Apple Watch ECG and recorded Heart Rate data

@moey2720 You have a lot of complex issues, and so it’s very important that you have a doctor whom you trust who can work with you in navigating these. The thoughts below are more general comments for your consideration.
First, regarding your question about using an Apple Watch or Kardia device with a pacemaker: they are not incompatible, and you can use both. However, a pacemaker has electrodes inside the heart that record the heart’s electrical activity very accurately. Thus, if you have fast heartbeats, they should be well detected by the pacemaker, although there are exceptions and technical situations where it may not be sufficient. In general, however, a pacemaker would provide the most accurate determination as to whether or not you have atrial fibrillation (a fast heart rhythm in the top chambers of the heart) and how much of it you have.
Importantly, while some people with atrial fibrillation feel their heart racing, other people do not. That’s because the top chambers are racing, but your pulse is driven by the bottom chambers—the ventricles. In some people, not all of the signals from the top chambers make it to the bottom chambers, so part of the heart is racing while the main part that controls your pulse may be normal or slow in its rate.
You asked a lot about whether or not a Watchman device or blood thinners are needed. This, again, is something that is very important to discuss with your doctor. In general, when atrial fibrillation is present, the top chambers are not squeezing effectively. All of us are born with a left atrial appendage, a small cul-de-sac or reservoir in the top left chamber of the heart. Ninety percent of the clots that form in the heart in patients with atrial fibrillation come from that area. If a clot forms (because the blood doesn’t circulate effectively in AF, it may clot) and leaves the heart it can plug an artery; if that artery is in the brain, the part of the brain doesn’t get enough blood and oxygen and those cells die: a stroke. If you are at risk for a stroke, the ways to prevent it in AF are either to use a blood thinner so that clots do not form, or to place a plug in the appendage (the pouch where blood is most likely to stagnate and clot), such as a Watchman device or a different device. This, in the long term, may eliminate the need for blood thinners and prevent the risk of stroke, because clots cannot form in the appendage and then leave the heart to plug arteries in other parts of the body.
The risk of stroke is not determined only by whether or not atrial fibrillation is present, but also by other risk factors. There is a scoring system called the CHA₂DS₂-VASc score, with each letter representing a risk factor: congestive heart failure, hypertension, age over 65, prior stroke or TIA, vascular disease, age over 75, and female sex. Thus, determining whether or not you are at risk is important in guiding these decisions, and the score is one tool widely used clinially. Getting back to my previous point, it is really important that you have a doctor you trust who is well-versed in this area and can guide you through it.
Best of luck as you navigate these complex decisions.

Inconclusive can also mean your hands are not making a good contact with the watch or are trembling and not giving a true reading. Even something as supposedly simple as reading your heart rate will be effected by the placement of the watch sensor on your wrist. It's suppose to be about an 1" above the wrist bone.
Really not that different than taking your BP. All sorts of rules and conditions supposedly get a correct measurement. Definitely a lot different that getting on a scale to weigh yourself.

While some people on this board will swear by their Apple Watch data, my three year experience with it has been mediocre. A couple of years ago it picked up afib when I did a random EKG. I have elected the weekly report of afib options and it will indicate afib anywhere from 7% to 25% of the time. My Mayo cardiologist thinks it’s confusing PACs (multiple Holter Monitors have had my load at 10-12%) with afib and its algorithm does something funky with the data. Electing the Apple Watch option for identifying an irregular heartbeat in real time has never alerted to anything. I wear it to monitor my heart rate on my runs and get little use out of it otherwise.

If whatever wearable you have can upload a graphic ECG representation that you and a professional can read, it will show a proper depiction of a PQRST wave complex and you can see, for yourself if educated about reading them, what kind of problem is depicted. Atrial fibrillation shows no discernible P-wave, and the R-to-R peaks are all over the place in terms of distance/time between them...no reliable pattern. If PACs, you can see the close couplets or triplets, followed by an obvious long pause, and then the catch-up beat. https://en.wikipedia.org/wiki/Premature_atrial_contraction
The wearables aren't licensed or certified to do more than to report AF, which along with VF, are the two most problematic or concerning arrhythmias, with the latter being potentially lethal inside of a few minutes. But if you take pains to learn how to read an ECG, you will soon learn what AF looks like and when you have PACs with bigeminy, trigeminy, or even bundle branch block if your wearable has the accuracy in the one lead to detect it....which pretty much none do. In fact, most pros will tell you that a 12 lead ECG is what works best to show clearly what is going on in the heart's rhythm.

@gloaming Thanks for the tip. Do you have a recommendation of a good resource to start learning how to read an ECG? I have quite a few 'strips' that my Apple watch have recorded.