ECG Kindergarten

An electrocardiogram measures the electrical signals that travel through the heart while it beats.  Doctors are looking at how long it takes the electrical wave to pass through the heart, as well as how much signal there is.

The printout from an ECG is more than just a bunch of squiggly lines.  A closer look will reveal that not only are there squiggly lines, but there are also a few letters and numbers scattered about the page.  What does it all mean?

ecgStrip Leads

All Those Wires

If you have an ECG done, you’ll rest flat on your back and they’ll hook up a bunch of electrodes. It does not hurt.  These electrodes allow the doctor to look at the heart’s electrical activity from different angles.

To illustrate how this works, consider these pictures:


These pictures are quite different but they’re all photos of the same thing, just from different angles.  Likewise, the different leads used in an ECG give doctors heart-activity pictures from a bunch of different angles.  It’s one heart, but the electrical waves look different depending on your perspective.

Chest Electrodes and Their Leads

Six electrodes are attached to the chest at specific places to provide a picture of how the heart is functioning. These six chest electrodes show the electrical signal looking from the horizontal plane.

  • V1 and V2 look at the heart from the center (septal)
  • V3 and V4 look at the heart from the front (anterior)
  • V5 and V6 look at the heart from the side (lateral)

Limb Electrodes and Their Leads

There will also be an electrode for each limb: right arm, right leg, left arm, left leg. One peculiar thing is that the leg electrodes can be positioned anywhere between your torso and ankle.  As long as they’re the same location on both sides of the body it doesn’t seem to matter (I’ve had them near my ankle and also had them on my lower abdomen, and was confused about the variation depending on who’s doing the test – but now it makes more sense).  These limb electrodes generate views from a vertical plane.

  • When measuring the flow of electricity toward the right arm, this is called augmented vector right (aVR)

  • When measuring the flow of electricity toward the left arm, this is called augmented vector left (aVL)
  • When measuring the flow of electricity toward the left foot, this is called augmented vector foot (aVF)
  • When measuring the flow of electricity toward the right foot – nope, that doesn’t happen. They only consider the left electrode; the one on the right is neutral.


Maybe you’re puzzled, as I was, about how it can be a 12-lead ECG when there are only ten electrodes (6 chest + 4 limbs).  It turns out that leads are not synonymous with electrodes.  The six electrodes for the chest are the same as the leads, but to understand the others, we have to recognize that those leads are made up of pairs of electrodes.  Think back to high school science class and what we learned about electricity.  Or maybe it might help to picture the terminals on your car battery, where we know that electricity flows from the negative to the positive.

An ECG also measures the flow between the limb electrodes (from negative to positive):

  • Lead I measures the flow from the right arm’s electrode to the left arm’s electrode
  • Lead II measures the flow from the right arm to the left leg
  • Lead III measures the flow from the left arm to the left leg

If you ever want to have even a fuzzy idea of what your ECG shows, it’s important to know about the leads, because the printout of your heart’s rhythm will reference those leads.  The letters and numbers on the ECG’s printout are referring to the lead used for that portion of the tracing.  The ten electrodes give twelve leads: six chest and six limb.

The Strip (Printout)

The printout from an ECG shows the heart’s electrical signal as waves.

  • If there is no electrical impulse, the line on the ECG is basically flat. This is called the baseline.
  • When an electrical impulse is travelling toward a lead, the line on the graph will move upward.
  • When an electrical impulse is travelling away from a lead, the line on the graph will move downward.

Just as the front and back of my nativity scene look very different, waves look different depending on which lead is being used.  For example, this shows the same heartbeats as seen from two different leads:

ecg updown

But what does it mean?  Notice that the squiggles seem to have a pattern.  Every distinct portion of the ECG means something specific. First the heart is at rest, and the horizontal line showing no electrical activity is the baseline.

ECGPartsPtoT in colorThe P-wave indicates the heart’s electrical signal traveling through the atria (top chambers of the heart).

Following the P-wave, the QRS complex shows the electrical signal traveling through the ventricles (bottom part of the heart).  When this happens, the ventricles contract and the atria re-set.

