This study is designed to compare the performance of both 6 and 10 electrode ECGs from the handheld device with the conventional 12 lead ECG. As well as comparing the detection of atrial fibrillation, the study will also compare the detection of other heart problems and of normal heart rhythm.

An Electrocardiogram (ECG) 6 electrode, wireless handheld device held on the chest is being developed to allow diagnosis of heart rhythm problems without the need for connecting electrodes to the chest, arms and legs as in a standard 10 electrode (referred to as a 12-lead) ECG measurement. A faster and simpler yet accurate method for acquiring ECG data may be useful in many healthcare settings, including screening for irregular heart rhythms such as Atrial Fibrillation (AF), which is a risk factor for stroke. The wireless 6 electrode device has an extension arm for the handset with 4 additional electrodes (also positioned on the chest) to give a full 12 lead ECG signal. This study is designed to compare the performance of both 6 and 10 electrode ECGs from the handheld device (used on the chest with the subject seated) with the conventional 12 lead ECG (used with electrodes on the chest, arms and legs with the subject lying down). As well as comparing the detection of atrial fibrillation, the study will also compare the detection of other heart problems and of normal heart rhythm. Adult patients attending the clinics at Central Manchester University Hospitals NHS Foundation Trust for an ECG assessment are eligible to participate in the study. A maximum of 500 patients will be recruited to the study in order to find the number of cases with Atrial Fibrillation required to properly compare the methods. A subset of patients with normal ECGs will have additional measurements with both methods whilst lying down, reclining at an angle and sitting upright to investigate any effects of body posture on chest based ECGs.

Inclusion Criteria:

1. Patient attending an adult cardiology or anti-coagulation clinic appointment, at clinics at Central Manchester University Hospitals NHS Foundation Trust (including the Manchester Heart Centre).
2. Patients on cardiac wards 3 and 4.
3. Aged 18 years or above.
4. Male or Female.

Exclusion Criteria:

1. Aged less than 18 years.
2. Unable to give informed consent.
3. Does not wish to participate in the study.
4. Any patients with visible breaks to the skin, rashes or inflammation in the chest area on the day of the test
5. Bedridden or otherwise unable to transfer between chair and bed for both seated and supine measurements