The U wave is a smaller structure after the T wave that resembles a second T wave, kind of like Baby Mario, M&M’s Minis or Pichu. It’s best seen in V2 and V3.
Prominent U waves are most commonly found in:
Inverted U waves are abnormal and point to cardiac disease.
It’s normal for blood pressure to drop when breathing in.
When you breathe in, the negative intrathoracic pressure increases. That basically means the extra force of all the air you’re leeching from the atmosphere pushes on the insides of the body, squishing the important bits of the cardiovascular system. So, the blood flow gushing out to the rest of the body is reduced a bit, referring to the cardiac output emitting from the left side of the heart. Note that venous return to the right side of the heart increases with inspiration.
A drop in SBP<10 is normal during inspiration. When it’s greater than this, it’s pulsus paradoxus. That can happen in things like:
Smoked seafood has, unfortunately, been cast into the same category as preserved meats. These traitors have been linked with an increased risk of malignancy. Shun them all!
On the plus side, chicken is still in season(ing). As long as you’re not a greedy pig about it. Moderation, which basically means not over-gorging, is the key to success. That is, health.
Which side of the heart does each atrioventricular valve correspond to? Memory aids enlighten us all!
What about the semilunar valves? They must not be forgotten! And so they shan’t be!
There are three major ones, plus more!
The way to remember this is that, in line with the subpar nature of hypokalaemia, everything is weak and low!
ST depression is a depression, so it is low.
The T waves have low amplitude, so they too are low.
The dip of the letter U, as in U waves, looks like the minimum point of a parabola, so it’s also low.
Conveniently, it all follows an alphabetical pattern: ST, T, U.
Without the heart, there is no mindless muscle bag to pump blood all around the body. That would, unfortunately, lead to death.
Fortunately, cardiology exists to cure, palliate and address issues of this important organ!
In this episode, Professor Chris talks about his work as a specialist cardiologist, why he campaigned for public defibrillators and the crucial contribution of being passionate about your work.
Podcast
About the guest speaker
Dr Chris Semsarian is a cardiologist and professor with a specific research focus in the genetic basis of cardiovascular disease. He trained at the University of Sydney, Royal Prince Alfred Hospital and Harvard Medical School.
Professor Chris was awarded a Member in the General Division of the Order of Australia (AM) on January 26, 2017 for significant service to medicine in the field of cardiology as a clinician, administrator and educator and to the community. He has a large number of other letters behind his name too: MBBS PhD MPH FAHMS FRACP FRCPA FCSANZ FAHA FHRS.
Professor Chris has published over 200 peer-reviewed scientific publications, in the highest-ranking cardiovascular and general medical journals. A focus area of his research is in the investigation and prevention of sudden cardiac death in the young, particularly amongst children and young adults. He has been the primary supervisor of over 30 PhD, honours and medical honours students since 2003 and led major community programs in the area of prevention of sudden death.
Music credits
Opening and closing themes by Lily Chen.
Medications don’t cure people. Acronyms do.
Well, maybe medications do a little bit.
Maybe.
Anyway, here’s how to remember how to treat acute heart failure in an examination setting.
Let’s explore the inner workings of the heart in a highly summarised form!
Tricuspid: right, which is commonly the dominant hand.
Mitral: left. The only bicuspid valve, as the other three heart valves all have three cusps or leaflets. In normal situations, anyway!
Let’s learn about a good friend: ACE inhibitors!
Renin (from those pesky organs called kidneys) turns angiotensinogen (also known as renin substrate) into angiotensin I.
ACE (whose full title is angiotensin-converting enzyme) turns angiotensin I into angiotensin II.
Angiotensin II has numerous magical properties: vasoconstriction, stimulating aldosterone release and more…so magical!
Angiotensin II normally clears bradykinin. When ACE inhibitors block that, bradykinin builds up and makes the person cough.
Aldosterone retains sodium and kicks out potassium. Take that, distal kidney parts! That’s where it acts.
Spironolactone, a medication well-known for its alluring gynaecomastia properties, is an aldosterone antagonist. It’s a potassium-sparing diuretic, which means it helps pass more urine without destroying the person’s blood potassium level to low, low amounts.
Let’s return to aldosterone itself, however. Aldosterone is like a vindictive, electrolyte-discriminating landlord that takes in sodium but evicts potassium from the rental property. It’s the excessively muscly security guard who stops that drunken, disorderly potassium from trying to enter the blood club.
Given the above, inhibition of aldosterone causes the opposite of its normal effects: not ejecting as much potassium from the system. Too much potassium is in the nightclub of your blood! That means hyperkalaemia!
