What is QT? (Yes yes, it can be your texting shorthand to get your groove on)
QT refers to the interval on the electrocardiocgram, in milliseconds, between the START of the QRS complex to the END of the T Wave
(as the graph shows, if you wanna be super fancy, we calculate the end of the T wave by intersecting the maximum slope with the isoelectric baseline)
Why is QT important?
It is the electrical approximation of the time it takes for the ventricles to contract and relax
If the QT is too long (or short, think hypercalcemia and be careful, but we'll address this later), there is a risk for ventricular dysthymia and sudden death.
Long QT can lead to Torsades de Pointes (literally "twisting of the peaks"), which looks like a ventricular tachycardia rotating (like a helix).
TdP spontaneously and quickly reverts to normal rhythm, but it is likely to return & can lead to ventricular fibrillation and death.
So then what is QTc?
Well because rate will affect all intervals, it is necessary to adjust for rate to detect clinically important QT. With a fast rate, a shorter QT might be important, so you don't want to miss it. Conversely, you can tolerate longer QTs with a slow rate.
QTc is calculated by three main formulas. There is debate over which is best... but most of the cardiologists I respect tell me the Frederica formula is probably the closest.
1) calculate: RR interval in seconds 2) cube root that 3) use that number as the divisor of the QT
Example:
HR is 80bpm (RR = 60/HR = 0.75)
QT is 425msec
The cube root of RR is .9086
QTc=425msec/.9086=468 msec
So you have your QTc, now what?
1) please do your best to understand how your QTc will be calculated. Many machines that calculate it automatically will give you the Bazetts Formula (square root not cube root), which overcalls prolonged QTc at faster rates.
2) have your yellow/red zone set:
♀️:
caution: 450-460 msec
uh-oh: 460+
♂️:
caution: 430-450 msec
uh-oh: 450+
3) know your medications effect on QT!
The most FAMOUS psychiatric meds that prolong QT are antidepressants, but MOST DO NOT (except citalopram, escitalopram, and TCAs like amitriptyline)
The meds you need to be really careful about? ANTIPSYCHOTICS AND METHADONE. (No, not ADHD meds)
Lurasidone is so far the only "OK" antipsychotic for QT prolongation.
Methadone can increase QTc by more than 20s.
So ECG for all potential QT starts (*citalopram, TCAs, APs)?
I'm on team "yes." It's far higher value than the stupid MRIs and TSHs we order (brainlessly w/no benefit) and if a problem occurs, having a baseline ECG will be of huge value.
I'd also monitor regularly anyone who:
So please , learners, physicians, and psychiatrists, consider QTc knowledge as an important part of your medical practice, especially when you prescribe medications.
Also, when in doubt, work with your pharmacy colleagues to check interactions/additive effects.
/End thread
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Talking to kids when they're struggling🧵
For parents (or anyone who cares for kids!)
It can be really scary to notice something in your kid & be worried suicidality/self-harm.
How do you approach kids?
I've had this conversation >10000 times so I have some tips!
Be CALM
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CALM is a memory-trick to remember the key concepts of communicating to a struggling kid but also to remind you to be in control of your own emotions. If you are prepared, you will defeat your initial instinct, which will be to FREAK THE BLEEP OUT!
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First, COOPERATE!
You & your kid are a team, and you have a common goal: their present & future wellbeing. Don't set yourself up as the security guard, jailor, punisher, or antagonist. Don't push. Don't pull. Be alongside them, tell them you're willing to walk with them.
A recent study looking at >2M Americans presenting to ERs with MH concern shows the difficulty of "predicting suicide" - we can't predict suicide to help guide important clinical decisions.
The problem: Sensitivity vs PPV
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They used machine learning EMR-coded variables (outpatient visits, medications, previous appointments, age, etc etc) - you can see the entire dictionary used to "predict" here (word doc):
They had 2,069,170 ER visits and 899 suicides within 90 days.
After running the model and letting machine learning do its thing, the best fit had the following predictive properties at the 95% percentile cutoff of risk:
Debunking Antivaxxer Tropes:
"Antivaxxer is a slur" 🧵
Many many many accuse me of using a "slur" when I say "antivaxxer". It is a twitter shorthand for sure, but it is not a "slur", and I use it without regret or remorse.
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I certainly believe that if one is an "anti-vaxxer", they are not using science, reason, or reality to understand vaccines.
& I note a distrubing trend in antivax and some concerning other beliefs.
That being said, when I say antivax, I only mean "antivaccine belief holder"
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Check out my "antivax misinfo" threads. Someday take a look at the "hidden replies" & note that the antivax profiles are quite.. well.. recognizable.
Note: Do not assume every "Antivaxxer" is, I just notice the trend. As do many of my colleagues here space fighting misinfo.
Debunking Antivaxxer Myths
"🇪🇺 Vaxxed Countries have higher mortality"
No, they don't.
This is COMPLEX:
a) countries had different PRE-VACCINE infection (offers more dangerous protection than vax but indeed protection). Obv, vaccination NOT correlated with pre-vax death.
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b) The FIRST VACCINATION SERIES against OG COVID was phenomenally effective at preventing infection, transmission, illness, hospitalization, and death (VE >80-90% in all).
This is clearly evident by one of the most striking correlations you'll see!
COVID deaths vs Vax:
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And because COVID was the primary driver of excess mortality in 2021, excess ALL CAUSE mortality was almost identical to COVID MORTALITY.
He presents data to scare people into believing that vaccines have caused harm, & he continuously is on the bandwagon that C19 vaccines cause cancer. This is contrary to the damage.
Here, he's using a report using 1998-2019 data.
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In fact, there was such a DROP in incidence (assumed to be due to lack of access to health care) in 2020, that they had to amputate the model at 1998-2019 so that it wouldn't project a decrease! (a reasonable thing to do!)
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In their report, they clearly show that their trending is based off of models that ONLY end at 2019. ZERO PERCENT of this report is suggesting, implying, or reporting that vaccines have led to an increase in cancers.
He will have a huge platform & can say what ever he wants as long as there is right wing grift.
He is a licensed professional being held standard.
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It is against his license to publicly suggest to die by suicide.
It is against his license to publicly & intentionally call physicians 'criminals,' people "not beautiful" or "appalling self-righteous moralizing things."
His license prohibits misgender people intentionally.
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The standards of his college are publicly available; including social media. By being licensed, he represents his college and the profession, and that college/profession gets to have a say in how they are represented.