Today was the first day of my cardiology rotation, so this morning Arthur and I observed Dr. Huang (a cardiologist, not the same Dr. Huang from the pulmonology rotation) perform 2 cardiac catheterization procedures.
Cardiac catheterization is a medical procedure that is performed in order to diagnose and treat some heart conditions. A catheter, which is a thin and flexible tube, is inserted into a blood vessel and then threaded to the heart. In Asia, including Taiwan, and Europe, transradial catheterization is the more popular method (using the radial artery for cardiac catheterization). According to Dr. Huang about 90% of coronary angiograms are done by this method in Asia. In the United States, the femoral artery is the primary method of arterial access for this procedure because the femoral artery is a larger vessel and provides a more direct route to the heart. However the radial approach is gaining popularity in the United States (http://emedicine.medscape.com/article/2039370-overview). Advantages to doing radial artery catheterization include patient comfortability (patients can move around right after the procedure) and reduced access-site complications- minimal bleeding, less risk of of injury to nerves, faster recovery. Due to the size and superficiality of the radial artery, it is easily compressible, and therefore bleeding complications are rare. In contrast, cardiac catheterization via the femoral artery carries a greater risk of access-site bleeding complications; occurance of hematomas and pseudoaneurysms are more common and painful complications that are usually not associated with transradial cardiac catheterization. Since more radial artery cardiac catheterizations are being performed in the United States, I wonder if it will become the primary method of access in the future.
The first patient had a PMH of diabetes mellitus and coronary artery disease. Last year, an intervention (stent in LAD, left anterior descending, artery) was done and he came back to the hospital because he was experiencing chest pain. During the procedure, it was found that there there was re-stenosis in the LAD. The stent in the proximal portion of the LAD was opened and another stent was placed in the middle portion of the LAD because there was vessel dissection. Because this patient could not afford a drug-eluting stent, a bare-metal stent was used, which only provides symptomatic relief for about 6-12 months. After the procedure, Dr. Huang told us that bypass surgery would be the best option for this patient, however, the patient had previously declined this surgery. Dr. Huang will bring up the topic of bypass surgery with the patient again. Immediately after the procedure, the patient and a family member had a discussion with Dr. Huang, and he showed them the images that were taken during the procedure. I could see why patients would prefer the transradial access method because right after the procedure, patients are able to get off the table and sit in a wheelchair so that they can talk to the doctor.
Between the 2 procedures, Dr. Huang brought us into the procedure room to show and explain to us the equipment that was used, which included:
-sheath with a one way valve
-diagnostic catheters (one for the RCA and one for the LCA)
-intervention catheters
-wire (balloon and stent are brought to the correct position via the wire)
-gauge for balloon dilation
-balloon and stent
The second patient had coronary microvascular disease and his angiography was normal. Dr. Huang also checked the systolic function of the left ventricle, which was normal. A vasodilator will be prescribed to the patient. In order to improve microvascular circulation, there should be risk factor reduction and vasodilator use. Once again, right after the procedure, Dr. Huang talked to the patient and a family member and showed them images from the procedure.
Even though many procedures are covered by the National Health Insurance (NHI), apparently there are certain procedures that not covered and must be paid for by the patient. It is for this reason that the patient did not elect to use the drug-eluting catheter, which was developed to reduce the high risk of re-stenosis. The bare-metal stent will only last for a short period of time and the patient will once again have to return for another procedure. So even in one of the better health care systems in the world, it appears that there still exists inequities in access to health care.
I am looking forward rotating with the cardiology department this week because I am hoping to strengthen my knowledge regarding the diagnostic imaging techniques used in cardiovascular disease.
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