The ABCs of a Coronary Angiography – Dr. Chiam Keng Hoong

Source: phc.org.au

Picture: phc.org.au

An Introduction – What Is A Coronary Angiography?

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Picture 1:- A cartoon depiction showing potential areas where an access can be gained to start the procedure as mentioned above, radial Artery in your wrist and femoral Artery in your groin. Image source University of Ottawa Heart Institute.

Easy terms should be used when discussing any form of procedure with the patient, in particular when one is dealing with an invasive procedure. A coronary angiography is essentially a procedure which allows the cardiologist to mark out the location of blockages in one’s blood vessels of the heart (technically termed coronary vessels). This is done by using a live imaging X-ray coupled with a liquid contrast to light up the blood vessels of interest. This procedure assists the doctor to delineate the severity and extent of the occlusion thereby allowing him/her to decide on further forms of intervention. This terminology differs from that of coronary angioplasty in which a form of intervention conducted to relieve the occlusion of the coronary vessels through the insertion of a balloon or a stent. Both procedures can be done in one setting depending on the decision made on the day. I have omitted the various technicalities of angioplasty from this article as it is a totally different topic altogether.

Picture 2:- Cartoon depiction of coronary angioplasty where a balloon (L) and a stent (R) is inserted to widen the narrowed blood vessel. Image source; National Heart, Lung and Blood Institute & ADAM Images

Picture 2:- Cartoon depiction of coronary angioplasty where a balloon (L) and a stent (R) is inserted to widen the narrowed blood vessel. Image source; National Heart, Lung and Blood Institute & ADAM Images

The Indication of Coronary Angiography – Why Is It Done?

  • A positive exercise stress test – changes in the electrical recordings of your heart during exertion is an indication of potential blockage of the coronaries although such non-invasive diagnostic tools are incapable of saying how many or how severe the occlusion is.
  • A recent heart attack – depending on the risk scoring of the variant of your heart attack, your doctor should advise you for an inpatient coronary angiography
  • A recent heart attack – where conventional medical/pharmacological treatment has failed to relieve your chest pain and the electrical recordings of your heart fails to show any evidence of improvement.
  • A recent heart attack – where you present too late for pharmacological treatment in the form of a special blood thinner to remove the clot.
  • An elective screening tool prior to undergoing a heart valve operation if you are above 40 as the risk of heart attack increases during that time. A coronary angiography will help to determine the presence of an existing coronary vessel block that will aid the surgeons to do something for you for that blocked vessel during the open heart surgery. This would inevitably prevent you from undergoing a second open-heart surgery at a later date.
  • Symptoms of typical cardiac chest pain not otherwise explained despite undergoing all forms of non-invasive cardiac investigations to no avail.
  • An investigative tool for heart failure as coronary vessel occlusion or ischemic heart disease is one of the many (if not the main one) causes to a weak heart.
  • Recurrence of typical cardiac chest pain following years of your bypass surgery to determine blockages of the grafts (blood vessels used for bypassing the occlusion of original coronary vessels) and at the same time allowing the cardiologist to intervene as necessary.

The Technicalities of Coronary Angiography – What To Expect

Picture 3:- A state-of-the-art angiographic suite equipped with modern scanners, monitors and resuscitation equipment. Image source; Medgadget.com.

Picture 3:- A state-of-the-art angiographic suite equipped with modern scanners, monitors and resuscitation equipment. Image source; Medgadget.com.

When it is decided for you that coronary angiography is required, your doctor will often sit with you and talk to you about the procedure. At the same time consent is taken to allow him/her to carry out the procedure at a later date. It is at this time that jitters and nervousness start to haunt you so it is in your best interest to allow your next-of-kin to be present. Having this support will allow you a second pair of ears and also another brain should yours get clouded from anxiety. Do not be afraid to stop the doctor at any time should you have any doubt about the procedure which you feel require immediate attention lest you forget if left towards the end.

With the advancement of technical skills of currently available cardiologists, complications are minimized. Nowaways there are centers which offer daycare units for coronary angiography. This means that you could be admitted in the morning itself to a holding ward, get the procedure done on the same day, and be discharged later in the afternoon. This has allowed doctors to be able to do a higher volume of procedures which is able to benefit a lot more patients who requires both diagnostic and interventional therapy.

A typical procedure is described: Bloods for screening inclusive of assessing your kidney and liver function, blood counts, clotting profile, biohazard panels and sugar levels is done a week prior to the procedure. Your doctor will require you to fast from 12 midnight the day before this blood taking. When you arrive in the holding ward, you will be accompanied to your suite/ward/room upon registration. The procedure is explained to you again in brief before a needle is inserted into your left hand to allow the nurses to channel in the fluids to keep you hydrated throughout the day’s procedure. While this is all going on, your vital signs in the form of blood pressure, heart rate, oxygen saturation and temperature is taken and recorded. Your information is counter-checked to make sure that you are who you are i.e. no mistaken identity.

