Ever had an electrocardiogram (EKG/ECG)? Be grateful you didn’t have to get one back when it was first developed!
Though a significant amount of the “electro-medicine” that arose during the age where electricity was a “mysterious power” was complete quackery, this is one development that was a true boon to cardiology, and medicine in general.
Constructed by Cambridge Scientific Instrument company in 1911, this EKG machine [bottom illustration] was built to the specifications of one William Einthoven, who developed the string galvanometer in 1903, to measure the electrical currents produced by the heartbeat.
Prior to Einthoven’s time, it was known that the heart produced electric currents, but there was no way to measure them that didn’t involve putting electrodes directly on the heart. I don’t mean right over the heart, on the breastbone - the chest had to be opened to actually measure this phenomenon. Einthoven’s device made it possible to measure the electric currents given off by the heart despite the insulation of fat and skin, and thus made it possible to measure the heartbeat without actually opening someone up.
The string galvanometer worked by using a thin conductive wire passing between powerful electromagnets. When a current passed through the filament, the electromagnetic field would cause the string to move, and form the familiar heartbeat pattern (or not, if their heart is impaired). A light shining on the string would cast a shadow on a moving roll of photographic paper, forming a continuous curve showing the movement of the string [see top illustration].
The original machine required water cooling for the powerful electromagnets, required 5 people to operate it and weighed some 600 lb. Despite the advances made in technology and design, the concept of today’s electrocardiograms is almost identical to the machines that earned Einthoven the 1927 Nobel Prize. Advances in cardiovascular treatment and surgery mean that discrepancies in the results of the EKG readout can be addressed, as opposed to just known to exist, but we still read the same P, Q, R, S, and T waves that were named by him, and still use “Einthoven’s Triangle” - the equilateral triangle that the electrical leads are placed in.
Top: Initial concept work of William Einthoven. Diseases of the Heart and Aorta. Arthur Douglass Hirschfelder, 1912.
Bottom: 1911 ECG Machine. A Brief History of Electrocardiography - Progress through Technology, Christoph Zyweitz.
Got rhythm?
I prefer a bit of sexy sinus...
Getting out of bed on a cold, snowy day to make him a cup of tea and biscuits to dunk ^_^
(Source: inspiring-pictures.com, via everything-inspiring)
Sorry for not posting in a while guys! On a good note I now own an R&K Originals 1950s dress and I’ve relaxed my hair! I have a few weddings to go to this year and I’m sorted. ^_^
(Source: thomasdestry, via thepinupgal)
PSA of the Day: The single greatest CPR instructional video starring Vinnie Jones and set to the Bee Gees’ “Stayin’ Alive” you’ll see today, guaranteed.
[mefi.]
(via fuckyeahcardiology)
Ohk I have to say this is one my big bug bears (alliteration ftw). I hate when people ask me if I just do ECGs all day and that’s it. Let’s take this for instance. This particular post was posted as atrial fibrillation. I nearly scrolled past and then I did a “WHA!?” Atrial fibrillation. You’re joking right? Let’s break this ECG down one by one.
Rate is roughly 60 bpm. Rhythm is definitely irregular. No discernible P waves. So far yes I’ll give that is indicative of atrial fibrillation. But I mean look at the QRS complexes! They are wide. There’s a whole lot of ST elevation going on. Classic tombstoning. That indicates an acute STEMI! This is why people who aren’t trained in analysing ECGs shouldn’t be performing them. If they can’t recognise someone having a heart attack then they should pass the task on to someone who can.
/rant over
(Source: medicalschool)
“Ready!” Or my first experience in the cardiac catheter lab
So as the title suggests this last week was my first experience as a cardiac physiologist in the cath lab. While in there one of my colleagues said that people are either echo physiologists or cath physiologists and I can definitely say that I am more of a cath physiologist! I just find it very interesting sitting there looking at pressure waves and working as part of a team with the patient on the table.
There were four angiograms and one VVI pacemaker implant. With the angiograms we just look at the monitors and look at the pressure waves and make sure there aren’t any pressure drops or that the pressure waves look like what we expect for that part of the heart (simple version). It was interesting to see the X rays of the coronary arteries in real time, although my colleague had to get a little X-ray help guide because I didn’t have a clue what part of the heart I was looking at at first.
The pacemaker was really interesting to observe as I’ve never seen someone cut into someone before. I can’t really call it surgery as it’s performed by a doctor and not a surgeon and it’s not all that bloody to be honest. Although apparently it can be quite bloody and this patient wasn’t much of a bleeder… I had to wear leads because of the X ray being on while they’re implanting it and I had a look over the shoulder of my colleague as she tested the impedance and whatnot to make sure the pacemaker was working properly for the patient. It’s really amazing to think that one day all this stuff will make sense to me and I’ll properly understand all the theory behind it! Yeah…I am a bit of a cardiology geek..
This has to be the best ask I have ever gotten.
The Importance of Word Choice: Terms with multiple meanings for scientists and the public
When “What Scientists Are Talking ‘Bout” isn’t the same as “What Everyone Else is Talking ‘Bout”
(via Southern Fried Science)
(via jtotheizzoe)
A little poem about Dr. Starling and his law!
This is a funny poem found in my Cardio book. It was written by Alan Burton regarding the Starling law of the heart.
“WHAT GOES IN MUST COME OUT”
The great Dr. Starling, in his Law of the Heart
Said the output was greater, if, right at the start,
The cardiac fibers were stretched a bit more,
So their force of contraction would be more than before.
Thus, the larger the volume in diastole,
The greater the output was likely to be.
If the right heart keeps pumping more blood than the left,
The lung circuit’s congested; the systemic —bereft.
Since no one is healthy with pulmo-congestion,
The law of Doc. Starling’s a splendid suggestion.
The balance of outputs is made automatic
And blood-volume partition becomes steady-static.
But when the heart reaches a much larger size,
This leads to Heart Failure, and often, Demise.
The relevant law is not Starling’s, alas,
But the classical law of Lecompte de Laplace.
Your patient is dying of Decompensations,
So reduce his Blood Volume, or call his Relations.
