Invasive Cardiology Procedures
Invasive cardiology is one aspect of the assessment and treatment of people with suspected cardiac problems and
complements the non-invasive assessments that can be undertaken by Echocardiography, Cardiac CT, Nuclear Medicine
and Cardiac MRI.
Invasive cardiology procedures require the insertion of a device into the body to allow us to gain more information
about a range of medical issues that may be affecting a person.
That device can be something as simple as a tube or as sophisticated as a miniaturised ultrasound probe small
enough to be used inside the coronary arteries. Because we are putting things inside the body these procedures
do have a small risk, and as such are often used when non-invasive tests do not give a conclusive answer or
when there is a high suspicion that a patient requires a procedure such as a stent or is likely to need bypass
surgery. I always discuss with patients the approach that is best suited to them and any particular issues
that are specific to them, but below is a very brief overview of some of the procedures.
Coronary Angiogram
This test allows us to visually assess the coronary arteries that supply blood to the muscle of your heart.
It is narrowings and blockages in these arteries that cause chest pain when you exercise and a sudden blockage
of an artery causes a heart attack. To perform the procedure a small tube is inserted via the artery in the
wrist or at the top of your leg and a special type of dye that is only seen by an x-ray machine is injected
directly into the arteries. If the procedure is performed by an interventional cardiologist and a narrowing
is identified it is often possible to carry on directly to performing a treatment at the same sitting.
Pressure Wire
Sometimes we cannot tell from our visual assessment of the artery how significant a narrowing is and to give us additional information I may insert a wire into the artery to
measure the effect the narrowing is having on the blood supply to your heart. This way I can refine your treatment and avoid the risk of placing unnecessary stents. This
procedure is performed usually directly after coronary angiogram and requires a slightly different tube to be inserted and the use of a medicine to get an accurate reading.
The medicine used gives a strange sensation for the 2 minutes that we use it for.
Intravascular Ultrasound and Optical Coherence Tomography
These tests are used less frequently as an individual test but are often used as part of the procedure of inserting a stent or treating a heart attack. They involve passing a small device inside the coronary artery to give very detailed images from inside the artery. In IVUS (Intravascular Ultrasound) this is a tiny ultrasound probe and in OCT (Optical Coherence Tomography) the probe emits light that is similar to infra red and gives us slightly different information. They are used to look at the cause of heart attacks, to judge the correct size of an artery or stent and to check that a stent has been inserted as well as possible.
Angioplasty and Stenting
If you have a narrowing in your artery then a decision about the best treatment has to be made. For some patients this will be a treatment
based primarily on prescribing medication, for others it means bypass surgery or treatment by placing a stent in the artery. The appropriate
strategy varies from patient to patient and you will be guided through this, particularly if there are multiple options. My expertise lies in
performing coronary angioplasty and inserting stents. Coronary angioplasty is the stretching of an artery with a balloon that is passed into the artery in the heart all
the way from the artery in the wrist or the leg in a similar manner to the way a coronary angiogram is performed. Coronary angioplasty is just the stretching of the artery
with a balloon but in almost all cases this is followed by the placement of a tiny metal scaffold inside the artery. Angioplasty and stenting do not require a general anaesthetic
and recovery is usually very quick with you able to leave the hospital the same or following day.
Drug Eluting and Bare Metal Stents
You may have heard about drug coated stents and bare metal stents, in the majority of cases I use a drug coated stent
but occasionally it is better or only possible to use a bare metal stent. The drug coated stents reduce the likelihood of a treated area becoming narrow again compared to the bare metal stents. Between 2006-2008 there was concern that these stents had
a higher risk of becoming blocked by clots, this risk was much debated over the coming years but with the newer drug coated stents the risks are very small and in some cases seem better than some of the bare metal stents.
This is not something that I usually discuss at length with patients
but I know there has been a lot of conflicting media attention so if it is of interest or concern please ask me to discuss it with you.
Rotablation and Laser
Rotablation, also sometimes called rotational atherectomy and laser are procedures that we occasionally employ to help in preparing an artery for the placement of a stent. Rotablation uses a diamond tipped burr to remove hard chalky deposits of calcium from some peoples arteries that would otherwise prevent us from stretching the artery or placing a stent. It has a slightly higher risk than a standard stenting procedure but is used in cases where placing a stent without it would either be risky or likely to be unsuccessful. This allows us to treat patients with symptoms who we could not otherwise treat adequately. Laser is much less often used, but uses a laser inside the coronary artery to perform a similar role helping to prepare an artery for placement of a stent.
CTO - Chronic Total Occlusions
This refers to arteries that are not just narrowed but completely blocked and usually for a long period of time. Whilst simple measures often can successfully lead to a stent placement,
treatment of these arteries requires different skills and is a more involved procedure that may require a greater amount of time and
devices to successfully treat. If we find you have such a problem we will not usually be able to treat it right away but will discuss in detail the pros and cons of the different approaches.
