KC is a 79 year old man, presenting to the emergency room with chest pain radiating to
his left jaw.
His wife Jane, tells the admitting nurse that earlier in the morning, he had become short
of breath.
He felt nauseous, and light headed, before collapsing to the floor.
You see, KC was observing a yearly time change enacted by US Law, Daylight Saving Time, where
everyone in the country would set their clock forward 1 hour at 2am the second Sunday in
March.
Officially, the reason to do this is to save energy and boost the economy by increasing
the number of daylight hours during spring and summer seasons, but KC’s case is part
of a building body of evidence: this time change can negatively affect human health.
Immediately after setting his clock an hour forward, KC felt disoriented.
He had done this before for the last 45 years of his life, so there’s nothing different
on this Sunday in March.
He did have trouble sleeping that weekend because of the time change, though he didn’t
think too much of it.
But the next day on Monday morning, just before breakfast, KC suddenly felt his jaw become
stiff.
His chest instantly tightened up.
He gripped the armrests of his chair, because every breath he tried to take, was a struggle.
He didn’t want to tell his son downstairs, because he thought it would frighten the grandkids.
He didn’t want to tell his wife, because he thought she’d overreact.
He didn’t think this was a big deal.
At lunchtime, KC tried to lay down because he thought he could sleep this off.
But 20 minutes later, he vomited 3 times with no relief.
KC couldn’t take it anymore.
He could barely breathe anymore.
His wife found him collapsed on the floor as she called for 911, and he’s brought
to the emergency room where we are now.
Given this history of present illness, there’s a few clues as to what’s happening.
Chest pain with shortness of breath could be a problem of the lungs.
But it could also be a problem of the heart.
KC had a prior history of diabetes and asthma, which could be the main problem here, but
there’s more going on.
The medical team immediately draws some of KC’s blood, and they hook him up to an ECG.
Proteins and enzymes from his heart muscle were found floating around in his blood, and
the ECG confirmed the medical team’s suspicions: KC is having an ST-elevation Myocardial Infarction.
Myo meaning muscle.
Cardia from Ancient Greek referring to the heart.
Infarction from Latin farcire meaning to stuff into, and more modernly meaning a blockage
of blood flow, causing cell death.
Death of heart muscle, due to a blockage of blood flow.
And ST-elevation referring to the ECG reading that he has a specific change in the electricity
of his heart, meaning he is having a heart attack, which brings us to the next clue.
KC told the medical team that he was a type 2 diabetic.
This means that his body’s cells are resistant to insulin.
This is a hormone your body releases after you eat.
Insulin enables the shift of those nutrients you just ate, in to the cells, like sugar.
When the body doesn’t respond to insulin anymore, blood sugars stay high, because they’re
not going in to the cells, but also, the body starts putting out wrong signals because it
thinks that insulin isn’t being released, so it asks for more.
The body, thinks it’s starving and starts metabolizing fat stores in to the blood stream.
As these fats float around, some of them, get transported in to the liver, to make cholesterol.
All of this causing hyperlipidemia.
Hyper meaning high.
Lipid referring to fats, And emia meaning presence in blood.
High fat presence in blood.
This means these blood fats will start pooling in the vessels that supply blood to the heart,
called the coronary arteries.
The heart is a large muscle.
Big muscles are very oxygen hungry, so they need a lot of it to function.
Blocking the coronary arteries will starve the heart of oxygen, and cause parts of it
to die.
And in KC, parts of his heart, were starting to die, bringing us back to the name ST-elevation
Myocardial Infarction.
KC was at increased risk of heart attack to begin with.
At 79 years old, his heart has degraded over time because of normal wear and tear.
No one at 80, has the same heart as they did when they were 20.
But KC’s heart also degraded more because his diabetes means his body’s metabolism
can’t get his blood sugars right.
His body can’t get his blood fats right.
And his body can’t signal right with the correct hormones.
Fats start to pool in his coronary arteries.