The T-wave indicates that the ventricles are resetting and getting ready for the next heartbeat.

ecg contractions

When we combine what we know about leads with what we know about these waves, we can look at the printout from an ECG and see how it all fits together.  This illustration is color-coded to show which leads view the heart from different angles, and where that information shows on the ECG’s printout.

Certainly this isn’t enough information to allow patients to read an ECG, but it does give us some background to have a hope of understanding what doctors are saying if they ever attempt to explain what they’re seeing on the printout of our electrocardiogram.

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About Pericarditis ECG’s:

Technology as health tools

I thought that being an RA patient was a full-time job.  If so, then taking care of an aging parent qualifies not just for overtime, but for double-time! It is exhausting, which hasn’t been so good for my RA.  Fortunately, I’ve learned a few things that have actually helped me improve my own health.  My brothers are assisting with mom, and between us all we’ve done a few things that have helped my mom to be in better health now than she has been in at least a decade.  Two of those things we’ve done might be helpful for RA patients, too.  Technology is great.

The first thing we did involved gadgets.  We got Mom a Fitbit Charge2 (and an iPhone). There’s some interesting research showing that use of a pedometer can ease RA fatigue, so we might all want to make ourselves get up and get moving. If all you want is a pedometer, spend $5 at WalMart.  The fitbit does so much more than count your steps, though.  This is a pretty neat little gadget. It’s a wristwatch. It’s an exercise tracker. There’s a setting that will make the thing vibrate every hour if you haven’t taken at least 250 steps (but not at night), so you get a gentle reminder to get up and get moving (which I need).  I knew that with my RA diagnosis I’d learned to conserve steps, but didn’t realize quite how sedentary I’d gotten until I started looking at my step-counts. You can set a goal for how many steps you want to take each day, and when you reach your goal, the fitbit congratulates you 🙂  Adding in an app to sync the fitbit with your phone makes it easy to set exercise goals, sleep goals, and even track how much water you drink each day.

The next thing we did was take a look at mom’s glucose readings.  (skip this paragraph if you don’t care about diabetes) There have been problems with mom’s medicare-approved glucose meter, the most significant being that mom’s anemia is severe enough that the meter often gives errors instead of reporting results.  Nearly as important, imo, is that the black numbers on a grey background are nearly impossible for her to read. Why Medicare pays for something that’s basically useless, I don’t know.  We found a solution! We bought a meter that is able to give results in spite of the anemia, and which has a white background and extra-large numbers so that mom can read the display. This solves both problems. (OneTouch Verio, if you’re in need of a good glucose meter.)  What we’re really liking is that this meter syncs with the OneTouch Reveal app on mom’s phone, so there is an easily-viewed record of all mom’s glucose readings.  We showed her doctor at the last appointment, and the doctor loved it. My brothers and I also put the app on our phones and logged into mom’s account, then set reminders to check mom’s glucose readings about 10 minutes after her meal times.  It’s nice to see those numbers and know that mom’s okay. Before switching to this meter, we’d asked her to text us every time she tested, which she found a little more cumbersome than she wanted to deal with. Now she just tests like normal, and we can see her numbers. The way the report is set up, it’s easy to look at it and see patterns.  “Gee, mom, you’re always high at lunch time; maybe you should consider changing what you eat for breakfast.” We’re finding the right balance between, “You’re an adult; do what you want,” and “Given your family’s life expectancy, you probably have another 20-25 years; controlling your glucose will have a significant impact on what those years are like, so you might want to get this under control.” If her numbers are high, then my brother texts, “What did you eat?!” and that helps her be mindful of her diet. If she doesn’t post something, or if her reading is low, I contact her to make sure she’s vertical and not in need of assistance.  Never again will she nearly die because nobody knew she was sick.

The final thing we did that seems to be helping mom tremendously, and is helping my brothers and me lose weight, too, is set up a free MyFitnessPal account. We all set up accounts and friended one another so we can help mom keep track of what she’s eating and how that affects her glucose levels. I know that the fitbit app allows tracking of what you eat, but we’ve found MFP to be easier to use.  It also displays the info we want (and it syncs with the fitbit so the data is both places).  We did the math to help mom figure out how much protein and how many carbs she should be eating (and did the same for ourselves). We named the meals with that information because she was having a tendency to forget, so, for example, her meal names are:

  • 7:30 am: Breakfast (32g carb, 15g protein)
  • Noon: Lunch (32g carb, 15g protein)
  • 4:30 pm: Dinner (32g carb, 15g protein)
  • 7:30 pm: Bedtime snack (32g carb, 15g protein)

Combining these three things (three apps on our phones) has made it really easy for mom to see the correlation between what she eats, how much she moves, and what happens to her glucose. She thought she was controlling what she ate, but seeing exact protein:carb numbers has been extremely helpful. She got her A1c down to 7.0 ! It helps me, too, because I can do a virtual check on my mom at any time.  Honestly, it was exhausting when I had to drive to her house  Getting mom to really get things under control with the help of these tools (apps) has made my fatigue level decrease 🙂  If you have diabetes, or are caring for someone with diabetes, maybe these things can help you, too.

As for RA, I find these apps quite useful in a couple different ways.  First, using MyFitnessPal makes it easier to keep macronutrients in the right proportions, which means that I have to eliminate foods that provoke inflammation, so my disease is better controlled. As a bonus, eating the right proportion of macronutrients means that I don’t get hungry between meals so am not tempted to snack.  Second, the “friends” aspect of MyFitnessPal means that others in my family can see what I eat, which inspires me to make choices that I won’t be ashamed to have them see :).  Finally, getting a fitbit has me moving way more than I used to. Although it seems counter-intuitive, the extra activity actually decreases fatigue.

I’m looking forward to browsing the iMedicalApps site to see what other helpful tools might be out there!

In the Kitchen

Wouldn’t it be nice to have hands that worked without aching?  Unfortunately, meds to treat autoimmune arthritis only slow the disease; they don’t halt progression or provide a cure.  In the kitchen, achy hands make meal prep a challenge.

CanOpenerAlthough I try to cook with fresh ingredients, sometimes it is necessary to open cans.  My preferred method of opening a can has been to hand the can and opener to someone and raise my eyebrows in a silent plea for help.  Unfortunately, my kids are growing up and either playing sports or heading to college, which throws a wrench in my can-opening options.  Everyone in the house recognized the problem, so my kids did some research in an attempt to find me the best electric can opener on the market.  I have great kids!  They gave me a Hamilton Beach 76606Z for Christmas, which means I’ve had it long enough to know that it is a very good can opener.  I can now open cans even if there’s nobody else in the house and my hands and wrists prevent use of a traditional-style can opener.

MandolineThe other kitchen acquisition that has helped tremendously is a good-quality mandoline.  Note the “good quality” modifier. I used to have an inexpensive model, and cutting things with it was an exercise in frustration.  The one I replaced it with is fabulous.  I first saw it demonstrated at a fair, then did some research before buying.  The price on Amazon has come down in the past year and beats the fair price by a good bit.  This mandoline will slice tomatoes, pickles, mushrooms, potatoes, and probably anything else you might want to slice (except avocados — it gets jammed on the pit when slicing so effortlessly you don’t realize you’re already that far into the fruit).  I like the fact that the slice thickness is determined by a fixed bed.  You choose the thickness you want and easily insert the appropriate cutting bed. My old mandoline had a knob that I turned to adjust the cut-depth and it had a tendency to slip while in use.  With this setup, there is nothing that can slip and inadvertently change the slice-size.  I also like the V-blade, because it will slice soft things like tomatoes just as perfectly as it slices firm foods like potatoes.  I also like that it’s mostly stainless steel instead of plastic. The Borner V6 comes with a holder that can be mounted on the kitchen wall.  Since there’s no space on my walls to mount anything, I just leave it sitting on the counter beside my KA.

My favorite cooking tool is a crockpot.  Any kind, every kind.  Start oatmeal at bedtime and it’s ready in the morning when you get up.  Start supper in the morning, and it will be ready to eat when you get home in the evening.  Everyone should own at least one crockpot (IMHO).

If your budget is like mine, you can’t afford a personal chef. A few good kitchen tools will make a world of difference.

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Disclaimer:  while I’m not opposed to people sending me gadgets or money, that didn’t happen here.  I bought my mandoline and crockpots, and my kids bought my can opener.