Long Qt Syndrome C0023976
A heart rhythm condition causing dangerously fast heartbeats that can trigger fainting or sudden cardiac arrest. Treatment with beta-blockers and lifestyle changes can reduce risk.
Key facts at a glance
- ICD-10
- I45.81
- ICD-11
- BA00.0
- Body system
- cardiovascular
- Severity
- severe
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Syncope
Chest discomfort or palpitations
(cardiovascular)Significant symptoms that substantially affect daily functioning.
Frequency: Common at all stages
Palpitations
(cardiovascular)Dizziness
(cardiovascular)Ventricular arrhythmia
(cardiovascular)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Beta-Blocker Therapy
First-line pharmacotherapy with non-selective beta-blockers to reduce sympathetic-triggered arrhythmias and prevent sudden cardiac death.
Disease management and monitoring
Active treatment with regular monitoring by a healthcare provider is recommended.
Trigger Avoidance and Activity Restriction
Identification and avoidance of arrhythmia triggers including swimming alone, extreme emotional stress, and QT-prolonging medications.
Additional treatment options
ICD Implantation
Implantable cardioverter-defibrillator placement for secondary prevention after cardiac arrest or for primary prevention in high-risk patients.
procedureLeft Cardiac Sympathetic Denervation
Surgical removal of the left stellate ganglion to reduce sympathetic innervation to the heart and decrease arrhythmia susceptibility.
surgicalContinuous ECG Monitoring and Drug Avoidance
Ambulatory monitoring combined with patient education on avoiding QT-interval prolonging medications.
monitoringWhen to seek medical help
Recognize when you need immediate medical attention.
See a doctor within 24 hours
Moderate to severe symptoms that may indicate worsening of this condition. Prompt medical evaluation is recommended.
Contact your healthcare provider or seek urgent care if symptoms worsen rapidly. Go to the emergency department for life-threatening symptoms.
Frequently asked questions
Common questions about this topic.
What is Long Qt Syndrome C0023976?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalMedication Comparisons
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View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 27, 2026. · Read our editorial policy