Clinical Trials Directory

Trials / Conditions / Sleep Disordered Breathing

Sleep Disordered Breathing

164 registered clinical trials studyying Sleep Disordered Breathing18 currently recruiting.

StatusTrialSponsorPhase
Not Yet RecruitingCentral Apnea in Heart Failure: Physiological Mechanisms to Inform Treatment
NCT07210606
VA Office of Research and DevelopmentPhase 4
Not Yet RecruitingEvolution of Hypoxic Burden and Sympathetic/Parasympathetic Balance in Patients With Pulmonary Hypertension
NCT07464184
University Hospital, RouenN/A
WithdrawnImpact of Nocturnal Hypoxemia on Glucose in High Altitude Sleep Disordered Breathing
NCT05462834
Johns Hopkins UniversityN/A
Active Not RecruitingSleep Quality in Patients With Non-cystic Fibrosis Bronchiectasis
NCT07147803
Assiut University
Not Yet RecruitingExploring the Patterns of Sleep Disordered Breathing in Systemic Sclerosis Patients
NCT07175246
Assiut University
RecruitingOptimization of Pediatric Tonsillectomy to IMprove AnaLgesia
NCT06576830
Duke UniversityPhase 4
Active Not RecruitingValidation of Belun Ring Gen3 Deep Learning Algorithms With Subxiphoid Body Sensor
NCT06255613
Belun Technology Company LimitedN/A
RecruitingHighCycle Study: Effect of Acetazolamide on Sleep Disordered Breathing in Women Compared to Men
NCT06498531
University of ZurichPhase 4
RecruitingHighCycle Study: Effect of High Altitude on Sleep Disordered Breathing in Women Related to Their Menstrual Cyc
NCT06498544
University of Zurich
RecruitingComparison of Two Reeducation Methods in Children With Persistent Sleep Apnea, a Randomized Controlled Trial
NCT06634264
Université de MontréalN/A
RecruitingThe PARS Study: Paediatric Advanced Respiratory Service Study - An Observational Diagnostic Feasibility Study
NCT06292299
NHS Greater Clyde and Glasgow
UnknownImpact of Pulmonary Endarterectomy on Sleep-Related Breathing Disorders in CTEPH: The IPES Trial
NCT06060366
Marmara University
WithdrawnSGLT2-Inhibitors for Sleep Apnea in Heart Failure
NCT04640493
Columbia UniversityPhase 2
CompletedManaging Opioid Related Sleep Apnea With Acetazolamide
NCT06043830
University of California, San DiegoPhase 2
UnknownSMILES: Study of Montelukast in Sickle Cell Disease
NCT04351698
Great Ormond Street Hospital for Children NHS Foundation TrustPhase 2 / Phase 3
RecruitingHome Initiation of Noninvasive Positive Pressure Ventilation in Children With Medical Complexity
NCT05881031
The Hospital for Sick ChildrenN/A
Enrolling By InvitationThe Meaning of Dopaminergic Pathway in Sleep Breathing Disorders.
NCT05890911
Wroclaw Medical University
CompletedPolysomnography Validation of the Sansa Device
NCT06070389
Huxley Medical, Inc.N/A
RecruitingEvaluating the Genetics and Immunology of Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adeni
NCT05656365
National Institute of Allergy and Infectious Diseases (NIAID)
RecruitingLateral Pharyngoplasty Outcomes in Children Undergoing Tonsillectomy
NCT05575401
Loma Linda UniversityN/A
CompletedTongue Morphology and Posterior Airway Space as Predictors of Response in Patientswith Hypoglossal Nerve Stimu
NCT06154577
Cantonal Hosptal, Baselland
RecruitingSleep Disordered Breathing, Endothelial Function, and Adverse Events in Pregnancy
NCT05908591
University of Alberta
CompletedComparative Assessment of Compumedics Somfit Sleep Monitoring Device
NCT05647746
Compumedics LimitedN/A
RecruitingPost-Vent, the Sequelae: Personalized Prognostic Modeling for Consequences of Neonatal Intermittent Hypoxemia
NCT05336890
Ann & Robert H Lurie Children's Hospital of Chicago
UnknownBarbed Reposition Pharyngoplasty in Patients Complaining of Unilevel Palatal Snoring
NCT05643352
AZ DeltaN/A
UnknownContinuous EMG Measurements in Children With Asthma During Sleep
NCT05547477
Medisch Spectrum Twente
CompletedEfficacy of Clinical Decision Support and Sleep Navigation (Sleep PASS)
NCT05353998
Children's Hospital of PhiladelphiaN/A
UnknownSleep in Late Pregnancy - Artificial Intelligence Development for the Detection of Disturbances and Disorders
NCT05376475
Shiphrah Biomedical Inc.
