Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
About Pacemakers and Implantable Defibrillators
An arrhythmia is any disorder of your heart rate or rhythm. It means that your heart beats too quickly, too slowly, or with an irregular pattern. Most arrhythmias result from problems in the electrical system of the heart. If your arrhythmia is serious, you may need a cardiac pacemaker or an implantable cardioverter defibrillator (ICD). They are devices that are implanted in your chest or abdomen.
A pacemaker helps control abnormal heart rhythms. It uses electrical pulses to prompt the heart to beat at a normal rate. It can speed up a slow heart rhythm, control a fast heart rhythm, and coordinate the chambers of the heart.
An ICD monitors heart rhythms. If it senses dangerous rhythms, it delivers shocks. This treatment is called defibrillation. An ICD can help control life-threatening arrhythmias, especially those that can cause sudden cardiac arrest (SCA). Most new ICDs can act as both a pacemaker and a defibrillator. Many ICDs also record the heart's electrical patterns when there is an abnormal heartbeat. This can help the doctor plan future treatment.
Getting a pacemaker or ICD requires minor surgery. You usually need to stay in the hospital for a day or two, so your doctor can make sure that the device is working well. You will probably be back to your normal activities within a few days.
It sits within Blood, Heart and Circulation.
The lead U.S. institute for this subject is the National Heart, Lung, and Blood Institute.
When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.
Research on Pacemakers and Implantable Defibrillators
67 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.
What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.
Research currently under way
- Predicting Development of SCAF in Device PatientsOttawa Heart Institute Research Corporation
- BIO|STREAM.CSP StudyBiotronik SE & Co. KG
- Product Performance Report: Evaluate Long-term Reliability & Performance of Medtronic Marketed Cardiac Therapy ProductsMedtronic
- Evaluation of Chronic Postsurgical Pain Risk in Patients Undergoing CIED Implantation Using an AID Support SystemIstanbul University - Cerrahpasa
- Right Ventricular Function Changes After CIED Implantation: The RIGHT-CIED StudyIstanbul University - Cerrahpasa
- Magnetic Resonance Imaging (MRI) in Patients With Pacemakers and Implanted Cardioverter DefibrillatorsJohns Hopkins University
Research already completed
- Impact of Virtual Reality on Anxiety and Pain During Implantation of Cardiac Implantable Electronic Devices (CIED)Muhammed Kurt
- Comparison of Upper Extremity Function, Physical Activity Levels and Peripheral Muscle Strength, Fear of Movement, Balance, Activities of Daily Living and Quality of Life in Patients With Pacemakers According to Pacemaker TypeErol Olcok Corum Training and Research Hospital
- Ultrasound-guided Axillary Vein Access Versus Cephalic Venous Cutdown for Implantation of Cardiac Electronic Devices.Hospices Civils de Lyon
- PANORAMA Observational StudyMedtronic Cardiac Rhythm and Heart Failure
- Investigation of Therapeutic Ablation Versus Cardioversion for AFBarts & The London NHS Trust
- Truncal Ultrasound Guided Regional Anesthesia for Implantation and Revision of Automatic Implantable Cardioverter Defibrillators (AICDs) and Pacemakers in Pediatric PatientsThe University of Texas Health Science Center, Houston
Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.
Where to read more
Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.
Start Here
- What Are Defibrillators?National Heart, Lung, and Blood Institute
- What Are Pacemakers?National Heart, Lung, and Blood Institute
- What Is a Pacemaker?American Heart Association
Living With
- Coping with My Partner's ICD and Cardiac DiseaseAmerican Heart Association
- Living with Your Implantable Cardioverter Defibrillator (ICD)American Heart Association
Related Issues
- Coping with Trauma and Stressful Events As a Patient with an Implantable Cardioverter-DefibrillatorAmerican Heart Association
- Devices that May Interfere with ICDs and PacemakersAmerican Heart Association
- Questions to Ask Your Doctor: Implantable Cardioverter Defibrillator (ICD)American Heart Association
- Sexual Health for Patients with an Implantable Cardioverter DefibrillatorAmerican Heart Association
Clinical Trials
- ClinicalTrials.gov: Defibrillators, ImplantableNational Institutes of Health
- ClinicalTrials.gov: Pacemaker, ArtificialNational Institutes of Health
Medical subject headings
Clinicians and researchers index this subject under Defibrillators, Implantable, Pacemaker, Artificial. These are the terms to use when searching medical literature.
This page is built from the MedlinePlus health topic record for Pacemakers and Implantable Defibrillators, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.