This causes the smooth muscle lining inside the arteries, to die.
But it’s not done h ere.
White blood cells rush in to the site because they detect damage.
They start to engulf the dead cells of the artery wall, but they also engulf the fats.
And as more fats keep accumulating, these white blood cells start to die too [necrotic
core].
Smooth muscle cells start to make collagen and proteins, to cover up this dead necrotic
core.
This fibrous cap seals the area, and the plaque formation is complete.
But while this plaque can cause a heart attack by itself
,it isn’t always an ST-elevation heart attack.
ST-elevation means full blockage, meaning whatever is there isn’t just fat, but something
else too.
But what could it be?
Well, it would have to be something that’s already in the blood.
It could be more fat, but probably not likely since this is so sudden.
It’s not sugar because that’s probably not going to clump up in solution.
But speaking of clumping up, how about a blood clot?
This additional blockage can happen suddenly.
It can block the whole thing.
It can cause immediate changes in an ECG reading, that changes over minutes, as heart muscle
keeps dying from the lack of oxygen.
Without fresh blood flowing in, waste products from cells begin to accumulate.
The heart tries to compensate, but as each minute passes by, parts of KC’s heart keep
dying.
But why would this blood clot form?
Clots usually form when you get a cut, like on your skin, so did he get a cut inside a
coronary artery?
How would that even happen?
Well, the plaque is made of cholesterols, and white blood cells that died when they
engulfed too much fat.
The plaque is inflamed.
Inflammation is what happens like when you get a cut.
Diabetes put someone in a pro-inflammatory state.
The immune system expands the blood vessels so more fluid can flow in, and more immune
cells can enter the area.
The thing is, the chemicals released by the immune cells during inflammation in and around
the plaque, breakdown the fibrous cap.
The plaque ruptures.
Other blood cells think the vessel wall is injured, like a cut, and start clumping there.
This completely blocks artery very quickly, causing KC’s sudden heart attack.
So that’s the how of KC’s heart attack.
But why did it happen?
And what does it have to do with Daylight Saving time?
Well, it might have a lot to do with it.
This brings us to a concept called the circadian rhythm.
This refers to our body’s natural clock.
Science suggests that human circadian rhythms are based around sunlight.
So this directly ties our internal clocks with sleep.
This is why it’s harder to take a nap in the morning if you’ve been sleeping well
the past few nights.
It’s why many people feel gross pulling all-nighters and waking up at night time when
it’s dark outside.
And the sunlight hypothesis is why we think computer screens, which mimic daylight, keeps
us up at night and disrupts sleep.
There are differences between people in terms of their biological clock.
Some are early morning people.
Some are night owls, but the overwhelming majority of people show differences in the
activity in their bodies at different times of day.
In human experiments, we’ve found that sleep deprivation increases inflammation.
The average sleep duration in Western societies decreased from 9.0 to 7.5 hours in the last
100 years, and it looks like it’s decreasing still.
In that same experiment, scientists found that depriving someone of sleep, impairs their
insulin sensitivity and glucose tolerance.
More evidence from decades worth of studies show that night shift workers, that is people
who work overnights, do have a higher chance of developing diabetes and cardiovascular
disease over years if they keep working those tough shifts, due increased inflammation,
decreased insulin sensitivity and impaired glucose tolerance.
All three of these, were already a problem in KC because he had diabetes, but there’s
more.
Daylight saving time has been shown to disrupt human circadian seasonal adjustment.
On the second Sunday in March, most of the United States sets their clock forward one
hour.
This date, sits about a week and a half from the northern hemisphere spring equinox.
Right around this time, sunrise and sunset widen dramatically, which means our bodies
are already adapting to seasonal change.
But when an arbitrary one hour shift happens, it forces yet another change on our bodies.
This extra disruption in circadian rhythm significantly changes what genes are expressed
in the bodies.
It inflicts signal changes disrupting sleep, increasing inflammation, decreasing insulin
sensitivity, causing a cascade of metabolic derangements.
