ECG wavelet analysis for the detection of gene mutations in patients with Brugada syndrome

We applied wavelet transform (WT) to digital electrocardiograms (ECG) acquired during positive ajmaline test for Brugada syndrome (BrS) in 12 patients (pts) with and 14 pts without gene mutations. Continuous WT was applied to the QRS complex and the ST-T wave on leads V1 to V3 in 4^th and 3^rd intercostal space (i.c.s.) (Group A, 13 pts) and leads V1 and V2 from 4^th, 3^rd and 2^nd i.c.s. (Group B, 13 pts) using 256 levels. In group A, there was significantly higher QRS energy at high frequencies in pts with mutations (n=4) both at baseline and during maximum drug effect. In group B, patients with mutations (n=7) had higher QRS energy at low frequencies and higher ST-T energy at low frequencies at baseline and during drug effect. Continuous WT can help identify carriers of gene mutations among patients with BrS, especially when applied to leads V1 and V2 from the 4^th to 2^nd i.c.s.