Cardiac Rhythm Implantable Device Training

For the official list of detailed indications, the Heart Rhythm Society and American College of Cardiology created a document which is attached in this section.  This document is very inclusive and detailed, so I recommend that you use it as a reference rather than trying to memorize every indication.  Here is an overview of the most common indications:

Generally, pacing indications are pretty simple, though sometimes it gets involved enough to need to pull the reference to see if the patient is truly indicated or not.  Most patients who get a pacemaker get it for symptomatic bradycardia.  Usually the symptom is syncope or near syncope associated with sinus node dysfunction, pauses, or AV block.

Implantable cardiac defibrillator (ICD) indications are more complex and have been driven by a number of large randomized clinical trials.  These indications fall into two types: primary prevention and secondary prevention.  I'll address secondary prevention first because it is more obvious.  A patient who has survived a cardiac arrest (or sustained, symptomatic ventricular tachycardia[VT]) receives an ICD after their first event, so they are benefiting from secondary prevention.  For patients who are at risk for sudden cardiac death, but have never had an event, ICD's are placed to prevent sudden death from their first (primary) event.  The most common primary prevention indication is  for patients with weak heart muscle, shown by an ejection fraction (EF) of 35% or less, especially if the patient has heart failure symptoms.  There are criteria for the indications and reimbursements for the procedures, such as having the patient on optimal medical therapy, and sometimes having a time period after diagnosis or some cardiac procedures.

Cardiac resynchronization therapy (CRT or BiV, for biventricular pacing) indications have changed as recently as 2012 to include more patients.  This type of pacemaker or defibrillator is prescribed to help heart failure by pacing both ventricles at the same time.  In this case also, the EF should be 35% or less, with a wide QRS on the ECG and mild to severe heart failure symptoms. 

In every case, if there are questions, please use the formal document and refer to the details.