Long QT Syndrome : Causes-Symptoms-Diagnosis-Treatment

 What Is Long QT Syndrome?

(LQTS) is a strange function of the coronary heart’s electrical machine which could result in a probable existence-threatening arrhythmia referred to as torsades de pointes (said torsade de point). Torsades de pointes may additionally result in syncope (fainting) or surprising cardiac loss of life.

What Is Long QT Syndrome?
Long QT Syndrome

Long QT syndrome (LQTS) is an ailment which can cause a dangerous rapid heart charge and abnormal rhythm regarding the lowest pumping chambers of the coronary heart (ventricles). The coronary heart has muscular and electrical components. Electricity flowing through the heart muscle triggers the muscle to squeeze (agreement) or beat. Heart muscle cells use rather coordinated ion channels to keep the drift of power transferring to generate regular heartbeats. Ion channels are what the electrolytes potassium, sodium, and calcium go with the flow via within the heart's cells. In LQTS, a trouble in the ion channels ends in a disenchanted within the glide of strength that causes an extended "repolarizing" of the coronary heart cells. This put off means the heart isn't always geared up for the following beat. This can create a hard and fast-up for a completely speedy and threatening heart rhythm (arrhythmia) which can motivate fainting or unexpected death. These arrhythmias are called ventricular tachycardia, ventricular fibrillation, or Torsades de pointes.

  1. Circulatory system

Medical terms

  • Long QT syndrome (LQTS) is coronary heart signaling sickness that may cause fast, chaotic heartbeats (arrhythmias). A heart signaling disorder is also known as a heart conduction ailment.
  • Some humans are born with altered DNA that causes long QT syndrome (congenital long QT syndrome). Long QT syndrome may arise later in existence (received long QT syndrome) as the result of some clinical situations, certain drugs or mineral imbalances.
  • Long QT syndrome can cause surprising fainting and seizures. Young human beings with LQTS syndrome have a multiplied hazard of surprising dying.

Treatment for long QT syndrome includes life-style modifications and medicinal drugs to prevent risky heartbeats. Sometimes surgery is used to implant a tool to govern the coronary heart's rhythm.

It is not likely that Long QT syndrome patients are at risk of sudden death due to abnormal heart rhythms which can occur at any age. The condition is therefore dangerous and requires lifelong treatment.

  • Long Q-T syndrome is a disorder of the heart’s electrical system.

  • The electric pastime of the heart is produced by using the drift of ions (electrically charged debris of sodium, calcium, potassium, and chloride) inside and out of the cells of the heart. Tiny ion channels control this flow.

  • The Q-T c language is the phase at the electrocardiogram (ECG) - that represents the time it takes for the electrical device to fire an impulse via the ventricles and then recharge. It is translated to the time it takes for the coronary heart muscle to settle and then recover.

  • LQTS occurs because of the end result of a defect inside the ion channels, inflicting a postponement of the time it takes for the electric system to recharge after every heartbeat. When the Q-T c programming language is longer than regular, it will increase the threat for torsade de pointes, a life-threatening shape of ventricular tachycardia.

  • LQTS is rare. The occurrence is about 1 in 5,000 men and women inside the United States.

Symptoms Long QT syndrome

Some human beings with long QT syndrome do no longer have any signs and symptoms. They may also best come to be aware of their circumstance after having an electrocardiogram (ECG) for any other purpose.Some humans with lengthy QT syndrome (LQTS) no longer have any substantive signs. The condition may be located whilst an electrocardiogram (ECG) or genetic testing is completed for other motives.

Fainting (syncope) is the most common symptom of lengthy QT syndrome. A fainting spell from lengthy QT syndrome can occur with little to no caution. Some humans have fainting caution signs first, which include:

  • Blurred vision

  • Lightheadedness

  • Pounding heartbeats (palpitations)

  • Weakness

Fainting happens whilst the coronary heart temporarily beats in an unorganized manner. You would possibly faint whilst you're excited, angry or scared or in the course of workout. Things that startle you — as an example, a smartphone or an alarm clock — can cause you to lose recognition.

Long QT syndrome might also reason seizures in some people. Symptoms of long QT syndrome every now and then arise during sleep.

Most people with symptoms of LQTS have their first episode by age 40. When the situation is gifted at birth (congenital long QT syndrome), signs and symptoms may arise for the duration of the primary weeks to months of lifestyles or later in adolescence.

Generally, after an extended QT episode, the heart returns to its ordinary rhythm. If the heart does not reset itself or if an outside defibrillator is not utilized in time to reset the heart rhythm, unexpected dying will occur.

