Typical electrophysiology catheters

The heart is basically a pump.  As is true of motor drive pumps, there is an electrical system controlling the heart which tells the heart when to beat and how fast to beat. Ordinarily, we are completely unaware of the functioning of this vital system.  Our heart speeds up when we exercise to provide more fuel for the body and slows down when were at rest.  The pulse is regular and can be easily measured.  Unfortunately, disorders of this normal electrical system are common.  Disorders which affect the hearts electrical system can make the heart go either too fast or too slow (or a combination of these two problems).  Symptoms of a disordered electrical system include palpitations, fainting spells, episodes of racing or irregular pulses, fatigue and tiredness and even sudden death.

A Steerable EPS Catheter

When an EPS study is performed catheters are inserted into the heart via femoral vein which is a vein located in the groin.  Typical catheters are pictured above.  These soft catheters can record electrical signals from inside the heart and can also be used for pacing the heart at various points to map the hearts electrical system and induce abnormal rhythms.

The normal hearts electrical system

Catheters are inserted and can record the electrical signals as they travel through the normal, and in some cases abnormal, areas of the hearts electrical system

Catheters inserted during an EPS study

From the recordings and measurements made during an EPS study one can determine many important facts.  For example, an EP study can determine if someone needs a pacemaker or an implantable defibrillator.  EPS testing is also useful in determining the cause of palpitations and fainting spells.  In some cases an EP study will show that the patients heart has an abnormal pathway in it which is producing spells of tachycardia (or rapid heart beats).  This situation can often times be permanently cured with a procedure sometimes done in conjunction with the EPS study called radiofrequency catheter ablation.

Following EPS testing the catheters are removed from the groin and pressure held on the vein.  The patient is usually allowed to ambulate within four hours and will often go home the same day.  Patients can usually return to work the next day following EPS testing.