What is Causing Your Cardiac Flip-flops? PVCs Revisited with Kardia’s Advanced Determinations

The skeptical cardiologist woke up in the middle of the night recently and noted that every 30 seconds or so he felt like someone or something had briefly squeezed his heart. This awareness of the heart beating (a palpitation) I knew to be from premature ventricular contractions or PVCs, something I’ve experienced in the past (and written about here and here) when stressed or overly hyped on caffeine.

I confirmed the renegade ventricular contractions by palpating my radial pulse and noting that concurrent with the flip-flop in my chest there was a delay in the pulse (the premature beat is less forceful) followed by a stronger beat, (the post-PVC beat has prolonged time for filling resulting in a more forceful contraction.)

Even though I knew my flip-flops were benign I found that they disrupted my ability to fall back to sleep. My cerebral cortex began assessing what might have brought them on and then pondering miscellanea.

In the past I’ve documented my PVCs by using my Alivecor Kardia ECG. For patients with Kardia devices who can’t interpret ECGs, however, diagnosis of PVCs heretofore had remained elusive.

Fortunately, now for those with unexplained palpitations, Alivecor’s recently released Advanced Determinations algorithm identifies both PVCs and premature atrial contractions (PACs.)

I had a little too much coffee this morning and began feeling the PVCs again and made a recording on my Kardia single-lead ECG.

Lo and behold, the Kardia AI algorithm had correctly diagnosed my PVCs! It even placed a black triangle right on top of the nefarious beat.

Six normal (sinus) beats followed by at the early occurrence of a PVC (within red circle) followed by a pause

The PDF of this ECG can be shared by email with physicians or friends.

My posts on PVCs and their treatment continue to gather hundreds of views daily and readers have left many descriptions of their experience with these pesky contractions.

In particular, PVC sufferers are interested in what might be causing the extra beats and what they can do to reduce or eliminate them.

Certainly, being able to personally and independently document the occurrence of extra-systoles with Kardia’s Advanced Determinations algorithm should provide insights that will provide some answers to causes and effective treatments.

Personally, I’m still racking my brain on what brought my PVCs back: Was it the new cocktail I drank? Was it those Peanut M&M’s I snacked on?

If you are using the Kardia with Advanced Determinations please share your experiences in PVC and PAC detection so we can get a better understanding of how it is working in the real world.

It should be noted that the Apple Watch ECG algorithm is incapable of identifying PVCs or PACs and Alivecor stands alone as a reliable, FDA-approved resource in this space.

Deterministically Yours,


N.B. The new cocktail was The Aviation (gin (the botanist), maraschino liqueur fresh lemon juice and crème de violette liqueur). The peanut M&M’s contain chocolate which contains significant amounts of the methylxanthines, caffeine and theobromine. These chemicals have complex effects on both the neurological and cardiovascular systems.

Interestingly, even though conventional wisdom in cardiology has tied methylxanthine consumption to cardiac arrhythmias and I’m convinced my PVCs can be triggered by episodic excess caffeine or chocolate consumption, this 2016 paper did not find such an association with chronic consumption:

In an investigation of nearly 1400 older adults, we found no evidence that the frequency of habitual coffee, tea, or chocolate consumption was associated with cardiac ectopy before or after multivariable adjustment.


31 thoughts on “What is Causing Your Cardiac Flip-flops? PVCs Revisited with Kardia’s Advanced Determinations”

  1. Hi, I’ve just found your blog! I’m a 58 year old biomedical scientist who has been getting a lot of PVCs or the past 8 weeks. I’m awaiting a 24 hour, 12 lead ECG and echocardiogram through the NHS in England (3 month wait…). Meanwhile I invested in a Kardia Mobile 6L with advanced determination that detects my PVCs. I’d like to post a screenshot of them but I don’t think I can do so in a comment. The PVCs all look the same on the Kardia 6L trace so I’m presuming they’re monomorphic. Please can you tell me whether it’s possible to determine the morphology of PVCs recorded by Kardia Mobile 6L from the trace provided?

