Heart and blood vessel diseases

Congenital long QT syndrome (LQTS)

An inherited disease that affects the heart's electrical system. The heart takes longer to recover after each beat. This can cause sudden rhythm problems and fainting.

Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source

Orphanet has a guideline for emergency doctors for this disease (language: French, German, Spanish, Italian, Portuguese). See on Orphanet

Prepare an emergency card

This page is translated from the Turkish original.

This disease is followed through the “Heart and blood vessel diseases” group.

Understanding the disease

This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.

What happens in this disease?

After each beat, the heart resets itself. This recovery happens through tiny channels in the heart cells. In this disease, the channels do not work well and the recovery takes longer. On an ECG this is called a long QT. This can lead to sudden, fast and irregular rhythms.

Which symptoms can occur?

Many people have no symptoms at all. About half of those who carry the gene develop symptoms.

Palpitations
Fainting
Seizure-like episodes; sometimes mistaken for epilepsy
Symptoms during sport, especially swimming (in some types)
Symptoms brought on by a sudden noise, fright or excitement (in some types)
Symptoms at rest or during sleep (in some types)
Severe hearing loss from birth (in one rare type)

How is it diagnosed?

The diagnosis is made with a heart tracing (ECG). If needed, a 24-hour heart recording or an exercise test is done. A genetic test supports the diagnosis and can show the type. Testing is also recommended for the close family of the person diagnosed.

Treatment and care

Most people take medicines that regulate the heart rhythm every day. If the risk is high, a pacemaker-like device may be placed under the skin of the chest. Rarely, an operation that cuts some of the nerves going to the heart is done. Avoiding medicines that prolong the QT interval is important; ask the doctor before any new medicine. Avoiding triggers and regular follow-up are part of care. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

The most common types are passed on through dominant inheritance. For each child of an affected parent, the chance of passing it on is 1 in 2. Not everyone who carries the gene has symptoms. The rare type with hearing loss is passed on through recessive inheritance. In this type, for a carrier couple, the chance of an affected child in each pregnancy is 1 in 4. Family screening and genetic counselling are recommended.

Source: NHS: Long QT syndrome · MedlinePlus Genetics: Romano-Ward syndrome · MedlinePlus Genetics: Jervell and Lange-Nielsen syndrome · NORD: Isolated congenital long QT syndrome (Romano-Ward)

Key facts

How is it inherited?: Autosomal dominant · Autosomal recessive
When does it usually start?: Adolescence, Adulthood, Childhood
Reliable sources: MedlinePlus (for families) · Orphanet

These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.

You are not alone: patient associations in Türkiye

Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.

We could not find a patient association specific to this disease.

For all rare diseases: Nadir Hastalıklar Federasyonu

Support and help

In an emergency in Türkiye, call 112.
For psychological and social support, the ALO 183 Social Support Line (24/7, free from within Türkiye): alo183.aile.gov.tr
For carers: Looking after yourself as a caregiver
Preparing for a doctor visit · Collect your questions and symptom notes on one page, then print it and take it with you.

Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.

News about Long QT syndrome

TürkiyeResearch and clinical trialsAugust 1, 2025

Families of children with inherited heart rhythm disorders experience anxiety: a 53-patient study from Hacettepe

Hacettepe University measured anxiety in children with inherited rhythm disorders and in their families.

Peer-reviewed publicationLong QT syndrome

Clinical trials (ClinicalTrials.gov)

A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.

This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.

Questions you can ask your doctor

Could this trial be suitable for us?
If we take part, how would current treatment and check-ups be affected?
Where does the trial take place, and how are travel and accommodation handled?
What happens if we want to leave the trial?

ClinicalTrials.gov lists 4 active interventional studies for this disease. 3 are recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.

Selected records (studies with a site in Türkiye first):

Evaluation of the Efficacy and Safety of THRV-1268 in Participants With Long QT Syndrome Type 2 (LQTS2) and Type 3 (LQTS3)
Late stage: the effect is being compared in a large group · Phase 2 / Phase 3 · investigational (experimental)RecruitingNCT07277582
Comparing Direct vs Indirect Methods for Cascade Screening
Non-drug study (device, procedure, care, etc.)RecruitingNCT05348564
Continuous Versus Intermittent cARdiac Electrical moNitorinG
Non-drug study (device, procedure, care, etc.)RecruitingNCT04336644
Frequency of Hypoglycemia in Children With Beta-blocker Treated Long QT-syndrome
Non-drug study (device, procedure, care, etc.)Enrolling by invitationNCT07233421

See all studies on ClinicalTrials.gov · Joining clinical trials

Heart and blood vessel diseases: other news

TürkiyeResearch and clinical trialsApril 10, 2026

12 children with Marfan syndrome in Ordu: half had widening at the root of the main artery

The heart findings of children with Marfan syndrome were studied at Ordu University.

Peer-reviewed publicationMarfan

ThailandResearch and clinical trialsApril 26, 2025

Ablation reduced dangerous rhythm episodes in Brugada syndrome

In Thailand, a trial was carried out in patients with Brugada syndrome who had an implanted shock device (defibrillator).

Peer-reviewed publicationBrugada

EuropeResearch and clinical trialsFebruary 5, 2025

Blood pressure drug irbesartan reduced vascular events over two years in vascular EDS

Irbesartan was tested in a trial with 57 adults with vascular EDS.

Peer-reviewed publicationVascular EDS

Medical codes (for talking with your doctor and finding sources)

These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.

Orphanet code: ORPHA:768 · ICD-11 BC65.0

Codes checked against WHO ICD-11 and Orphanet on October 7, 2026.

This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.