This is a heart rhythm condition that provokes fast and chaotic heartbeats. Irregular heartbeats can be life-threatening. Long QT syndrome (LQTS) negatively affects the electrical signals that go through the heart and provoke it to beat.
Sometimes, people are born with DNA changes that provoke this heart rhythm condition. In such cases, it is called congenital long QT syndrome. However, this condition can be caused by other health problems later in life (acquired long QT syndrome).
Those who suffer from LQTS can experience sudden fainting and seizures. Moreover, young people are at increased risk of sudden cardiac death.
The treatment goal is to prevent life-threatening heartbeats. It involves lifestyle changes, medicines, and sometimes surgery or a medical device.
Symptoms
One of the most common LQTS symptoms is fainting (also known as syncope). This symptom usually happens when a person has irregular heartbeats for a short period. For instance, fainting occurs when a person is excited, angry, scared, or during exercise. Check below some symptoms that usually happen before fainting:
- Weakness
- Palpitations (pounding heartbeats)
- Lightheadedness
- Blurred vision
Furthermore, newborns with long QT syndrome experience symptoms within a few months after birth. Less commonly the symptoms start later in childhood. LQTS symptoms can happen even during sleep.
Rarely, those who suffer from LQTS do not notice any symptoms, and the condition is identified during a heart test (electrocardiogram) or genetic testing. If you experience any of the previous symptoms, you are advised to visit a doctor immediately.
Causes
To understand the cause of long QT syndrome it is important to know how the heart beats in normal cases. The heart sends out the blood in the body each time the heart beats. To maintain normal heartbeats it involves an electrical system that helps to coordinate the action. These electrical impulses (signals) go from the top to the bottom part of the heart. Moreover, this electrical system recharges and prepares for the next heartbeat and in people with LQTS it takes more time to recharge (also known as prolonged QT interval).
There are two types of long QT syndrome. For example:
- Congenital long QT syndrome β In such cases, people are born with this condition. It occurs due to certain DNA changes that usually pass from biological parents.
- Acquired long QT syndrome β This LQTS happens due to another health condition or medications. You can get rid of acquired long QT syndrome by treating the underlying condition or stopping the use of medicine that provokes it.
Congenital Long QT Syndrome Causes
There are different gene changes associated with long QT syndrome. Check below congenital long QT syndrome types:
- Romano-Ward syndrome β This type of congenital LQTS occurs when the mutated gene passes to children from one parent.
- Jervell and Lange-Nielsen syndrome β This type occurs quite rarely and usually, it is very severe. Furthermore, children with this congenital LQTS type are deaf and get mutated genes from both parents (also known as autosomal recessive inheritance pattern).
Acquired Long QT Syndrome Causes
If a person experiences this LQTS type it is usually caused by a health condition or medications. It is also called drug-induced long QT syndrome. However, there are more than 100 medicines that could provoke this condition. For example:
- Antibiotics β Erythromycin, Azithromycin, and others
- Antifungal medications (these drugs are used to treat yeast infections)
- Water pills (diuretics)
- Heart rhythm medications (antiarrhythmics)
- Mental health problems medicines (used to treat anxiety and depression)
- Drugs used to treat stomach upset
Check below also some conditions often associated with long QT syndrome:
- Hypothermia (body temperature that is lower than 95 F or 35 C degrees)
- Hypocalcemia (low Calcium levels in the body)
- Reduced Magnesium or Potassium levels
- Stroke
- Brain bleeding
- Adrenal gland tumors (pheochromocytoma)
- Hypothyroidism (underactive thyroid gland)
Risk Factors
Anyone can develop this health problem and the following factors could increase your risk. Examples include:
- Persistent vomiting or diarrhea
- Eating disorders (including anorexia nervosa)
- Females who administer certain medicines
- A family history of long QT syndrome
- Medical history of cardiac arrest
- The use of medications that cause prolonged QT intervals
Consult with your healthcare professional if you have long QT syndrome and plan to get pregnant.
What Are The Possible Complications of Long QT Syndrome?
Commonly, after LQTS episodes the heart returns to a regular rhythm. However, in some cases, if the heart rhythm is not quickly corrected it may lead to sudden cardiac death. Check below some complications:
- Torsades de pointes β In such cases, people experience life-threatening fast heartbeats. The most common symptom of this complication is sudden fainting due to reduced blood flow to the brain.
- Ventricular fibrillation β In such cases, a defibrillator is required to correct heart rhythm. Otherwise, it may lead to brain damage and even death.
- Sudden cardiac death β It means the end of the heart activity which usually happens without any signs. Moreover, long QT syndrome can provoke certain abnormalities in children and young adults (such as drowning, seizures, or fainting).
One way to prevent previous complications is early diagnosis and proper treatment.
How to Prevent Long QT Syndrome?
However, it is not possible to prevent congenital LQTS but with proper treatment, it is possible to lessen the symptoms and improve your quality of life. Talk with a healthcare professional for more details.
Diagnosis
Physicians usually diagnose this condition by asking questions about symptoms and family history and performing several tests. Check below some of them:
Electrocardiogram (EKG or ECG)
This is one of the most common tests used by doctors to diagnose this syndrome. It measures the electrical signals in the heart which help to understand how fast your heart beats. An EKG cannot determine long QT syndrome only if the symptoms happen rarely. In such cases, doctors recommend to monitor the heart at home. Check below some of them:
- Holter monitor β This is a portable device that records the activity of the heart.
- Event recorder β This device is worn for about 30 days and it records automatically when an abnormal heart rhythm is detected.
Exercise Stress Tests
In some cases, doctors may measure the heartβs activity while you exercise. These tests often involve pedaling a stationary bike or walking on a treadmill.
Genetic Testing
Healthcare providers may perform a genetic test if you have long QT syndrome. This test usually helps to determine all inherited types of LQTS.
Treatment
Commonly, treatment is different among people because it depends on different factors such as the severity of the condition, medicines you are using, existing health problems, and others. It often involves a medical device, surgery, medicines, and lifestyle changes. Some people with acquired long QT syndrome can receive IV fluids or minerals (including Magnesium).
Medicines
Doctors can order you to interrupt using the medication if it provokes this syndrome. Moreover, some patients need some medicines that will help to prevent life-threatening symptoms. Examples include:
- Beta-blockers β This group of medications is used to slow the heart rate, which helps to prevent long QT episodes. These include Nadolol and Propranolol.
- Mexiletine β This medication can reduce the risk of fainting, seizures, or sudden cardiac death.
Other Treatment Options
- LCSD (left cardiac sympathetic denervation) surgery β This surgery is usually performed when beta-blockers do not work for you. However, it cannot cure long QT syndrome but reduces the risk of sudden cardiac death.
- Implantable cardioverter-defibrillator (ICD) β A special device is placed under the skin near the collarbone that sends high-energy shocks to reset the rhythm of the heart.
Frequently Asked Questions
What is the life expectancy for people with LQTS?
With proper treatment, the death rate is about 1% but without treatment, the death rate increases up to 21%.
What are the main long QT syndrome symptoms?
These include:
- Cardiac arrest
- Fainting
- Lightheadedness
- Breathing problems
- Chest pain
- Palpitations (chest fluttering)
How common is LQTS?
This is considered a rare health condition that affects up to 1 in 2,000 people. Most people experience this condition due to DNA changes but it can also happen due to some medications. Ask your healthcare professional if you have additional questions.