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Areas of Expertise

Liryc – the Electrophysiology and Heart Modeling Institute (L’Institut de RYthmologie et modélisation Cardiaque) - is a University-Hospital Institute (IHU) led by Professor Pierre Jaïs.

It is a unique centre in the world which aims to understand and treat heart rhythm disorders better.

By bringing national and international expertise from many disciplines together in a single institute, Liryc is primarily dedicated to 3 areas in cardiac electrophysiology : 

  • atrial fibrillation,
  • ventricular fibrillation,
  • heart failure.
Atrial fibrillation

Atrial fibrillation, the most common arrhythmia, currently affects more than 10 million people in Europe, with a projection of 14-17 million by 2030.

It is characterized by irregular and rapid heartbeats. Very disabling, its impact on the quality of life of those affected is as great as that of coronary artery disease (myocardial infarction). It is the most common cause of cardioembolic stroke and a risk factor for heart failure and dementia.

Understanding atrial fibrillation

Atrial fibrillation manifests itself by an uncontrolled electrical activation and thus an ineffective contraction of the atrium, which promotes the formation of blood clots. The heartbeat becomes rapid and irregular.

Treating atrial fibrillation

Several years ago, Liryc doctors identified the triggers of atrial fibrillation in the pulmonary veins. This discovery led to the development of a non-pharmaceutical treatment of this disease.

This treatment consists of cauterizing the pulmonary veins by a radiofrequency catheter so as to exclude these arrhythmia triggers. This approach has become the treatment of reference: to date, over 300,000 patients undergo it each year worldwide.


Ventricular fibrillation

Ventricular fibrillation is responsible for 50,000 sudden cardiac deaths in France each year, i.e. one sudden death every 10 minutes. This is a death that we consider to be 'illegitimate', as it mainly strikes individuals with an intact or slightly altered heart, "too good to die".

Understanding ventricular fibrillation

Ventricular fibrillation manifests itself by a fast and disorganized electrical activation of the ventricles, with the immediate consequence of the loss of any effective cardiac contraction. Failure to intervene within 5 minutes can be fatal (sudden death) or lead to irreversible brain damage.

The only treatment is an electric shock delivered by a defibrillator.

Treating ventricular fibrillation

Liryc's clinicians have identified some of the triggers of sudden death by ventricular fibrillation

These triggers are located in the heart, at the Purkinje network. This electrical network is essential for heart contraction.

The localized destruction of these sources of arrhythmias by thermoablation represents an innovative and curative approach to ventricular fibrillation in order to prevent sudden death.


Heart failure

Heart failure affects 9 million people in Europe, including 1 million in France, i.e. 1 in 10 hospital admissions. It mainly affects people aged 65 or over, but it can also affect children and pregnant women. It has a very strong impact on the quality of life over the long term.

Understanding heart failure

Heart failure is a failure of the heart's pump that becomes unable to adequately provide the necessary supply of oxygen and nutrients (blood flow) required for the proper functioning of the organs. It results in a shortness of breath and extreme fatigue, among other things. 

This condition stems from damage to the heart muscle or to its irrigation by the coronary vessels, impaired energy metabolism or cardiac desynchronization. A desynchronized heart is a heart which has lost harmony in propagating electrical impulses and hence the resulting contraction. As a result, one wall may contract while another rests with a consequently significant loss in efficiency and a progressive exhaustion.

Treating heart failure

Liryc’s clinicians have contributed to develop cardiac resynchronization therapy in heart failure. This therapy involves implanting pacing leads in the ventricles. It aims to specifically correct electrical desynchronizations in order to harmonise ventricular contraction and ensure better cardiac output.