When to see a doctor

Call your health care provider if you abruptly faint in the course of bodily hobby or emotional exhilaration or after taking any new medication. If you have got a figure, sibling or baby with lengthy QT syndrome, it is crucial to let your company realize. Long QT syndrome can run in families.

Causes Long QT syndrome

Often LQTS is surpassed down through households (genetic). But it's also feasible to expand LQTS from disorder or medication (acquired). Only one discern desires the genetic problem for it to be surpassed on to the kid. If certainly one of your family participants is recognized with LQTS, experts propose that you and your other circle of relatives participants—mother and father, siblings, youngsters—get examined as well. In rare cases, positive sicknesses or drug treatments can motivate obtained LQTS. These illnesses or drugs may additionally affect the ion channels within the coronary heart or motivate electrolyte issues which include low potassium and calcium. More than 50 drugs list LQTS as a threat. Ask your healthcare provider about the risks of all drug treatments you are taking.

Long QT syndrome is a heart rhythm sickness resulting from modifications inside the heart's electric recharging device. It does not affect the heart's shape.

In a regular heart, the coronary heart sends blood out to the body at some point of each heartbeat. The heart's chambers squeeze (settlement) and relax to pump the blood. This coordinated movement is managed with the aid of the coronary heart's electrical device. Electrical indicators (impulses) tour from the pinnacle to the bottom of the heart. They inform the heart to agree and beat. After each heartbeat, the device recharges to prepare for the following heartbeat.

In long QT syndrome, the heart's electric device takes longer than normal to recharge among beats. This delay is referred to as a prolonged QT c language. It may be seen on an electrocardiogram (ECG).

Long QT syndrome is frequently grouped into two main classes, relying on the motive.

  • If you're born with the circumstance, it is known as congenital lengthy QT syndrome. Some forms of lengthy QT syndrome end result from altered DNA that is passed down through families (inherited).

  • If an underlying scientific situation or remedy causes it, it's known as long QT syndrome. This type of lengthy QT syndrome is typically reversible whilst the underlying motive is identified and dealt with.

Causes of congenital long QT syndrome

More than a dozen genes had been related to long QT syndrome to this point. Researchers have diagnosed loads of alterations within these genes.

There are two styles of congenital lengthy QT syndrome:

  • Romano-Ward syndrome (autosomal dominant form). This extra common shape occurs in those who inherit handiest unmarried gene variation from one discern.

  • Jervell and Lange-Nielsen syndrome (autosomal recessive form). Episodes of this rare shape of LQTS generally occur very early in existence and are greater intense. In this syndrome, youngsters receive the altered gene versions from both mother and father. The children are born with lengthy QT syndrome and deafness.

Causes of acquired long QT syndrome

More than one hundred medicines — lots of them commonplace — can motivate extended QT intervals in any other case wholesome human beings.

If a medication causes long QT syndrome (LQTS), the condition can be referred to as drug-brought on long QT syndrome. Medications that could motive LQTS encompass:

  • Certain antibiotics, such as erythromycin (Eryc, Erythrocin, others), azithromycin (Zithromax) and others

  • 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

Always tell your fitness care provider approximately all of the medicines you take, consisting of those you purchase without a prescription.

Health conditions that could lead to received long QT syndrome consist of:

  • Body temperature below 95 degrees Fahrenheit (37 degrees Celsius), a condition called hypothermia

  • Low calcium (hypocalcemia)

  • Low magnesium (hypomagnesemia)

  • Low potassium (hypokalemia)

  • Noncancerous tumor of the adrenal gland (pheochromocytoma)

  • Stroke or brain (intracranial) bleed

  • Underactive thyroid (hypothyroidism)

Risk factors Long QT syndrome

If you've got a family history of LQTS, you are liable to grow in this circumstance. Specialists accept as true that in case you're liable to long QT syndrome, you are much more likely to be tormented by drugs that increase your threat for the condition. Medicines inclusive of antibiotics, antidepressants, antihistamines, diuretics, and coronary heart drug treatments may also increase your chance for LQTS.

The following things might also growth the chance of developing lengthy QT syndrome:

  • 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

If you've got lengthy QT syndrome and are considering being pregnant, tell your fitness care issuer. Your health care provider will want to cautiously reveal you for the duration of pregnancy to help prevent things which can cause an LQTS episode.

Complications Long QT Syndrome

Proper clinical treatment and life-style modifications can help prevent complications associated with lengthy QT syndrome.

