What is cardiac electrophysiology

EPU (electrophysiological examination)

The electrophysiological examination, or EPU for short, is a special cardiac catheter examination for patients with cardiac arrhythmias. If the mechanism of rapid cardiac arrhythmia has been found in an EPU, treatment by catheter ablation can in many cases also be carried out in the same session.

How is the EPU (electrophysiological examination) carried out?

Fig. 1: Catheter position for diagnostic EPU

The EPU provides a special cardiac catheter examination for patients with cardiac arrhythmias. This is done over the groin or the clavicle vein Electrocatheter in the heart brought in. These special catheters can pick up electrical signals at various points in the heart. The catheters are attached in the right atrium, in the right ventricle at the conduction between atrium and ventricle, the AV node and in the great cardiac vein, the coronary sinus (Fig. 1).

The analysis of the temporal sequence of the heart rhythm signals is crucial for the determination of the rhythm disturbances. The comparison of the time sequence of the electrical excitations during resting heart rate and during palpitations also helps to make the correct diagnosis. In addition to deriving the local electrical signals, artificial extra blows be delivered through the electrocatheter.

Fig. 2: Life-threatening ventricular fibrillation during an EPU

The doctor tries to trigger the abnormal cardiac arrhythmia by means of programmed stimulation. It can also stop various types of palpitations by stimulating the heart with the catheter. If life-threatening cardiac arrhythmias arise (ventricular fibrillation, Fig. 2), he can stop this at any time using a defibrillator. An external defibrillator is part of every EPU.

An EPU usually lasts 1-2 hours, but can also take significantly longer in the case of complex cardiac arrhythmias.

What are the advantages of the EPU (electrophysiological examination)?

The electrophysiological examination (EPU) offers the possibility of inducing cardiac arrhythmias in order to then precisely examine their development mechanism in the heart. These results offer the opportunity to then create a suitable therapy plan.

Without this option, one is dependent on recording cardiac arrhythmias in the ECG. Simple ECG registrations that are carried out over and over again often have no special features, since the Symptoms only occur occasionally. Attempts to record the cardiac arrhythmias complained about through continuous ECG recordings over 24 hours often fail due to the unforeseeable occurrence of the symptoms. Emergency doctor consultations and inpatient emergency rooms on the “hunt” for an ECG document then often shape the patient's history of suffering combined with the feeling of not being understood and not being taken seriously.

With the help of the electrophysiological examination (EPU), the doctor can try in these cases to provoke the arrhythmias directly in the heart. He inserts 2-3 electrode catheters from the inguinal vein into the heart in order to then derive special signals from the heart. By stimulating the heart at the various points, the doctor analyzes the conduction properties and reveals any peculiarities.

Treatment of cardiac arrhythmias as part of the EPU by means of catheter ablation

Once the mechanism of the rapid cardiac arrhythmia has been found, treatment by catheter ablation can in many cases also be carried out in the same session. Heat impulses destroy it the causative heart muscle tissue. These destructions are very small (4-6 mm in diameter and depth) and do not leave any discernible heart muscle scars.

A special invasive therapy method in electrophysiology is the "ablation treatment" or the sclerotherapy of cardiac arrhythmias directly on the heart. The doctor first localizes the origin of the cardiac arrhythmia. He then places the tip of the ablation catheter directly at this point. The catheter tip is then heated to approx. 60 degrees Celsius by high-frequency electricity. This results in a very circumscribed, precisely localized warming of the tissue, which results in a small scar at this point. In over 90% of the cases, cathode ablation can be the treatment Permanently eliminate cardiac arrhythmias. In many cases, invasive electrophysiology offers not only a precise diagnosis but also a curative treatment option.

Prof. Dr. med. Christian White
Dr. med. D. Baumgart
Dr. med. Ch. K. Naber
Prof. Dr. med. R. Erbel