| Recruiting | National Network for Cardiovascular Genomics: Advancing Cardiovascular Healthcare for Hereditary Diseases in B NCT06546137 | Hospital do Coracao | — |
| Recruiting | Wearable Devices for Patient Monitoring in Long QT Syndrome NCT06887387 | Queen Mary University of London | — |
| Recruiting | Evaluation of Exercise Testing and Physical Activity in Children and Adolescents Living With Inherited Arrhyth NCT06661278 | Royal Brompton & Harefield NHS Foundation Trust | — |
| Enrolling By Invitation | Frequency of Hypoglycemia in Children With Beta-blocker Treated Long QT-syndrome NCT07233421 | Helsinki University Central Hospital | N/A |
| Recruiting | Continuous Versus Intermittent cARdiac Electrical moNitorinG NCT04336644 | Washington University School of Medicine | N/A |
| Unknown | A Study to Evaluate Accuracy and Validity of the Chang Gung ECG Abnormality Detection Software NCT05903313 | Chang Gung Memorial Hospital | — |
| Recruiting | Comparing Direct vs Indirect Methods for Cascade Screening NCT05348564 | University of Maryland, Baltimore | N/A |
| Completed | QT Changes in Geriatric Patients: a Comparison of Spinal and General Anesthesia NCT06375863 | Haseki Training and Research Hospital | N/A |
| Terminated | Study of LQT-1213 on QTc-induced Prolongation in Healthy Adult Subjects (Part1) and on Congenital Long QT in P NCT05906732 | Thryv Therapeutics, Inc. | Phase 1 / Phase 2 |
| Completed | Phase 1 Study of LQT-1213 in Healthy Adults NCT05759962 | Thryv Therapeutics, Inc. | Phase 1 |
| Completed | Impact on Risk Stratification of Overlap Syndrome Phenotype in Patients With E1784K Mutation in SCN5A NCT05274646 | Centre Hospitalier Universitaire de la Réunion | — |
| Completed | Cardiac Rehabilitation of Children and Adolescent With Long QT Syndrome NCT05964322 | University Hospital, Montpellier | — |
| Recruiting | Building of a Diagnostic/Prognostic Database for Human ERG Variant Effects NCT06087367 | Nantes University Hospital | — |
| Completed | Novel Approaches for Minimizing Drug-Induced QT Interval Lengthening NCT04675788 | Indiana University | Phase 4 |
| Completed | Mutation-specific Therapy for the Long QT Syndrome NCT04581408 | Istituto Auxologico Italiano | Phase 2 |
| Completed | LQT and Smartphone/Smartwatch NCT04728100 | Hospices Civils de Lyon | — |
| Recruiting | Clinical Cohort Study - TRUST NCT05521451 | Universitätsklinikum Hamburg-Eppendorf | — |
| Completed | Healthy-related Quality of Life and Physical Activity of Children With Cardiac Malformations NCT04712136 | University Hospital, Montpellier | N/A |
| Unknown | Evaluation of the Effects of KCNQ1 Mutation on Insulin Tolerance and Obsessive Compulsive Features in Long QT NCT04715256 | Biotrial | N/A |
| Completed | QT Measurement Techniques and Anesthesia Management NCT04706104 | Ankara City Hospital Bilkent | — |
| Completed | Measurement of the Electromechanical Window to Improve the Diagnosis of Congenital Long QT Syndrome NCT04328376 | University Hospital, Bordeaux | N/A |
| Completed | The Effect of Azithromycin Use on Conduction System of Heart in COVID-19 Positive Children NCT04699097 | Kayseri City Hospital | — |
| Completed | Physical Activity in Children With Inherited Cardiac Diseases NCT04650009 | University Hospital, Montpellier | — |
| Unknown | Electromechanical Profiling of the Long-QT Syndrome (LQTS) NCT04074122 | Maastricht University Medical Center | — |
| Completed | Reducing the Risk of Drug-Induced QT Interval Lengthening in Women NCT03834883 | Indiana University | Phase 4 |
| Completed | Long QT Syndrome and Sleep Apnea NCT03678311 | The Cleveland Clinic | N/A |
| Terminated | KCNQ1 Cascade Screening NCT03783975 | University of Maryland, Baltimore | N/A |
| Terminated | Low Cost QTc Meter for Long QT Syndrome Screening in Primary Care NCT04441892 | Mayo Clinic | N/A |
| Completed | The Physiological Effects of Human Ether-a-go-go-Related Gene (hERG)Blockade on Metabolism NCT03868657 | Signe Torekov | N/A |
| Unknown | Drug-induced Repolarization ECG Changes NCT03642405 | Copenhagen University Hospital at Herlev | — |
| Recruiting | Fetal Electrophysiologic Abnormalities in High-Risk Pregnancies Associated With Fetal Demise NCT03775954 | Medical College of Wisconsin | — |