  2. Registered nurse here and actually in the middle of my own journey with not PVCs but PACs. As much as I can recall, I started feeling them last year after I spent most of the summer cycling really intensely. Since I’m a nurse and have palpated a lot of afib, I was 99% sure that I wasn’t having afib when they started happening. I thought probably PVCs, but I actually bought a Kardia 1L and ended up diagnosing myself with PACs before I ever went to the cardiologist.

    I’m 40 years old now and since my early 30’s I’ve had what they used to call pre-hypertension. So, we shall see what this is all about. I’m actually wearing a Zio patch now and had an echo the other day. Per my own informal record keeping, they almost always happen in the evening while I am lying down and seem to be associated with some combination of intense exercise during the day and alcohol, salt, sugar. If I sit up while I’m having them on the couch, they’ll go away and I can’t capture them on EKG.

    All very interesting to me.

  3. I’ve had the odd PVC for years but they became much more noticeable after Bariatric surgery—enough so that I had a Holter (because I thought I was bradycardic). They have always been triggered by laying down or reclining immediately after a burst of activity (ie walking up the stairs, then getting into bed). Three days ago, out of nowhere, they started to happen literally every time I sit down or start moving, and haven’t gone away since. I finally went to emergency (nurses hate doing this haha) around 36 hours on and my ECG showed near-constant bigeminy with the odd run of couplets for fun. Bloodwork is normal (potassium is 3.7 though so I’m going to see if getting it up helps) and I’m just waiting for my TSH to come back—but I’m curious to know if there’s an explanation for why they stop happening when I’m moving around. I’m for sure in a sinus rhythm as soon as I start moving my body, and very quickly back in bigeminy when I stop (Apple Watch actually calls my little ECGs inconclusive when I’m having the PVCs, and catches the sinus rhythm quite well).

    Anyway. Why postural PVCs? They’re not scary but they are freaking annoying, especially the quite forceful beat after the couplets, and I actually feel like the cardiac muscle is “sore,” like I’ve done too many squats but in my chest wall (I am seeing a cardiology freak here shortly, don’t worry, but things move slowly here in Canada!). Currently they’re keeping me awake when I have a shift in 5 hours so I’m looking forward to them going away ?

  4. Just celebrated my 25th anniversary of a mitral valve replacement (St. Jude’s bileaflet) and things had been going well until the last couple of years. Came back from Munich Oktoberfest (2019) with an exceptional case of holiday-heart leading to sporadic tachycardia. EP performed an ablation and I cut back on celebratory consumption and things were perfect until earlier this year (2021). Overdid it while rebuilding my raised garden beds and wound up in the ER with an arrythmia I’d never previously felt. Surprise, it was just PVCs but since that episode they’ve become chronic. Have wracked my brain trying to find a trigger, any combination of food/drink/activity, but so far nothing definitive. Regardless of sleep, stress, exercise, caffeine/alcohol, or diet it just comes and goes without root cause or reason. I’ll go weeks or a month with only mild, occasional symptoms (verified with my single-lead Kardia) and then bam! days or weeks of PVC that simply wear me out. Have you seen this cyclical pattern before in your patients (or yourself) and can PVC simply “happen” without a trigger or root cause?

    • Joe,
      Yes and yes. For many of my patients (and me) no clear-cut explanations for the PVC comings and goings.
      It can be very frustrating.
      Dr P

      • Dr. P
        Yes, very frustrating indeed. Just a quick follow-up question, I’ve observed some correlation with my INR and the severity of the PVCs. Usually I’m between 2.5 – 3.5 but when I dip to 2 or below the “pressure” of the PVC seems stronger. Since this is just a clotting factor is it just another one of those random things and I’m grasping for a pattern? Obviously I try to stay above an INR of 2 but last week it dipped to 1.6 and I really felt the PVCs. Now I’m back in a therapeutic range the PVC is barely noticeable (although the activity is happening).
        Thanks again

