Gas station without pumps

2022 January 27

PVC again

Filed under: Circuits course — gasstationwithoutpumps @ 17:34
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In PVC: Premature Ventricular Contraction and PVC and pulse, I posted some ECG recordings of my heart to show the premature ventricular contractions.

I recorded for about 209 seconds, and I got 119 spikes and 56 PVCs.  The overall pulse rate was 50.0bpm, but the sinus rhythm was only about 33.9bpm with 15.8 PVCs/min.  That is a very high rate of PVCs.

Here are the averaged waveforms for Nov 25 again (about 209 seconds with 119 normal spikes and 56 PVCs).  The overall pulse rate was 50.0bpm, but the sinus rhythm was only about 33.9bpm with 15.8 PVCs/min. The PVC burden was 32%, which is very high (anything over 10% is considered frequent).

Lead-I-2021-Nov-25

The solid lines are the ECG signals (in mV) and the dashed lines are the optical pulse signal (in dB, because I was using a log-transimpedance amplifier).

I have still do not have a setup that lets me record my heart beat while exercising—the ECG gets too many movement artifacts (enough to cause clipping), and my hand is not steady enough for the optical pulse monitor to work.  I plan to build a new ECG amplifier with lower gain (particularly in the first stage), so that I won’t get clipping. I still haven’t figured out how to get the pulse monitor to work—I probably need a gentle clamp, like a pulse oximeter uses, but I’ve not figured out how to make one yet—I’ll probably need to 3D print something, but coming up with the right strength of spring to get appropriate pressure is the hard part.

In the meantime, I’ll do resting ECG recordings occasionally, to see if there is any change.  I made some recordings on 26 Jan 2022 while lying down.  Here is the average of Lead I from the longest of them (628 seconds, 48.1bpm, 355 normal spikes and 150 PVCs, 30% PVC burden)—the shorter recordings were completely consistent with this longer one.

Lead-I-2022-Jan-26

The spikes were a little smaller than before, so I had to tweak the program a little to find all of them. The shape of the PVC waveform in the S region is a little different, but overall the results are much the same as in November. My hand was not relaxed and steady enough while lying down, so the optical pulse measurements were not good, and so I did not bother plotting their average here.

I did a little library research on PVCs, because the consumer-level information about them said that they were generally harmless, but frequent ones could increase the risk of cardiomyopathy. The best review I found was Evaluation and Management of Premature Ventricular Complexes by Gregory M. Marcus, Circulation. 2020;141:1404–1418 https://doi.org/10.1161/CIRCULATIONAHA.119.042434

The article suggests that over 10% of pulses being PVCs is associated with increased risk, but that people in my situation (normal left-ventricular ejection fraction (LVEF), no symptoms, >10% burden) should be given an echocardiogram annually and not otherwise treated until something changes.  I will pass on that citation to my physician before my next annual checkup, unless I find a better one in the meantime. There seems to still be a lack of knowledge about whether PVCs are a serious risk factor or not (or under what conditions they are a risk factor).

2 Comments »

  1. […] PVC: Premature Ventricular Contraction, PVC and pulse, and PVC again I posted some ECG recordings of my heart to show the premature ventricular […]

    Pingback by No PVC while exercising | Gas station without pumps — 2022 February 18 @ 14:44 | Reply

  2. […] PVC: Premature Ventricular Contraction, PVC and pulse, PVC again, and No PVC while exercising I posted some ECG recordings of my heart to show the premature […]

    Pingback by Lower PVC frequency | Gas station without pumps — 2022 March 24 @ 09:58 | Reply


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