Potential complications of long QT syndrome encompass:

  • Torsades de pointes ("twisting of the points' '). This is a life-threatening irregular heartbeat (arrhythmia). The coronary heart's two decreased chambers (ventricles) beat speedily and chaotically, making the waves on an ECG monitor appear twisted. The heart pumps out less blood. The loss of blood to the brain causes surprising fainting, often without caution.
    If the episode lasts for a long term, fainting can be accompanied by means of a complete-body seizure. If the damaging rhythm does not correct itself, then a life-threatening arrhythmia known as ventricular traumatic inflammation follows.

  • Ventricular fibrillation. This situation causes the lower coronary heart chambers to beat so speedy that the heart quivers and forestalls pumping blood. Unless a defibrillator is used to reset the heart's rhythm, ventricular traumatic inflammation can result in brain damage and surprising loss of life.

  • Sudden death. Long QT syndrome has been connected to sudden demise in young folks who in any other case seem wholesome. The condition is probably answerable for a few unexplained activities in children and teenagers, together with unexplained fainting, drownings or seizures.

Prevention Long QT Syndrome

Regular fitness checkups and right communication with your fitness care company may assist prevent health conditions that lead to some styles of received long QT syndrome. It's mainly vital to keep away from medicinal drugs that can affect the coronary heart rhythm and cause a prolonged QT c programming language.

There is no known prevention for congenital long QT syndrome. Families with inherited lengthy QT syndrome may consider genetic screening. With the right treatment, you may manipulate and save you from the harmful heartbeats that could result in long QT syndrome headaches.

Diagnosis Long QT syndrome

Some diagnostic exams take place on a website in a medical doctor’s workplace or sanatorium. Other exams offer tracking at home as you observe your daily routine.

To diagnose lengthy QT syndrome, a fitness care issuer does a physical examination and asks questions about your symptoms and medical and family records. The fitness care issuer uses a stethoscope to listen to your coronary heart. If your company thinks you've got an abnormal heartbeat, checks may be carried out to check the coronary heart's rhythm.


Tests are accomplished to verify a prognosis of long QT syndrome or take a look at for different conditions that can have an effect on the coronary heart's rhythm or improve the danger of irregular heartbeats.

Electrocardiogram (ECG or EKG)

This is the most common check used to diagnose long QT syndrome. An ECG is a short and painless take a look at that information about the electrical signals in the heart. During an ECG, sensors (electrodes) are connected to the chest and once in a while to the hands or legs. An ECG measures the timing and length of every electric phase inside the heartbeat. The alerts are proven as waves on a connected computer display or printer.

  • An ECG labels the heart's electrical signals as five waves using the letters P, Q, R, S and T.

  • Waves Q through T show the electrical activity in the heart's lower chambers (ventricles).

  • The QT c language is the distance between the start of the Q wave and the give up of the T wave. The c language is the time it takes for the heart to contract and replenish with blood before it beats once more. If the interval takes longer than normal to occur, it's called a prolonged QT c language.

An most excellent QT c programming language relies upon your age, your intercourse and your man or woman heart charge.

If lengthy QT symptoms are rare, they will not be seen on a popular ECG. If this takes place, faraway ECG monitoring can be advocated. There are several different sorts.

  • Holter monitor. Your fitness care provider may suggest this transportable ECG device to reveal your heartbeat at home. It's worn for an afternoon or more to record the coronary heart's interest throughout each day's activities.

  • Event monitor. This transportable ECG tool is worn for as much as 30 days or till you have an arrhythmia or signs and symptoms. You usually press a button while symptoms arise. Some devices routinely report whilst an abnormal heartbeat (arrhythmia) is detected.

Some personal devices, together with smartwatches, provide electrocardiogram monitoring. Ask your fitness care issuer if this is an option for you.

Exercise stress test

This kind of check regularly includes strolling on a treadmill or using a desk bound motorcycle even as the heart is monitored with an ECG. Exercise checks assist monitor how the heart responds to bodily pastime. If you are not able to exercise, you may be given medication that stimulates the heart in a manner like exercising.

  1. Electromyography

Genetic testing

A genetic take a look at for lengthy QT syndrome is to be had to confirm the analysis. Check together with your insurer to peer if it's far protected.

If you've got an effective genetic take a look at for long QT syndrome, your health care provider may also propose that other family members also be tested to determine whether they inherited the identical gene.

It's important to understand that genetic exams for long QT syndrome can not come across all inherited instances of lengthy QT syndrome. It's encouraged that families communicate to a genetic counselor before and after checking out.

  1. Complementation test
  2. fluorescence in situ hybridization
  3. preimplantation genetic diagnosis

Treatment Long QT syndrome

Most human beings with inherited lengthy QT syndrome will want treatment with medicines. Beta blockers, including propranolol or nadolol, can be prescribed to assist manipulate abnormal heartbeats and slow down your coronary heart charge.

