Heart Rhythm Specialty


What is a Heart Rhythm Specialist?

A Heart Rhythm Specialist is a Cardiologist who received additional specialized training to treat abnormalities in the rhythm of the heart, often called arrhythmias. Heart Rhythm Specialists are also referred to as Electrophysiologists. Treatment options may vary along a wide spectrum and may include: medications or procedures including cardioversion, electrophysiology study, catheter ablation procedures, and cardiac device implantation.



What kinds of Arrythmias Do Heart rhythm Specialists Treat?

An arrythmia is a disturbance in the electrical conduction of the heart. When this happens, the heart does not beat properly and cannot pump effectively. The disturbance may involve the rate of the heart in which the heart may beat too fast (tachycardia), or too slow (bradycardia). It may also involve the rhythm of the heart in which it may beat erratically or irregularly.


Arrythmias can originate anywhere along the electrical conduction system of the heart. Fast arrhythmias, or tachyarrythmias, that arise from the upper chambers, or atria, of the heart  are often referred to as Supraventricular Tachycardias (SVT). Types of SVT include:

AV nodal reentrant tachycardia (AVNRT)
AV reciprocating tachycardia (AVRT)
Atrial tachycardia (AT)

Atrial fibrillation (AF)- most common type of arrhythmia
Atrial flutter


Ventricular arrhythmias originate in the bottom chambers, or ventricles, of the heart.  These rhythms can result from damage from the heart muscle from a heart attack or cardiomyopathy, or they can occur in patients with hearts that seem structurally normal. Types of ventricular arrhythmias include:

  • Premature ventricular contractions (PVCs)
  • Ventricular Tachycardia
  • Ventricular Fibrillation

Slow arrhythmias, called bradyarrythmias, occur when the heart’s electrical signal cannot travel from the upper sinus node in the atria to the heart’s lower chambers in the ventricles.

What Symptoms do arrhythmias cause?

The type of arrhythmia and the health of your heart will determine what symptoms you may experience. Symptoms depend on how severe the arrhythmia is, how often it happens, and how long it lasts. Some arrhythmias do not produce any symptoms.

Symptoms of bradycardia

  • You may feel fatigue, short of breath, dizzy, faint

Symptoms of tachycardia

  • You may feel a strong pulse in your neck, or a fluttering, racing heart beat in your chest
  • You may feel chest discomfort, weakness, shortness of breath, sweaty, dizzy

Symptoms of irregular rhythms

  • You may feel any of the symptoms listed above as well as skipped beats or an erratic heart rhythm which can be fast, slow or at a normal rate

How is an Arrythmia Diagnosed?

The following tests are performed in our office and are used to diagnose arrhythmias and their symptoms:

  • Electrocardiogram (ECG or EKG). This test is performed during your office visit and provides a six second analysis of the rate and rhythm of your heart
  • Holter monitoring provides a continuous reading of your heart rhythm over a 24 hour or 3-5 day period.  

Holter Monitoring

Holter monitoring provides a continuous reading of your heart’s electrical activity or a 24-hour or 3-day period. An electrode (small conducting patch) is applied to your chest and attached to a small recording monitor.  

How the Test is Performed 

The area where the monitor is applied is prepped with alcohol, trace tape, and skin barrier to ensure proper contact between the patch and skin. The technician may use a small abrasive pad to help remove any dead or oily skin. Some patients may need to have their chest shaved so the electrode can stick (you can shave your own chest prior to your appointment if you would rather do it yourself, see photo). The purpose of this prep is to ensure optimal skin contact with the electrode(s). Once the prep is completed the patch and monitor will be placed on your chest. 


You will have the capability to do a recording on the monitor should you experience any symptoms while completing the test. You will be asked to keep a diary of what activities you do while wearing the monitor and any symptoms you may experience and when you have them.  It is very important that you accurately record your symptoms and activities so the doctor can match them with your Holter monitor findings. Continue your normal activities while wearing the monitor. You may be asked to exercise while being monitored if your symptoms have occurred in the past while you were exercising. 

Although your monitor is continuously watching my heart rhythm, the monitor does not notify the doctor’s office if there are abnormalities. When you return the monitor, the information will be processed and reported to your cardiologist. If there are any significant abnormalities, you may be called to discuss symptoms and/or move up to a follow-up appointment. If less severe abnormalities are present, you will not be called as I will be reviewing the results with your cardiologist at your scheduled follow up. 

It is recommended during the monitoring period that you should take action should symptoms or a change in your medical condition occur (as you would when not wearing a monitor). This includes calling the office to notify of such changes or go to the emergency if severe or life-threatening symptoms occur. 

If you cancel your follow-up appointment for review of testing, you will need to reschedule that appointment to review you monitor results. 

How to Prepare for the Test

Make sure you shower or bathe before you start the test. Please refrain from applying any lotions, powders, or oils to your body on the day of the test. If you have hair on your chest you may shave before coming in if you wish to do so (see image). Tell your doctor if you are allergic to any tape or other adhesives. Wear comfortable and loose-fitting clothing and please avoid wearing a dress on the day you are scheduled for the monitor. You will be asked to remove your shirt to ensure proper placement of the electrode. If you do not want to remove your top for the test, we would recommend that you wear a button-down shirt. Take your usual medications unless otherwise instructed by your physician.  

