Abstract
Background
A conclusive estimate of the eligibility rate for the use of subcutaneous implantable cardioverter defibrillators (S-ICD) in patients with Brugada Syndrome (BrS) is lacking.
Objective
We aimed to: 1) evaluate the eligibility for S-ICD in patients with BrS using a novel automated tool; 2) investigate predictors of ineligibility for S-ICD, based on baseline 12-lead electrocardiogram.
Methods
Automated screening for S-ICD was performed in 118 consecutive BrS patients using the programmer provided by the S-ICD producer. The system automatically assessed the acceptability of each of the three sense vectors used by the S-ICD for the detection of cardiac rhythm. Eligibility was defined when at least one vector was acceptable both in supine and standing position.
Results
The clinical characteristics of 118 BrS patients were as follow: age 43±11 years; 89% males; 2% with aborted cardiac arrest; 14% with a history of syncope; 81% with spontaneous type 1 ECG pattern; 21% with a familial history of sudden cardiac death; 24% with an SCN5A mutation. No patients had an indication for pacing. Only 8/118 (7%) patients were ineligible for S-ICD. Of note, 5/8 (63%) patients who failed the screening exhibited a slurred S wave of ≥80 ms duration in the peripheral lead aVF on the 12-lead baseline electrocardiogram, vs. 4/110 (4%) of those who passed the screening (sensitivity of S wave in aVF for screening failure 63%, specificity 97%; p<0.001). Remarkably, the presence of a slurred S wave of ≥80 ms duration in lead aVF remained significantly associated to the failure of eligibility for S-ICD (odds ratio 50, p<0.001) in a multivariable analysis that included the previous history of symptoms, the presence of a spontaneous type 1 ECG pattern, the gender and the presence of SCN5A mutations.
ECG predictor of S-ICD screening
Conclusion
Up to 93% of BrS patients are eligible for S-ICD when the automated screening tool is used. The presence of a slurred S wave in lead aVF on the 12-lead electrocardiogram is a powerful predictor of screening failure.
Ajmaline infusion during automated screening in Brugada syndrome and spontaneous Type 1 electrocardiogram unmasks non-suitability for subcutaneous implantable cardioverter-defibrillator