  5. I have been on a quest, like most of us, to find out the culprit of these seemingly random PVCs. I have cut out regular coffee, I drink one decaf cup in the morning, cut out all chocolate, keep hydrated, very small amounts of carbs and no alcohol, but I still experience PVC episodes.
    I have been wearing a Fitbit on my wrist for many many years, I was obsessed with tracking my sleep every night and of course keeping track of my HR during sleep, workouts and generally throughout the day.
    One day I took it off before my shower, like I
    ve done thousands of times before, but for some reason I noticed the two green lights that constantly flickered and flashed on the bottom of the device, which would have direct contact with my skin on the inside of my wrist.
    I began to wonder what sort of electrical signal has been coursing through my body as a result of wearing this device non stop for years, and is it possible that whatever it was could possibly be the source of the interruption of the normal electrical signals to my heart?
    I took it off that day, which was about 6 months ago, and I can honestly say that Ive had a 90% reduction in PVC episodes. I have gone weeks without an episode, whereas before I may have only gone 2 consecutive days without them.
    s the only thing that Ive tried eliminating that actually had a long-lasting effect. And in fact, I have tested a little alcohol and chocolate and have not experienced any PVCs afterwards.
    I know its nothing scientific, but I thought I would throw it out there to see if anyone else experienced this.

    • Deano,
      Fascinating. Could the Fitbits and Garmins and Apple Watches we have all been wearing to enhance our fitness been creating cardiovascular issues?
      dr P

      • Just google…”EMF radiation from Fitbit devices”, their is one video that actually uses a device that measures the amount of EMFs being emitted from the Fitbit(or any fitness watch I would think). We are around Bluetooth devices all day, but I realized that I had this thing strapped to my body 24/7 constantly flooding me with EMFs all day and night, not to mention wearing my Bluetooth ear buds at the gym, using my Bluetooth mouse and keyboard all day long and of course having my 5G phone close by and many times right in my pants pocket. Im no expert, but if the heart’s electrical system is responsible for making and conducting signals that trigger the heart to beat, any electrical interference cant be good.

        • Deano,
          Interesting. I wear my Apple Watch continuously when awake. For a while when I was evaluating various sleep trackers I was wearing the aw or other wrist devices (Garmin) . I typically sleep on my left side with my left hand. under my face which put the watch or wrist band right next to my brain.
          I became a little worried about the radiation I was getting at night and switched bands to the right arm or tried to put my hand away from my face. No apparent symptoms.
          Dr P

  6. I just purchased Kardia 6L to record palpitations at home. I know very little about any of this, but m report PDF was 4 pages of some odd stuff and labeled “normal”. Please explain Advanced Determination feature. My kit said the device only reports a fib or hr out of range.

  7. I have paroxysmal atrial tachycardia, ventricular & atrial ectopics, atrial bigemy/trigemy, and since the new determinations, have recorded sinus arrhythmia! The r-r interval plot can be quite dramatic! I always found pvcs easy to recognise anyway but the new algorithm is good at picking up PACs which i found difficult to sometimes to pick out. I always feel the pac/pvcs as they make me feel like I’m about to gasp.

  8. I discovered that I had SEV’s and PVC’s about six months ago by using the 6-lead Kardia device. I can watch the trace live in real time, feel the PVC and then see it on the trace (easy to see with the 6 lead version) about a second after I actually feel it. I went to an electro cardiologist and he offered me the option of monitoring with a Zio patch for two weeks. So I followed the incidence of PVC’S with my Kardia in parallel with the patch. The results matched up well.
    So I have an imperfect experiment to share. See the attached log from the Zio report. Some years ago I cut over to decaf coffee, but I actually drink a lot of it; two large mugs in the morning which turns out to be 6 official measure cups (3 scoops of Petes decaf). My guess is that its 30-50 mg caffeine in total. For the fist week of the Zio I kept up my decaf coffee habit and then on the second week (03/08/2021) I cut out all the decaf. As you can see from the data the second week had a dramatic decrease in PVC’S. I resumed the decaf drinking the morning of 3-11-2021, but did not see an immediate return of the PCC’s until 3 days later.
    However, the experiment is imperfect because a second variable was changed in the second week. I re-introduced the decaf on I got sick of using the Kardia all the time and sick of worrying about this whole situation and pretty much forgot about it. I suspect that measuring the PVC’s with the Kardia actually causes them to be worse because I am tensed up while measuring. Other scientists might understand why I call this a Heisenberg problem. So was the decreased PVC’s in week 2 due to the reduced caffeine or the reduced stress due to an attitude adjustment?
    I share this with a grain of salt for what its worth.
    PS: im not sure I uploaded the picture from my Zio patch report properly