Showering with the Monitor

The monitor CANNOT be submerged in water. If you are to receive a 24-hour monitor, you should NOT shower with the monitor on. For patients receiving the extended monitor (3 days) the monitor cannot be removed during your testing period, therefore, you may shower with the monitor. While showering you should face away from the water and avoid direct spray to you chest.  

Return Policy:

The monitor needs to be returned to the office on the designated return date and time below. We have a labeled monitor drop box on the side of the building should you want to drop it off earlier. The monitor is expected to be returned in the same condition as it was given to you in, any damage could result in you being billed for the cost of the damages. 

1-Day monitoring: I agree to return the monitor by 8am the following day after receiving the monitor  

3-day monitoring: I agree to return the monitor by 10 am on the designated day after receiving the monitor (date will be given when monitor is placed) 


Event Monitoring

Event Monitor: is a device used to record your heart’s rhythm. The device is used for a maximum period of 30 days and should be worn as directed. Event monitors have the ability to detect abnormal rhythms in the absence of symptoms. 

How to Prepare for the Test: 

We ask that you shower or bathe before coming to the office to ensure your skin is clean for good contact.  Please refrain from applying any lotions, powders, or oils to your torso for the duration of the test. Tell your doctor if you are allergic to any tape or other adhesives. Wear comfortable, loose-fitting clothing and please avoid wearing a dress for your initial hook-up. Take your usual medications unless otherwise instructed by your physician. 

How the Test Will Feel: 

The technician will show you how to place the electrodes on your skin, since you will be replacing them daily.  Your skin will be prepped by using a small pad that will abrade off any dead skin cells.  Some people may need to have their chest shaved so the electrodes can stick. The purpose of this prep is to ensure optimal skin contact with the electrodes. 

How the Test is Performed: 

On the day of the test the technician will review the device and how to use and return it.  Once placed, the monitor will capture any arrhythmia you experience while wearing it.  However, if you should have any symptoms, the technician will demonstrate how to record.  Please remember to continue your normal activities while wearing the monitor.  

Remember, although this monitor is continuously watching your heart rhythm, the monitor does not instantly notify the doctor’s office if there are abnormalities.  There are many steps in transmitting rhythm information from your monitor to Hamilton Cardiology. This includes your physical distance to your transmitter, local cellular signal availability and quality, and availability of remote monitoring company technicians to receive and process the information that they will then notify our office.  If one step is not working well there may be a delay in the office receiving information.  There are designated criteria that our office or BioTel might contact you for during the business day and on nights and weekends. You might be called about these issues, so you need to ensure your contact information is up to date.  Please note you will not be called with every abnormality, especially if not life threatening, as you will review the final monitoring report with your cardiologist at your follow up testing visit.  It is recommended to take action should symptoms or a change in your medical condition occur while you are wearing the monitor.  This includes calling the office to notify of such changes or go to the emergency room if severe or life-threatening symptoms occur. 

If you cancel your follow up appointment for review of testing, you will need to reschedule that appointment to review your monitor results. 

Return Policy:

You may be called to return the monitor sooner if we get the data needed sooner than the 30 days. The monitor is expected to be returned in the same condition as it was given to you in. You may be held financially responsible for any damage that is incurred to the monitor during usage. 

If you are given a Biotel Patch monitor, you will need to return the device via a FedEx or UPS drop-off location using the pre-labeled bag inside of your return box.

Tilt Table Test

A Tilt Table Test is used to evaluate the cause of unexplained fainting (syncope) or lightheadedness. The goal is to trigger your symptoms during close monitoring.  The test is performed in the hospital, under the direct supervision of your doctor and specially trained nurses. You will be awake during the test, which lasts about 90 minutes and involves 2 phases. During the test, you will be asked to lie flat on a special table that can change positions. For this reason, straps like a seat belt will be applied to your waist and knees to keep you in position on the table.  You will be connected to continuous heart rate and blood pressure monitoring. An intravenous line (IV) will be inserted.

During the first phase of testing, the table will be stood up, or tilted, so that your body is raised to a head-up position, simulating a change in position from lying down to sitting up.  You will be monitored for up to 45 minutes during this phase. The test is normal if your average blood pressure remains stable and your heart rate increases by a normal amount as the table changes your position.

Depending on the results of the first phase of the test, you may proceed to the second phase, which involves the administration of medication either through the IV or under the tongue to speed up your heart rate. The medicine will stimulate stress and may make you feel as if you are exercising, and may make you more sensitive to the tilt table than you were at rest during phase one.

There are very few risks to this procedure. The most common is fainting and this passes quickly when the treatment is ended by lying the table down, in a safe environment under the direct supervision of the doctor and nurses. You may receive your results as soon as the test is complete.

You will be provided with instructions from the hospital prior to your appointment. You will be advised not to eat or drink anything after midnight prior to your test and will not be permitted to drive yourself home after the procedure.

