Pacemakers, Implantable Cardioverter Defibrillators (ICD) and Cardiac Resynchronization Therapy (CRT)
Curators: Justin D Pearlman, MD, PhD, FACC and Aviva Lev-Ari, PhD, RN
Updated on 2/16/2015
Mild, non-ischemic heart failure might be more deadly than thought, an Austrian group found, calling for broader ICD use.
The voice of our Series A Content Consultant: Justin D Pearlman, MD, PhD, FACC
Pacemakers place one or more wires into heart muscle to trigger electro-mechanically coupled contraction. A single wire to the right atrium is called an AAI pacemaker (atrial sensing, atrial triggering, inhibit triggering if sensed). A single wire to the right ventricle is called a VVI pacemaker (ventricular sensing, ventricular triggering, inhibit if sensed). With two wires to the heart more combinations are possible, including atrial-ventricular sequential activation, a closer mimic to normal function (DDDR pacemaker: dual sensing, dual triggering, dual functions, and rate-responsive to mimic exercise adjustment of heart rate). Three wires are used for synchronization: one to the right atrium, one to the right ventricle apex, and a third lead into a distal branch of the coronary sinus to activate the far side of the left ventricle. Resynchronization is used to compensate for a dilated ventricle, especially one with conduction delays, where the timing of activation is so unbalanced that the heart contraction approaches a wobbling motion rather than a well coordinated contraction. Adjusting timing of activation of the right ventricle and left ventricle can offset dysynchrony (unbalanced timing) and thereby increase the amount of blood ejected by each heart beat contraction (ejection fraction). Patients with dilated cardiomyopathy and significant conduction delays can improve the ejection fraction by 10 or more percentage points, which offers a significant improvement in exertion tolerance and heart failure symptoms.
Patients with ejection fraction below 35%, among others, have an elevated risk of life-ending arrhythmias such as ventricular tachycardia. Ventricular tachycardia is an extreme example of a wobbling heart in which the electrical activation sequence circles around the heart sequentially activating a portion and blocking its ability to respond until the electric signal comes around again. Whenever a portion of the heart is activated, ions shift location, and further activation of that region is not possible until sufficient time passes so that the compartmentalized ion concentrations can be restored (repolarization). Pacing can interrupt ventricular tachycardia by depolarizing a region that supported the circular activation pattern. Failing that, an electric shock can stop an ineffective rhythm. After all regions stop activation, they will generally reactivate in the normal pulsatile synchronous manner. An implanted cardiac defibrillator is a device designed to apply an internal electric shock to pause all activation and thereby interrupt ventricular tachycardia.
UPDATED on 12/31/2013
Published on Friday, 27 December 2013
S-ICD – Subcutaneous Implantable Cardioverter Defibrillator – Boston Scientific
S-ICD – Subcutaneous Implantable Cardioverter Defibrillator – Boston Scientific
|‘Regular’ Pacemaker/ICD with Leads and a ‘Can’|
- Systemic Infection – Infections travelling down the Leads into the Heart
- Lead Displacement – The Lead moving away from the heart tissue and thus becoming pretty useless.
- Vascular/Organ Injury – Damage to the blood vessels being used for access or perforation of heart wall.
- Pneumothorax (damage to the lining around the Lung), Haemothorax (build up of blood in the chest cavity), and air embolism (air bubble trapped in a blood vessel).
Positioning of the S-ICD.
How is an S-ICD Implanted?
|Image Courtesy of
How does the S-ICD Work?
Sensing in an S-ICD.
- Normal Sinus Rhythm Template (Do your heart beats look as they should)
- Dynamic Morphology Analysis (A live comparison of heart beat to previous heart beat, do they all look the same or do they keep changing?)
- QRS Width analysis (Are the tall ‘peaks’ on your ECG, the QRS’, wider than they normally are?)
|Image Courtesy of http://www.bostonscientific.com/|
How does Insight and the S-ICD compare to other ICD Devices?
|Template used to assess eligibility!