| Completed | Effect of Grapefruit on QT Interval in Healthy Volunteers and Patients With Congenital Long QT Syndrome NCT02680080 | Tel-Aviv Sourasky Medical Center | N/A |
| Completed | Influence of Testosterone Administration on Drug-Induced QT Interval Prolongation and Torsades de Pointes NCT02513940 | Indiana University | Phase 4 |
| Completed | Abnormal QT-Response to the Sudden Tachycardia Provoked by Standing in Individuals With Drug-induced Long QT S NCT02581241 | Tel-Aviv Sourasky Medical Center | N/A |
| Unknown | Hydroxyzine and Risk of Prolongation of QT Interval NCT02814981 | University Hospital, Caen | — |
| Unknown | Long QT Syndrome Screening in Newborns NCT02412709 | QT Medical, Inc. | Phase 2 |
| Completed | Prevalence of Congenital Long QT Syndrome and Acquired QT Prolongation in a Hospital Cohort NCT03544918 | Sykehuset Telemark | — |
| Completed | Long Term Monitoring for Risk of Sudden Death NCT04124237 | University of British Columbia | — |
| Completed | Safety of Local Dental Anesthesia in Patients With Cardiac Channelopathies NCT03182777 | University of Sao Paulo General Hospital | N/A |
| Completed | Pharmacokinetics of Eleclazine in Adults With Normal and Impaired Renal Function NCT02441829 | Gilead Sciences | Phase 1 |
| Completed | Exercise in Genetic Cardiovascular Conditions NCT02549664 | Yale University | — |
| Completed | Pharmacokinetics of Eleclazine in Adults With Normal and Impaired Hepatic Function NCT02412098 | Gilead Sciences | Phase 1 |
| Completed | Effect of Oral GS-6615 on Dofetilide-Induced QT Prolongation, Safety, and Tolerability in Healthy Adults NCT02365532 | Gilead Sciences | Phase 1 |
| Completed | The Canadian National Long QT Syndrome Registry NCT02425189 | Andrew Krahn | — |
| Completed | Prospective Identification of Long QT Syndrome in Fetal Life NCT02876380 | University of Colorado, Denver | — |
| Completed | Determine the Incidence of Long QT Amongst a Large Cohort of Subjects Diagnosed With Unilateral or Bilateral S NCT02082431 | Pediatrix | — |
| Completed | Fetal and Neonatal Magnetophysiology NCT01903564 | University of Wisconsin, Madison | — |
| Unknown | Genetics of QT Prolongation With Antiarrhythmics NCT02439658 | Massachusetts General Hospital | — |
| Terminated | A Registry to Determine the Clinical and Genetic Risk Factors for Torsade De Pointes NCT02439645 | Massachusetts General Hospital | — |
| Completed | Study of the Effect of GS-6615 in Subjects With LQT-3 NCT01849003 | Gilead Sciences | Phase 1 |
| Completed | Long-term Efficacy Study of Sodium Channel Blocker in LQT3 Patients NCT01648205 | University of Rochester | Phase 2 |
| Completed | Multicenter Evaluation of Children and Young Adults With Genotype Positive Long QT Syndrome NCT01705925 | Pediatrix | — |
| Unknown | Novel Form of Acquired Long QT Syndrome NCT04169100 | Narrows Institute for Biomedical Research | Phase 4 |
| Unknown | Metabolism of Patients With Genetically Caused Cardiac Arrhythmia NCT02775513 | University of Copenhagen | — |
| Completed | Effect of Beta-blocker Therapy on QTc Response in Exercise and Recovery in Normal Subjects NCT00588965 | MetroHealth Medical Center | N/A |
| Completed | The Long QT Syndrome in Pregnancy NCT00488254 | University of British Columbia | — |
| Completed | ECG Signal Collection From Long QT Syndrome, Wide QRS Complexes, Heart Failure, and Cardiac Resynchronization NCT00399412 | Boston Scientific Corporation | — |
| Terminated | Pediatric Lead Extractability and Survival Evaluation (PLEASE) NCT00335036 | Charles Berul | N/A |
| Completed | Study Evaluating the Effects of Multiple Oral Doses of ERB-041 on Cardiac Repolarization in Healthy Subjects NCT00316459 | Wyeth is now a wholly owned subsidiary of Pfizer | Phase 1 |
| Completed | Registry of Unexplained Cardiac Arrest NCT00292032 | University of British Columbia | — |
| Unknown | Molecular Genetic Screening and Identification of Congenital Arrhythmogenic Diseases NCT00221832 | Heidelberg University | — |
| Completed | Epidemiology of Long QTand Asian Sudden Death in Sleep NCT00005367 | Utah State University | — |
| Completed | Linkage Study of Long QT Syndrome In An Amish Kindred NCT00005250 | National Heart, Lung, and Blood Institute (NHLBI) | — |
| Completed | Long QT Syndrome-Population Genetics and Cardiac Studies NCT00005176 | University of Rochester | — |