WithdrawnDISE in Pediatric Sleep Disordered Breathing
NCT06756971
University of IowaPhase 2 / Phase 3
UnknownScreening of OSA in Hospitalized Stroke Patients Using BSP
NCT05466864
Taipei Medical University Shuang Ho HospitalN/A
UnknownDental Appliance to Treat SDB in Children
NCT05661747
Vivos BioTechnologies, Inc.Phase 4
CompletedRemote Monitoring to Improve Low Adherence in Non-invasive Ventilation
NCT04884165
Guy's and St Thomas' NHS Foundation TrustN/A
UnknownVolume Mode Non-invasive Ventilation in Amyotrophic Lateral Sclerosis
NCT05328492
University Hospitals Coventry and Warwickshire NHS TrustN/A
CompletedKetorolac on Postoperative Pain Reduction in Pediatric Patients with Adenotonsillectomy
NCT05074056
St. Louis UniversityPhase 4
UnknownUse of the ExVent Accessory With the O2Vent Optima Oral Appliance for the Treatment of Obstructive Sleep Apnea
NCT05954026
Centre for Sleep and Chronobiology, CanadaN/A
CompletedThe Impact of Interscalene Block on Sleep Disordered Breathing
NCT03718858
Women's College HospitalN/A
TerminatedPhysiological Study to Compare Noninvasive Ventilation (NIV) Masks
NCT04926805
Fisher and Paykel HealthcareN/A
CompletedAssessment of the Accuracy of the Non-invasive Wireless Armband Gabi Baby Band for Continuous Vital Parameters
NCT04886583
Gabi SmartCare
CompletedBelun Ring Platform With an Improved Algorithm for OSA Assessment
NCT04885062
Belun Technology Company LimitedN/A
RecruitingCentral Sleep Apnea : Physiologic Mechanisms to Inform Treatment
NCT04118387
VA Office of Research and DevelopmentPhase 4
CompletedPharmacological Intervention for Symptomatic Mild Sleep Disordered Breathing
NCT04611750
Brigham and Women's HospitalPhase 2
WithdrawnContribution of an Educational Game for Continuous Positive Pressure/Non-invasive Ventilation Therapeutic Educ
NCT04660994
Assistance Publique - Hôpitaux de Paris
Active Not RecruitingSleep-disordered Breathing in Infants With Myelomeningocele
NCT04251806
University of Michigan
CompletedSIESTA (Sleep of Inpatients: Empower Staff to Act) for Acute Stroke Rehabilitation
NCT04254484
University of ChicagoN/A
CompletedRing-type Pulse Oximeter for Evaluation for Sleep Assessment Study
NCT06221124
Belun Technology Company LimitedN/A
RecruitingApnea, Stroke and Incident Cardiovascular Events
NCT04399200
University Hospital, Grenoble
CompletedSleep Health Program for Patients With Chronic Pain
NCT04299100
University Health Network, TorontoN/A
Completed3D Printing of Positive Airway Pressure (PAP) Therapy Masks: a Single Site Pilot and Feasibility Study
NCT04179123
University College, LondonN/A
TerminatedUniSA BackOff! Study: Adelaide PrenaBelt Trial
NCT04437407
Shiphrah Biomedical Inc.N/A
UnknownAssociation of Hypertensive Disorder of Pregnancy With Sleep-disordered Breathing.