If your signs are frequent or severe, and you've got an excessive risk of having a lifestyle-threatening arrhythmia, you may need to have a pacemaker or implantable cardioverter defibrillator (ICD) fitted.

In some instances of lengthy QT syndrome, surgery may be had to control the waft of chemicals into the coronary heart. This is referred to as a sympathectomy.

If drug treatments are causing lengthy QT syndrome, your medicines may be reviewed and an alternative can be prescribed.

Treatment for lengthy QT syndrome (LQTS) may additionally consist of lifestyle changes, medicines, and surgical treatment or different tactics.

The aim of LQTS treatment is to save you from erratic heartbeats and unexpected demise. Your fitness care provider will talk with you about the most suitable remedy alternatives based on your signs and symptoms and your type of long QT syndrome. You may additionally want treatment even if you do not regularly have signs and symptoms.

If you have drug-triggered lengthy QT syndrome, preventing the medication inflicting the signs may be all it's needed to deal with the circumstance. Your health care issuer can let you know a way to correctly accomplish that.

For different kinds of acquired lengthy QT syndrome, treating the underlying situation is vital. Treatment varies but can also encompass magnesium or other fluids given via IV to accurate electrolyte imbalances.


Medications might not treat long QT syndrome, however they could assist protection in opposition to feasible life-threatening heart rhythm modifications.

Medications used to treat long QT syndrome may additionally consist of:

  • Beta blockers. These heart pills are standard therapy for most patients with lengthy QT syndrome. They slow the heart rate and make long QT episodes much less probable. Beta blockers used to treat long QT syndrome encompass nadolol (Corgard) and propranolol (Inderal LA, InnoPran XL).

  • Mexiletine. Taking this coronary heart rhythm drug with a beta blocker would possibly help shorten the QT interval and decrease the chance of fainting, seizure or unexpected demise.

Always take medications as directed.

Surgery or other procedures

Some human beings with lengthy QT syndrome need surgical procedure to control the pulse. Surgery or different approaches used to treat LQTS may also consist of:

  • Left cardiac sympathetic denervation (LCSD) surgery. LCSD surgery is normally only encouraged for people with lengthy QT syndrome and persistent heart rhythm problems who can't take or tolerate beta blockers. It does not remedy long QT syndrome, but it does help lessen the danger of surprising dying. In this manner, surgeons do away with particular nerves alongside the left side of the backbone within the chest. These nerves are part of the body's sympathetic frightened machine, which helps manage the coronary heart rhythm.

  • Implantable cardioverter-defibrillator (ICD). An ICD is a battery-powered unit that is implanted underneath the skin near the collarbone — similar to a pacemaker. The ICD continuously monitors the coronary heart rhythm. If the tool detects an irregular heartbeat, it sends out shocks to reset the heart's rhythm. It can forestall a doubtlessly life-threatening arrhythmia.
    Most people with long QT syndrome don't want an ICD. However, an ICD can be recommended for positive athletes to allow return to aggressive sports activities. The selection to implant an ICD, mainly in kids, desires to be carefully considered. Implanting an ICD is a major process and can bring about irrelevant shocks and other headaches.

Lifestyle and home remedies

Lifestyle modifications may be recommended to reduce the probabilities of a protracted QT syndrome-associated fainting spell or sudden cardiac dying.

  • Know which sports are safe. It can be feasible to stay completely active in sports, such as competitive sports, after carefully reviewing the dangers and blessings with your healthcare provider. In standard, people with long QT syndrome need to by no means swim alone. Recreational activities are likely to be OK in case you take a friend alongside if you have a fainting episode.

  • Check for startling sounds. Turn down the extent on doorbells and other gadgets (along with phones) which could startle you, particularly in the course of sleep.

  • Manage emotions. Being very excited, angry or surprised can trigger heartbeat adjustments in some people with lengthy QT syndrome.

  • Check your medicines. Avoid pills that might purposely extend QT periods. If you are no longer positive, ask your fitness care company. It's an awesome concept to allow your issuer to realize about all of the medicinal drugs and supplements you're taking, even the ones you buy without a prescription.

  • Get regular health checkups. If you have adjustments on your symptoms or circumstance, your fitness care provider may also replace your treatment plan or endorse additional treatments.

Coping and support

Worrying approximately feasible dangerous heart rhythms related to lengthy QT syndrome (LQTS) may also cause strain for you and your family. It might be useful to take steps to assist your family better recognize the way to support you and care for you in the course of an LQTS episode.

  • Tell other people you have LQTS. Make family, pals, teachers, neighbors and anybody else who has regular touch with you aware about your coronary heart condition and your symptoms. Wear a scientific alert identity to notify others of your condition.

