Patients with long QT syndrome exhibit excessively prolonged right ventricular monophasic action potentials and abnormally long effective refractory periods.
In 3 patients with the long QT syndrome, one caused by quinidine and 2 of congenital origin, right ventricular monophasic action potentials were excessively prolonged and of varying shapes in different recording sites. In addition, effective refractory periods of the ventricular muscle were abnormally long.
Gavrilescu et al. (Fri,) studied this question.