Abstract 2823: Influence of Intra- as well as Inter- Ventricular Conduction Delay to Right and Left Ventricular TEI Indexes in Patients with Brugada type ECG: Evaluated by Tissue Doppler Imaging with Pilsicanide Challenge
Background: In patients with Brugada type ECG (Brug), the delay in right ventricular (RV) activation with ST-elevation in the right precordial leads by sodium channel blocker was reported. However, the behavior of both RV and left ventricular (LV) function in such condition is unknown.
Method: Forty patients with Brug were studied. Pure sodium channel blocker, pilsicainide (PIL 1mg/kg; i.v. over 10 minutes), was infused to provoke a ECG response. Before and after PIL, apical 4-chamber view was obtained by tissue Doppler imaging. Regions of interest were placed in base of interventricular septum (IVS), LV lateral and RV wall. The time delays (TD) in onset of ventricular ejection between the IVS and RV (RV-TD) or LV lateral wall (LV-TD) were measured. Both LV and RV TEI indexes were also measured by pulsed-Doppler echocardiography.
Results: Patients were subdivided into three groups according to their ECG responses. Eleven of 40 patients had persistent coved type ST-elevation (Persistent) and 12 had a positive ECG response provoked by PIL (type 1, coved type; Inducible), and 17 had a negative ECG response (Negative) after PIL infusion. Before PIL, there were no differences in RV- and LV-TD among 3 groups. The RV- and LV-TD were prolonged and both RV- and LV- TEI indexes increased after PIL in Persistent and Inducible groups. In Negative group, both TD and TEI index in RV and LV did not change.
Conclusion: Tissue Doppler imaging revealed not only RV but intra-LV activation delay with right precordial ST-elevation. The appearance of inter- and intra-ventricular conduction delay may be attributed to deterioration of biventricular TEI indexes after PIL infusion in patients with Brugada type ECG.