  • Have an emergency plan. Family contributors may additionally need to study cardiopulmonary resuscitation (CPR) in order that they assist if you ever need it. It can be suitable to have or be able to hastily get right of entry to an automated outside defibrillator (AED).

  • Seek support or counseling. Some human beings find it beneficial to enroll in an assisted institution, wherein they could share their reports and emotions with different folks that are acquainted with lengthy QT syndrome. Families with inherited lengthy QT syndrome may also find it helpful to speak to a genetic counselor.

Preparing for your appointment

If you have pounding, fast or abnormal heartbeats, make an appointment with your fitness care issuer. You may be referred to a fitness card issuer with unique education in heart situations. Providers that help take care of people with long QT syndrome include:

  • Doctors trained in diagnosing and treating heart conditions (cardiologists)

  • Doctor trained in heart rhythm conditions (electrophysiologists)

  • Doctors who specialize in genetic heart conditions (genetic cardiologists)

Here's some facts to help you prepare for your appointment and realize what to expect from your health care company.

What you can do

  • Write down any symptoms you've had, And for the way long. Include those that may seem unrelated to lengthy QT syndrome.

  • Write down important medical information, Consisting of every other health situation you have and the names and doses of any medications which you take. It's additionally essential to percentage any own family history of irregular heartbeats (arrhythmias) or surprising loss of life together with your health care issuer.

  • Write down the questions you want to be sure to ask your healthcare provider.

Questions to ask the fitness care issuer at your first appointment consist of:

  • 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?

Questions to ask if you're referred to a cardiologist or electrophysiologist encompass:

  • Do I have long QT syndrome? Which type?

  • 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?

  • If you're recommending medications, what are the possible side effects?

Questions to ask if your health care provider recommends surgery include:

  • What type of procedure is most likely to be effective in my case and why?

  • Where should I have my surgery performed?

  • Should I be referred to a long QT syndrome center of excellence?

  • What should I expect from my recovery and rehabilitation after surgery?

Additional questions include:

  • Will I need frequent exams and lifelong treatment for this condition?

  • What emergency symptoms of long QT syndrome should I be aware of?

  • What activity restrictions will I need to follow?

  • Could diet changes help me manage this condition?

  • What medicines should I avoid?

  • What is my long-term outlook with treatment?

  • Will it be safe for me to become pregnant in the future?

  • What is the risk that my future children will have long QT syndrome?

  • How can genetic counseling help my family?

In addition to the questions which you've prepared ahead of time, do not hesitate to ask different questions all through your appointment if you don't recognize something.

What to expect from your doctor

A health care provider who sees you for possible lengthy QT syndrome would possibly ask numerous questions, along with:

  • What are your symptoms?

  • When did the symptoms start?

  • Have the symptoms gotten worse over time?

  • Do strong emotions — such as anger, excitement or surprise — trigger your symptoms?

  • Does exercise cause symptoms?

  • Does being startled — such as by a doorbell or phone ringing — trigger your symptoms?

  • Do your symptoms include feeling lightheaded or dizzy?

  • Have you ever fainted?

  • Have you ever had a seizure?

  • Do you have any other medical conditions?

  • Are you aware of any history of heart conditions in your family?

  • Has a parent, brother, sister or child ever died unexpectedly, such as by drowning, or died suddenly without explanation?

  • What medications are you currently taking, including those bought without a prescription as well as vitamins and supplements?

  • Have you ever used recreational drugs? If so, which ones?

  • Do you use caffeine? How much?

What you can do in the meantime

While you wait for your appointment, test along with your family members to discover when you have a family history of lengthy QT syndrome or unexplained loss of life.

Tell your fitness care provider when you have a primary-diploma relative — inclusive of a parent, brother or sister — who died of a sudden motive along with unexpected toddler loss of life syndrome (SIDS), drowning or other accident. In standard, understanding as much as feasible about your own family's health records facilitates your health care issuer decide the following steps for your analysis and remedy.

General summary

  1. The call, lengthy QT, stems from an analysis at the electrocardiogram (ECG) gadget. Healthcare providers use the ECG to evaluate your heartbeat and rhythm. The ECG device records and measures each of your heartbeats as five “waves.” Each wave has an exceptional letter designation: P, Q, R, S, and T. The relationship among the Q and T waves is crucial and is known as the QT c language. During this c programming language, the lower chambers (ventricles) are "repolarizing" or making ready for the following wave of strength so that it will elicit a heartbeat. When the c programming language lasts longer than it generally should, it disrupts the timing of your heartbeat and can cause dangerous arrhythmias, or irregular heart rates.

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