Arrhythmias & electrophysiology
Characteristics, clinical course, and cardiac events of patients with previously asymptomatic long QT syndrome
Authors' conclusion
Patients with asymptomatic LQTS have an extremely low chance of having an LQTS-triggered cardiac event (<1%). Necessary treatment should account for sex, subtype, corrected QT interval, age, and quality of life and should adapt as situational risk factors arise.
Study context
- Population
- Patients with type 1, 2, or 3 long QT syndrome (LQTS) who were asymptomatic at the first evaluationasymptomatic at first evaluation, of 1547 patients with type 1, 2, or 3 LQTS
- Participants
- 1,139 patients
- Outcome
- BCE
- Follow-up
- Average of 8 ± 7.5 years
Methodological detailssingle specialty center
- Single specialty center
Main finding
As reported in the abstract
- Patients who experienced a breakthrough cardiac event (BCE)
- 13 patients (1%)
- Of those with a BCE, nonadherent to treatment at the time of an event
- 5 (38%)
- Of the 8 patients with a true treatment-refractory BCE, female
- 7 (88%)
- Of the 8 patients with a true treatment-refractory BCE, mean age at BCE
- 15 ± 6 years
- Of the 8 treatment-refractory BCEs, syncope/seizure
- 4 (50%)
- Of the 8 treatment-refractory BCEs, implantable cardioverter-defibrillator shock
- 3 (37.5%)
- Of the 8 treatment-refractory BCEs, sudden cardiac arrest
- 1 (12.5%)
Observational data: associations, not effects.
Further findings
Characteristics of asymptomatic patients at first evaluation
- Asymptomatic LQTS at first evaluation
- 1139 of 1547 patients (74%)
- Women
- n = 636 women [56%]
- Mean age
- 31 ± 16 years
- Mean corrected QT interval
- 462 ± 34
- LQT1
- 55%
- LQT2
- 33%
- LQT3
- 12%
Treatment
- Started on beta-blockers
- 755 patients (66%)
- On sodium channel blockers
- 27 (2%)
- Underwent left cardiac sympathetic denervation
- 11 (1%)
- Received combination therapy
- 71 (6%)
- Managed with an intentional nontherapy
- 275 qualified patients (24%)
Original publication
Characteristics, clinical course, and cardiac events of patients with previously asymptomatic long QT syndrome. Heart Rhythm. Published 30 June 2025. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →