Online CPR Certification Blog
A cardiologist explains about vascular disease screening
Date: February 5th, 2014
Just a few days ago, there was a full page ad appearing in a newspaper for several medical screening tests– echocardiogram, EKG and aorta ultrasound among others. ‘Certified doctors’ interpreted all these tests which you can arrange for a loved one or yourself. Newspaper readers were informed that they can arrange to have the tests done provided they were ready to meet the cost on their own. There were even testimonials sourced from lucky survivors where proactive testing helped them save their lives.
Those purveying the imaging clinics are simply searching for people without any particular symptoms but are anxious about having an occult disease in their bodies. Typically, no insurer can sport such tests unless your doctor notes some symptoms that require you to go for the test.
This seems to be like a bargain. With some hundred bucks, you will either have the much desired peace of mind or the early detection could help save your life. However, before you make up your mind, let’s have a look at a very common test.
Carotid Doppler ultrasound
CDUS or carotid Doppler ultrasound is test aimed at detecting blockages in neck arteries which supply the brain with blood. High grade CAS/ carotid artery stenosis is one of the risk factors for stroke. CDUS is one of the critical parts in evaluation of patients who have suffered a transient ischemic attack or a stroke. However, what happens to people without numbness, slurred speech or weakness. A little research about this subject can help you understand about the whole thing in a much better way.
Out of 1000 asymptomatic people aged above 65 years in US, just about 1 percent of them have significant CAS. This is defined to be a narrowing that is more than the 70 percent of the vessels diameter. As such, for 1000 people screened, we will only be looking for ten patients.
What makes CDUS a less perfect test?
There is no doubt that CDUS isn’t really a perfect test as such mainly because it over-diagnoses some people while under-diagnosing others. False positive results occur when CDUS suggest a blockage which is really not there and false negative implied that the CDUS wasn’t able to detect blockage while the individual has a significant narrowing. Sensitivity and specificity concepts are used for quantifying the accuracy of the diagnostic tests. In real life, it is very hard to say if or not you get screened.
Talking in terms of the ‘populations’ is one thing that is different from discussing you personally. For at high risks forces especially if you are a smoker or have high cholesterol or high blood pressure, you have a considerably high possibility of getting a stroke and CAS. In such a case, spending your money in getting screened is something that you should really consider.