Implantable Loop Recorder (ILR) An Implantable Loop Recorder (ILR) is a small device about the size of a AAA battery that is implanted just under the skin of the chest to the left of the breast bone. The device can track abnormal rhythms by two mechanisms: heart rate parameters and patient activation. The device allows high and low heart rate parameters to be set by your Heart Rhythm Specialist. If your heart rate falls out of the range set, the monitor will record the fast or slow heart rhythm. The second mechanism involves patient participation and allows rhythms that were triggered by a symptom to be captured.
The ILR is useful for patients who are experiencing symptoms of dizziness, passing out (syncope) or palpitations for which arrhythmias have not been able to be captured by a traditional holter or event monitor. The device is placed under local anesthesia in the hospital as an outpatient procedure by one of our Heart Rhythm Specialists. A small pocket is created under the skin and the device is placed in the pocket. Unlike a pacemaker, no wires are inserted into the heart, and patients go home the same day. The battery life of this device is two years or more, allowing ample time for it to detect an arrhythmia. There is a remote monitoring system that communicates with the device and sends reports to our office. The reports will tell us about rhythm problems even if you are unaware of them. This feature makes the ILR very useful, particularly if there is concern for rhythms with serious consequences. Once the device is no longer needed or the battery expires, the device is often left in place rather than being removed.

You will be provided with instructions from the hospital prior to your appointment. You will be advised not to eat or drink anything after midnight prior to your test and will be permitted to drive yourself home after the procedure.

Electrophysiology (EP) Study

Depending on your clinical arrhythmia, or heart rhythm disturbance, and the frequency of the episodes, your physician may refer you for an Electrophysiology (EP) study. These studies are typically performed by Electrophysiologists, or Heart Rhythm Specialists, in patients with:

  • Symptomatic arrhythmias despite medications
  • Intolerable side effects from medications prescribed for the arrhythmia
  • Desire for a curative catheter ablation procedure as a first-line to avoid medications, or secondary to occupational risks (pilots, public servants – police, fireman, etc)
  • For risk stratification for sudden cardiac death in the presence of structural heart disease or clinically documented arrhythmias , to determine a need for an Implantable Cardiac Defibrillator (ICD)
  • To evaluate the need for a Permanent Pacemaker

An EP study is a procedure performed to study the electrical system of your heart. The Electrophysiologist will place several catheters, typically via the groin, into the heart under fluoroscopic, or X-ray, guidance. These catheters are placed in well-defined regions critical to the heart’s normal conduction system, such as the right atrium, bundle of HIS, and the right ventricle. These catheters allow your physician to stimulate your heart and to electrically map the origin and characteristics of your clinical arrhythmia.

What is the Treatment for Arrythmias?

Once your diagnostic testing is complete and your arrhythmia has been determined, your Heart Rhythm Specialist will discuss treatment options, which may depend on the symptoms that are being experienced. Not all arrhythmias require treatment.

Treating fast heart beats (Tachyarrythmias)

Treatment of fast heart beats may include one or more of the following:


Cardioversion is a procedure that is used to restore a regular heart rhythm. There are two types of cardioversion: electrical, which involves the delivery of a shock to the heart, and pharmacological (chemical), in which medication is used to chemically restore the hearts regular rhythm. Cardioversion may be considered for a fast and/or an irregular rhythm that is causing symptoms. It may also be used to treat life threatening arrhythmias. Sometimes your doctor may use a combination of both types of cardioversions to try to restore a normal rhythm. Depending on the medication being administered, chemical cardioversion alone may occur as an inpatient or an outpatient.

Electrical cardioversion is performed in the hospital, under the close supervision of a cardiologist and nursing staff. It is an outpatient procedure and you should be expected to return home on the same day.  During electrical cardioversion you will be given medication to make you sleepy. You should not feel pain during the procedure. Your doctor will deliver an electrical shock to your heart through two special paddles that are attached to your skin. The shock lasts less than a second, and briefly stops (resets) your heart rhythm. In most cases, patients wake up quickly and do not remember the shock.

Certain arrhythmias like atrial flutter and atrial fibrillation  are associated with blood clot formation in the left atrium of the heart. Performing a cardioversion under these circumstances may dislodge the clot from the heart to the brain and cause a stroke. For this reason, you may be required to have a Tranesophageal Echocardiogram (TEE)  prior to the cardioversion . The instructions for electrical cardioversion are similar as those for TEE.

Catheter Ablation

Catheter Ablation is typically performed during the same EP study.   By using specialized intracardiac catheters, heat or cold energy can be delivered to the local heart tissue to terminate the tachycardia. The success rates of catheter ablation for types of arrhythmias listed below can be greater than 95%, and in some cases may be curative.

Catheter ablation for supraventricular tachycardias (SVT), or those that arise from the upper chambers, or atria, is, as a group, typically more successful and more often performed than for ventricular arrhythmias. These types of SVT include:

  • Atrial fibrillation (AF)
  • Atrial flutter
  • AV nodal reentrant tachycardia (AVNRT)
  • AV reciprocating tachycardia (AVRT)
  • Atrial tachycardia (AT)

Catheter ablation for ventricular tachycardia (VT) is fundamentally more complex.  Those patients with “focal” ventricular tachycardia with no evidence of structural heart disease (including outflow tract variants) can be ablated with a high-rate of success if they fail medical therapy. Patients with structural heart disease and “reentrant” ventricular tachycardia are a more challenging subset of patients. These patients typically have an ICD implanted and are referred to a heart rhythm specialist after failed antiarrhythmic therapy for recurrent ICD shocks.  Catheter ablation of VT can be performed in these patients with success rates that vary based on the location of the arrhythmia focus. A careful discussion with your heart rhythm specialist to design a customized treatment plan is important.

