JERVELL AND LANGE-NIELSEN SYNDROME

SYMPTOMS

The symptoms of Jervell and Lange-Nielsen syndrome may vary depending on the severity of the underlying arrhythmias but may include:

• Congenital sensorineural deafness, typically present from birth.
• Episodes of syncope (fainting) or seizures, often triggered by emotional stress, physical exertion, or auditory stimuli.
• Palpitations or irregular heartbeat (arrhythmias), particularly ventricular tachycardia or torsades de pointes.
• Sudden cardiac arrest or sudden cardiac death, particularly in untreated or inadequately managed cases.

Symptoms may first appear in infancy or childhood but can occur at any age, with the risk of arrhythmic events increasing during adolescence and young adulthood.

DIAGNOSIS

Diagnosing Jervell and Lange-Nielsen syndrome typically involves a combination of medical history, family history, physical examination, and diagnostic tests. Diagnostic steps may include:

• Electrocardiography (ECG): ECG is used to assess the electrical activity of the heart and measure the QT interval. Prolongation of the QT interval (> 450 milliseconds in males or > 470 milliseconds in females) is a hallmark feature of long QT syndrome.
• Holter monitoring: Ambulatory ECG monitoring over a 24-hour period (Holter monitoring) may be performed to capture and evaluate episodes of arrhythmia or QT interval prolongation.
• Genetic testing: Genetic testing may be performed to identify mutations in the KCNQ1 or KCNE1 genes associated with Jervell and Lange-Nielsen syndrome. Identification of pathogenic mutations confirms the diagnosis and can help guide family counseling and management strategies.

TREATMENT

Treatment of Jervell and Lange-Nielsen syndrome aims to reduce the risk of life-threatening arrhythmias and sudden cardiac death. Treatment options may include:

• Beta-blockers: Medications such as beta-blockers (e.g., propranolol, nadolol) are commonly prescribed to reduce sympathetic tone and prevent arrhythmias by slowing the heart rate and decreasing myocardial contractility.
• Implantable cardioverter-defibrillator (ICD): In individuals with a history of severe arrhythmias or syncope despite medical therapy, placement of an ICD may be considered. An ICD is a device implanted under the skin that monitors the heart rhythm and delivers an electrical shock to terminate life-threatening arrhythmias.
• Avoidance of triggers: Lifestyle modifications to avoid triggers of arrhythmias, such as emotional stress, strenuous exercise, or medications known to prolong the QT interval, may help reduce the risk of arrhythmic events.
• Audiologic evaluation and intervention: Early identification of congenital deafness and appropriate management with hearing aids or cochlear implants can help optimize communication and quality of life for individuals with Jervell and Lange-Nielsen syndrome.