1. DANTE PAZZANESE INSTITUTE OF CARDIOLOGY, SÃO PAULO, BRAZIL
Renal sympathetic denervation: new treatment for the electrical storm in patients with ICD. D.Moreira, L.V Armaganijan, R. Staico, R.G Habib, P.T.J Medeiros, A. Abizaid
DANTE PAZZANESE INSTITUTE OF CARDIOLOGY, SÃO PAULO, BRAZIL
INTRODUCTION
Electrical storm is a catastrophic event that affects patients (P) with severe cardiomyopathy and is not a rare complication in P with ICD. The causes are multifactorial. Adrenergic hyperactivity plays an important role in the initiation and maintenance of ventricular arrhythmias (VA). Treatment of this severe condition may include radiofrequency ablation, complete sedation and sometimes intraaortic baloon counterpulsation. The results, however are not always encouraging and other approaches may be necessary. Renal sympathetic denervation (RSD) has been demonstrated to decrease the adrenergic influence on cardiovascular system and it has been used for the treatment of P with refractory hypertension. There are anecdotal reports showing benefits of this procedure for the treatment of P with electrical storm.
Objective: To evaluate the effects of RSD in P with ICD hospitalized with electrical storm
METHODS
We included in this series 10P (mean age 64±6 years; 6P with Chagas disease, 2P with dilated idiopathic cardiomyopathy and 2P with ischemic cardiomyopathy, mean EF 31.7±11 %) admitted with at least three episodes of VT/VF (ranging from 8 to 106 episodes) requiring shocks or repeated ATP therapies within 24h. All P were considered refractory to antiarrhythmic therapy, including maximum tolerated dose of amiodarone, lidocaine, magnesium sulfate and beta- blocker and were not candidates
for ablation of the arrhythmogenic focus (3P had intracavitary thrombus; 5P polymorphic VT, and 2P had prior failed ablation). After clinical stabilization, all P underwent RSD. Radiofrequency energy was applied to both renal arteries, starting from the distal portion towards the proximal portion with a distance of at least 0.5 cm between each lesion by means of irrigated tip catheter. Mean procedure time was 30 min.
RESULTS
All P tolerated the procedure well without complications. The mean number of lesions was 5.5±3.4/artery/P. After the prodeure two P had VT within the first week after RSD and were successfully treated by 5J internal shock with no VA recurrence. One P had accelerated idioventricular rhythm one week later which was successfully treated by RF ablation. In one P, RSD was unsuccesfull (multiple renal arteries) and was submitted to RF ablation thirty days later. Three patients died 18 days and 30 days due to refractory congestive heart failure and, 75 days after RSD due to sepsis . No more episodes of sustained VA were seen during the follow-up (mean of 6.3±3 mo, ranging from 2 mo to 15 mo). The median number of VT/ATP/shocks decreased from 28.5/20.5/8 to 1/0/0 at 1 mo and 6 mo after RSD, respectively (p<0,001).
CONCLUSIONS
a) RSD is an effective and safe technique for the treatment of electrical storm b) RSD may be indicated in P when other forms of nonpharmacological treatments are contraindicated or ineffective; c) larger sample size and longer follow-up are needed to confirm our results.