The risks of an EP study and catheter ablation are small, but, as with any invasive procedure, it is not risk-free. Not all arrhythmias can be cured with catheter ablation and an individually-tailored discussion of your treatment options with your physician is paramount.

Treating slow heart beats (Bradyarrythmias)

Treatment of slow heart beats may include one or more of the following:

  • Treating underlying disorders
  • Change in medications
  • Permanent Pacemaker (PPM)

Permanent Pacemaker Insertion (PPM)7



What is an artificial pacemaker?

A PPM is a small battery-operated device that helps the heart beat in a regular rhythm. There are two types of pacemakers, the traditional pacemaker which has two parts: a generator and wires (leads). The generator is a small battery-powered unit. It produces the electrical impulses that stimulate your heart to beat. The generator may be implanted under your skin through a small incision. The generator is connected to your heart through tiny wires that are implanted at the same time. The impulses flow through these leads to your heart and are timed to flow at regular intervals just as impulses from your heart’s natural pacemaker would. Some pacemakers are external and temporary, not surgically implanted.


The second type of Pacemaker is the Micra Leadless Pacemaker. A Micra Pacemaker is a small implanted device that sends electrical impulses to the heart when it senses that the heartbeat is too slow. Unlike a traditional pacemaker that is inserted in the chest wall, the Micra is a much smaller device that is implanted directly into the heart through a vein in your groin. With this, there is no chest incision, scar, or bump that a traditional pacemaker leaves.


Why do I need one?

Your doctor may recommend an artificial pacemaker to make your heart beat more regularly if:

  •  Your heartbeat is too slow and often irregular.
  •  Your heartbeat is sometimes normal and sometimes too fast or too slow.

How does it work?

A PPM replaces the heart’s defective natural pacemaker functions. The sinoatrial (SA) node or sinus node is the heart’s natural pacemaker. It’s a small mass of specialized cells in the top of the right atrium (upper chamber of the heart). It produces the electrical impulses that cause your heart to beat. A chamber of the heart contracts when an electrical impulse or signal moves across it. For the heart to beat properly, the signal must travel down a specific path to reach the ventricles (the heart’s lower chambers). When the natural pacemaker is defective, the heartbeat may be too fast, too slow or irregular. Rhythm problems also can occur because of a blockage of your heart’s electrical pathways. The artificial pacemaker’s pulse generator sends electrical impulses to the heart to help it pump properly. An electrode is placed next to the heart wall and small electrical charges travel through the wire to the heart. Most pacemakers have a sensing mode that inhibits the pacemaker from sending impulses when the heartbeat is above a certain level. It allows the pacemaker to fire when the heartbeat is too slow. These are called demand pacemakers.

How is a Pacemaker implanted?

A traditional pacemaker is implanted in a pouch under the skin of the chest or abdomen, often just below the collarbone. The generator is about the size of a pocket watch. Wires or leads run from the pulse generator to positions on the surface of or inside the heart and can be installed through blood vessels, eliminating the need for open-chest surgery. Newer devices are entirely placed below the skin without wires inside the blood vessels.

A Micra Leadless Pacemaker is inserted by a straw-like catheter system into a vein, typically near the upper thigh area of your leg. The catheter system moves the Micra into the right ventricle of the heart (bottom chamber). The Micra pacing capsule is then placed against the heart wall and secured. Your doctor will test the Micra to verify that it is working properly, and then the catheter system is then removed.

American Heart Association (AHA) Recommendation
If you have an artificial pacemaker, be aware of your surroundings and the devices that may interfere with pulse generators:

Home appliances

CB radios, electric drills, electric blankets, electric shavers, hand radios, heating pads, metal detectors, microwave ovens, TV transmitters and remote control TV changers, in general, have not been shown to damage pacemaker pulse generators, change pacing rates or totally inhibit pacemaker output.
Several of these devices have a remote potential to cause interference by occasionally inhibiting a single beat. However, most people can continue to use these devices without significant worry about damage or interference with their pacemakers.
Power-generating equipment, arc welding equipment and powerful magnets (as in medical devices, heavy equipment or motors) can inhibit pulse generators. Patients who work with or near such equipment should know that their pacemakers may not work properly in those conditions, and may be prohibited from doing so after their procedure.

Cell Phones

Cell phones available in the United States (less than 3 watts) don’t seem to damage pulse generators or affect how the pacemaker works.
Technology is rapidly changing as the Federal Communications Commission (FCC) is making new frequencies available. Newer cell phones using these new frequencies might make pacemakers less reliable. A group of cell phone companies is studying that possibility.

Medical equipment

Carry a wallet Pacemaker ID card with you. Equipment used by doctors and dentists can affect your pacemaker, so tell them you have one.

Magnetic Resonance imaging (MRI) uses a powerful magnet to produce images of internal organs and functions. Metal objects are attracted to the magnet and are normally not allowed near MRI machines. The magnet can interrupt the pacing and inhibit the output of pacemakers. If MRI must be done, the pacemaker output in some models can be reprogrammed. Discuss with your doctor the possible risks and benefits before you undergo MRI scanning. Newer pacemakers are now MRI compatible, but the MRI must be performed at a center that is certified in treating patients with pacemakers.