Picture 4:- A coronary angiography is being carried out. Operators are on the right side of the patient whereas the monitors are on the left. Notice the vertical arm of the scanning machine towards the back portion of this picture. They provide live image feeds to the computer monitors that you see in this picture. And also take note that you are covered from the neck done, exposing your head so that you can communicate with your doctor at any time during the procedure. Image source; The Wellington Cardiac Services.

Picture 4:- A coronary angiography is being carried out. Operators are on the right side of the patient whereas the monitors are on the left. Notice the vertical arm of the scanning machine towards the back portion of this picture. They provide live image feeds to the computer monitors that you see in this picture. And also take note that you are covered from the neck done, exposing your head so that you can communicate with your doctor at any time during the procedure. Image source; The Wellington Cardiac Services.

Below is what you would be expecting throughout the procedure:-

  • When your turn is due, you will be wheeled into the angiography suite whilst lying on your bed. You will then be aligned next to the procedural bed where the nurses would help you move across and atop to the specially designed platform. There would be several monitors on your left and a few huge arms attached to your bed with a control panel at the end of your special bed. You might be anxious and therefore the doctor may order sedatives to keep you calm throughout the procedure. The monitor records your vital signs and flash images to help the cardiologist in mapping out your coronary vessels, while the arm attached to your bed produces these images by sending out radiation at a fixed and safe dose. The control panel at the end of your bed helps another technician, often called a radiographer to swiftly change the direction of the arms so that various angle of your coronary vessels can be appreciated while the angiography is being carried out.
  • Your doctor will then cover you up from neck down using sterile drapes to keep the area clean after applying sufficient cleansing and sterilizing agent onto the site where the puncture is made. Another route aside from the blood vessel on the insides of your wrist (radial artery) is that of the groin region where the blood vessels (femoral artery) are considerably larger. Depending on the site chosen, the cleansing agent and the drapes is applied at the selected location. (See Picture 1)
  • A numbing agent – local anesthetic – would be injected at the site of puncture so you won’t feel any pain. A few seconds would pass before your doctor inserts the needle and starts the procedure of coronary angiography.
  • A long guide-wire is then inserted through the needle-hole. The wire is guided to the heart. Through gentle maneuverability, the wire is anchored onto the coronary vessels and a liquid contrast is then injected to light up the blood vessels like a Christmas tree.
  • Depending on the majority of cases, the procedure will last anywhere between 30-45 minutes for diagnostic purposes. Interventional procedures are often more complicated and can take a longer duration, sometimes even more than an hour.
  • It is worth mentioning that throughout the whole procedure you can converse with your doctor. Some discomfort and occasional palpitations might be felt during the procedure and some patients report some form of burning sensation over the chest when the contrast is injected. These symptoms are self-limiting. During the procedure, you may be asked to breathe in deeply, cough or adjust your arms to assist you doctor in the technical aspects of the procedure.
  • Another separate team sits outside the room charting down the step-by-step procedure, observing your vital signs and alerting the cardiologist as to any concern the latter may have overlooked. Such double-checking mechanism is a form of a failsafe protocol to maintain patient safety and prevent complications from happening.

Complications

Local – pain, bleeding and bruises would be expected from the puncture site and occasionally, slight swelling can happen. These are often self-limiting and will go away in a week or so.

Other systemic complications include:

  • Heart attack (less than 1 in 1000 patients)
  • Stroke (less than 1 in 1000 patients)
  • Tear to your major arteries of your heart
  • Irregular heart rate and rhythm
  • Allergic to the liquid contrast
  • Damage to the kidneys due to the liquid contrast
  • Infection at site of puncture
  • Radiation exposure

Although reading through these complications may raise some concern, patients should be reassured that such risks are extremely rare in elective situations rather than emergency ones. As patient safety is of the utmost priority, your cardiologist and his team members will monitor for early signs of complications and avoid them. Should any problem arise the procedure would be halted.

Do inform your doctor should you feel any discomfort during the procedure. The manipulation of the wires inside your blood vessels shouldn’t give rise to any tingling sensation or pain. With a normal kidney function, the chances of damage is highly unlikely. Advances to contrast development have allowed kidney failure patients to undergo coronary angiography without significant further damage or deterioration to their residual kidney function. In terms of allergic reaction, your doctor should be informed prior to the procedure itself.

Results

Picture 5:- How a coronary angiographic film looks like.

Picture 5:- How a coronary angiographic film looks like.

These will be made available to you immediately. Your cardiologist is often by your side the moment you are wheeled out from the angiographic suite. He/she will talk to you and/or your next-of-kin regarding the findings and explain the best management in light of the results and include either oral medications, coronary angioplasty or bypass heart surgery.

After procedure

It is best to avoid from carrying heavy objects with the hand which was used to puncture the blood vessel and should it bleed again, you should return immediately to the hospital.

Conclusion

In conclusion, coronary angiography, is practically a safe procedure with minimal risks.

Dr. Chiam Keng Hoong is an internal medicine physician and a MRCP holder. He currently works in Sabah.

References

  • Morteza Tavakol MD et. al; Risks and Complications of Coronary Angiography: A Comprehensive Review; Global Journal of Health Science; Vol. 4, No. 1; January 2012

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