Observational Study to Describe Health-Related Quality of Life and Measure Disease Burden Among Patients With Long QT Syndrome Types (LQTS) 2 and 3

Launched by THRYV THERAPEUTICS, INC. · Jul 10, 2025

Keywords

ClinConnect Summary

This clinical study is looking at how Long QT Syndrome (LQTS) types 2 and 3 affect people’s daily lives and overall well-being. LQTS is a heart condition that can cause irregular heartbeats and increase the risk of fainting or sudden cardiac events. The study wants to better understand the challenges people with these specific types of LQTS face by having participants answer some simple questionnaires about their health and quality of life just once during the study period.

To join, participants need to be at least 18 years old, speak English, and have a confirmed genetic diagnosis of LQTS type 2 or 3, which means their doctor has identified the condition through genetic testing or medical records. They also need to have recent heart test results showing a longer-than-normal heart rhythm (called a QTc of 480 milliseconds or more). Participants should be comfortable using an iPhone and Apple Watch, as these devices will be used during the study. The study plans to include up to 200 people and will not involve any treatment changes or medications—it's purely observational to learn about how the condition impacts daily life.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • 1. The participant is willing and provides written informed consent to participate in this study.
• • 2. Male or female participant of at least 18 years of age, English-speaking.
• 3. Confirmed genetic diagnosis of LQT2 or 3, demonstrated by one of the following:
• • Genetic testing report (pathogenic or likely pathogenic (P/LP) mutation) in KCHN2 or SCN5a genes) or,
• • A signed physician's letter confirming genetic diagnosis of LQTS 2 or 3.
• 4. Documented QTc ≥ 480 ms within the last year, demonstrated by one of the following:
• • 12-lead electrocardiogram (ECG), or
• • A signed physician's letter confirming an ECG demonstrating QTc value ≥ 480 ms.
• • 5. The participant is able to operate a smartphone and a companion watch. \*The number of participants with QTc between 480 and 500 ms will be limited to 50.
• Exclusion Criteria:
• • 1. Current participation in another clinical trial involving a drug or device.
• • 2. Participants unwilling to use an iPhone or Apple Watch for the duration of the study.
• • 3. Known diagnosis of Brugada Syndrome
• • 4. Participants unwilling to comply with outlined procedures.