ICD therapy effective in patients with Brugada syndrome
In patients with Brugada syndrome, implantable cardioverter defibrillator therapy was effective and treated potentially lethal arrhythmias in 17% of patients during a 20-year, single-center study.
“The purpose of this study was to analyze our single-center experience with ICD therapy in patients with Brugada syndrome over the past 20 years, since the first description of the syndrome,” researchers wrote.
The prospective study included 176 consecutive patients included in a registry who received an ICD for Brugada syndrome between 1992 and 2012.
Patient clinical follow-up included physical examinations and electrocardiology at least every 6 months. Device follow-up was conducted at 1 month and 3 months postimplantation and subsequently, every 6 months. Mean follow-up was 83.8 ± 57.3 months.
Episodes of arrhythmia that received ICD therapies were predefined based on the cycle lengths of the arrhythmias. At least two investigators individually reviewed all available electrograms of appropriate and inappropriate shocks.
Appropriate therapies were defined as shocks or anti-tachycardia pacing administered for ventricular tachycardia or ventricular fibrillation. Inappropriate therapies were defined as those administered in the absence of ventricular arrhythmias. The researchers defined electrical storm as three or more sustained events of ventricular tachycardia, ventricular fibrillation or appropriate ICD therapy within 24 hours.
Thirty patients had spontaneous, sustained ventricular arrhythmias (17%) and eight (4.5%) patients died. In addition, 28 patients (15.9%) received appropriate ICD shocks, 33 patients (18.7%) received inappropriate shocks and four of the patients experienced electrical storm (2.3%). Twenty-eight (15.9%) patients had device-related complications including fractures of the ventricular electrode and subsequent extraction and replacement, lead dislocations and pulse generator migration; all complications led to revisions of the device.
Multivariate Cox regression analysis revealed that aborted sudden cardiac death and ventricular arrhythmias and ability to induce ventricular arrhythmias on electrophysiologic studies were independently predictive of appropriate shock delivery.
According to the researchers, the use of electrophysiologic studies may be useful in better understanding patient risk.
“On the basis of our findings, risk stratification by means of [electrophysiologic] studies might identify asymptomatic patients at risk for arrhythmic events and could be helpful in investigating syncope potentially not related to ventricular arrhythmias,” the researchers wrote. “ICD placement is frequently associated with device-related complications, affecting 16% of patients. Moreover, inappropriate shock rates remain high regardless of careful device programming.” – by Jennifer Byrne
Disclosures: The researchers report no relevant financial disclosures.