DIFFERENT RESPONSE BETWEENELECTROPHYSIOLOGICAL TEST AND CHALLENGE TEST WITH SODIUM CHANNEL BLOCKER IN THE BRUGADA SYNDROME WITH SADDLEBACK-TYPE ST ELEVATION

摘要

Background: Diagnostic approach for Brugada syndrome with saddleback ST elevation (STE) was pivotal. Appearance of morphologic change from saddleback to coved-type STE or STE augmentation >2mm after drug challenge is considered significant, but clinical significance of electrophysiological inducibility of VF is controversial. Methods: We performed challenge test with sodium channel blocker and electrophysiological study in 31 patients (pts) with Brugada syndrome. We examined STE in lead Vl-3 on ECG during challenge test and compared two tests. Result: Twenty-two of 31 pts had saddleback STE at challenge test. All 22 pts had inducible VF. Morphologic changes from saddleback to coved type STE were less frequently observed in challenge test (15/22pts;68%) compared with incidence of inducibility of VF (22/22pts;100%, P<0.01). Incidence of STE augmentation>2mm was significantly lower than those >lmm in challenge test (15/22pts; 68% vs 22/22pts; 100%, P<0.01). Incidence of family history of sudden cardiac death or episode of syncope or VF was low in patients with morphologic change (8/15pts:sensitivity;53%, 3/7pts:specificity;42%), STE >2mm (7/15pts:sensitivity;46%,2/7pts:specificity:,28%) and STE >lmm (12/22pts:sensitivity;54%, O/Opts:specificity;O%), respectively. Conclusions: The findings suggested that the Brugada syndrome with saddleback STE had different response between two tests, and low relationship between challenge test and incidence of family history or symptom.