Image Courtesy of
There you have it a quick overview of the Boston Scientific S-ICD.
Thanks for Reading
UPDATED on 10/15/2013
Frequency and Determinants of Implantable Cardioverter Defibrillator Deployment Among Primary Prevention Candidates With Subsequent Sudden Cardiac Arrest in the Community
- Kumar Narayanan, MD;
- Kyndaron Reinier, PhD;
- Audrey Uy-Evanado, MD;
- Carmen Teodorescu, MD, PhD;
- Harpriya Chugh, BS;
- Eloi Marijon, MD;
- Karen Gunson, MD;
- Jonathan Jui, MD, MPH;
- Sumeet S. Chugh, MD
From The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (K.N., K.R., A.U.-E., C.T., H.C., E.M., S.S.C.); and Departments of Pathology (K.G.) and Emergency Medicine (J.J.), Oregon Health and Science University, Portland, OR.
- Correspondence to Sumeet S. Chugh, MD, Cedars-Sinai Medical Center, The Heart Institute, AHSP Suite A3100, 127 S. San Vicente Blvd., Los Angeles, CA 90048, Los Angeles, CA 90048. E-mail email@example.com
Background—The prevalence rates and influencing factors for deployment of primary prevention implantable cardioverter defibrillators (ICDs) among subjects who eventually experience sudden cardiac arrest in the general population have not been evaluated.
Methods and Results—Cases of adult sudden cardiac arrest with echocardiographic evaluation before the event were identified from the ongoing Oregon Sudden Unexpected Death Study (population approximately 1 million). Eligibility for primary ICD implantation was determined from medical records based on established guidelines. The frequency of prior primary ICD implantation in eligible subjects was evaluated, and ICD nonrecipients were characterized. Of 2093 cases (2003–2012), 448 had appropriate pre– sudden cardiac arrest left ventricular ejection fraction information available. Of these, 92 (20.5%) were eligible for primary ICD implantation, 304 (67.9%) were ineligible because of left ventricular ejection fraction >35%, and the remainder (52, 11.6%) had left ventricular ejection fraction ≤35% but were ineligible on the basis of clinical guideline criteria. Among eligible subjects, only 12 (13.0%; 95% confidence interval, 6.1%–19.9%) received a primary ICD. Compared with recipients, primary ICD nonrecipients were older (age at ejection fraction assessment, 67.1±13.6 versus 58.5±14.8 years, P=0.05), with 20% aged ≥80 years (versus 0% among recipients, P=0.11). Additionally, a subgroup (26%) had either a clinical history of dementia or were undergoing chronic dialysis.
Conclusions—Only one fifth of the sudden cardiac arrest cases in the community were eligible for a primary prevention ICD before the event, but among these, a small proportion (13%) were actually implanted. Although older age and comorbidity may explain nondeployment in a subgroup of these cases, other determinants such as socioeconomic factors, health insurance, patient preference, and clinical practice patterns warrant further detailed investigation.
- Received March 11, 2013.
- Accepted August 21, 2013
UPDATED on 9/15/2013
based on 9/6/2013 Trials and Fibrillations — The Heart.org
Cardiac resynchronization therapy (CRT) is a multilead pacing device that can extend lives and improve the quality of life of selected patients who suffer from reduced performance of the heart due to adverse timing of contraction (wobbling motion from conduction delays that cause asynchrony or delayed activation of one portion of the left ventricle compared to others reducing net blood ejection).
The degree of benefit in CRT responders depends not only on the degree of asynchrony, but also on the delayed activity location in relation to the available locations for lead placement. CRT is an adjustment in the timing of muscle activiation to improve the concerted impact on blood ejection. Only patients likely to improve should be exposed to the risks and costs of CRT.
