Pacemakers and ICDs

By: Kelsey Morgan and Caylan Oliver

What are pacemakers and ICDs

Pacemakers and Implantable Cardioverter Difibrillators are implanted into your chest or abdomen if your arrhythmia (a condition in which the heart beats with an irregular or abnormal rhythm) is serious.

  • The pacemaker helps control abnormal heart rhythms by pumping electrical pulses to help the heart beat at a normal rate.
  • If the ICD detects an irregular rhythm, it sends low-energy electrical pulses to prompt your heart to beat at a normal rate. If the low-energy pulses restore your heart's normal rhythm, you might avoid the high-energy pulses or shocks of the defibrillator (which can be painful).

Who is most likely to get it?

  • Doctors recommend pacemakers for many reasons. The most common reason is heart block. Heart block can happen as a result of aging.
  • Fewer than one in ten older patients with low ejection fractions received ICDs within a year after myocardial infarction. ( The ejection fractions refers to the amount, or percentage, of blood that is pumped (or ejected) out of the ventricles with each contraction.)


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
  • A congenital heart disease or other underlying conditions for sudden cardiac arrest.

How is it diagnosed?

Pacemakers are recommended by your doctor if:

  • Aging or heart disease damages your sinus node's ability to set the correct pace for your heartbeat.
  • You've had a medical procedure to treat an arrhythmia
  • You faint or have other symptoms of a slow heartbeat.
  • You have heart muscle problems that cause electrical signals to travel too slowly through your heart muscle.
  • You have long QT syndrome which puts you at risk for dangerous arrhythmias.

Treatment methods?

An ICD monitors heart rhythms. If it senses dangerous rhythms, it delivers shocks. This treatment is called defibrillation. An ICD can help control life-threatening arrhythmias, especially those that can cause sudden cardiac arrest (SCA).

Getting a pacemaker or ICD requires minor surgery. You usually need to stay in the hospital for a day or two, so your doctor can make sure that the device is working well. You will probably be back to your normal activities within a few days

How are they implanted?

Pacemaker implantation animation
Animation of an Implantable Cardioverter Defibrillator (ICD) being implanted


After implantation of a pacemaker, the patient may lead a normal active life for his age. The improvement is sometimes only observed after several weeks. However, those patients who did get ICDs had a 36% lower risk of dying within 2 years.
What Is a Pacemaker and How Does It Work?
Implantable Cardioverter Defibrillator (ICD)