Some of the data shows that there is an increased incidence of heart attack in the days following
the 1 hour forward adjustment, in line with the scientific reason for why it happens.
Young people can tolerate these changes, but elderly with preexisting conditions likely
cannot handle this, which brings us back to KC.
As each minute passes, his chances of dying from his heart attack increase.
He’s immediately sent in to the hospital’s Cath lab.
This is a place where doctors can use imaging equipment to see the arteries and chambers
of his heart.
They send a small wire through a blood vessel in his wrist, to reach his heart.
They find the blood vessel that’s completely blocked.
A balloon is placed on the wire and through the blockage, and it’s inflated, popping
the blood vessel open.
A mesh called a stent is placed to help keep that artery open.
The stent also releases medicine that helps prevent scar tissue from forming at the site.
This process is called percutaneous coronary intervention, PCI and it’s part of something
called reperfusion therapy, meaning it helps get blood flowing in to the heart again.
So, cases like KC’s bring up a lot of issues.
Data does show an increase in heart attacks in the few days right after the 1 hour forward.
A Letter to the Editor in the New England Journal Of Medicine in 2008 wrote that in
Sweden, from 1987 to 2006, the incidence of all heart attacks increased in Spring Daylight
Saving Time, mainly in the first 3 days after the time change, and continuing for the week.
Interestingly enough, during the Autumn Time Change, where we go back an hour, incidence
of heart attack decreased in the days afterwards.
OK, that’s Sweden.
Their Daylight Saving time is later in March compared to the United States.
They’re in a different part of the world, on a different latitude.
How about data in America?
Well, the published data is more limited.
It’s mostly focused on Michigan,
they do show that there is an increase in heart attacks in the immediate days following
DST.
So the evidence that it happens, is there.
The scientific rationale that it happens, is there.
Going an hour forward just before the spring disturbs sleep quantity and sleep quality
in humans.
Altering this circadian rhythm, leads to increased activity of the sympathetic nervous system,
which directly affects the heart.
Metabolic derangements that mimic type 2 diabetes happen during this change, along with increased
inflammation.
For people at risk of developing heart attacks in the first place, all of these disruptions
can be that straw that breaks the camel’s back, and be that final blockage in the coronary
artery, causing a heart attack.
KC was allowed to rest after his PCI.
Days later, he was discharged.
Having an ST elevation Myocardial infarction puts his 30 day risk of dying between 2-3%.
His chances of presenting to the emergency room again in the next 30 days is max 25%.
But not missing his doses of his medicine, and trying to control his diabetes helped
him be in that 97% that don’t die after a successfully treated heart attack.
And it helped him be in that 75% of patients who aren’t rehospitalized.
So the point of this video is to tell you how a specific type of heart attack happens.
If you’re young, and healthy, you probably don’t have a coronary plaque.
It’s not just getting enough sleep, it’s also getting the right kind of sleep.
Slow wave sleep happens hours after sunset, between around 10pm and 1am.
You might miss out on this part if you sleep late, and miss out on the growth hormone that’s
usually released during this time, as dictated by the circadian clock.
Over years, if you don’t sleep well, and don’t eat well, and don’t exercise, and
you smoke, these will add up.
Human hearts deteriorate over time no matter what, but it’s in your control as to how
quick that decline happens, based on your habits and behaviors.
But no matter what, that one hour forward is throwing off hundreds of millions of people,
with what looks like minimal benefit, with harm for patients like KC.
Every year there’s a lot more entering that age 65 and up demographic because of the baby
boom generation.
Those are the ones who are gonna get hit the hardest by this.
I would prefer we stay on standard time all year, from a health standpoint.
With care from the medical team, diligence in keeping up with his medicines and staying
on top of his diabetes control, KC was able to make a recovery.
And thanks to my good friend, Cardiologist and YouTuber, Dr. Rohin Francis for reviewing this video.
Thanks so much for watching.
Take care of yourself.
And Be Well.