The Echo-CRT trial, presented September 3, 2013 at the European Society of Cardiology (ESC) 2013 Congressand simultaneously published in the New England Journal of Medicine, helps identify which patients may benefit from CRT devices. (See Steve Stiles’ report on heartwire),
Echo-CRT trial summary
Background is important
Previous CRT studies enrolled patients with QRS duration >120 or >130 ms for synchronizing biventricular pacing. Additional work confirmed the greatest benefit occurred in patients with QRS durations >150 ms and typical left bundle branch block (LBBB). Conflicting observational and small randomized trials were less clear for patients with shorter QRS durations—the majority of heart-failure patients. What’s more, most cardiologists have seen patients with “modest” QRS durations respond to CRT. In theory, wide QRS is only expected if the axis of significant delay projects onto the standard ECG views, whereas significant opportunity for benefit can be missed if the axis of significant delay is not wide in the standard views. CRT implanters have heard of patients with normal-duration QRS where echo shows marked dyssynchrony. This raised the question: Are there CHF patients with mechanical dyssynchrony (determined by echo) but no electrical delay (as measured by the ECG) benefit from CRT?Unfortunately, echo does not resolve the issue either. Thus there is the residual question of who should be evaluated by a true 3D syncrhony assessment by cardiac MRI.
Echocardiographic techniques held promise to identify mechanical dyssynchrony, but like the standard 12 lead ECG, they also utilize limited orientations of views of the heart and hence the directions in which delays can be detected. Cardiac MRI Research (not limited in view angle) by JDPearlman showed that the axis of maximal delay in patients with asynchrony is within 30 degrees of the ECG and echo views in a majority of patients with asynchrony, but it can be 70-110 degrees away from the views used by echocardiography and by ECG in 20% of cases. Hence some patients who may benefit can be missed by ECG or Echo criteria.
Echo-CRT was an industry-sponsored (Biotronik) investigator-initiated prospective international randomized controlled trial. All patients had mechanical dyssynchrony by echo, QRS <130 ms, and an ICD indication. CRT-D devices were implanted in all patients. Blinded randomization to CRT-on (404 patients) vs CRT-off (405 patients) was performed after implantation. Programming in the CRT-off group was set to minimize RV pacing. The primary outcome was a composite of all-cause mortality or hospitalization.
Six key findings
1. Although entry criteria for the trial was a QRS duration <130 ms, the mean QRS duration of both groups was 105 ms.
2. The data safety monitoring board terminated the trial prematurely because of an increased death rate in the CRT group.
3. No differences were noted in the primary outcome.
4. More patients died in the CRT group (hazard ratio=1.8).
5. The higher death rate in the CRT group was driven by cardiovascular death.
6. More patients in the CRT group were hospitalized, due primarily to device-related issues.
These findings send clear and simple messages to all involved with treating patients with heart failure. My interpretation of Echo-CRT is as follows:
Do not implant CRT devices in patients with “narrow” QRS complexes.
The signal of increased death was strong. A hazard ratio of 1.8 translates to an almost doubling of the risk of death. This finding is unlikely to be a statistical anomaly, as it was driven by CV death. The risks of CRT in nonresponders are well-known and include: increased RV pacing, possible proarrhythmia from LV pacing, and the need for more device-related surgery. Patients who do not respond to CRT get none of the benefits but all the potential harms—an unfavorable ratio indeed.
Echo is not useful for assessing dyssynchrony in patients with narrow QRS complexes.
Dr Samuel Asirvatham explains the concept of electropathy in a review article in the Journal of Cardiovascular Electrophysiology. He teaches us that the later the LV lateral wall is activated relative to the RV, the more the benefit of preexciting the lateral wall with an LV lead. That’s why the benefit from CRT in many cases increases with QRS duration, because—in a majority—a wide QRS means late activation of the lateral LV.
Simple triumphs over complicated—CRT response best estimated with the old-fashioned ECG.
In a right bundle branch block, the left ventricle is activated first; in LBBB, the LV lateral wall is last, and with a nonspecific ICD, there’s delayed conduction in either the His-Purkinje system or in ventricular muscle. What does a normal QRS say? It says the wave front of activation as projected onto the electric views obtained activates the LV and RV simultaneously. If those views capture the worst delay then they can eliminate the need for resynchrony.
