RDN were 4(range 0 – 28)and 1.17(range 0 – 11.67)and were significantly reduced to 0.11(range 0 – 10.5)and 0.04(range 0 – 3.33)after RDN(P < 0.05).Six months after RDN,ceatinine,heart rate and blood pressure were unchanged,but N-terminal pro-brain natriuretic peptide was significantly decreased from 661.37 ng/L to 461.86 ng/L.Conclusion: RDN is an effective suppressor of ventricular arrhythmia in patients with ICD,and it can serve as a useful adjunct treatment to cardiac RFCA.RDN is especially suitable for patients who have heart failure and refractory ventricular arrhythmia,and patients who cannot tolerate large dosage of beta-blockers or cannot carry out cardiac RFCA.