lqt2 form of romano–ward syndrome should avoid sudden loud noises such as alarm clocks as these may trigger arrhythmias. fevers should be treated promptly with paracetamol. grapefruit juice should be avoided as it contains a chemical which decreases ikr and further prolongs the qt interval. medications that further prolong the qt interval such as sotalol should be avoided, lists of which can be found in publicly accessible online databases. beta blockers such as propranolol or nadolol blunt the effects of adrenaline on the heart and thereby reduce the risk of arrhythmias. mexiletine, flecainide and ranolazine decrease the late sodium current and are of particular use in the lqt3 form of romano–ward syndrome, and mexiletine may also be of benefit in other subtypes. potassium supplements may be used at times when potassium is being lost such as when experiencing diarrhoea or vomiting, but medications that encourage the retention of potassium such as spironolactone or amiloride may also be required. an implantable defibrillator, a small device that monitors the heart rhythm and can automatically deliver an electric shock to restart the heart, may be recommended. these devices are recommended for those with romano–ward syndrome who have experienced a cardiac arrest or a blackout whilst taking beta blockers. in those who experience recurrent arrhythmias despite medical therapy, a surgical procedure called sympathetic denervation can be used to interrupt the nerves that stimulate the heart. epidemiology romano–ward syndrome is the most common form of inherited long qt syndrome, affecting an estimated 1 in 7,000 people worldwide.