Extracorporeal shock-wave lithotripsy (ESWL) is a noninvasive treatment that uses hydraulic shocks to dissolve kidney stones. This procedure is safe for most pacemaker patients, with some reprogramming of the pacing. You’ll need careful follow-up after the procedure and for several months to be sure your unit is working properly. Patients with certain kinds of pacemakers implanted in the abdomen should avoid ESWL. Discuss your specific case with your doctor before and after the treatment.

Radiofrequency (RF) ablation uses radio waves to manage a wide variety of arrhythmias. Recent studies of patients with implanted pacing systems measured the units before, during and after RF catheter ablation. They showed that most permanent pacemakers aren’t adversely affected by radio frequencies during catheter ablation. A variety of changes in your pacemaker can occur during and after the treatment. Your doctor should carefully evaluate your pacing system after the procedure.

Transcutaneous electrical nerve stimulation (TENS) is used to relieve acute or chronic pain. Several electrodes are placed on the skin and connected to a pulse generator. Most studies have shown that TENS rarely inhibits bipolar pacing. It may sometimes briefly inhibit unipolar pacing. This can be treated by reprogramming the pulse generator.

Diagnostic radiation (such as screening X-ray) appears to have no effect on pacemaker pulse generators. However, therapeutic radiation (such as for treating cancerous tumors) may damage the pacemaker’s circuits. The degree of damage is unpredictable and may vary with different systems. But the risk is significant and builds up as the radiation dose increases. The American Heart Association recommends that the pacemaker be shielded as much as possible, and moved if it lies directly in the radiation field. If you depend on your pacemaker for normal heart pacing, the electrocardiogram (ECG) should be monitored during the treatment, and your pulse generator should be tested often after and between radiation sessions.

Dental equipment doesn’t appear to affect pacemakers adversely. Some patients may feel an increase in pacing rates during dental drilling.
Electroconvulsive therapy (such as for certain mental disorders) appears to be safely used in patients with pacemakers.
Short-wave or microwave diathermy uses high-frequency, high-intensity signals. These may bypass your pacemaker’s noise protection and interfere with or permanently damage the pulse generator.

Implantable Cardioverter Defibrillator (ICD)


ICDs are useful in preventing sudden death in patients with known, sustained ventricular tachycardia or fibrillation. Studies have shown ICDs to have a role in preventing cardiac arrest in high-risk patients who haven’t had, but are at risk for, life-threatening ventricular arrhythmias.

All ICDs have a dual function which includes the ability to serve as a pacemaker. The pacemaker feature would stimulate the heart to beat if the heart rate is detected to be too slow

Informative Video about ICDs

What is an Implantable Cardioverter Defibrillator (ICD)?

An ICD is a battery-powered device placed under the skin that keeps track of your heart rate. There are two types of defibrillators; the traditional defibrillators have thin wires that connect the ICD to your heart. If an abnormal heart rhythm is detected the device will deliver an electric shock to restore a normal heartbeat to stop your heart from beating chaotically and much too fast.

ICDs have been very useful in preventing sudden death in patients with known, sustained ventricular tachycardia or fibrillation (View an animation of an ICD). Studies have shown that they may have a role in preventing cardiac arrest in high-risk patients who haven’t had, but are at risk for, life-threatening ventricular arrhythmias.

The American Heart Association recommends that before a patient is considered to be a candidate for an ICD, the arrhythmia in question must be life threatening and doctors have ruled out correctable causes of the arrhythmia, such as:

  • Acute myocardial infarction (heart attack)
  • Myocardial ischemia (inadequate blood flow to the heart muscle)
  • Electrolyte imbalance and drug toxicity

Because many people do not understand their underlying condition – such as heart failure or genetic predisposition for risk of sudden cardiac arrest– and because ICDs are used primarily for prevention, they in turn may not understand the benefits versus the limitations of having an ICD implanted. If you are one of those people, you will find information and guidance here.

thumbnail of ICD SDM Tool

Is an ICD Right for Me? Click to Read.

Why do I need an ICD?

Your doctor may recommend an ICD if you or your child is at risk of a life-threatening ventricular arrhythmia because of having:

  • Had a ventricular arrhythmia
  • Had a heart attack
  • Survived a sudden cardiac arrest
  • Long QT Syndrome
  • Brugada syndrome
  • A congenital heart disease or other underlying conditions for sudden cardiac arrest
  • A weak heart (cardiomyopathy), in spite of optimal medical therapy

How is an ICD implanted?

A battery-powered pulse generator is implanted in a pouch under the skin of the chest or abdomen, often just below the collarbone. The generator is about the size of a pocket watch. Wires or leads run from the pulse generator to positions on the surface of or inside the heart and can be installed through blood vessels, eliminating the need for open-chest surgery. Newer devices are entirely placed below the skin without wires inside the blood vessels.

How does an ICD work?

  • It knows when the heartbeat is not normal and tries to return the heartbeat to normal.
  • If your ICD has a pacemaker feature when your heartbeat is too slow, it works as a pacemaker and sends tiny electric signals to your heart.
  • When your heartbeat is too fast or chaotic, it gives defibrillation shocks to stop the abnormal rhythm.
  • It works 24 hours a day.

New devices also provide “overdrive” pacing to electrically convert a sustained ventricular tachycardia (fast heart rhythm) and “backup” pacing if bradycardia (slow heart rhythm) occurs. They also offer a host of other sophisticated functions such as storage of detected arrhythmic events and the ability to perform electrophysiologic testing. Stored information can help your doctor optimize the ICD for your needs.

