The purpose of this study is to validate the quality of the ECG-signal acquired with the Cortrium C3 monitor. The intention is to evaluate whether the diagnosis of atrial fibrillation based on the ECG signal from the C3 monitor concurs with the current monitoring methods used in clinical practice.

Development of new cost effective mobile devices and wireless technology has great potential in supervision of critically ill patients in wards as well as ambulant. Through continuous wireless monitoring in both the hospital and the patients home, detection of heart arrhythmias such as atrial fibrillation (AF) will be possible.

AF is the cause of a sizeable amount of strokes (15% of all, and more than 35% of the population over 80 years of age), which can be prevented through anticoagulation treatment if provided in time. Thus, many patients are referred to cardiologic ambulatory to be examined for AF, and are subjected to heart monitoring with a so-called Holter or event monitor. This entails the patient be equipped with several electrodes on the chest, to which leads are attached and connected to a sizable and bulky box. The patient carries this box around hanging from the shoulder, belt or something similar for one or several days. It is then required of the patient to come back and deliver the device, after which the data must be read and analysed, in order to work out a further plan for the patient. During admission, a similar system can be attached for continuous heart monitoring.

Cortrium (http://cortrium.com) has developed a wireless technology, where a small C3 monitor is attached to the chest with standard electrodes and the leads are built into the actual monitor. The quality of the signal has been tested on healthy adults, but is yet to be tested on patients suffering from arrhythmias

The purpose of this study is to validate the quality of the ECG-signal acquired with the Cortrium C3 monitor. The intention is to evaluate whether the diagnosis of atrial fibrillation based on the ECG signal from the C3 monitor concurs with the current monitoring methods used in clinical practice.

The measurements are performed on patients under investigation for AF at cardiology ambulatory Y at Frederiksberg-Bispebjerg Hospital and Aleris-Hamlet Hospital, Copenhagen. The patients are outfitted with a C3 monitor simultaneous with the use of the conventional ambulatory apparatus. This is a "Holter monitor" (Rozinn station RZ152+12 and RZ153+ from ScottCare Holter for Windows 2010 (CE0120) and "EventCare SA version" (CE0120), both bought via SEMCA Ap, Skævinge, Denmark.

Recordings with the usual apparatus are analysed in the usual fashion in the cardiology ambulatory. A copy of the recordings is registered anonymously and paired with the simultaneous recordings from the C3. The diagnosis is made by two observers, blinded to both patient identity and data source. Thus, data will not be personally identifiable. Validation is performed in collaboration with the department of cardiology.

Statistics:

With simultaneous supervision of 77 patients with increased incidence of AF it will be possible to determine whether the C3 is capable of detecting AF in at least 95% of the cases which Holter detects. Since the incidence of AF Is lower in the total patient group referred to Holter monitoring, we plan to include 150 patients to acquire the usable number of examinations.

Economic Conditions Helen Dominguez is the unfunded, and the responsible consultant of the study. Opeon Aps delivers C3 monitors for this clinical trial as well as brochure guides for patients and health care personnel. There are no economic benefits connected with the present clinical trial.

Publication of Results:

Opeon ApS (owner of Cortrium) is responsible for processing the material for publication of results in an international peer-reviewed journal as well as in the Danish popular scientific press related to new Medical equipment. Positive, negative and inconclusive results will be published.

Recruitment of Participants:

Patients who have planned ambulatory arrhythmia recording for diagnosis of intermittent AF will be asked by telephone to consider participating in the study.

After reading the participant information flyer, the subjects are invited to in-depth verbal information in the ambulatory. If the subjects accept to participate and provide a signed informed consent, they outfitted with a C3 monitor along with the standard Holter apparatus.

The study only includes subjects scheduled for Holter monitoring referred for atrial fibrillation examination, quantification of paroxysms, or heart rate during paroxysms.

Ethical Considerations:

Ethical Considerations: If the patient agrees to take part in the study, the main disadvantages are that it entails attachment of another three electrodes for the C3 monitor, increasing the risk of skin irritation, and receiving additional instructions for two devices. Since ECG recordings are non-invasive, and the C3 recordings do not result in further ambulatory visits than otherwise planned, we estimated that the strain on the patients is very limited.

The use of C3 for estimation of AF in future patients will decrease the trouble of loose leads. For this reason, using the C3 will also simplify the work of the healthcare personnel during the attachment procedure. Overall it may lead to an increase in quality as well as increase the capacity for examining cardiac arrhythmia in the cardiology ambulatory.

Inclusion Criteria:

• Clinical diagnosis of atrial fibrillation
• Investigation of atrial fibrillation

Exclusion Criteria:

• Language difficulties
• Impaired cognitive function.