NCT04126629
The Cooper Health System
UnknownEffects of Exercise on Obstructive Sleep Apnea Severity in Elderly
NCT04120428
Federal University of ParaíbaN/A
CompletedNasal High Flow Therapy in Surgical Patients with Unrecognized Obstructive Sleep Apnea
NCT03964376
University Health Network, TorontoN/A
CompletedSleep Disordered Breathing and Cardiopulmonary Disease in Peruvian Highlanders
NCT03927547
Johns Hopkins UniversityN/A
UnknownPRedictOrs, PHEnotypes and Timing of Obstructive Sleep Apnea in Acute Coronary Syndrome
NCT04002739
Fondazione Policlinico Universitario Agostino Gemelli IRCCSN/A
CompletedHealthy Sleep for Children With Down Syndrome
NCT03922165
Brigham and Women's Hospital
RecruitingSleep Disordered Breathing With Opioid Use
NCT05589753
VA Office of Research and DevelopmentPhase 1 / Phase 2
Active Not RecruitingHigh Blood Pressure in Paediatric Patients With Sleep Disorder Breathing.
NCT03696654
Fundacion del Hospital Nacional de Paraplejicos para la Investigacion y la IntegracionN/A
Active Not RecruitingIdiopathic Scoliosis Progression and Sleep-disordered Breathing in Children
NCT03858244
Second Affiliated Hospital of Wenzhou Medical University
CompletedSleep-Disordered Breathing in Patients With Severe Valvular Regurgitation Undergoing Clip Procedure
NCT03813511
Heart and Diabetes Center North-Rhine Westfalia
CompletedThe Evaluation of an Interface for the Treatment of Obstructive Sleep Apnea (OSA)
NCT03725839
Fisher and Paykel HealthcareN/A
CompletedAn Investigation to Test a Prototype Nasal Mask in the Home Setting
NCT03752580
Fisher and Paykel HealthcareN/A
CompletedSleep and Breathing in the General Population - Chemical Stimuli
NCT04720547
Wayne State UniversityPhase 4
CompletedOpioid Use, Storage, and Disposal Among Pediatric Patients After Surgery
NCT03575377
Nationwide Children's HospitalN/A
CompletedHemodynamics Response to Upper Airway Obstruction in Marfan Syndrome
NCT03985657
Johns Hopkins UniversityN/A
CompletedApneaLink Air Home Sleep Testing (HST) Device Validation Study
NCT03470493
ResMedN/A
CompletedComparison of Two Telemonitoring Auto-titrating Modalities in OSA Patients
NCT03734341
Basque Health ServiceN/A
CompletedAT1R Blockade and Periodic Breathing During Sleep in Hypoxia
NCT03335904
University of British ColumbiaPhase 4
UnknownOutcomes of Post-operative Diet in Children Following Tonsillectomy and Adenoidectomy
NCT03437954
Georgetown UniversityN/A
TerminatedTelemedicine for Improving Outcome in Inner City Patient Population With Hypercapneic Respiratory Failure
NCT03353064
Albert Einstein Healthcare NetworkN/A
CompletedEfficacy of Opioid-free Anesthesia in Reducing Postoperative Respiratory Depression in Children Undergoing Ton
NCT02987985
University of SaskatchewanPhase 3
CompletedThe Evaluation of an Alternative Sizing Model in Comparison of a Conventional Sizing Model for Full Face Masks
NCT02851628
Fisher and Paykel HealthcareN/A
CompletedHeart Function in Patients Assessed for Sleep Apnoea
NCT03226652
Imperial College London
CompletedPredictive Accuracy of MATRx Plus in Identifying Favorable Candidates for Oral Appliance Therapy
NCT03217383
Zephyr Sleep TechnologiesN/A
CompletedPediatric Adenotonsillectomy Trial for Snoring
NCT02562040
Brigham and Women's HospitalN/A
CompletedThe Evaluation of a Nasal Mask for the Treatment of Obstructive Sleep Apnea
NCT03156413
Fisher and Paykel HealthcareN/A
CompletedTreatment of Sleep-disordered Breathing in Patients With SCI
NCT02830074
VA Office of Research and DevelopmentN/A
CompletedThe Evaluation of a Mask Seal/Mask for the Treatment of Obstructive Sleep Apnea (OSA)
NCT03092921
Fisher and Paykel HealthcareN/A
CompletedThe Sleep in Pregnancy Study
NCT03248219
