A new study published in PLoS One aimed to determine the differences in effectiveness of beta blockers on risk reduction according to congenital long QT syndrome LQTS genotype. Here a search was conducted on MEDLINE EMBASE and CENTRAL databases to investigate the use of beta blockers atenolol nadolol propranolol and metoprolol in patients with LQTS. The findings showed that the use of beta blocker was associated with significant risk reduction of all cardiac events and serious cardiac events. In both LQT1 and LQT2 the risk was reduced with beta blocker therapy in 7 registry based cohort studies as well as in 3 interrupted time series studies ITS . Among the beta blockers nadolol showed a marked risk reduction in both LQT1 and LQT2 whereas atenolol and propranolol decreased the risk only in LQT1. On the other hand metoprolol showed no significant reduction in either genotype. In LQT3 beta blocker therapy was not as effective as LQT1 or LQT2 however it was inconclusive due to data insufficiency. From the results it was inferred that beta blockers were effective in reducing risk of cardiac events in patients with LQTS. Nadolol was effective in LQT1 and LQT2 whereas other drugs showed different effectiveness depending on LQT genotype.