  9. I have noticed my PVCs are episodic in nature and unrelated to caffeine, chocolate or exercise. When I hit one of these bad periods, I will be in and out of PVCs ranging from irregular approx q 5-6 secs to bigeminy for minutes to hours over several days to weeks and then they subside. Currently, all is quiet in there. Have experimented with increased electrolytes, magnesium and potassium without apparent affect. Conclusion- idiosyncratic at this stage of medical knowledge.

    • I’m the same, I think. I feel like mine are related more to posture, and how full (in the belly) I feel. Also, sleep deprivation and too much alcohol!

  10. Using the KadiaMobile 6 lead device for a month now to record arrhythmias which are mainly PVCs:

    The advanced diagnostics mode only analyzes Lead 1 of the six traces. Viewing the file after a recording, obvious PVCs are evident in the other traces but often are not flagged on the Lead 1 trace by the diagnostic algorithm. The additional information provided by the 6 Lead recording is substantial and allows easy observation of PVCs which are not detected by Lead 1 analysis.

  11. Hi Dr. P.,

    You stated:

    “Lo and behold, the Kardia AI algorithm had correctly diagnosed my PVCs! It even placed a black triangle right on top of the nefarious beat.”

    I am using the Kardia AI algorithm and I do not see the black triangle on my chart when the the ECG is completed and the instant analysis provides “Sinus Rhythm with Premature Ventricular Contractions.” This is with me looking at the Kardia ECG chart (in the Kardia app) on the iPhone after it was completed and scrolling through the trace.

    So, I wondered “where the heck is the triangle?”

    After I made this observation I wondered what I would see if I emailed the ECG trace to myself as a pdf. Well, you get a lot more information in the pdf than what you see as you scroll the iPhone screen. You get 3 pages in the pdf.

    Page 1 is the ECG trace with triangles shown designating the PVC.
    Page 2 is called a “R-R Interval Plot.” Could you explain what this is and how I can best use it?
    Page 3 is called “Average Beat Plot.”

    So, bottom line: it’s best to send the ECG to yourself as a pdf and see the black triangle and 2 other pages of information you may not know even existed when the ECG was analyzed.

    Also, FYI, If I run an ECG on my Apple watch 6 immediately after the Kardia chart was run, the Apple instant analysis says “Sinus Rhythm.” My examination of the Apple watch ECG shows 1 and maybe 3 PVC’s are present. If you send the Apple watch ECG to yourself you get a pdf with a single page showing the same thing you see when you scroll the ECG on you iPhone.


    • Jim,
      Excellent observation! I had not noticed the additional information in the PDF. The R-R interval plot shows the time between QRS beats on the y-axis and time on x-axis. This should be relatively constant in SR but with extrasystoles or afib will vary. I’ll put together a post on this as time allows with examples. I ‘m not sure of its value to patients but it would be of interest to doctors. The average beat plot as implied sums up the entirety of the QRS complexes and displays them as a single large beat. Interesting, again but not of patient interest.
      Dr P

