Long Q-T syndrome (LQTS) is a rare, hereditary disorder of the heart’s electrical rhythm that can happen in otherwise healthy people. It generally affects kids or young adults. The fast heartbeats, caused by changes in the part of your heart that causes it to beat, may lead to fainting. In some cases, your heart’s rhythm may beat so erratically that it can cause sudden death. The most common symptom of LQTS is a sudden loss of consciousness, also known as syncope. The condition may also cause seizures and in some instances, cardiac arrest and sudden death.
Some different genetic problems may cause the condition; some are passed on in an autosomal dominant manner, some as autosomal recessive. LQTS is caused by mutations of the genes for cardiac potassium and sodium or calcium ion channels; 8 genes have been identified. It may be as prevalent as 1 in 5,000 people and may cause 2,000 – 3,000 sudden deaths in children and young adults each year in the United States. Long QT syndrome affects about one in 7,000 people. People with this syndrome may show prolongation of the Q-T interval during physical exercise, intense emotion (such as fright, anger or pain) or when startled by a noise.
Some arrhythmias are potentially fatal, causing sudden death. In one type of inherited LQTS, the person may also become deaf. LQTS is more common in women than men. Women who have LQTS are more prone to experience fainting or impulsive death from the condition during menstruation and shortly after giving birth. Treatment for inherited long QT syndrome can engage medications, medical devices, and surgery or lifestyle changes. Beta blocker heart medicines prevent the heart from beating faster in response to physical or emotional stress. Implanted cardioverter-defibrillators (ICDs) seem to be the most helpful therapy for high-risk patients.
The aim of treatment is to manage signs and symptoms and to stop impulsive death. If you have LQTS, you should try to avoid, if possible, the specific triggers you have for an irregular heartbeat. Many people with LQTS also benefit from adding more potassium to their diets. Avoid medicines that may trigger an irregular heartbeat. These medicines include those used to treat allergies, infections, high blood pressure, high cholesterol, and depression. If exercise triggers an irregular heartbeat, your doctor may recommend that you avoid any strenuous exercise, especially swimming. Avoid unexpected noises in your bedroom if you have LQTS 2.