Therapy of Long QT syndrome:
Implantable cardioverter defibrillators are indicated in cardiac arrest survivors and patients with recurrent syncope despite β blocker treatment and for primary prevention in high-risk patients, usually with β blockers.
The following recommendations have been proposed for ICD implantation:
◆ Patients who have survived a cardiac arrest on therapy.
◆ Many of those who have survived a cardiac arrest off therapy, except those with a reversible/preventable cause, but noting that, for most LQT1 grown-up patients, full-dose beta blockers might be sufficient.
◆ Patients who continue to have syncope, despite full-dose beta blockade, whenever the option of left cardiac sympathetic denervation is either not available or is discarded after discussion with the patients.
◆ Patients with two mutations who continue to have syncope despite beta blockade.
◆ Asymptomatic patients with a QTc > 550 ms who also manifest signs of high electric instability (e.g. T wave alternans) or other evidence of being at very high risk (e.g. very long sinus pauses that might favour early after-depolarizations).
◆ The identification of LQT2 or LQT3 genotypes does not, by itself, constitute an indication of ICD implantation.