Therefore, anything that stops the triggering of aldosterone creates a risk of hyperkalaemia.
But an ACE inhibitor stops angiotensin II from being formed! And that indirectly reduces the triggering of aldosterone that otherwise would have occurred! Hyperkalaemia might ensue! Chaos everywhere!
That explains one of the potential side effects of ACE inhibitors.
If an ACE inhibitor triggers this, the patient can be switched to an ARB, which is an angiotensin II receptor blocker. It achieves a similar effect without as much risk of the side effects of ACE inhibitors.
Well, well, well, ACE inhibitors. We’ve figured you out now!
Have you ever thought about dropping out of medical school? Have you ever felt that it’s all just too hard?
Perhaps it’s the night before your big multiple-choice examination. You suddenly realise that guessing C isn’t as solid a strategy as you once thought it was.
No! Your world comes crashing down.
You then do the unthinkable; you idly dream about how easy life would be if you were in some other profession. Wouldn’t engineering or law be nice?
“Oh! If I’d gone and worked in management consulting instead, I’d be rich by now!”
“I could have been a professional Morse code translator, but I chose to study medicine. I would have been so loaded if I’d done that instead of going through medical school for all these years.”
It’s not uncommon to hear people say things like this. The presumption is that life would have been just as successful, if not even more so, in some alternate leg of reality.
Unfortunately, the truth isn’t so simple.
Your unrequited love
Let’s talk about romance for a second.
The person you’re interested in, stalking or uncomfortably fantasising about performs some tiny action, like saying hello to you. What does that mean? WHAT DOES THAT MEAN?!
Nothing, really. But it becomes over-interpreted by a lot of people.
Even if you’ve been married for 40 years, you never fully know what another person is thinking. Despite that, many singletons will still resort to detective work, insisting on picking apart the complex signals that are supposedly being transmitted to them.
Example 1
Scenario: He or she texted you back with a playful emoticon.
Over-analytical interpretation: HE OR SHE IS JUST SO INTO YOU. HE OR SHE IS INTENTIONALLY USING PICTORIAL COMMUNICATION TO EXPRESS THIS DEEP CONNECTION.
Actual meaning: He or she texted you back with a playful emoticon.
Example 2
Scenario: He or she lightly brushed your hand.
Over-analytical interpretation: THERE IS NO WAY IT WAS AN ACCIDENT. HE OR SHE WAS SUBTLY DECLARING HIS OR HER UNDYING LOVE AND THIS MEANS HE OR SHE IS THE ONE. YOU SHOULD START PLANNING THE WEDDING NOW.
Actual meaning: He or she lightly brushed your hand.
The lesson
Event A having occurred means that Event A occurred. Anything else is additional inference at best or unfounded assumption at worst.
Medicine is your reality
In the same way, being a doctor does not automatically mean that you’re smart or that you could do any other job. Passing medical school means you were able to pass medical school. That’s a good achievement in itself, but it doesn’t explicitly prove anything more than that.
The difficult thing is that you can’t quite exist in two jobs at once; simultaneously being a doctor and a lawyer was what made the Crazy Cat Lazy start her cat collection.
It began with one.
And then it ended with many.
Because the what if? situation didn’t occur, it’s hard for anyone to prove you wrong. Maybe you would have been a great computer programmer. Maybe you wouldn’t have been. Maybe you would have been successful enough to invent Facebook before Mark Zuckerberg did. Maybe you would have been terrible, gone bankrupt and lived in a dumpster for 20 years.
You cannot accurately say that you would have earned a vast amount of money in an industry you never actually tried. You just wouldn’t know, because thinking in terms of what if? is not productive or real.
It’s entirely possible that the set of skills you have is best suited to medicine. It’s entirely possible that your personality works in internal medicine but would have been utterly crushed in financial planning. Even if medicine seems to be working out for you, you might well have drowned in some other industry.
Because really, maybe this is where you fit. Maybe this is where your best contribution to society lies.
So remain grateful that you managed to find a place in this great industry. Stay happy for this fit and the fact that it has worked out. Or is working out. Or looks like it will work out.
Health economics considers the best use of scarce medical resources and you, an individual, are still a scarce medical resource. You are special and unique. You snowflake, you. There is only one of you in this world and it’s wonderful that you’ve crawled your way into the industry you fit into.
This is in fact a once-in-a-lifetime opportunity. This is the reality that came true. This is where you belong, not in a world of second-guessing.
In learning the great art of medicine, you have been given an amazing privilege. If not for society’s sake, make the most of it for your own sake.
References
How To Win Friends & Influenza 