University of Colorado, Denver
CompletedThe Evaluation of a Nasal Mask for the Treatment of Obstructive Sleep Apnea (OSA): Comfort & Performance Trial
NCT03075722
Fisher and Paykel HealthcareN/A
CompletedSleep-Disordered Breathing in Chronic Thromboembolic Pulmonary Hypertension
NCT03074539
Medical University of ViennaN/A
UnknownThe Effect of Tooth Position During Orthodontic Treatment on the Apnea/ Hypopnea Index (AHI)
NCT03299023
Harvard School of Dental Medicine
CompletedRole of Mirtazapine in Ameliorating Sleep Disordered Breathing
NCT04799782
Wayne State UniversityPhase 2
CompletedSleep Disordered Breathing, Adenotonsillectomy, Cognition and Pre-school Age Children
NCT02945306
South Tees Hospitals NHS Foundation TrustN/A
CompletedApnea Hypopnea Index Severity Versus Head Position During Sleep
NCT04086407
Sleep SystemsN/A
CompletedAn Investigation to Test a Prototype Full-face Mask in the Home Setting
NCT02938208
Fisher and Paykel HealthcareN/A
CompletedThe Evaluation of a Nasal Pillows Mask for the Treatment of Obstructive Sleep Apnea (OSA)
NCT02894242
Fisher and Paykel HealthcareN/A
CompletedEffect of Positive Airway Pressure Therapy on Hospitalization and Mortality in SDB Patients With Comorbid Chro
NCT02923505
Wissenschaftliches Institut Bethanien e.V
UnknownPrevalence, Severity and Natural Course of Sleep Apnea After Cardiac Surgery
NCT02632162
Zürcher RehaZentrum Wald
CompletedDrug-Induced Sleep Endoscopy for the Optimisation of Treatment of Patients With Obstruction Sleep Apnoea
NCT02855515
University Hospital OstravaN/A
CompletedThe Evaluation of a Nasal Mask for the Treatment of Obstructive Sleep Apnea (OSA)
NCT02730273
Fisher and Paykel HealthcareN/A
CompletedSleep Apnea in Lung Cancer: A Prospective Study
NCT02764866
Instituto de Investigación Sanitaria de la Fundación Jiménez DíazN/A
CompletedEffect of Treatment of Sleep Apnea in Patients With Paroxysmal Atrial Fibrillation
NCT02727192
Oslo University HospitalN/A
CompletedSleep-Disordered Breathing and PAP in Perinatal Depression
NCT02507297
University of MichiganN/A
CompletedRole of Enhancing Serotonin Receptors Activity for Sleep Apnea Treatment in Patients With SCI
NCT02458469
VA Office of Research and DevelopmentPhase 2
TerminatedMultinight CPAP for Sleep Apnea Patients
NCT02635100
NYU Langone HealthN/A
CompletedOpioid Safety Program in Pain Clinics (Op-Safe):
NCT02513836
University Health Network, TorontoN/A
CompletedEffect of CPAP Treatment on Glycemic Control in Gestational Diabetes: A Pilot Randomized-Controlled Trial
NCT02245659
McGill University Health Centre/Research Institute of the McGill University Health CentreN/A
CompletedValidation of the Peripheral Arterial Tone to Detect Sleep-disordered Breathing in Patients With Chronic Heart
NCT02760680
Heart and Diabetes Center North-Rhine WestfaliaN/A
CompletedCPAP vs ASV for Insomnia
NCT02365064
ResMedN/A
RecruitingSleep-disordered Breathing After Solid Organ Transplantation
NCT03142022
Universitaire Ziekenhuizen KU Leuven
TerminatedPost-operative Pain Control After Pediatric Adenotonsillectomy
NCT02296840
Emory UniversityPhase 4
CompletedEvaluation of a "Fast Track" Respiratory Therapy Clinic for Patients With Suspected Severe Sleep-Disordered Br
NCT02191085
University of CalgaryN/A
CompletedSleep Disordered Breathing, Obesity and Pregnancy Study (SOAP)
NCT02086448
Francesca Facco, MDN/A
SuspendedThe Effect of CRT on the Hypercapnic Ventilatory Response
NCT02203383
Royal Brompton & Harefield NHS Foundation Trust
CompletedPostpartum Weight Loss and Sleep Amongst Obese Women
NCT01968330
University of South FloridaN/A
CompletedDetermination of the Predictors of Nocturnal Desaturation in Postpartum Women
NCT02330055
