Long QT syndrome

Long QT syndrome type 1

Long QT syndrome (LQTS) is a genetic disorder that affects the heart's electrical activity. It is characterized by a prolonged QT interval on an electrocardiogram (ECG), which can lead to arrhythmias, syncope, and sudden cardiac arrest.

Pathophysiology[edit | edit source]

Long QT syndrome is caused by mutations in genes that encode for ion channels in the heart. These ion channels are responsible for the flow of potassium, sodium, and calcium ions, which are crucial for the heart's electrical activity. The most commonly affected genes include KCNQ1, KCNH2, and SCN5A. Mutations in these genes can disrupt the normal flow of ions, leading to a prolonged QT interval.

Types[edit | edit source]

There are several types of Long QT syndrome, classified based on the specific gene mutation:

LQT1: Caused by mutations in the KCNQ1 gene.
LQT2: Caused by mutations in the KCNH2 gene.
LQT3: Caused by mutations in the SCN5A gene.

Symptoms[edit | edit source]

Individuals with Long QT syndrome may experience:

Diagnosis[edit | edit source]

Diagnosis of Long QT syndrome typically involves:

Electrocardiogram (ECG) to measure the QT interval.
Genetic testing to identify specific mutations.
Holter monitor to record heart activity over 24-48 hours.
Exercise stress test to observe heart activity during physical exertion.

Treatment[edit | edit source]

Treatment options for Long QT syndrome include:

Beta blockers to reduce the risk of arrhythmias.
Implantable cardioverter-defibrillator (ICD) for individuals at high risk of sudden cardiac arrest.
Lifestyle modifications such as avoiding strenuous exercise and certain medications that can prolong the QT interval.

Prognosis[edit | edit source]

With appropriate treatment and lifestyle modifications, individuals with Long QT syndrome can lead relatively normal lives. However, the risk of sudden cardiac arrest remains, particularly in untreated individuals.