Differences in Brugada Syndrome Patients Through Ventricular Repolarization Analysis During Sleep

Area of Science:

• Cardiology
• Genetics
• Sleep Medicine

Background:

• Brugada syndrome (BS) is a genetic heart condition linked to sudden cardiac death (SCD) in structurally normal hearts.
• Repolarization abnormalities during rest or sleep are potential triggers for cardiac arrhythmias in BS patients.

Purpose of the Study:

• To characterize ventricular repolarization markers during sleep in Brugada syndrome patients.
• To investigate differences in repolarization markers between symptomatic and asymptomatic BS individuals.

Main Methods:

• Analysis of standard 12-lead ECG recordings in 110 BS patients (25 symptomatic).
• Assessment of QT and T-wave peak to T-wave end (Tpe) intervals from lead V5.
• Linear modeling of repolarization markers against heart rate (RR interval) throughout sleep.
• Calculation of corrected QT (QT60, QT_HR) and Tpe (Tpe60, Tpe_HR) intervals.

Main Results:

• Symptomatic BS patients displayed significantly higher Tpe (Tpe60, Tpe_HR) compared to asymptomatic patients (p < 0.0015).
• Both QT and Tpe intervals were elevated in symptomatic patients, especially during the last 3 hours of sleep (p < 0.01).
• Temporal profiles of repolarization markers differed significantly between BS subgroups during sleep.

Conclusions:

• Brugada syndrome patients exhibit altered repolarization properties that vary with symptomatology.
• Ventricular repolarization markers, particularly Tpe, are significantly different in symptomatic BS patients during sleep.
• Sleep stage influences repolarization abnormalities in Brugada syndrome, with notable changes in later sleep hours.