Based on known triggering stimuli, patients with LQT1
are advised to avoid strenuous exercise (particularly swimming and competitive sports), patients with LQT2 should try to avoid unexpected auditory stimuli, whereas patients with LQT3 may be advised to be monitored or accompanied while sleeping (21).
In contrast, isoproterenol that mimics cardiac stimulation by the sympathetic system causes arrhythmias in single cells only in LQT1
Mutations in the K+ channel genes KVLQT1 or KCNQ1, on chromosome 11 result in LQT1
(about 40-55% of cases).
Long QT and Jervelle Lange-Nielsen syndromes: Genetic defects and channel abnormalities Syndrome Gene Function Autosomal dominant LQT1
The majority of mutations have been identified in LQT1
(40%-55%), LQT2 (35%-45%), and LQT3 (2%-8%), which represent the genes KCNQ1, KCNH2, and SCN5A, respectively.