Abstract 1825: Abnormal ECG Markers suggest that Accentuated Intracardiac Conduction Delay is The Common and Distinguishing Feature of Patients with Spontaneous Type 1 ECG or SCN5A Mutation in Brugadas Syndrome
The conclusive diagnosis of Brugada Syndrome (BrS) is established in patients (pts) with spontaneous type 1 ECG or in carriers of a loss of function SCN5A mutation. We carried out a systematic analysis of ECG recordings in BrS pts to test the hypothesis that the presence of intraventricular (Intra-Ven) and atrioventricular (A-Ven) conduction delay is the distinguishing common feature of pts with SCN5A mutations (Mut+) and in pts with a spontaneous type 1 ECG pattern (spont-ECG). We assessed the following 5 ECG parameters: late potentials (quantified as RMS at 40 Hz), aVR sign (relative size of the R and q waves in aVR), QRS complex fragmentation (defined as an additional R′ or notching of the of S wave), PQ and QRS duration. We studied 200 consecutive BrS pts to define whether the prevalence of ECG markers correlate with 1) the presence of a SCN5A mutation (Mut+) or 2) the presence of a spontaneous type 1 pattern ECG (spont-ECG). Results are summarized in the table⇓. Interestingly, Mut+ not only presented prolonged PQ (p<0.003 vs Mut÷) as previously reported but more significantly they showed the presence of abnormal markers of intraventricular conduction (QRS duration, aVR sign and late potentials). Similarly, also the presence of a spont-ECG was associated with prolonged PQ and QRS intervals and with late potentials. Based on our ECG analysis we propose that
Brugada syndrome is a disease characterized by impairment of A-Ven and Intra-Ven conduction,
the presence of a mutation in the SCN5A gene and,
the presence of a spontaneous type 1 ECG identify patients with accentuated conduction defects.
These findings suggest that the presence of interventricular conduction delay is a landmark of BrS and should be considered as diagnostic markers in BrS.