Cardiac Re-synchronization Therapy

As part of our mission here at Iridia to promote heart disease, we are constantly drawing awareness to Automated External Defibrillators (AEDs) and their importance in fighting Sudden Cardiac Arrest (SCA). One area we haven’t talked is  the “what comes next area.” What happens when you survive a SCA or are diagnosed with heart disease? There are treatment options available and Cardiac Resynchronization Therapy (CRT) is one of them.

Cardiac Re-synchronization Therapy

CRT is used to treat the delay in heart ventricle contractions that occur in some people with advanced heart failure.

In other words, CRT is a therapy to provide a weakened heart with the ability to be re-synced and restore proper pumping functions.

Currently, CRT is one of the most advanced cardiac treatment options available for heart disease sufferers.

In order to re-sync the heart, a CRT pacing device (also called a biventricular pacemaker) is surgically implanted under the skin. This specially designed pacemaker stimulates the lower chambers of the heart to contract at the same time, making the heart more effective and efficient.

How does a Biventricular Pacemaker work? When a heart rate drops below a set rate (programmed by a doctor), the pacing device generates small electrical impulses that pass through the leads to the heart muscle. Theseimpulses make the lower chambers of the heart muscle contract, causing the right and left ventricles to pump together. In many cases, the end result is improved cardiac function.

Cardiac Re-synchronization Therapy

Studies have shown CRT improves symptoms of heart failure in about 50% of patients. Many of these patients had previously been treated with medications but still suffered severe or moderately severe heart failure symptoms.

CRT not only improves survival, but also quality of life, heart function, ability to exercise, and helps decrease hospitalizations in many patients with severe heart disease.

The procedure itself is generally very safe. Given the success of CRT, if an individual is a good candidate for the procedure, CRT will give them an increased chance at a normal life.

Cleveland Clinic, a non-profit academic medical research centre, has shown that on average, CRT improves the amount of blood pumped out with each heart beat by 5% to 10%. In some cases, patients with a CRT device can even develop normal ventricular function. It is not rare for a patient to see an increase of blood pumped out by each beat by up to 40%.

Given the health benefits, it is unfortunate that CRT is not available to all heart disease sufferers. CRT is only appropriate for people who:

  • have severe or moderately severe heart failure symptoms
  • are taking medications to treat heart failure
  • have delayed electrical activation of the heart 
  • have a history of cardiac arrest or are at risk for cardiac arrest

What does the future hold for CRT? According to recent studies, allowing implantation of CRT devices in patients with moderate heart failure could help stem progression of heart failure.