CRT benefit with mild-moderate QRS prolongation still not settled
Consider how this applies to QRS duration: COMPANION and CARE-HF are clinical trials that showed definitive CRT benefit. Entry required a QRS duration >120 ms (130 ms in CARE-HF). But the actual mean QRS duration of enrolled patients was 160 ms. A meta-analysis of CRT trials confirmed benefit at longer QRS durations and questioned it below 150 ms. CRT guideline recommendations incorporate study entry criteria, not the mean values of actual patients in the trial. Patients enrolled in Echo-CRT had very narrow QRS complexes (105 ms). What to recommend in the common situation when a patient with a typical LBBB has a QRS duration straddling 130 ms is not entirely clear. The results of Echo-CRT might have been different had the actual QRS duration values been closer to 130 ms.
Echo-CRT study reinforces expectations based on cardiac physiology. In the practice of medicine, it’s quite useful to know when not to do something.
The trial should not dampen enthusiasm for CRT. Rather, it should focus our attention to patient selection—and the value of the 12-lead ECG.
Rethinking QRS Duration as an Indication for CRT
SMITA MEHTA M.D.1 and SAMUEL J. ASIRVATHAM M.D., F.A.C.C.2,3
Indications for Implantable Cardioverter-Defibrillators Based on Evidence and Judgment FREE
Implantable Cardioverter–Defibrillators after Myocardial Infarction
Robert J. Myerburg, M.D.
Division of Cardiology, University of Miami Miller School of Medicine, Miami.
END OF UPDATE
Electrical conduction of the Human Heart
- Physiology and
were explained by us in the following articles:
Below, we present the following complementary topics:
Options for Cardiac Resynchronization Therapy (CRT) to Arrhythmias:
- Implantable Pacemaker
- Insertable Programmable Cardioverter Defibrillator (ICD)
Medtronic Pacemaker Recall
Australia’s regulatory authority, the Therapeutic Goods Administration (TGA) has issued a hazard alert pertaining to one of Medtronic’s pacing devices, the Consulta® Cardiac Resynchronization Therapy Pacemaker (CRT-P). The alert coincides somewhat with Medtronic’s own issuance of a field safety notice concerning Consulta and Syncra® CRT-P devices.
Consulta and Syncra CRT-Ps are implantable medical devices used to treat heart failure. The devices provide pacing to help coordinate the heart’s pumping action and improve blood flow.
The two devices are the subject of a global manufacturer recall after Medtronic had identified an issue with a subset of both during production, although as yet there had been no reported or confirmed device failures. However, because of the potential for malfunction, Medtronic is requiring the return of non-implanted devices manufactured between April 1 and May 13, 2013 for re-inspection.
Seemingly this manufacturing issue could compromise the sealing of the device. Should an out-of-spec weld fail this could result in body fluids entering the device, which could cause it to malfunction leading to loss of pacing output. This could potentially see the return of symptoms including
- fainting or lightheadedness,
- dyspnoea (shortness of breath),
- fatigue and
Medtronic’s recall is thought to relate to 265 devices, 44 of which have been implanted in the US.
The Australian warning letter, issued by the TGA states that only one “at risk” Consulta CRT-P device has been implanted in the country and there have been no reports of device failures or patient injuries relating to this issue.
Neither Medtronic nor the TGA are suggesting any specific patient management measures other than routine follow-up in accordance with labelling instructions.
Pacemaker/Implantable Cardioverter Defibrillator (ICD) Insertion
In Summary: Who Needs a Pacemaker?
Doctors recommend pacemakers for many reasons. The most common reasons are bradycardia and heart block.
Bradycardia is a heartbeat that is slower than normal. Heart block is a disorder that occurs if an electrical signal is slowed or disrupted as it moves through the heart.
Heart block can happen as a result of aging, damage to the heart from a heart attack, or other conditions that disrupt the heart’s electrical activity. Some nerve and muscle disorders also can cause heart block, including muscular dystrophy.
