Table 1: The frequency occurrence of LQTS1-3, ECG characteristics for each type of the disease, and the most common stimuli leading to fatal cardiac events.

Type of the diseaseIon currentFunctional consequenceFrequency of occurrence among all types of LQTSECG characteristicsStimuli leading to fatal cardiac eventsPenetrance

LQTS1K40%–50%418604.tab.001aGymnastics 68%
Stress 14%
Sleep, auditory stimulus 9%,
Others 9%
62%
LQTS2K35%–40%418604.tab.001bGymnastics 29%
Stress 48%
Sleep, auditory stimulus 22%,
Others 1%
75%
LQTS3Na2%–8%418604.tab.001cGymnastics 4%
Stress 12%
Sleep, auditory stimulus 64%,
Others 20%
90%