Danbury Hospital provides a variety of Electrophysiology services for patients with irregular heartbeat, including atrial fibrillation. They include:

  • Pacemakers and implantable cardiac defibrillators (ICD)
  • Pacemaker and ICD follow-up services
  • Diagnostic electrophysiology studies (EPS)
  • Ablations
  • Holter Monitoring
  • 30-day heart monitor testing
  • Tilt Table Tests

Electrophysiology is for patients with abnormal heart rhythms and disorders. Our electrophysiologists and cardiologists are trained with advanced equipment to record, diagnose and treat rhythm disorders, including those caused by heart valve defects.

Pacemakers and Defibrillators


This device, implanted underneath the skin is connected to wires or "leads" that sends small electrical impulses to the heart muscle to maintain a normal heart rate. Pacemakers are mostly used to prevent the heart from beating too slowly.

Implantable Cardioverter Defibrillator (ICD)

This device is used primarily to treat very fast and possibly life-threatening heart rhythms. The ICD constantly monitors the heart rhythm and when it detects a very fast abnormal heart rhythm, it delivers energy to the heart muscle, returning its rhythm to normal.

Bi-Ventricular Pacemaker or ICD

Sometimes called Cardiac Resynchronization Therapy (CRT), this device includes an additional wire or "lead" that is used to help coordinate the timing of the contractions of the blood-pumping chambers of the heart, sometimes improving the symptoms of advanced heart failure.

Follow-up Services for Patients with Pacemakers

A pacemaker is a device that is implanted beneath the skin of the chest with wires that continue into the heart. It delivers small amounts of energy to the heart to help keep you pulse at a normal rate if your own pulse is too slow. At least once per year you will receive a full interrogation of the lead and battery system of your pacemaker.

At the same time, your cardiologist may make changes in the settings of the pacemaker, as he or she deems necessary. This procedure is non-invasive and requires a 10–15 minute visit to Cardiac Services.

Follow-Up for Patients with Implantable Cardiac Defibrillators

An Implantable Cardiac Defibrillator or ICD is a device designed to administer an electric shock to control rapid heartbeats. The power source is implanted in a pouch beneath the skin of the chest or abdomen and is connected to wires placed within the heart.

Today, our patients arrive in Cardiac Services where they are seen by a fully trained technician for a 15-minute visit. Through the use of a programmer, the device is interrogated (checked) for episodes of arrhythmia and defibrillation. The lead and battery system is thoroughly checked and setting changes are made, as the cardiologist deems necessary. All reports are sent to the patient's electrophysiologist.

Danbury Hospital provides a Support Group for Defibrillator Patients.

Diagnostic Electrophysiology Study (EPS)

This is a procedure that is performed on patients who have been diagnosed with an abnormal heart rhythm (arrhythmia). During this procedure catheters threaded through a vein into the heart, help to determine the exact location and type of arrhythmia you may have. The result of this test helps your physician to determine how best to treat your arrhythmia.


This procedure uses catheters, threaded through a vein into the heart to the exact location of abnormal heart rhythm and delivers energy to the heart tissue that is causing the your arrhythmia so that a normal heart rhythm can be restored.

Holter Monitoring and Arrhythmia Monitoring

These are portable devices for patients to wear. They record a ECG for 24 to 72 hours continuously. Doctors use Holter monitoring to detect intermittent heart rhythms and irregularities that may accompany certain heart conditions.

Tilt Table Tests

Tilt table tests are a diagnostic tool to identify fainting. The patient lays on a table that tilts. Their head is always above their feet, they never go upside down. While the patient is tilted an ECG records the electrical activity of the patient’s heart. In some patients this test will reveal abnormal cardiovascular reflexes that cause fainting.

For More Information

If you have questions about Cardiology, visit our patient and visitor information section, or ask your doctor about Danbury Hospital. For a doctor referral call us at 1-(800) 511-7821, or search our Find a Doctor online tool to find a doctor near you.