Paroxysmal Atrial Fibrillation Detection and Heart Beat Classification in Multi-Channel Esophageal Long-Term ECG

Background

The fast and correct diagnosis of heart rhythm disorders is very important to reduce morbidity and mortality in cardiovascular patients. Atrial fibrillation is of special interest, because it is an important cause of devastating brain strokes. A significant number of strokes have a cardioembolic genesis due to paroxysmal atrial fibrillation which was not diagnosed early enough. Therefore, it is very important to detect atrial fibrillation as soon as possible. With oral anticoagulation an effective therapeutic option in available to prevent cardioembolisms.

In the clinical routine, mostly 24-hour or 7-day ECGs are made to look for cardiac arrhythmias. The use of such devices is well established. Nevertheless, they have some side effects/limitations. Skin electrodes used for derivation of the ECG often cause skin irritation, sometimes leading to premature termination of the recording. Because of dryout of the contact gel (causes artifacts), small p-waves and especially also motion artifacts, triggered recording or semi-automatic analysis of the recording is problematic, but for longer recording times such a semi-automatic analysis would be helpful. As an alternative esophageal electrocardiography can be performed. Signal quality of the ECG recording (especially of the left atrium) is better than in the standard surface ECG because of the vicinity of the esophagus and the left atrium. The esophagus tolerates well foreign bodies as the investigators know from long-term nasogastric intubation. Therefore use of the esophageal technique for long-term rhythm monitoring is an interesting and promising alternative to conventional surface Holter ECGs.

Earlier studies have already shown the improved p-wave in eECG signals, but the automatic or semi-automatic wave analysis algorithms were not satisfactory. By increasing the number of measuring channels on the esophageal catheter, new classes of algorithm can be applied in order to increase the detection reliability. Using multiple channels to increase the quality of the result is an intuitive and widely used method e.g. in 12 lead ECG or EECG, etc.

Objective