The mechanism of 2:1 atrioventricular block in infants with the congenital long QT syndrome has been postulated to result from a long ventricular effective refractory period interrupting ...

SACT at CLm increased from 65±19 to 134±30ms (+105%). SN effective refractory period (ERP)(at a paced CL of 400ms) increased from 158±37 to 261±45ms (+66%). All changes in SN function related ...