Your doctor also may recommend a pacemaker if:
- Aging or heart disease damages your sinus node’s ability to set the correct pace for your heartbeat. Such damage can cause slower than normal heartbeats or long pauses between heartbeats. The damage also can cause your heart to switch between slow and fast rhythms. This condition is called sick sinus syndrome.
- You’ve had a medical procedure to treat an arrhythmia called atrial fibrillation. A pacemaker can help regulate your heartbeat after the procedure.
- You need to take certain heart medicines, such as beta blockers. These medicines can slow your heartbeat too much.
- You faint or have other symptoms of a slow heartbeat. For example, this may happen if the main artery in your neck that supplies your brain with blood is sensitive to pressure. Just quickly turning your neck can cause your heart to beat slower than normal. As a result, your brain might not get enough blood flow, causing you to feel faint or collapse.
- You have heart muscle problems that cause electrical signals to travel too slowly through your heart muscle. Your pacemaker may provide cardiac resynchronization therapy (CRT) for this problem. CRT devices coordinate electrical signaling between the heart’s lower chambers.
- You have long QT syndrome, which puts you at risk for dangerous arrhythmias.
Before recommending a pacemaker, your doctor will consider any arrhythmia symptoms you have, such as dizziness, unexplained fainting, or shortness of breath. He or she also will consider whether you have a history of heart disease, what medicines you’re currently taking, and the results of heart tests.
Many tests are used to detect arrhythmias. You may have one or more of the following tests.
An EKG is a simple, painless test that detects and records the heart’s electrical activity. The test shows how fast your heart is beating and its rhythm (steady or irregular).
An EKG also records the strength and timing of electrical signals as they pass through your heart. The test can help diagnose bradycardia and heart block (the most common reasons for needing a pacemaker).
A standard EKG only records the heartbeat for a few seconds. It won’t detect arrhythmias that don’t happen during the test.
To diagnose heart rhythm problems that come and go, your doctor may have you wear a portable EKG monitor. The two most common types of portable EKGs are Holter and event monitors.
Holter and Event Monitors
A Holter monitor records the heart’s electrical activity for a full 24- or 48-hour period. You wear one while you do your normal daily activities. This allows the monitor to record your heart for a longer time than a standard EKG.
An event monitor is similar to a Holter monitor. You wear an event monitor while doing your normal activities. However, an event monitor only records your heart’s electrical activity at certain times while you’re wearing it.
For many event monitors, you push a button to start the monitor when you feel symptoms. Other event monitors start automatically when they sense abnormal heart rhythms.
You can wear an event monitor for weeks or until symptoms occur.
Echocardiography (echo) uses sound waves to create a moving picture of your heart. The test shows the size and shape of your heart and how well your heart chambers and valves are working.
Echo also can show areas of poor blood flow to the heart, areas of heart muscle that aren’t contracting normally, and injury to the heart muscle caused by poor blood flow.
For this test, a thin, flexible wire is passed through a vein in your groin (upper thigh) or arm to your heart. The wire records the heart’s electrical signals.
Your doctor uses the wire to electrically stimulate your heart. This allows him or her to see how your heart’s electrical system responds. This test helps pinpoint where the heart’s electrical system is damaged.
Some heart problems are easier to diagnose when your heart is working hard and beating fast.
During stress testing, you exercise to make your heart work hard and beat fast while heart tests, such as an EKG or echo, are done. If you can’t exercise, you may be given medicine to raise your heart rate.
What Are the Risks of Pacemaker Surgery?
Pacemaker surgery generally is safe. If problems do occur, they may include:
- Swelling, bleeding, bruising, or infection in the area where the pacemaker was placed
- Blood vessel or nerve damage
- A collapsed lung
- A bad reaction to the medicine used during the procedure
Talk with your doctor about the benefits and risks of pacemaker surgery.
How Does a Pacemaker Work?
A pacemaker consists of a battery, a computerized generator, and wires with sensors at their tips. (The sensors are called electrodes.) The battery powers the generator, and both are surrounded by a thin metal box. The wires connect the generator to the heart.
