Electrophysiology (EP) study
Electrophysiology (EP) is the science of understanding, diagnosing and treating the electrical activity of the heart.
An EP study is conducted to diagnose an abnormal heart rhythm problem. This diagnostic procedure also indicates whether catheter ablation can treat the problem and if it is safe to do so. The catheter ablation procedure is usually performed directly following the EP study, while the patient is in the EP lab.
The heart's electrical system
- The heart's rhythmic contractions depend on its electrical system to conduct electrical impulses throughout the heart.
- The sinus node (SA node), a group of specialized cells in the right atrium, is where the electrical impulse normally begins. The sinus node functions as the heart's “natural pacemaker,” setting the pace for the heartbeat.
- The electrical impulse spreads throughout the left and right atria, causing the muscle in the atrial walls to contract and squeeze blood into the ventricles.
- From the atria, the electrical impulse reaches the atrioventricular node (AV node) located between the atria and the ventricles.
- This node acts like a gate, slowing down each electrical impulse before allowing it to pass on to the ventricles.
- The impulse then travels throughout the ventricles via a system of specialised muscle fibres referred to as a pathway. The impulse stimulates the ventricular muscle, causing it to contract and pump blood back into the circulatory system.