Programmed electrical stimulation in Brugada syndrome: how reproducible are the results?
BACKGROUND
Inducibility of ventricular arrhythmias at programmed electrical stimulation (PES) ranges between 50% and 80% of patients with Brugada syndrome. However, the variety of PES protocols and the lack of data relative to a control group or to ventricular arrhythmia reproducibility contribute to a still undefined interpretation of PES outcome in Brugada syndrome.


RESULTS
Twenty-one patients with Brugada syndrome (18 men and 3 women; mean age 34 years; 9/21 symptomatic; 8/21 with SCN5A gene mutation) underwent a PES protocol from two right ventricular sites. The endpoint was PES protocol completion or induction of sustained or reproducible (>6 consecutive inductions) nonsustained (>6 beats) fast ventricular arrhythmia. In 17 of 21 patients with Brugada syndrome, PES was repeated 2 months later to test ventricular arrhythmia reproducibility. Twenty-five healthy patients (17 men; mean age 36 years) formed the control group. In patients with Brugada syndrome, ventricular arrhythmia inducibility rate at PES was high (18/21 patients [85%]) and increased with protocol aggressiveness, independent of clinical presentation. In control subjects, no ventricular arrhythmias were induced. Among patients with Brugada syndrome, 14 (82%) of 17 patients remained inducible at a second PES.


CONCLUSIONS
In our experience, ventricular arrhythmia inducibility in patients with Brugada syndrome, at variance with healthy controls, is high and does not correlate with clinical presentation. PES inducibility is deeply influenced by the protocol used. PES outcome is reproducible at a mid-term follow-up mainly if a categorical endpoint (inducible vs noninducible) is used. The need to assess the predictive value of specific PES protocols in targeted studies is widely emerging and is confirmed by our results.
Gasparini
Maurizio
M
Cardiac Electrophysiology and Pacing Unit, Istituto Clinico Humanitas, Milan, Italy. maurizio.gasparini@humanitas.it
Priori
Silvia G
SG
Mantica
Massimo
M
Coltorti
Fernando
F
Napolitano
Carlo
C
Galimberti
Paola
P
Bloise
Raffaella
R
Ceriotti
Carlo
C
D000328:Adult; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000503:physiopathology / Q000601:surgery; D006352:Heart Ventricles / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012307:Risk Factors; D013577:Syndrome; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy