EPI Life, the first ever ECG cell phone is bringing a huge amount of hype. The phone has been featured on CNET[credit picture] and Engadget, with both outlets hyping its life saving potential – but the exact method of how the integrated ECG unit in the mobile phone works is not clear. Chow U-Jin, medical director at Ephone International, which developed the EPI Life, has said the device records readings by having the user touch their fingers on the side of the phone – basically how it’s being held in the picture.

A trip over to the EPI Life website doesn’t yield many clues, except they do say it has an integrated “multi-lead ECG”. From the output shown in the pictures though and the limited data available – it appears to be useful for heart arrhythmias at best, where changes in the sequence of the ECG tracing may be enough to make the diagnosis.

Heart attacks and other more subtle cardiovascular pathologies require a more detailed scan, usually obtained with “12 lead ECG” where a dozen leads are arrayed in a specific pattern across the chest. When performed properly,  the portion of the heart that is affected can even be determined (for example, a lateral heart attack would be reflected on the V5-V6, 1 & aVL leads). Some types of heart attacks are not even reflected on the ECG and only discovered later by blood tests showing abnormally elevated cardiac enzymes.

Basically, if you think you’re having a heart attack, you should first be calling 911, and not performing a self administered ECG that provides limited data.

Then the question is, how well do portable “leadless” ECG monitors work for monitoring arrhythmias? I went through some literature to see if I could dig anything up.

I found only one recent study on this topic, “Prospective comparison of the diagnostic utility of a standard event monitor versus a “leadless” portable ECG monitor in the evaluation of patients with palpitations“, by Scherr, Dalal, Henrikson and colleagues (2008).

This prospective comparative study used a standard patient activated event monitor system and a “leadless” portable ECG monitor. There were 18 patients, and each patient spent 30 days with the standard monitor, and then 30 days with the leadless portable ECG monitor. The portable leadless ECG monitor used in the study was the Omron ECG monitor.

Note, compared to the EPI life ECG mobile phone, this portable monitor is actually placed on the chest and most closely approximates the vector for lead 1 of a 12 lead ECG. With the sensors in the EPI life phone though, I wouldn’t be surprised if you could use the phone in the same fashion as the picture shown above.

The conclusion of the study was that the leadless ECG monitor (Omron), had a high patient compliance rate and had high quality ECG recordings. The authors concluded that the diagnostic yield of this monitoring system is equivalent to a standard event monitor.

However, the study had several limitations. First, with only 18 patients, the study lacked the power to make definitive conclusions. Also, the study participants were not randomized by any means, rather all picked on a single day of clinic visits.

What does this all mean? There is hope that portable ECG monitors are just as effective as typical standard event monitors, but a more definitive study with a larger patient population needs to be undertaken.

As the mobile health movement continues to grow, these types of innovative technologies are critical towards advancing how patients and medical providers will interact – but at the same time, we need to have studies or data that show emerging mobile health technologies are at least as good as the technology we have at present.