Your Heart Beat Can Tell On You

Pacemaker and Defibrillator Basics by Jordan M. Chiasson, MD, FACC Cardiac Electrophysiologist

Afib or Atrial Fibrillation is a common condition affecting the heart’s beat, rhythm and rate that many people hear about and that is becoming more common.  By the year 2050 it is predicted that it will affect between 6-12 million Americans.  Afib is the most common type of an irregular heart beat that if left untreated can cause complications, even stroke.  An electrophysiologist is a cardiologist specializing in the heart’s circuitry system and addresses issues with the timing on one’s heartbeat.

There are numerous types of technology, medications and monitoring systems to assist patients in addressing complications when the heart’s electrical system is disturbed and can make significant life changing improvements. 

Pacemakers and defibrillators regulate the heart’s rate & rhythm. following are some frequently asked questions and answers.  

1.      What is a pacemaker?

A pacemaker is an electronic device made up of a battery or “pulse generator” connected to one or more wires or “leads” that monitors and regulates the heart rate and rhythm.  There are several different types of pacemakers, and they work by stimulating the heart or “pacing” it with electrical impulses programmed to restore a normal heartbeat.

2.      What is the difference between a pacemaker and a defibrillator?

A defibrillator is composed of a thicker lead and larger battery.  In addition to being able to pace the heart, defibrillators have advanced monitoring and treatment capabilities if dangerous or life-threatening rhythms are detected.  Defibrillators are generally reserved for patients with a diagnosis of congestive heart failure or those who have survived a cardiac arrest.

3.      How are these devices implanted?

In the electrophysiology laboratory, similar to a cardiac catheterization laboratory, the leads are inserted into the axillary or subclavian vein, which is the main route from the arm or shoulder to the heart.  The leads are then positioned under X-ray guidance and tested to be sure they will function properly.  Next the leads are attached to the battery, which is tucked into a small pocket created under the skin.  The incision is generally no more than 1-2 inches long and is closed with dissolving stitches. 

4.      What’s new with pacemakers and defibrillators these days?

Leadless pacemakers are now commercially available and are widely used to treat certain rhythm disorders.  These devices are about the size of a paperclip or vitamin, and do not require an incision or pocket.  Ask your doctor if this is the right type of pacemaker for you.

In addition, new implantation techniques are emerging that can allow pacemakers and defibrillators to better simulate the heart’s normal electrical conduction.  There is ongoing research to determine if this is better for the heart over the long term, and early data has shown promising results.

5.      I have a pacemaker or a defibrillator, what happens next?

The device will need to be periodically checked or “interrogated” to be sure it is programmed appropriately and individually optimized.  This can often be done remotely, or from home, with the aid of a trans-telephonic monitor.  The pulse generators are usually powered by lithium batteries that function for an average of 5-8 years before they need to be replaced.