Overview
Long QT syndrome is a heart rhythm disorder caused by changes in the heart's electrical recharging system. It doesn't affect the heart's structure. In a typical heart, the heart sends blood out to the body during each heartbeat. The heart's chambers squeeze and relax to pump the blood. This coordinated action is controlled by the heart's electrical system. Electrical signals (impulses) travel from the top to the bottom of the heart, telling it to contract and beat. After each heartbeat, the system recharges to prepare for the next heartbeat. In long QT syndrome, the heart's electrical system takes longer than usual to recharge between beats. This delay is called a prolonged QT interval. It may be seen on an electrocardiogram (ECG). Long QT syndrome is often grouped into two main categories, depending on the cause: congenital long QT syndrome, which is present at birth, and acquired long QT syndrome, which develops later in life due to certain medical conditions, medications, or mineral imbalances. Symptoms of long QT syndrome may include sudden fainting, seizures, and an increased risk of sudden death, particularly in young people. Treatment may involve lifestyle changes, medications, and, in some cases, surgery to implant a device to control the heart's rhythm. Proper medical treatment and lifestyle changes can help prevent complications related to long QT syndrome, such as torsades de pointes, ventricular fibrillation, and sudden death.
Understanding the disease
Symptoms
The symptoms of long QT syndrome may include fainting (syncope), blurred vision, lightheadedness, pounding heartbeats (palpitations), weakness, seizures, and symptoms that occur during sleep. Fainting is the most common symptom, and it can happen with little to no warning. Long QT syndrome can also cause a life-threatening irregular heartbeat called Torsades de pointes or ventricular fibrillation. If you experience symptoms or have a family history of the condition, it is important to consult your healthcare provider.
Risk Factors
Risk factors for developing long QT syndrome may include:
- A history of cardiac arrest
- Having a parent, sibling, or child with long QT syndrome
- Using medications known to cause prolonged QT intervals
- Being female and on heart medication
- Excessive vomiting or diarrhea, which causes electrolyte imbalances
- Eating disorders, such as anorexia nervosa, which cause electrolyte imbalances In addition to these factors, other health conditions such as hypothermia, hypocalcemia, hypomagnesemia, and hypokalemia can lead to acquired long QT syndrome. It's essential to be aware of these risk factors and inform your healthcare provider about any family history or personal medical conditions. Proper medical treatment and lifestyle changes can help prevent complications related to long QT syndrome.
Development
Long QT syndrome (LQTS) develops due to changes in the heart's electrical recharging system, leading to a prolonged QT interval. It is often grouped into two main categories: congenital long QT syndrome and acquired long QT syndrome. Congenital long QT syndrome is genetic and occurs when a person is born with altered DNA. Some forms of long QT syndrome result from inherited alterations within specific genes. There are two forms of congenital long QT syndrome: Romano-Ward syndrome (autosomal dominant form) and Jervell and Lange-Nielsen syndrome (autosomal recessive form). Acquired long QT syndrome is usually reversible when the underlying cause is identified and treated. It can be caused by various medical conditions, medications, or mineral imbalances. Some examples include:
- Certain antibiotics (erythromycin, azithromycin, etc.)
- Certain antifungal pills used to treat yeast infections
- Diuretics that cause an electrolyte imbalance (low potassium, most commonly)
- Heart rhythm drugs (anti-arrhythmics) that lengthen the QT interval
- Some antidepressant and antipsychotic medications
- Some anti-nausea medications
- Certain health conditions, such as hypothermia, low calcium, low magnesium, low potassium, pheochromocytoma, stroke or brain bleed, and hypothyroidism If you have concerns about your risk for long QT syndrome or are experiencing symptoms, consult your healthcare provider for proper evaluation and guidance.
Assessment and Diagnosis
Triage
You should see a doctor if long QT syndrome is suspected, especially if you experience symptoms such as fainting, seizures, or palpitations, or if you have a family history of the condition. It's important to inform your healthcare provider about any new medications you are taking or pre-existing medical conditions that may increase your risk of developing long QT syndrome.
Diagnosis
To diagnose long QT syndrome, a healthcare provider will perform a physical exam, ask questions about your symptoms and medical history, and use a stethoscope to listen to your heart. If an irregular heartbeat is suspected, tests like an electrocardiogram (ECG) and genetic testing may be performed to confirm the diagnosis or check for other conditions affecting the heart's rhythm. ECG is the most common test used to diagnose long QT syndrome.
Management and Treatment
Complications
Potential complications of long QT syndrome include torsades de pointes, a life-threatening irregular heartbeat, and ventricular fibrillation, which can lead to sudden death. Other complications may include seizures, brain damage, and heart failure. It is important to manage risk factors and seek proper medical treatment to prevent these complications.
Treatment
Treatment for long QT syndrome includes lifestyle changes and medications to prevent dangerous heartbeats. Some common medications that can cause long QT syndrome should be avoided. In some cases, surgery may be necessary to implant a device that controls the heart's rhythm. Always consult with a healthcare provider for personalized recommendations and guidance on managing long QT syndrome.
Preparing for medical consultation
To prepare for an appointment for long QT syndrome, you can follow these steps:
- Make a list of your symptoms: Write down any symptoms you've experienced, including those that may seem unrelated to long QT syndrome. Be prepared to share information about when the symptoms started, how long they last, and any triggers, such as emotional stress, exercise, or being startled.
- Gather medical information: Compile a list of your current health conditions, any medications you're taking, and any family history of irregular heartbeats or sudden death. Sharing this information with your health care provider will help them better understand your situation.
- Prepare a list of questions: Write down the questions you want to ask your health care provider during the appointment. Some important questions to ask include:
- What is likely causing my symptoms?
- Are there any other possible causes for these symptoms?
- What tests do I need?
- Should I consult a specialist?
- What is my risk of complications from this condition?
- What treatment approach do you recommend?
- If the first treatment doesn't work, what will you recommend next?
- Be ready to discuss your family history: Long QT syndrome is a genetic condition, so it's important to share any family history of irregular heartbeats or sudden death. This information will help your health care provider determine the best course of action for your diagnosis and treatment.
- Consider bringing a family member: It can be helpful to have a family member or friend accompany you to the appointment, as they can provide additional information, ask questions, and support you during the appointment. By preparing in advance and being proactive, you'll be better equipped to get the most out of your appointment and work with your health care provider to manage your long QT syndrome.