Treatment is aimed at preventing symptoms such as syncope or cardiac arrest. Specific medications, avoidance of triggering events and QT prolonging medication, and certain medical devices may all be used to treat individuals with Long QT syndrome. Genetic counseling is of great benefit for affected individuals and their families to understand implications for family members, recurrence risk, family planning options, and psychological adjustment to disease and/or carrier status.
The treatment of choice for most affected individuals is drug therapy with beta-adrenergic blocking agents (beta blockers). Beta blockers prevent adrenergic stimulation of the heart via the beta-receptors and can be highly effective in treating long QT syndrome. Nadolol and propranolol are longer acting beta-blockers and the agents of choice in managing the condition. Even though many patients now diagnosed are asymptomatic due to better awareness of the condition and more effective family cascade testing (i.e. identifying family members who are at risk of also having long QT syndrome), beta-blockers are still recommended if any evidence of the condition can be elicited either at rest or with provocation such as exercise stress tests. Beta blockers need to be taken daily and the failure to do so (noncompliance) by affected individuals can lead to the development of symptoms including sudden death.
Individuals for whom beta blockers are unsuccessful or contraindicated may be treated by a surgical procedure in which the autonomic nerves supplying the heart are interrupted (left cardiac sympathetic denervation or sympathectomy). The autonomic nerves release catecholamines which stimulate the heart via the beta-receptors, so this can be considered another form of anti-adrenergic therapy. The heart rhythm is controlled by the sympathetic nervous system, which controls many of the involuntary actions of the body. These nerves work to regulate the heart rhythm and this procedure can significantly reduce the frequency of arrhythmic events. During the procedure, a small cut (incision) is made in the chest wall and specific autonomic nerves supplying the heart are cut. Left cardiac sympathetic denervation is usually reserved for individuals who are considered high risk, develop symptoms despite beta blocker therapy, or are contraindicated to or cannot tolerate beta blocker therapy.
For affected individuals who have been resuscitated from cardiac arrest (whether on or off beta blockers), treatment with an implantable automatic cardioverter-defibrillator or ICD should be considered. These small devices are implanted under the skin of the chest, and wires are passed down into the heart to monitor the heart rhythm on a beat by beat basis. The device detects episodes of torsades de pointes automatically and delivers an electrical shock to restore normal cardiac rhythm. ICDs are also considered for individuals who experience recurrent syncopal events despite therapy with beta blockers. ICDs do not prevent the occurrence of torsade de pointes and, therefore, are used in conjunction with beta blockers and/or cardiac sympathectomy. An ICD is a therapy that carries significant medical and psychological complications, especially in younger individuals, and should be undertaken only after detailed consultation with appropriate medical personnel experienced in the management of LQTS and a careful consideration of the risks and benefits. Specific therapeutic procedures and interventions may vary, depending upon numerous factors, such as specific subtype; effectiveness of medications; an individual’s previous history, age and general health; and/or other elements. Decisions concerning the use of particular drug regimens and/or other treatments should be made by physicians and other members of the healthcare team in careful consultation with the patient based upon the specifics of his or her case; a thorough discussion of the potential benefits and risks, including possible side effects and long-term effects; patient preference; and other appropriate factors.
Some individuals with long QT syndrome are encouraged to avoid potential triggering events such as jumping into cold water or amusement park rides. Individuals with Long QT syndrome who wish to participate in competitive sports should be referred to a clinical expert for evaluation of risk. Affected individuals need to avoid drugs that prolong the QT interval, a full list of such drugs can be found at www.crediblemeds.org.