A pacemaker helps monitor and control your heartbeat. The electrodes detect your heart’s electrical activity and send data through the wires to the computer in the generator.
If your heart rhythm is abnormal, the computer will direct the generator to send electrical pulses to your heart. The pulses travel through the wires to reach your heart.
Newer pacemakers can monitor your blood temperature, breathing, and other factors. They also can adjust your heart rate to changes in your activity.
The pacemaker’s computer also records your heart’s electrical activity and heart rhythm. Your doctor will use these recordings to adjust your pacemaker so it works better for you.
Your doctor can program the pacemaker’s computer with an external device. He or she doesn’t have to use needles or have direct contact with the pacemaker.
Pacemakers have one to three wires that are each placed in different chambers of the heart.
- The wires in a single-chamber pacemaker usually carry pulses from the generator to the right ventricle (the lower right chamber of your heart).
- The wires in a dual-chamber pacemaker carry pulses from the generator to the right atrium (the upper right chamber of your heart) and the right ventricle. The pulses help coordinate the timing of these two chambers’ contractions.
- The wires in a biventricular pacemaker carry pulses from the generator to an atrium and both ventricles. The pulses help coordinate electrical signaling between the two ventricles. This type of pacemaker also is called a cardiac resynchronization therapy (CRT) device.
Cross-Section of a Chest With a Pacemaker
The image shows a cross-section of a chest with a pacemaker. Figure A shows the location and general size of a double-lead, or dual-chamber, pacemaker in the upper chest. The wires with electrodes are inserted into the heart’s right atrium and ventricle through a vein in the upper chest. Figure B shows an electrode electrically stimulating the heart muscle. Figure C shows the location and general size of a single-lead, or single-chamber, pacemaker in the upper chest.
Types of Pacemaker Programming
The two main types of programming for pacemakers are
- demand pacing and
- rate-responsive pacing.
A demand pacemaker monitors your heart rhythm. It only sends electrical pulses to your heart if your heart is beating too slow or if it misses a beat.
A rate-responsive pacemaker will speed up or slow down your heart rate depending on how active you are. To do this, the device monitors your
- sinus node rate,
- blood temperature, and
- other factors to determine your activity level.
Your doctor will work with you to decide which type of pacemaker is best for you.
What To Expect During Pacemaker Surgery
Placing a pacemaker requires minor surgery. The surgery usually is done in a hospital or special heart treatment laboratory.
Before the surgery, an intravenous (IV) line will be inserted into one of your veins. You will receive medicine through the IV line to help you relax. The medicine also might make you sleepy.
Your doctor will numb the area where he or she will put the pacemaker so you don’t feel any pain. Your doctor also may give you antibiotics to prevent infection.
First, your doctor will insert a needle into a large vein, usually near the shoulder opposite your dominant hand. Your doctor will then use the needle to thread the pacemaker wires into the vein and to correctly place them in your heart.
An x-ray “movie” of the wires as they pass through your vein and into your heart will help your doctor place them. Once the wires are in place, your doctor will make a small cut into the skin of your chest or abdomen.
He or she will slip the pacemaker’s small metal box through the cut, place it just under your skin, and connect it to the wires that lead to your heart. The box contains the pacemaker’s battery and generator.
Once the pacemaker is in place, your doctor will test it to make sure it works properly. He or she will then sew up the cut. The entire surgery takes a few hours.
What To Expect After Pacemaker Surgery
Expect to stay in the hospital overnight so your health care team can check your heartbeat and make sure your pacemaker is working well. You’ll likely have to arrange for a ride to and from the hospital because your doctor may not want you to drive yourself.
For a few days to weeks after surgery, you may have pain, swelling, or tenderness in the area where your pacemaker was placed. The pain usually is mild; over-the-counter medicines often can relieve it. Talk to your doctor before taking any pain medicines.
Your doctor may ask you to avoid vigorous activities and heavy lifting for about a month after pacemaker surgery. Most people return to their normal activities within a few days of having the surgery.
