Q: Do I need a prescription for the Fourth Frontier X Plus?

Yes, but you don’t need one before buying. If you already have a prescription, you upload it after checkout. If you don’t, Fourth Frontier routes you to its physician network to obtain one as part of the order process. Either way, the device ships only once a prescription is on file. It’s a US-only product and won’t function in the UK until Fourth Frontier updates the app on its side.

Q: What does the Weekly Cardiac Rhythm Report cost?

It’s a separate subscription from the device itself: $30 a month, or $240 a year. It’s exclusive to the X Plus and isn’t available on the X2. Fourth Frontier states that the report is supplemental and not a substitute for clinical diagnosis or treatment.

Question 1

Is the Fourth Frontier X Plus a medical device?

Accepted Answer

Yes. Unlike the Fourth Frontier X2 or Zone, the X Plus holds FDA 510(k) clearance and requires clinical involvement to obtain. It&#8217;s built for people who already have, or are being investigated for, a heart condition rather than for general fitness use.

Question 2

What is the difference between the Fourth Frontier X Plus and the X2?

Accepted Answer

The X Plus holds FDA 510(k) clearance and offers an optional Weekly Cardiac Rhythm Report subscription ($30/month or $240/year) that the X2 doesn&#8217;t have. The X2 lacks FDA clearance but adds Heart Strain (ST-segment) monitoring, breath-based training load, Body Shock injury-risk tracking, and its own optional Frontier Premium subscription for VO2max, training readiness and sleep-stage metrics. Both are available in the US; Fourth Frontier&#8217;s newer Zone strap offers similar sport features but is currently sold in the UK.

Question 3

How accurate is the Fourth Frontier X Plus compared to a clinical ECG?

Accepted Answer

In a direct comparison against a clinical 12-lead ECG, the X Plus matched rate, rhythm, P wave presence and QRS morphology. It doesn&#8217;t report interval measurements such as PR, QRS or QT, and it can&#8217;t calculate electrical axis or assess voltage criteria for hypertrophy. Those require multiple leads.

Question 4

Do I need a prescription for the Fourth Frontier X Plus?

Accepted Answer

Yes, but you don&#8217;t need one before buying. If you already have a prescription, you upload it after checkout. If you don&#8217;t, Fourth Frontier routes you to its physician network to obtain one as part of the order process. Either way, the device ships only once a prescription is on file. It&#8217;s a US-only product and won&#8217;t function in the UK until Fourth Frontier updates the app on its side.

Question 5

What can the Fourth Frontier X Plus diagnose?

Accepted Answer

Its FDA 510(k) clearance (K240794) covers automated detection of five rhythm classifications: normal sinus rhythm, atrial fibrillation, bradycardia, tachycardia, and inconclusive or unreadable recordings. A physician reviewing the continuous trace may also identify patterns such as atrial flutter, SVT, VT or AV block, but those are outside the device&#8217;s cleared automated classifications. Fourth Frontier states explicitly that it isn&#8217;t indicated for diagnosing cardiac ischemia, myocardial infarction or left ventricular hypertrophy, and it hasn&#8217;t been tested for use with pacemakers or ICDs.

Question 6

What does the Weekly Cardiac Rhythm Report cost?

Accepted Answer

It&#8217;s a separate subscription from the device itself: $30 a month, or $240 a year. It&#8217;s exclusive to the X Plus and isn&#8217;t available on the X2. Fourth Frontier states that the report is supplemental and not a substitute for clinical diagnosis or treatment.

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