AliveCor (www.alivecor.com) has developed an ECG device (KardiaMobile) that interfaces with iOS and Android smartphones and tablets. This ECG consists of a lightweight hardware case with two metal electrodes that can snap onto the back of the phone and a software application. By holding the right finger(s) on the right electrode and the left finger(s) on the left electrode, an electrical circuit is completed and a lead-I, 30 second rhythm strip is created. KardiaMobile and a newer device, KardiaMobile 6L, were approved by FDA for ECG rhythm recording. Recently, AliveCor developed two new devices: Kardia 12L and Kardia 6L to record 12- lead and 6-lead ECGs, respectively. However, the data generated from the two new devices have not yet been validated for accuracy. The purpose of this study is to evaluate the accuracy of the ECGs recorded by AliveCor Kardia 12L and 6L devices. This will be compared to simultaneous standard of-care 12-lead ECG recordings. The ECGs will be analyzed for accuracy and statistical difference using root-mean-square error and cross correlation between the median beats.

Inclusion Criteria:

1. Male and female patients 18 years old or older
2. Ability to sit for an ECG and AliveCor Kardia 12L and Kardia 6L recordings for 20 minutes

Exclusion Criteria:

1. Any internal stimulator that would generate electrical interference with the recording system of the AliveCor Kardia 12L or Kardia 6L.
2. Open chest wounds or recent (<30 days) surgery to the chest or abdomen.
3. Absence of any limb that would require modification of the lead set-up