Help to interpret ECG

[Pab1]

I felt my heart behaving strangely and took an ECG on my Apple watch. The trace was unlike any I have seen before. After 10 mins I was back to normal and got a normal sinus ECG. Can anyone interpret the ECG for me and say what was going on? many thanks, Paul.

[BobD Volunteer]

Not a format I recognise since what little I do understand about ECGs is from 12 lead or Kardia.

[Autumn_Leaves]

It looks like artefacts to me. Please bear in mind the watch is not a medical device, and the algorithm applies a filter which typically smooths out the trace. I don’t know what’s happened here but I suspect it’s more to do with the way the watch has processed the signal. This is not a medical grade ECG, after all.

[mjames1]

Your bio mentions having a pacemaker. Kardia, for example, has never been tested with pacemakers, no neither may the Watch. I would therefore send this ekg off to your ep for analysis.

Jim

[Pab1]

thanks to all three I will do what you say.

[DunwichWilbur]

Looks like a pacemaker spike initiates your depolarization, with a ridiculously short PR interval, followed by a very narrow complex QRS, then a prominent T wave then a notable U wave - just trying to describe what I think I'm seeing. I didn't read about your pacemaker but it appears to have 'taken charge' suggesting a sudden bradyarrhythmia and I'd wonder where the atrial pacing wire was attached. I can't think of a proarrhythmic drug that would cause such compression of the whole P-QRS-T or how a glitch in the recording device could do this. There must be a recording device error- on an Apple watch, not a true office EKG - but I'll show my cardiologist tomorrow. My bet is it's your demand-status unipolar pacemaker taking over when HR is too slow or asystole. Oh, I'm an internist.

[Pab1 in reply to DunwichWilbur]

Thanks so much for that I will show my cardiologist the trace at my next appointment

[Hidden]

The ECG shows pacemaker spikes. If you have a ‘demand’ pacemaker it will only cut in when your own heart rate falls below a certain rate. That is why the pacemaker activity may show on one ECG trace but not another.

The shape of the ECG complexes will be different from usual when the pacemaker is active, and will depend on the location of the pacemaker lead (or leads) in the heart.

[baba in reply to Hidden]

Looks nothing like my paced heartbeats.

[Pab1 in reply to baba]

Thanks

[Hidden in reply to baba]

Not all pacemakers are the same - some have a single lead to the right ventricle, some have two leads, one atrial and one ventricular. The spike before the QRS shows that it is a paced rhythm.

[baba in reply to Hidden]

I am aware of different types of pacemaker, thanks.

[Tigger_2]

I may be wrong and have no experience with these devices personally, but I can't see how a watch, however smart, worn on one wrist can do anything like a an ECG in a clinic.

Where it could be useful would be to detect abnormal rhythms.

I need something right now to confirm that a pacemaker is not working overnight and why I am waking up with palpable heartrates 40-BPM or less when the pacemaker has a minimum of 70-BPM set.

[frazeej in reply to Tigger_2]

Of course a smartwatch or Kardia device cannot be as useful as an "in clinic" ecg. BUT, a smartwatch or Kardia IS available to you 24/7, and they are EXTREMELY valuable in detecting intermittent episodes such as paroxysmal afib-which is notoriously difficult to capture on an "in clinic" ecg or Holter monitors. These devices have been used numerous times to provide a definitive diagnosis of PAF........in my case, as one of many.

JimF

[Pab1 in reply to frazeej]

Agreed no doctor would believe I had AF until I bought an Apple watch and showed them

[Tigger_2 in reply to frazeej]

As I said.

[Ppiman]

I would say most definitely owing to some action of your PM on the Apple Watch’s algorithms. I’m sure you and they are fine despite this quirk!

Steve

[Pab1]

Yes thanks, I will be able to check what was happening at that precise time when I go for my pacemaker check shortly.