What should I ask my doctor or nurse about living with an ICD?

You most likely can resume a near normal lifestyle. But, it is best to ask your doctor what types of machines or equipment you should avoid. Also ask what you can and cannot do when you have an ICD.

Suggested questions for your healthcare providers:

  • When can I resume normal activities
  • Can I swim?
  • Can I run?
  • Can I have sex?
  • Can I play video games and use wireless devices?
  • What will the ICD feel like day to day?
  • When can I expect a shock?
  • Does the shock hurt?

AHA Recommendation

If you have an Implantable Cardioverter Defibrillator, be aware of your surroundings and the devices that may interfere with its operation. Potentially disruptive devices include those with strong magnetic fields. The following devices can disrupt the ICD’s signaling and prevent it from working properly, sometimes without your knowledge. The longer you are exposed to the potentially interruptive device and the closer it is in proximity to your ICD, the more likely it will affect your ICD’s performance.

Home Appliances and Tools

You can use most household devices such as microwave ovens and remote control TV changers, as long as you limit prolonged and close contact.

  • Stay at least two feet away from electric generators and light-welding equipment. They can interfere with the ICD.
  • Do not use industrial welders, magnetic mattress pads and pillows, electronic body fat scales, or abdominal stimulators.
  • Cell phones and MP3 Players
  • As a precaution, do not put your cell phone or MP3 player (if they are turned on) close to your ICD. For example, don’t carry your phone in your breast pocket over your ICD.
  • Use you cell phone with the ear opposite the side where your ICD was implanted.
  • If you strap an MP3 player to your arm, place it on the arm opposite the side where your ICD was implanted.
  • Keep headphones at least 6 inches away from any ICD.


  • Let airport or other screeners know you have an ICD.
  • Walk through security metal detectors at a normal pace.
  • Ask the security personnel not to use hand-held metal detectors on you. Ask them for an alternative form of personal search. If scanning with a hand-held metal detector is necessary, ask the screener not to hold it over your ICD area any longer than is absolutely necessary.
  • Don’t sit or stand close to a security system metal detector any longer than is necessary.
  • Don’t lean against the system.
  • It is rare, but ICDs have caused unnecessary shocks during long, high-altitude flights.

Medical Equipment

Carry an ICD wallet I.D. card with you. Your doctor can give you one. You may also want to wear a medical I.D. necklace or bracelet that states you have an ICD.

Equipment used by doctors, medical technicians, and dentists can affect your ICD, so tell them you have one before you schedule a procedure.

Magnetic Resonance Imaging (MRI) uses a powerful magnet to produce images of internal organs and functions. Metal objects are attracted to the magnet and are normally not allowed near MRI machines. The magnet can interrupt the ICD’s normal functioning. MRI scanning is not recommended for those with ICDs. Some newer devices are now MRI compatible, but the MRI must be performed at a center that is certified in treating patients with devices. Discuss with your doctor the possible risks and benefits before you undergo MRI scanning.

Extracorporeal shock-wave lithotripsy (ESWL) is a noninvasive treatment that uses hydraulic shocks to dissolve kidney stones. This procedure can disrupt your ICD’s normal operation. Discuss your specific case with your doctor before and after the treatment.

Sometimes electrocauterization is used to stop bleeding during surgery. Electrocauterization can interfere with your ICD so be sure to discuss your ICD implantation with your healthcare providers.

The bottom line is, consult with your healthcare providers before you undergo any tests, procedures or treatments. When in doubt, ask.

Device Clinic


Once a device is implanted, the next step is to establish care and follow-up at our Device Clinic. Our Heart Rhythm Specialists supervise our team of qualified cardiac technicians to make sure your device is working properly and optimally.

After your procedure you will be scheduled to be seen in our office within two weeks.  During this appointment, your doctor will examine the site of your device implant for infection and proper healing. Thereafter, you will be scheduled to return to the office in another 6-8 weeks.  This next appointment is to check for lead maturation, to make sure the device is working properly, and to see if any settings need to be adjusted.

After these initial appointments have been completed, your device will be monitored in two different ways: in the office and at home.  You will need to come into the office for an appointment with your Heart Rhythm Specialist at least every 6 months to 1 year depending upon your type of device. Below is an example schedule:

  • ICD= office visit every 4 months
  • Dual Chamber PPM= office visit every 6 months
  • Single Chamber PPM and ILR= office visit annually

These appointments may be more frequent depending on your clinical status. During these appointments a technician will interrogate your device with a wand that will sit right on top of your clothes where your device is.  The information received during this evaluation is then reviewed by your doctor during the visit. The data allows your doctor to evaluate your device parameters, identify abnormal events, measure the battery life and usage of the device, and also address any other clinical or technical concerns that may arise, as well as to make adjustments to your device if indicated.

Your device will also be checked at home by either Transtelephonic (TTM) or Remote Monitoring.  TTM is monitoring of a pacemaker over a landline phone and thus requires such availability in your home.  A box will be supplied to your home and when our technician calls you at your scheduled appointment time, you will be asked to place your phone in the box supplied. You will put the attached bands on your forearms, and for a portion of your test you will place a magnet over your device.  TTM’s will be done every 3 months while your device is still new, then after your device is over 60 months old the TTM’s will increase to monthly.

