Coronary angiography: What is it? What to expect.
A typical C-arm used for angiograms
What is a coronary angiogram?
During a coronary angiogram, a long tube called a catheter is threaded up to your hear via a groin, wrist or arm approach. Contrast dye is then injected under fluoroscopy (live x-ray) and recorded digitally.
The admitting and pre procedure process
I'm going to give a rundown on what a patient is to expect during their stay at the facility I work at. This hopefully will give you a better understanding of what your hospital stay will entail.
The night before the procedure we ask our patients to remain NPO, (Non per os) In other words no food or drink after midnight. The reason behind this is some of the medications given for sedation could make you nauseous and there is a possibility of vomiting during the procedure. Once in the hospital, patients are admitted and given a bed in our short term telemetry unit. Upon arrival in this unit, patients are asked to undress and put on our lovely hospital gowns, everyones personal favorite. The normal pre procedural questions are asked, what type of meds are taken daily, allergies etc. (These questions will be asked by numerous staff members, not that we dont read the chart, more of a confirmation of who you are and what you are there for.) After obtaining a baseling ECG (ElectroCardioGram) and blood pressure, the second semi uncomfortable portion begins...the groin prep. We shave either sides of your groins, for several reasons.
1. This is where we access your common femoral artery, the artery we mostly use to put our sheath in, more on that later.
2. Our sterile drapes have 2 holes, one for each groin, both of these openings have tape to hold them down to you body. When the procedure is completed these drapes come off, if there is hair in this region it comes out in a very painful fashion.
3. Steriliity, hair is a major source of infection, and infections in the groin region are very unpleasant...I assure you.
Patients will also typically have 2 I.V.'s placed. We use these I.V.'s during the procedure to give you various drugs throughout the case. A normal saline solution is typically connected to one I.V. to keep the patient hydrated and as well as the line patent. Once these steps are completed you are ready for your procedure. A side note, if your scheduled time has gone a little or sometimes a lot over, don't worry. In the cathlab we handle emergencies 24/7 and if a patient comes into the E.R. activly having a heart attack they take precedence over scheduled cases for obvious reasons.
The monitor boom in a cathlab
You're off to the cathlab
So you've made it this far and now its time to go. Our patients are taken via stretcher to our cathlab, once in the lab you will notice something immediately...It's FREEZING! No we don't do this to torture our patients, we do this for mainly 2 reasons.
1. Bugs dont like the cold, like I had mentioned previously we are always are of a possible infection, though extremely rare they do happen.
2. Our machinery, the C-arm as we call it, is the machine that produces our live image x-ray. This guy produces major heat, actually 99% of what comes out of the x-ray tube is heat, leaving only about 1% x-ray.
Once in the procedure room, we will ask you to shimmy on over to our table. This table is made up of composite that is both radiolucent meaning x-rays can pass through it, so we can see that beautiful heart of yours and lightweight so we can float the table around for positioning. The next step will be hooking up our monitoring equipment. This includes ECG, blood pressure, and a little doodad that goes on your finger that measures your oxygen saturation. We also always use a little supplemental oxygen, the reasoning is we want you to keep breathing, some of the sedatives we use can slow your respiratory rate and we want to be able to watch that.
Now the prepping and draping begins, we place a small sterile towel in between your legs, keeping you covered but still allowing access to your groin region. In our facility we use an alcohol based cleaner that sometimes may sting a little downstairs, but typically I hear no complaints. Once the solution dries, we place a large sterile drape over you...the special drape with the two fenestrations I had mentioned previously. At this point, the scrub tech or nurse will be setting up the manifold, the contraption we use to inject both saline and contrast (x-ray dye) into your arteries, it is almost go time.
ECG, heart rate/rhythm, aortic blood pressure on our monitoring screen
The Doctor is in, showtime!
Once prepped and draped the good Doctor is paged. When he/she arrives they scrub their precious hands and we begin. Once gowned and gloved the physician will administer some local anesthetic, much like the dentist does, but not nearly as painful or scary. Having assisted or monitored close to 6,000 of these procedures the consensus it, the dentist is much worse. We then gain access to the common femoral artery and place a small sheath into said artery. The sheath is approximately 1.3 mm in diameter, so it only requires a small knick in the skin. Once the sheath is in, the painful part of the procedure is over. Through the sheath we pass catheters with specific shapes up through the aorta and cannulate the left and right coronary arteries. The left coronary artery divides from a main artery that is referred to as the "left main" into the left anterior descending "LAD" and the circumflex artery "CX." The LAD feeds the front wall of your heart and the CX feeds the lateral or side wall of your heart. Once we inject dye and obtain our angiogram we exchange for another catheter designed to fit into the right coronary artery or RCA. The RCA feeds the back wall or posterior portion of your heart. After we have taken the images of the coronaries we exchange for our final catheter of the diagnostic procedure affectionately known as the "pigtail." The pigtail is designed to pass through your aortic valve into your left ventricle. Once in the left ventricle we record pressures and take our final angiogram, the ventriculogram. This may be the only portion of the test aside from the sheath that you feel, as the catheter tends to cause some skipped heart beats or PVC's (pre ventricular contraction's.) Don't let this alarm you as it is a normal portion of the exam. We then inject contrast dye into the left ventricle to measure the pumping function of your heart. This particular injection you will mostly feel in the form of a warm sensation throughout your body. Once the warmth subsides which it will in a few seconds, we pull the catheter and the diagnostic portion of the angiogram is completed. There are several possibilities that happen here, for sake of this article we will pretend the coronaries are "clean" or negative for coronary artery disease CAD.
Shapes of the most commonly used catheters, you can see the obvious "pigtail cathether"
Procedure is over, now what?
Once the procedure is finished, at least in my facility, the patient is transported back to their room with the femoral sheath still in place. Once back in the room, the nurse or patient care tech, pulls the sheath out and manual pressure is held for around 20 minutes. After the sheath is out, the patient then remains flat for approximately 4 more hours, so that the arteriotomy (hole in the artery) has completely closed. Once the 4 hours is up, we slowly get you up and walking around the hallways. When were positive all is well and good, we give you discharge papers and away you go.
It's not that bad, right?
All in all this is a very safe and relatively pain free procedure. Where as this procedure is completely routine to me, it's not for you "the patient on the table" and I respect that and personally try to alleviate anxieties with answering any questions I can. This segment was strictly dedicated to the "normal" or "negative" heart cath, if disease is found we have to think about other options, these include angioplasty/stenting, medicines, or bypass surgery. My next hub I will go into all of the options in depth. I hope you find this hub informative and hopefully answers some questions you might have had. Always remember the best patient advocate is the patient themselves.