I often hear stories of a guy who has a heart attack and come to find out that 95% of a major blood vessel to the heart was clogged.
How is this not picked up earlier during normal exams? Why isn’t it?
Can’t they do radiation shots to see where the blood flows or whatever?
In: Biology
There are two techniques, and both have a somewhat subjective aspect to the analysis.
The less invasive test is to put technicium 144 in your blood and then use a gamma-ray imager to create a 3D plot of your blood vessels. The procedure takes about 90 minutes and is often done in the cardiologist’s office. An expert then examines this plot to see if there is any blockage or pooling. No matter how skilled the expert, every person is different and may or may not have the “textbook” veins and arteries, so there is room for interpretation.
The other procedure is to put a catheter into a vein, generally from your groin but modern techniques can now do it through your wrist. The catheter can be steered as the vein branches. There is a real-time xray (flouroscope) as a die is injected and the dr. determines if the vein is suitable for blood flow. If not, an inflatable stent is inserted while the catheter is in place. At one point the die is injected into your heart and the dr. views the (one) heartbeat action to see if there is any trouble; it’s about 2oz of die delivered by a power-driven syringe. Everything is video taped. This procedure is outpatient but generally in a hospital or 3rd-party cardiology facility, and lasts a little over 4 hours. Go in after lunch, go home for dinner.
Tests cost money, and unfortunately with chronically understaffed facilities and overpriced everything the goal of most doctors is to get each patient out of the door as soon as possible. Basically, unless there is serious reason to suspect a problem, you won’t be referred to tests and exams just as a cautionary measure. This means that for a lot of people, the early stages of a serious condition go unnoticed until much later.
There is also the fact that people themselves usually aren’t thrilled to go to doctors so they might not be as diligent with their checkups.
A rule of thumb in medicine—don’t order a test if you’re not going to to do something about it. The problem w/ general screening exams w/o symptoms, the risks of diagnosis usually outweigh benefits (there are some exceptions like colonoscopy, mammogram, pap smears, CXR in smokers). In the case of asymptomatic atherosclerosis, no cardiologist worth their salt is going to stent a patient w/o symptoms.
Things like calcium score CT’s are used to risk stratify patients, like whether they should take aspirin or Statin
I also wish there was an affordable way to check for clogged arteries.
My story:
62M Asian
Fairly active my whole life (former pro skateboarder, avid road cyclist, hiker)
5′ 9″, BMI 25, no smoke, vape, drink, drug-free
Statins every day for past 27 years
Family history of cardiac disease
May, 2023: Out of breath at top of third floor stairs. No chest pain. Just out of breath. Doc visit just in case. No imminent heart attack determined.
Blood panel normal. Cholesterol 127 mg/DL
June, 2023: CT Scan shows calcium build up in all three arteries. Coronary Artery Calcium (Agagston) score: 3500+. Severe is 300 or higher. Yeah, 10X. Genetic.
August, 2023: Treadmill stress test. Did pretty good for for my age at 12 minutes. Max 170 bpm. Ultrasound video showed evidence of prior mild heart attack. I don’t remember that at all.
Sept, 2023: Stent #1 successful. 80% now 0%
Oct, 2023: Stent #2 successful. 80% now 0%. No stent needed in third artery after roto-rooter.
Feeling 1000% now but it all started with being out of breath and seeing a doctor out of an abundance of caution.
Lesson: Go see your doctor if you suspect anything.
Live long, live strong.
The test to check for this type of blockage in the heart carries some risks and requires a specialist doctor and technology, it is also in very high demand for people who are already having severe blockages and experiencing pain when they try to do daily things, or who have a sudden blockage (a heart attack)
In my area it may be a 2-3 month wait to get this type of test done in a non-urgent manner, and you may wind up getting bumped because someone more urgent or who is having an active blockage needs that doctor and that equipment.
There are other tests that can help predict this issue, but they aren’t as reliable or clear cut as the more dangerous, invasive procedure used to directly examine and image the arteries and blood flow to and within the heart.
Because its not worthy. Its a lot of work and resources which don’t give an accurate result except if you know what you’re looking for, and have real consequences like irradiating the patient.
My father-in-law had open heart surgery for a double bypass and the doctor mentioned afterward that they could feel a big chunk of hard plaque in another artery.
Someone asked if they removed it or did anything, and the doctor just stopped and stared at us.
Like it was the dumbest question ever.
He explained it was such a delicate surgery, and he was in such a precarious situation, it could have killed him to cut more and interfere. Apparently it’s not that easy to remove.
But we got a few more years with him, he got to see his grandchildren who were both born after that surgery.
They DO do radiation scans. One that is done fairly commonly on older men or those with other risk factors is called myocardial perfusion imaging. Also known as a cardiac stress test.
They use a generator (casually called a “cow”) that has a core of molydenum-99, a radioactive isotope, that decays at a known rate into metastable Technetium-99 (Tc-99m). Tc-99m is non-toxic, has a low activity (is not super radioactive), and a nice short half life of about 6 hours. So it will die down to below background level fairly rapidly (rather than stickinga round inside you exposing you to radiation). This makes it ideal for use in a lot of nuclear medecine scans. You periodically ‘milk’ the generator to get the Tc-99m, then combine that with various other compounds to create different types of imaging agents for different scans.
For myocardial perfusion imaging they will mix it with a drug called Cardiolite (or some other generic or equivalent), which is designed specifically to bind to only heart muscle tissue. So the idea is you take the patient, give them this injection, then put them in front of a gamma camera (that can detect the radiation the Tc-99m emits) and put them under some amount of cardiovascular stress (typically running on a treadmill, though for some patients they may sue an adrenaline dose to mimic the same response). Anywhere in the heart that is getting good blood supply will glow in the gamma camera (because the cardiolite-bonded Tc-99m will end up sticking there). Anywhere that is NOT getting good blood supply will be noticeable from the lack of gamma emission.
they have similar scans for all sorts of physiological processes (white blood cell labelling with indium for finding infections, kidney scans, gallbladder scans, etc etc). The cool thing about nuclear medicine is that unlike most other forms of medical imaging, it doesn;t just show anatomy, it shows physiology and metabolism. You can directly image not just the physical structure of the body, but also its actual biological and metabolic functioning.
Medicine isnt prevention, it’s reaction. It’s up to you to take care of yourself (which is a bit dumb).
I’m a nurse and I have worked in both the cath lab and the coronary care unit looking after the patients before and after.
One of the reasons that have not been mentioned here is availability. We have so many patients either having a time urgent heart attack (stemi,) a non urgent heart attack (non stemi) or chest pain that is suspicious that Cath labs are booked out. Heck COVID did not even slow down Cath labs.
We just don’t have the resources to blindly screen every one, so we limit to either heart attacks, and people with multiple risk factors that we feel is highly likely to have blockages.
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