Due to advances in wireless technology, use of the old landline phone is becoming obsolete. As such, Transtelephonic monitoring is being phased out and is being replaced by the more convenient Remote Monitoring method.  Remote Monitoring is available for both pacemakers and ICDs and provides more detailed information when compared with the TTM method, and allows us to catch abnormalities much sooner.  The remote monitors are small, portable, and easy to assemble using a land line, cell phone, or Wi-Fi.  This type of home monitoring is routinely performed on devices every 91 days, but can also be performed manually more frequently if you are experiencing symptoms.  These reports provide about the same information as the in-office device checks. The only difference is that changes cannot be made to your device remotely.  Remote Monitoring saves you time, allows less interruption in your schedule, and minimizes office appointments. Most patients prefer this method of monitoring over the TTM method.

The remote monitor will be distributed in one of two ways. It may be given to you in the hospital on the day of the device implantation or if you already have a device, the device company will mail it to you.  All of the remote monitors are accompanied with easy assembly directions.  If you have any questions, a customer service representative is available to assist you over the phone.

If you are a patient with a history of heart failure or are at an increased risk for heart failure, your device may also have the capability of automatically identifying early signs of a worsening in your condition at any point in the day, even while you are sleeping and before you experience any symptoms!   Most ICDs and BiV-PPMs that have been implanted since 2010 have this functionality.  Once identified, your cardiologist may contact you to assess and treat in the office before the condition worsens. This ability to intervene early with necessary treatment can minimize your suffering and may even prevent hospitalization.

Atrial Fibrillation


Atrial fibrillation (AF) is the most common cardiac arrhythmia and affects an estimated 2.7-6.1 million people in the United States. Its prevalence increases with age, and occurs in about 9% of those over 65 years of age. The normal pacemaker of the heart originates from the sinus node, a region in the upper wall of the top right atrium. It typically fires at a rate of 60 to 90 beats per minute, with depolarization and contraction of both the left and right atrium synchronized before contraction of their respective bottom ventricles. The electrical signal travels, as discussed in earlier sections, from the atria to the AV node, the “traffic control” center. It is here that the electrical signal is slightly delayed before it traverses to the bottom ventricles via the specialized conduction system of the bundle branches and terminal purkinje fibers (discussed in the “Your Heart” section).

During AF, the atria can contract anywhere from 400-600 beats per minute, in an irregular and chaotic fashion. Fortunately, the AV node, the “traffic control” center, prevents 1 to 1 conduction to the ventricles. It may allow every 2-3 atrial beats to pass to the ventricles in an irregular fashion. The resultant heartbeat on exam is typically fast, but with medications, it can be slow with an irregular pulse.

Atrial fibrillation can occur in patients with no structural heart disease (lone AF), typically seen in the younger population of patients. However, cardiac disorders such as coronary artery disease, congestive heart failure, and valvular heart disease can predispose patients to atrial fibrillation.


Atrial fibrillation (AF) is one of the most difficult cardiac arrhythmias to treat successfully. There are many treatment options, all with inherent risks. The treatment option chosen should be done after careful consultation with your physician given the severity of your symptoms, the compromise to your quality of life, and your coexistent medical conditions. Some patients, especially those with limited symptoms, may desire no treatment and may remain in AF. Other patients may desire to maintain sinus rhythm at all costs due to intolerable symptoms during AF. In general, medical therapy is first-line with invasive procedures reserved for patients who have failed or cannot tolerate medical therapy. In some patients, all attempts to suppress and maintain sinus rhythm may fail, leading to permanent AF. Therapy for patients suffering from AF, as with atrial flutter, has three components:

  • Control of the ventricular rate (heart rate)
  • Conversion and maintenance of sinus rhythm
  • Reduction of subsequent stroke risk with anticoagulation if indicated on risk profile

Control of Heart Rate

Medications used to control the ventricular rate during atrial fibrillation include b-blockers, calcium channel blockers, and less commonly digoxin. These medications can be administered orally on a routine outpatient basis, or via intravenous route if necessary in the emergency room. Some patients may need a combination of medications from different classes. Patients may experience alleviation of symptoms due to slowing of the ventricular response (heart rate) with the use of b-blockers or calcium-channel blockers that delay electrical conduction through the AV node.

Conversion and Maintenance of Sinus Rhythm

Attempts to convert and maintain sinus rhythm can be approached in one of three ways:

The presence of other conditions both cardiac and non-cardiac in some patients may limit the effectiveness of medications and procedures in the ability to maintain normal sinus rhythm. As a result, not every patient is an appropriate candidate for rhythm-control, and your physician may opt to treat with rate-control only.

The success rate of converting atrial fibrillation to normal sinus rhythm is very high with electrical cardioversion. However, it does not guarantee freedom from future reversion back to atrial fibrillation.  Outpatient oral antiarrhythmic therapy can be instituted in those patients who are typically on oral anticoagulation therapy. They can be helpful in maintaining normal sinus rhythm and prevent recurrences of AF after electrical cardioversion. Your physician may opt to start antiarrhythmic medications in the weeks prior to your cardioversion procedure. There are many antiarrhythmic medications, with only a few requiring a brief hospital stay for initiation. These pharmacologic therapies act directly on the heart by slowing electrical conduction and lengthening the time required for electrical recovery of heart tissue. Drug therapy for AF can be very frustrating for the patient and physician as it can be a “trial and error” proposition; it is not possible to determine ahead of time which medication will work the best in a particular patient. Maintenance of sinus rhythm with complete suppression of atrial fibrillation is typically not possible with medications. Improvements in your quality of life must constantly be reevaluated in relation to the small risks, discomfort, and potential side effects associated with your prescribed treatment regimen. Antiarrhythmic medications are not without risk, as they can increase the incidence of other cardiac arrhythmias.