  12. I’ve suffered from PVC’s / PAC’s for the past several years. It all started one day from a lot of pull ups. I did a PR of pull ups, got off, and noticed my heart skipping every beat. For the next few days, I had really bad PVC’s / PAC’s. Never had them before until that day I did a lot of pull ups. It got so bad, that I was getting light headed the following weekend. On a Sunday, decided to go to the ER. They ran a bunch of tests and on a pulmonary angio, saw evidence of CAD. I did a follow up with a couple of cardiologists and did a 24 hr holter. They found several thousands of PVC’s and PAC’s, but nothing else alarming. I figured if there’s nothing else they can do but put me on a beta blocker, I would just live with it. I cut out all caffeine, and honestly, that didn’t do anything for me. Also tried magnesium supplements. Nothing. I just basically learned to live with it. Eventually, over a period of a year, they slowly went away on their own. No one can explain it, and I still wonder what happened. But, I feel like they are related to my susceptibility to vasovagal syncope. I have had a few episodes (can count them on one hand) over my life starting when I was 19 — I’m 47 now. I had a really bad episode the week prior at the gym. Just did some warm up light cardio on the stairs, and a few warm up pull ups (only a few pull ups), and then out of the blue, a major vasovagal syncope attack. Had to lie down at the gym for 20 minutes to recover. Those episodes are pretty scary, and almost feel like a heart attack minus any of the pains (chest, arm, jaw).

    I still get episodic periods of them here and there. They can get fairly bad still, and these episodes last for several days even a few weeks. But, eventually, they calm down and go away. I feel like my PVC’s and PAC’s are not related to diet but something else.

  13. My PVC bursts were nocturnal, or early morning, and associated with prolonged hypoxia at night, caused by a severe case of sleep anea (AHI-45). Quad coronary bypass surgery in January 2018. Then I had Type 1 atrial flutter in July, for the same reasons of nocturnal apnea I guess, treated with ablation (unsuccessful) in August 2018.
    The same month I started nocturnal CPAP, and have not had any recurrence of PVCs nor AFL.
    Of course, I’m on other medications, including Nebivolol.
    I strongly believe chronic myocardial hypoxia, from sleep apnea, may be involved with these arrhythmic episodes. But as sone else mentiioned, electrolyte imbalances may also be causally related.

  14. Dr. Pearson, thank you so much for taking time to write about heart problems and other health interests. Your writings are very valuable to us who have no medical training. I believe your patients are fortunate to have you as their Cardiologist, but since I live in California that is not possible.
    Your term “flip flop” is very accurate with us that have experienced PACs/PVCs.
    Since Kardia ‘s new Advanced Determinations, when I feel a “flip flop” it generally reads: Kardia Advanced Determination “Sinus with Supraventricular Ectopy (SVE)” indicates sinus rhythm with occasional irregular beats originating from the top of the heart. A common reason for this is premature atrial contractions (PACs).
    Again thank You so much for your valuable information,
    Harvey Johnson

  15. Hmmm, getting distracted from updating a previous article…. now waking at night with palpitations… Are you still in Honeymoon Mode ?

  16. My cardiologist advised not to worry about my frequent PVC’s diagnosed via holter monitor, so I try not to. My diet is lower-carb, high-veg, and I have noticed that a high carb meal will bring them on.

  17. I have suffered from pvcs for years including bigeminy and trigeminy . I have used my Kardia mobile quite frequently. Now with the update , it reads my pvcs and most recently Supraventricular Ectopy. I was in a fleeting afib rhythm one time a couple years back . If I could figure out how to send a screen shot I would . Every time I have felt an out of the ordinary rhythm , I take a Kardia and every time it spots what I already know . My question is why do my pvcs sometimes look and feel like I’m falling off a cliff , while other times they are just little bumps on my read out ?

  18. I struggled with PACs and PVCs for ten years. My last holter monitor readout confirmed continuous bigeminy for hours at a time. After reading about electrolyte balance, I finally managed to completely eliminate them by increasing my intake of potassium food and drink. My electrolyte blood tests were always absolutely fine, but coconut water quite seriously cured the palpitations overnight. I already ate quite healthily, but perhaps a sodium/potassium intake imbalance? With daily coconut water, I am still almost palpitation free four years later.

  19. Having experienced PVCs from time to time, and being a coffee drinker and chocolate eater, my lay cerebral cortex follows a similar course when PVCs happen. The word “gin” here got my attention. FWIW I’ve noticed, I think, some correlation there compared to other spirits. I don’t see how that could be … but I have additional trials in mind to test the suspicion.


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