For $199.00, the AliveCor Heart Monitor turns your iPhone into an ECG
The AliveCor Heart Monitor gives you instant, portable screening opportunities. Utilize the device anytime, anywhere to evaluate heart rate and rhythm. The AliveCor Heart Monitor is cleared by the FDA for sale in the U.S. to licensed medical professionals and prescribed patients to record, display, store,
and transfer single-channel electrocardiogram (ECG) rhythms.
For more info check out their site: http://www.alivecor.com/en