For those patients who elect to forgo medication either due to intolerable symptoms or side effects from their medications, recurrent symptoms and episodes despite medical therapy, or lack of desire to take daily medications for an extended period of time, your physician may recommend you undergo an electrophysiology study (EPS) and possible catheter ablation.

With the use of specialized electronic and computer equipment, in conjunction with the intracardiac electrode catheters (placed into the heart via the femoral veins) and specialized 3-D electroanatomical mapping systems, your heart rhythm specialist will deliver radiofrequency energy (or cold energy with Cryoablation) to isolate each of the left atrial pulmonary veins. Radiofrequency energy employed during the catheter ablation procedure heats the tissue enough to destroy the local heart cell function, but without physically cutting through the tissue. The goal of the procedure is to electrically isolate the pulmonary veins which are felt to be the drivers for the initiation and perpetuation of AF. In addition, other areas in the left atrium may be additionally targeted for catheter ablation during the procedure to improve the success rate.

The published success rates at different institutions for preventing clinical recurrences in the paroxysmal AF subgroup ranges from 70-80%. These recurrences can be treated with a second catheter ablation procedure. These success rates decrease in the population with permanent chronic AF undergoing catheter ablation procedures.

Not every patient is a candidate for an AF catheter ablation procedure, and an extensive conversation with your physician is important to review the various treatment options with you. Withdrawal of anticoagulation therapy is not generally recommended immediately after your catheter ablation procedure for AF. Close monitoring post-ablation with Holters and Event monitors to determine the burden of asymptomatic AF is important. In a subset of patients with no recurrent atrial tachyarrhythmias either clinically or by repeat ambulatory monitoring in the months post-ablation, cautious withdrawal of warfarin therapy can be considered (after 6-12 months), but the long-term data is still limited.


Hybrid Operating Room at St Francis Medical Center

Ablation of atrial fibrillation at Hamilton Cardiology Associates is enhanced by the use of a Hybrid Operating Room at St Francis Medical Center, which opened in 2013. The room combines a traditional operating room with the advanced imaging systems of a catheterization lab. For arrhythmia patients, this means that our electrophysiologists, interventional cardiologists and cardiac surgeons can collaboratively perform procedures on patients, resulting in better outcomes for patients.   All ablations performed by our physicians are performed within the Hybrid Room which makes our program distinctive among heart centers across the country.

Reduction of Stroke Risk

Patients with untreated atrial fibrillation may be at a greater risk for stroke than those with normal rhythms. Blood clots may form in the heart, due to the top chambers of the heart, called the atria, not pumping correctly. If a blood clot forms in the heart and is dislodged it can travel through the blood stream to the brain and result in a stroke. In patients with atrial fibrillation not related to a heart valve problem (aka “non-valvular AF”), a naturally occurring small pouch on top of the heart called the left atrial appendage (LAA) is believed to be the source of the majority of stroke-causing blood clots.

Traditional treatment to prevent stroke involves a prescription anticoagulant mediation called warfarin (aka Coumadin), which can reduce the formation of blood clots. Many factors can interfere with the effectiveness of warfarin. For this reason, patients must be monitored closely with a blood test called an INR ( see Coumadin Clinic) to maintain therapeutic levels of the medication and prevent adverse events.  In recent years, newer anticoagulant agents (Eliquis, Pradaxa, Savaysa, Xarelto) have become available and are not affected by medications, food or other factors, and therefore do not require frequent blood testing.  All of these medications have been shown to decrease the risk of stroke in patients with atrial fibrillation. Many patients can safely take these medications for many years without serious side effects.

For some patients, however, long term use of oral anticoagulation is not an option or is not tolerated. As a result, such patients must assume a greater risk of stroke without the medication. In this select patient population, Left Atrial Appendage Closure procedure (aka WATCHMAN) is a new implant-based alternative to anticoagulant medication for patients with atrial fibrillation not caused by a heart valve problem.  The WATCHMAN is a onetime procedure that is implanted in the LAA and acts as a barrier to prevent LAA clots from entering the bloodstream and causing a stroke. It is as effective as warfarin in reducing the risk of stroke. But unlike warfarin and the newer anticoagulant medications, the WATCHMAN implant also reduces the long term risk of bleeding. In a clinical study, 92% of patients were able to stop taking warfarin just 45 days after receiving the WATCHMAN Implant, and 99% were able to stop warfarin within 1 year of the procedure.

The WATCHMAN is implanted like a stent, by means of a narrow tube inserted through a small incision in the upper leg. The procedure is performed under general anesthesia and takes about one hour. Patients commonly stay in the hospital overnight and leave the next day. The WATCHMAN Implant procedure has a proven record of safety and is the only device of its kind approved by the U.S. Food and Drug Administration. The procedure is covered for eligible Medicare patients who meet coverage criteria and is also covered by an increasing number of commercial insurers. Our Board Certified Heart Rhythm Specialists perform this procedure at St. Francis Medical Center.