How Will a Pacemaker Affect My Lifestyle?
Once you have a pacemaker, you have to avoid close or prolonged contact with electrical devices or devices that have strong magnetic fields. Devices that can interfere with a pacemaker include:
- Cell phones and MP3 players (for example, iPods)
- Household appliances, such as microwave ovens
- High-tension wires
- Metal detectors
- Industrial welders
- Electrical generators
These devices can disrupt the electrical signaling of your pacemaker and stop it from working properly. You may not be able to tell whether your pacemaker has been affected.
How likely a device is to disrupt your pacemaker depends on how long you’re exposed to it and how close it is to your pacemaker.
To be safe, some experts recommend not putting your cell phone or MP3 player in a shirt pocket over your pacemaker (if the devices are turned on).
You may want to hold your cell phone up to the ear that’s opposite the site where your pacemaker is implanted. If you strap your MP3 player to your arm while listening to it, put it on the arm that’s farther from your pacemaker.
You can still use household appliances, but avoid close and prolonged exposure, as it may interfere with your pacemaker.
You can walk through security system metal detectors at your normal pace. Security staff can check you with a metal detector wand as long as it isn’t held for too long over your pacemaker site. You should avoid sitting or standing close to a security system metal detector. Notify security staff if you have a pacemaker.
Also, stay at least 2 feet away from industrial welders and electrical generators.
Some medical procedures can disrupt your pacemaker. These procedures include:
- Magnetic resonance imaging, or MRI
- Shock-wave lithotripsy to get rid of kidney stones
- Electrocauterization to stop bleeding during surgery
Let all of your doctors, dentists, and medical technicians know that you have a pacemaker. Your doctor can give you a card that states what kind of pacemaker you have. Carry this card in your wallet. You may want to wear a medical ID bracelet or necklace that states that you have a pacemaker.
In most cases, having a pacemaker won’t limit you from doing sports and exercise, including strenuous activities.
You may need to avoid full-contact sports, such as football. Such contact could damage your pacemaker or shake loose the wires in your heart. Ask your doctor how much and what kinds of physical activity are safe for you.
Your doctor will want to check your pacemaker regularly (about every 3 months). Over time, a pacemaker can stop working properly because:
- Its wires get dislodged or broken
- Its battery gets weak or fails
- Your heart disease progresses
- Other devices have disrupted its electrical signaling
To check your pacemaker, your doctor may ask you to come in for an office visit several times a year. Some pacemaker functions can be checked remotely using a phone or the Internet.
Your doctor also may ask you to have an EKG (electrocardiogram) to check for changes in your heart’s electrical activity.
Pacemaker batteries last between 5 and 15 years (average 6 to 7 years), depending on how active the pacemaker is. Your doctor will replace the generator along with the battery before the battery starts to run down.
Replacing the generator and battery is less-involved surgery than the original surgery to implant the pacemaker. Your pacemaker wires also may need to be replaced eventually.
Your doctor can tell you whether your pacemaker or its wires need to be replaced when you see him or her for followup visits.
Clinical Trial on Pace Makers
clinical trials related to pacemakers, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:
For more information about clinical trials for children, visit the NHLBI’s Children and Clinical Studies Web page.
RESOUCES on PaceMakers
Links to Other Information About Pacemakers
- Arrhythmia (Health Topics)
- Atrial Fibrillation (Health Topics)
- Heart Block (Health Topics)
- How the Heart Works (Health Topics)
- Implantable Cardioverter Defibrillator (Health Topics)
- Long QT Syndrome (Health Topics)
- Pacemaker (MedlinePlus)
- Pacemakers and Implantable Defibrillators (MedlinePlus)
- Pacemaker Interactive Tutorial (MedlinePlus—Patient Education Institute)
- Children and Clinical Studies
- Clinical Trials (Health Topics)
- Current Research (ClinicalTrials.gov)
- NHLBI Clinical Trials
- NIH Clinical Research Trials and You (National Institutes of Health)
- ResearchMatch (funded by the National Institutes of Health)