Long QT Syndrome: Indications, Origins, and Further Insights
Long QT Syndrome (LQTS) is a condition that affects the heart's electrical rhythm, potentially leading to life-threatening arrhythmia. This condition, which causes the QT interval on an electrocardiogram to last longer than usual, can be inherited or acquired.
Inherited LQTS is caused by mutations in genes coding for ion channels in the heart. On the other hand, acquired LQTS can be caused by electrolyte imbalances and certain medications. Some medications, including antibiotics, antidepressants, and antihistamines, can affect the heart's ion channels and increase the risk of LQTS.
LQTS can lead to complications such as irregular heart rhythms like ventricular tachycardia and torsades de pointes (TdP). People with a family history of LQTS, unexplained seizures or fainting, drowning or near drowning, or unexplained sudden death may have an increased risk of LQTS.
While LQTS primarily affects the heart, it can also have non-cardiac symptoms. For instance, certain inherited types of LQTS may be associated with deafness, periodic paralysis, and facial dysmorphism. Jervell and Lange-Nielsen syndrome, a form of inherited LQTS, causes congenital deafness, while Andersen–Tawil syndrome (LQT7) is associated with periodic paralysis and also features muscle weakness and certain facial abnormalities.
In addition, individuals with LQTS may experience non-epileptic seizures triggered by reduced blood flow to the brain during arrhythmias. Epilepsy can also be associated with certain types of LQTS, although these are secondary neurological manifestations related to arrhythmia-induced brain hypoperfusion rather than primary neurological symptoms.
To manage LQTS, treatment may include medications, implantable devices, or surgery to improve electrolyte levels and shorten the QT interval. Lifestyle changes such as avoiding swimming alone, strenuous activities, startling sounds, stressful situations, and rehydrating can also help reduce the risk of fainting and sudden cardiac death associated with LQTS.
It's important to note that LQTS is more common in people assigned female at birth. Additionally, heart conditions such as congenital heart defects and cardiomyopathy can increase the risk of LQTS. Electrolyte disturbances like hypocalcemia, hypomagnesemia, and hypokalemia can also cause QT interval prolongation.
An implantable automatic cardioverter-defibrillator (ICD) is a device that detects life-threatening arrhythmias and sends a shock to the heart to prevent sudden death. Symptoms of LQTS can include fainting or syncope, arrhythmias, drowning or near drowning, noisy gasping while sleeping, cardiac arrest, seizures, hearing loss, skeletal abnormalities such as scoliosis, immune dysfunction, and cognitive issues.
Understanding LQTS and its symptoms, causes, and treatments is crucial for early detection and management, potentially saving lives. If you suspect you or someone you know may have LQTS, it's important to consult a healthcare professional for proper diagnosis and treatment.
[1] Goldstein M.L., Kassirer J.P. (2016). Long QT Syndrome: An Overview. InStatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–2021 Jan.
[2] Doss J.S., Schwartz P.J. (2019). Long QT Syndrome: Epidemiology. InStatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–2021 Jan.
- The heart disease, Long QT Syndrome (LQTS), can lead to life-threatening arrhythmia, and it can be either inherited due to gene mutations or acquired due to certain medications, electrolyte imbalances, or medical-conditions like congenital heart defects and cardiomyopathy.
- Inherited forms of LQTS, such as Jervell and Lange-Nielsen syndrome and Andersen–Tawil syndrome (LQT7), can also have non-cardiac symptoms like deafness, periodic paralysis, facial dysmorphism, skeletal abnormalities, and cognitive issues.
- Treating LQTS may involve medications, implantable devices like an implantable automatic cardioverter-defibrillator (ICD), or surgery to improve cardiovascular-health and shorten the QT interval, along with lifestyle changes such as avoidance of strenuous activities and rehydration.
- Besides fainting or syncope, arrhythmias, and cardiac arrest, some chronic-diseases like LQTS can also present with other symptoms like noisy gasping while sleeping, seizures, hearing loss, immune dysfunction, and mental-health issues.
- Early detection and management of LQTS are critical for potential life-saving measures, so it's crucial to understand the symptoms, causes, and treatments of this condition and seek medical advice if one suspects they or someone else may have LQTS.
