1062 Barnes Rd., Suite 300 Wallingford, CT 06492 Phone: (203) 265-9831       Fax: (203) 265-2977

Pacer/ICD Assessment, Resynchronization Therapy

Cardiology Associates offers a wide array of services for patients who have abnormal heart rhythms (arrhythmias) or heart conditions requiring a pacemaker or ICD to be placed and maintained.  This is a specialty area of cardiology.  The information contained on this page pertains only to patients who have been told by a doctor that they require a pacer or ICD.  Not all heart conditions will require a pacer or ICD.

Cardiologists and Electrophysiologists are the two kinds of doctors who specialize in the diagnosis and treatment of heart conditions that may require pacers or ICDs.  This team works together to diagnose the heart condition, arrange surgical placement of the appropriate device, and provide on-going monitoring and support for the device.

For certain heart conditions, the diagnosis is made with a simple Electrocardiogram (ECG).  Other times the diagnosis is more challenging and may require an Electrophysiology Study, or EP Study, to be performed.  You can read a description of both on our website.

Once a heart condition is diagnosed, the doctor may recommend a pacer, an ICD, or a device that does both.  All of these are called "devices".

Pacers and ICDs are similar in that they are all tiny devices that are surgically implanted under the skin of the chest.  This requires a short-term stay in a hospital setting.  The "device" contains a tiny generator housing a battery and a computer chip that can store information about heart function.  A lead wire(s) runs from the device to the heart tissue, either under the skin, or through a nearby blood vessel.  These devices are comfortable, help people return to their normal daily activities, and are easy to monitor and maintain.  The specific function of each device is discussed below.

Once a device is implanted, it is checked periodically and non-invasively by placing a small wand on the chest called a programmer.  The programmer allows the doctor to test the battery life, read the information stored on the computer chip, and make adjustments to the device settings.  Think of it like your TV remote control!


In a normal heart, the heart's natural pacemaker generates tiny electrical impulses.  These impulses are conducted through the heart via the "conduction system" (special heart cells that can transmit electrical impulses).  The electrical impulses cause the heart muscle to contract and pump blood into the body.

Implantable pacemakers or "pacers" are necessary when disease of the heart's conduction system  prevents the heart's natural pacemaker from doing its job.  Sometimes the heart's natural pacemaker stops generating the appropriate electrical impulses.  Other times the heart's conduction system can no longer transmit the impulses along.  Pacers will help in both of these situations; the pacer lead(s) are positioned so that they can generate and deliver tiny electrical impulses to the proper area(s) of the heart in order to maximize the pumping action of the heart muscle.

ICD stands for Implantable Defibrillator Device.  These devices deliver a slightly greater electrical charge to the heart than a pacer and are used to restart the heart or to interupt certain dangerous sustained arrhythmias. 

Not everyone who needs a pacemaker will need an ICD;  pacer/ICD combination device are available if indicated. 

Another application for pacemakers is Resynchronization Therapy, or CRT.  The CRT device is a special pacer with more than one lead.  It is also called a BiV (pronounced bi-vee) pacer, or biventricular pacer.  This type of pacer is used to get both ventricles (or "pumping chambers") of the heart to pump at the same time.  When the ventricles work together it results in more effective forward blood flow to the body, and can improve symptoms associated with advanced heart failure.  Not everyone needs this type of pacemaker.  CRT/ICD combination devices are also available.


There are special preparation instructions prior to implantation of a device which will be given by the doctor (or doctor's assistant) at the time the procedure is scheduled.


Patients are given a wallet-card with information about their device.  It is important to keep this card accessible and in a safe place.  Healthcare providers may need this information during examination or treatment.

Cardiology Associates offers appointments several times per month for the on-going monitoring and support of these implantable devices.  More frequent monitoring may be recommended if a patient becomes symptomatic, or as a device ages.  Depending on the device, sometimes transmissions are also made over the phone.  It is very important to attend the recommended appointments.  There is no special preparation for these appointments, and patients will be comfortable during these brief checkups.

We hope this has been helpful, but should you have further questions or concerns, please feel free to call us at (203)265-9831 and tell the operator you need information on our pacer/ICD services.