Validation of a Smartphone-based Recorder for Detection of Cardiac Arrhythmias

The investigators will evaluate the diagnostic yield of the new AliveCor device versus a 12 lead ECG when used simultaneously to detect cardiac arrhythmia

The investigators are planning to record 250 pre-defined abnormal ECGs (50 each of atrial fibrillation, atrial flutter, pre-excitation, ventricular tachycardia, , supraventricular tachycardia) and 150 control ECGs (100 sinus rhythm, 50 sinus tachycardia) using both the AliveCor Smartphone device and a 12-lead ECG. All 400 ECGs will then be read by 3 blinded reporters - a Consultant Electrophysiologist, a Consultant General Cardiologist and a General Practitioner. The output of the AliveCor automatic detection algorithm will also be recorded as a fourth reporter. The screening characteristics of all 4 reporters using the AliveCor device vs the definitive 12 lead ECG will be analysed and compared.

Recordings with Alivecor and 12 lead ECGs with be acquired from patients with known arrhythmias/normal heart rhythm and blinded physicians will report on recordings and ECGs. Reports for each patient will be compared at the end of the study in order to assess diagnostic accuracy of the Alivecor to detect and differentiate between different kinds of abnormal heart rhythms.

Patients with different kinds of abnormal heart rhythms will be enrolled in order to compare whether Alivecor can accurately differentiate between these abnormal heart rhythms and normal sinus rhythm/sinus tachycardia. Also, Alivecor diagnostic accuracy in differentiating between different kinds of arrhythmias will be assessed.

For each patient two diagnoses of their underlying heart rhythm will be provided by blinded reporters. The percentage match of these diagnoses (the ratio of identical diagnoses to mismatch in diagnoses between ECG report and Alivecor report will be used as a measure of accuracy of the Alivecor to differentiate between different heart rhythms, using the 12 lead ECG as the gold standard for cardiac rhythm diagnosis.

Diagnostic accuracy of Alivecor recording at the end of the study which will be 2 years after study start date.

Inclusion Criteria: Male or female patients >18 years 12 lead ECG finding of arrhythmia, manifest pre-excitation, pacing rhythm (in the EP lab), sinus rhythm or sinus tachycardia Exclusion Criteria: Age <18 years Patients unable to or unwilling to use the device Patients with cardiac pacemaker, ICDs, or other implanted electronic devices