Bilateral cardiac sympathetic denervation: the last resort?

Limited Left Thoracoscopic Sympathectomy Effectively Silences Refractory Electrical Storm

BACKGROUND

Electrical Storm is a life-threatening condition that affects up to 20% of patients with ICDs. In this small retrospective study, we report our results with left video-assisted thoracoscopic sympathectomy/ganglionectomy (VATSG) to treat refractory electrical storm in low ejection fraction patients who were not candidates for catheter ablations (CA).

METHODS

We identified 12 patients who presented with electrical storm and underwent a total of 14 video assisted thoracoscopic sympathectomy/ganglionectomy, including three patients on venoarterial extracorporeal membrane oxygenation (VA ECMO). We reviewed demographic data, survival to discharge, number of cardioversions (before and after VATSG), need for readmissions, and need for right-sided procedures.

RESULTS

In the 30 days prior to a left VATSG the mean number of shocks was 22.67 for all patients. For the patients who survived to discharge the mean was 3.55 since surgery with a median of zero shocks after a median follow up of 358 days. Six patients have not experienced any further cardioversions since their last VATSG and five have never been readmitted for VT. Two patients had staged bilateral procedures due to recurrences and of those, one never required any further cardioversions.

CONCLUSIONS

Limited left VATSG is an appropriate and effective initial treatment for ES patients who are not candidates for CA, including patients on VA ECMO for hemodynamic support.

Drug-induced fatal arrhythmias: Acquired long QT and Brugada syndromes

Since the early 1990s, the concept of primary "inherited" arrhythmia syndromes or ion channelopathies has evolved rapidly as a result of revolutionary progresses made in molecular genetics. Alterations in genes coding for membrane proteins such as ion channels or their associated proteins responsible for the generation of cardiac action potentials (AP) have been shown to cause specific malfunctions which eventually lead to cardiac arrhythmias. These arrhythmic disorders include congenital long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, short QT syndrome, progressive cardiac conduction disease, etc. Among these, long QT and Brugada syndromes are the most extensively studied, and drugs cause a phenocopy of these two diseases. To date, more than 10 different genes have been reported to be responsible for each syndrome. More recently, it was recognized that long QT syndrome can be latent, even in the presence of an unequivocally pathogenic mutation (silent mutation carrier). Co-existence of other pathological conditions in these silent mutation carriers may trigger a malignant form of ventricular arrhythmia, the so called torsade de pointes (TdP) that is most commonly brought about by drugs. In analogy to the drug-induced long QT syndrome, Brugada type 1 ECG can also be induced or unmasked by a wide variety of drugs and pathological conditions; so physicians may encounter patients with a latent form of Brugada syndrome. Of particular note, Brugada syndrome is frequently associated with atrial fibrillation whose therapeutic agents such as Vaughan Williams class IC drugs can unmask the dormant and asymptomatic Brugada syndrome. This review describes two types of drug-induced arrhythmias: the long QT and Brugada syndromes.