Pacemakers, Defibrillators, Cardiac Resynchronization Devices, and Remote Monitoring

Pacemakers

Pacemakers are implanted to correct a slow heart rhythm. A slow heart rhythm can result in symptoms of fatigue, shortness of breath with minimal activity, or passing out (syncope). The cause is most often an age related deterioration of the heart’s natural electrical system. A pacemaker implant is a minimally invasive, low risk procedure that involves a one inch incision just below the collar bone. The wire(s) are then advanced through a blood vessel (the subclavian vein) to the heart. The procedure takes less than one hour and can be done as an outpatient with discharge home the same day. The battery typically lasts 8-10 years. The modern pacemaker is safe around microwaves, cell phones, and even MRIs. In some uncommon situations we may recommend a wireless pacemaker which is inserted through the blood vessel in the groin. The heart rhythm team can show you models of the various devices and wires during your office visit. 

Implantable Cardiac Defibrillators (ICDs)

 

ICDs are devices intended to prevent you from dropping dead with no warning from a dangerous heart rhythm disorder that comes from the bottom chambers of the heart called ventricular tachycardia (VT) or ventricular fibrillation (VF). If you experience VT or VF and you do not have an implanted ICD your chance of survival is less than 1 in 100. ICDs are recommended for all patients with a reduced heart strength (cardiomyopathy) as defined by an ejection fraction of less than 35% (normal is 60%). There are two general types of ICDs. The standard type of ICD incorporates the same features as a pacemaker so it can also treat slow rhythm. This type of ICD is implanted using a minimally invasive, low risk procedure that involves a one inch incision just below the collar bone. The wire(s) are then advanced through a blood vessel (the subclavian vein) to the heart. The procedure takes less than one hour and can be done as an outpatient with discharge home the same day. The battery typically lasts 8-10 years. In some uncommon situations we may recommend a wireless ICD. This is called a subcutaneous ICD and it is implanted under the skin on the left side of the body halfway between the armpit and the waist. Both types of ICDs are safe around microwaves, cell phones, and even MRIs.      

Cardiac resynchronization therapy (CRT)

 

CRT involves the minimally invasive insertion of a wire that provides custom designed electrical stimulation to the left ventricle (the main pumping chamber of the heart). This results in an actual increase in the pumping strength of the heart which relieves symptoms of congestive heart failure (shortness of breath, fatigue, swelling of the legs). CRT can be incorporated into the implantation of either a pacemaker or ICD (see above for details). Our heart rhythm doctor will tell you whether you qualify for and would benefit from CRT. 

Remote Monitoring

Whether you receive an implantable loop recorder (ILR) to make a definitive heart rhythm diagnosis, a pacemaker to treat slow heart rhythm, or an implantable cardiac defibrillator (ICD) to protect you from a dangerous fast rhythm, all of these devices come with a home monitor. The home monitor does not require any action on your part and it wirelessly communicates with your implanted device and allows us to keep an eye on your cardiac status without the inconvenience of coming into the office.  

Electrophysiology Study (EPS) 

When our heart rhythm doctors are concerned about your rhythm and the results of a noninvasive (external monitor) or minimally invasive (ILR) evaluation are inconclusive they may recommend an electrophysiology study (EPS) to make a definitive diagnosis. This procedure involves temporarily inserting thin wires into the blood vessels in the leg and running them up to the heart to allow direct inspection of the electrical system of the heart. If used to make a diagnosis the procedure takes less than one hour and can be done as an outpatient with discharge home the same day. On the basis of the findings of the EPS the doctor may recommend a new medication, a pacemaker, an ICD, or a CRT. In many cases this procedure will be combined with a curative procedure called an ablation (see next section below).

Radiofrequency Ablation

Ablation is the procedure used to cure abnormal heart rhythms. This procedure is similar to an EPS with the exception that the tip of one of the thin wires that is advanced to the heart either gets hot using radiofrequency energy or extremely cold called cryoablation and this results in destruction of the microscopic area of cells that is causing the abnormal rhythm. The success rate and possible complications of the procedure varies depending on the complexity and nature of the rhythm. Our heart rhythm doctor will review the procedure in detail at that time of your office consultation. For abnormal heart rhythms such as paroxysmal supraventricular tachycardia (PSVT), Wolff-Parkinson-White (WPW), atrial flutter, and PVCs a successful ablation allows for the complete discontinuation of all heart rhythm medications. In atrial fibrillation, a successful ablation can result in an eventual discontinuation of heart rhythm medications but often requires at least a short term continuation of blood thinning medications. Please see section on atrial fibrillation for more details. 

Atrial Fibrillation

The most common heart rhythm problem is called atrial fibrillation, or “a.fib”. Millions of people have atrial fibrillation, and it causes different problems for different people. During atrial fibrillation, the upper chambers of the heart where the heart beat starts (the atrium) essentially short circuit like a spasm. As a result, the pulse becomes irregular and usually fast. It can cause a fluttering feeling in the chest, trouble breathing, fatigue, dizziness, fainting, or other problems. It is also a common cause of stroke, so many people with atrial fibrillation take blood thinners. There are many different treatments for atrial fibrillation, including medications, pacemakers, or a procedure called an ablation. A catheter ablation is a procedure that is done through IVs instead of incisions, so it does not require surgery. Ablation involves using either heat (like cautery) or freezing (cryoablation) to destroy the muscle tissue in the heart that is causing the abnormal irregular pulse. One type of ablation targets the tissue in the atrium that is actually causing atrial fibrillation (called a “pulmonary vein isolation” or PVI). The goal of this procedure is to permanently control atrial fibrillation and maintain a normal heart rhythm without using medications. It is done with general anesthesia and requires an overnight stay in the hospital. Another type of ablation involves implanting a pacemaker or CRT device and ablating or cauterizing the area in the heart that regulates the heart rate (called an AV node ablation). As a result, the pulse will remain consistently regular and normal without relying on medications. For some people with atrial fibrillation who cannot take blood thinners and are at risk for stroke, there is a procedure that uses a device called a Watchman to prevent blood clots in the heart and has been shown to lower the risk of stroke. The procedures are very effective and safe. Sometimes people require more than one ablation to get atrial fibrillation under control, but the result for most people is a regular heart rhythm and better quality of life.