Massachusetts General HospitalN/A
TerminatedSleep Disordered Breathing in Precapillary Pulmonary Hypertension: Effect of CPAP Treatment
NCT02583906
Universitaire Ziekenhuizen KU LeuvenN/A
TerminatedNasal High Flow Therapy for the Treatment of Respiratory Insufficiencies During Sleep
NCT02152566
Fisher and Paykel HealthcareN/A
UnknownValidation of the ApneaScan Algorithm in Sleep Disordered Breathing
NCT02204865
Royal Brompton & Harefield NHS Foundation Trust
CompletedA Short Term Open, Randomized Cross-over Trial Exploring the Effect of Carbonic Anhydrase Inhibition by Acetaz
NCT02220803
Göteborg UniversityPhase 2
TerminatedCardiovascular Improvements With MV ASV Therapy in Heart Failure
NCT01953874
ResMedN/A
CompletedUser Preference/Validation Evaluation of the New Philips Respironics Positive Airway Pressure Application
NCT03748264
Philips RespironicsN/A
UnknownEffects of Head Elevation by a Bed on Sleep-disordered Breathing
NCT01785199
Mackay Memorial HospitalPhase 1
CompletedElectrocardiography Data Analysis in Sleep Disorders
NCT02188498
Weill Medical College of Cornell University
CompletedSleep, Aging and Risk for Alzheimer's Disease
NCT01962779
NYU Langone HealthN/A
CompletedSleep Disorders and Their Cardiovascular Correlates in Atahualpa.
NCT01877616
Hospital Clínica KennedyN/A
CompletedSleep-disordered Breathing in Eisenmenger Syndrome
NCT02614417
Rigshospitalet, Denmark
CompletedAdenotonsillectomy for Obstructive Sleep-Disordered Breathing in Childhood:The Chania Community Oximetry-Based
NCT01918007
Chania General Hospital "St. George"N/A
WithdrawnIntranasal Steroids for the Treatment of Nocturnal Enuresis With Associated Obstructive Sleep Apnea
NCT01861145
University of AlbertaPhase 4
SuspendedAdaptive Servo Ventilation (ASV) in Heart Failure
NCT02440971
St Vincent's University Hospital, Ireland
TerminatedEvaluation of Sleep Disordered Breathing Following Ambulatory Surgery
NCT01851798
Walter Reed National Military Medical Center
CompletedA Pilot Study of the Effects on Sleep Disordered Breathing (SDB) When Using the Drug Liraglutide for 4 Weeks
NCT01832532
Children's Hospital Medical Center, CincinnatiPhase 1 / Phase 2
CompletedPeak(R) vs. Electrocautery in Children Undergoing Tonsillectomy With Adenoidectomy
NCT02533999
Nemours Children's ClinicN/A
CompletedRespicardia, Inc. Pivotal Trial of the remedē System
NCT01816776
Respicardia, Inc.N/A
UnknownMaternal Sleep Disordered Breathing and Fetal Growth
NCT01734460
Tel-Aviv Sourasky Medical Center
UnknownValidation of the "ApneaScan" Algorithm for the Detection of Sleep Disordered Breathing in Chronic Heart Failu
NCT01979120
Dr. Christoph Schukro
CompletedIncidence of Sleep-disordered Breathing and Upper Airway Collapsibility in Postpartum Patients and Its Interve
NCT01719224
Massachusetts General HospitalN/A
CompletedEffects of Continuous Positive Airway Pressure (CPAP) on Glucose Metabolism
NCT01503164
Johns Hopkins UniversityN/A
CompletedComparison of 2 Different Hook-up Protocols to Perform Home-based Polysomnography
NCT01361854
Centre Hospitalier Universitaire Saint PierreN/A
CompletedAdjustment of Mask Pressure, for Bilevel Positive Airways Pressure Therapy, by Automated Algorithm
NCT01403584
ResMedN/A
CompletedSleep Disordered Breathing and Its Impact on Neuro-cognitive Performance and Quality of Life in Parkinson Dise
NCT02034357
University of MiamiN/A
TerminatedContinuous Positive Airway Pressure and Cardiometabolic Risk
NCT01403194
Mayo ClinicN/A
UnknownLeukotrienes Pathway in Chinese Children With Sleep-disordered Breathing
NCT01344746
Beijing Children's Hospital
CompletedSleep Disordered Breathing
NCT01467856
Mark S. Nash, Ph.D., FACSM
