CARDIAC RESYNCHRONISATION THERAPY (CRT)

This is a treatment option for patients with heart failure who have evidence of slowed electrical conduction in their heart and is otherwise known as biventricular pacing.

What Is Cardiac Resynchronization Therapy?

Around a third of patients with heart failure (impaired heart function) have evidence of dysychrony – in this situation different parts of the left ventricle (main chamber of the heart) contract at different times, making the pumping process less efficient.  Patients with dysynchrony don’t generally know if they have dysychrony or not, but it is shown on an electrocardiogram (ECG) which should be performed regularly in every patient with heart failure.

Cardiac resynchronization therapy is performed by inserting a special pacemaker which has three leads rather than the normal two.  The extra lead is placed in a vein at the back of the heart, and the pacemaker sends signals down the different leads to activate the different parts of the heart at the same time, resynchronizing them.

When is Cardiac Resynchronisation Therapy used?

Not all patients with heart failure will benefit from Cardiac Resynchronisation Therapy.  The best indicator of who will benefit is the shape of the trace on an electrocardiogram (ECG).  If the time spent for the electrical signal to spread across the ventricles (known as the QRS interval) is long, then it is more likely that a patient will benefit from CRT.  If the time spent for the electrical signal is normal, then CRT will not help and may even be harmful.

For some patients, cardiac resynchronisation therapy is combined with an implantable cardioverter defibrillator (ICD) which monitors the heart for dangerous rhythms and treats them to reduce the risk of sudden death. 

How is a Cardiac Resynchronization Therapy pacemaker inserted?

The procedure is similar to the insertion of a conventional pacemaker, but involves an additional step of placing a third lead, which adds slightly to the time of the procedure. 

Patients are given some sedation, analgesia and local anaesthetic to make the procedure pain free and comfortable so that they are drowsy (but not asleep).  A sterile drape will be placed over your chest and a small incision made just under the collar bone (usually on the left of your chest if you are right-handed). 

The three leads of the pacemaker are inserted one after another into a large vein under your collarbone.  One lead is carefully moved round to the right atrium and one to the right ventricle as happens with other pacemakers.  In CRT, a third lead is moved round to lie in a vein at the back of the heart.  This additional lead is used to resynchronise the heart.

The leads are connected to the generator part of the pacemaker , similar in size to a small matchbox, and then placed in a small pocket right under the skin.

The pacemaker will be checked to make sure all the leads are working correctly and the settings are optimal.  A chest X-ray will be performed to document the lead positions and check there has not been any damage to the lungs from the procedure.  In most cases patients can go home later the same day or the following morning.   The pacemaker will need routine checkups to ensure that the device is performing optimally.

Schedule An Appointment

A cardiac resynchronization therapy (CRT) pacemaker can transform symptoms and outlook in heart failure but is a specialist procedure requiring expert Consultant Cardiologist input.   Our cardiologists are available for consultation on any day of the week and weekends as well.