CompletedSleep Apnea Treatment During Cardiac Rehabilitation of Congestive Heart Failure Patients
NCT01120548
French Cardiology SocietyN/A
UnknownSleep Disordered Breathing and Lung Transplantation
NCT01179087
KU Leuven
UnknownThe Natural History and Outcome of Sleep Disordered Breathing in Children
NCT02043353
Tel-Aviv Sourasky Medical Center
CompletedEvaluation of the Philips Respironics BiPAP autoSV Devices in Subjects With Sleep Disorders
NCT01626989
Philips RespironicsN/A
CompletedImpact of Exenatide on Sleep in Type 2 Diabetes
NCT01136798
University of ChicagoN/A
CompletedChronic Evaluation of Respicardia Therapy
NCT01124370
Respicardia, Inc.Phase 2
WithdrawnEffect of NT 201 (Botulinum Neurotoxin Type A Free of Complexing Proteins) on Sleep-related Breathing Disorder
NCT00773591
Merz Pharmaceuticals GmbHPhase 2
CompletedFat Biology, Sleep Disorders, and Cardiovascular Disease
NCT01229501
Mayo Clinic
CompletedOxygen Monitoring of Patients After Surgery on the Hospital General Care Floor
NCT01082575
Medtronic - MITG
CompletedTo Characterize the Performance of the Nasal Dilator Strip in Lowering Nasal Resistance During Sleep, Promotin
NCT03105297
GlaxoSmithKlinePhase 2
TerminatedEvaluation of Software Enhancements to the Respironics BiPAP autoSV Device Compared to BiPAP S/T Device
NCT01241604
Philips RespironicsN/A
CompletedSleep Disordered Breathing and Gestational Hypertension
NCT00757718
University of SaskatchewanN/A
CompletedEffects of Earplugs on Sleep and Sleep Apnea
NCT01062854
University of MichiganN/A
UnknownSleep Disordered Breathing in Patients With Chronic Heart Failure
NCT00863421
LudwLudwig Boltzmann Institute for COPD and Respiratory Epidemiology
CompletedAlice PDx User/Validation Extended Trial
NCT00841906
Philips RespironicsN/A
CompletedA Multi-Center Study to Assess the Performance of Saturation Patterns.
NCT00775346
Medtronic - MITG
CompletedEvaluation of Software Enhancements to the Respironics BiPAP Auto Servo Ventilation (AutoSV) Device
NCT00720213
Philips RespironicsN/A
CompletedTreatment of Predominant Central Sleep Apnoea by Adaptive Servo Ventilation in Patients With Heart Failure
NCT00733343
ResMedN/A
CompletedFeasibility Study to Determine the Effects of Phrenic Nerve Stimulation in Patients With Periodic Breathing
NCT00909259
Respicardia, Inc.Phase 1
CompletedCognitive Benefits of Treating Sleep Apnea in Parkinson's Disease
NCT00492115
University of California, San DiegoN/A
CompletedPre-operative Polysomnography Assessment of Cardiac Surgery Inpatients
NCT00922168
Cleveland Medical Devices Inc
CompletedESS as a Diagnosis Resource Aid of the Syndrome of Obstructive Sleep Apnea
NCT00989885
Fortaleza University
CompletedComparison of Sleep Study Results After Partial Intracapsular Tonsillectomy Versus Total Tonsillectomy
NCT00887471
State University of New York - Downstate Medical Center
CompletedPersonalized Asthma Care Team
NCT01423461
Brigham and Women's Hospital
UnknownInflammatory Response to Anti Inflammatory Therapy in Children With Sleep Disordered Breathing
NCT00299910
Soroka University Medical CenterPhase 4
CompletedIdentification of Sleep-Disordered Breathing in Children
NCT00233194
University of Michigan
CompletedSleepiness and the Effects of CPAP on Salivary Cortisol and Alpha-Amylase Levels in Patients With Sleep Apnea
NCT01196117
Medical College of WisconsinN/A
CompletedBehavioral Effects of Obstructive Sleep Apnea in Children
NCT00060723
University of Michigan
CompletedThe 1 Year Follow-up Objective Oral Appliance Compliance
NCT01533623
University Hospital, AntwerpN/A
CompletedIncorporating Flow Limitation Into the Diagnosis and Quantification of Sleep Disordered Breathing
NCT00004569
National Center for Research Resources (NCRR)N/A