A brief history
Before elaborating on this invasive procedure, it may interest some readers to know about the genesis of cardiac catheterization. A catheter is a medical-grade tube (catheter) inserted into the wrist or femoral artery (groin area).
Reportedly, Stephen Hales placed a catheter into the right and left ventricles of a horse in 1711. Over the next one hundred years, the technique evolved, culminating with the study of cardiac physiology by Claude Bernard, a French physician, in 1840. In 1927, Portuguese doctor, Egas Moniz, performed a cerebral angiography. Dr. Moniz was able to view the brain vasculature by X-ray with the aid of a contrast injected through the catheter.
Fast forward to the late 1960s when Dr. Melvin Judkins began using a flexible catheter to reach coronary arteries. Another pioneer was Dr. Andreas Grunztig, who performed the first successful percutaneous transluminal coronary angioplasty (PTCA) on a human in 1977. Today, this procedure is known as percutaneous coronary intervention or PCI.
The medical term refers to the use of non-surgical techniques with minimal incisions of one inch or less in the wrist or femoral (thigh) artery. The main types of procedures are as follows.
Angioplasty and stenting
These two may be used in tandem, although they are different procedures. Angioplasty or balloon angioplasty is the insertion of a catheter with a deflated balloon on the tip. Once the cardiologist guides the catheter with the aid of dye to the desired site, he/she inflates the balloon. The inflation results in the expansion of the blood vessel, thereby allowing normal or improved blood flow.
Following the balloon procedure or at the same time, wire mesh may be placed in the same location to ensure the vessel remains open.
This procedure cuts away plaque from an artery (blood vessel) to improve blood flow. The technique alleviates the buildup of fat, cholesterol, calcium, and other substances from the arteries by using tiny rotating blades or a laser on the end of a catheter. Therefore, the plaque is either cut away by the rotating blade or vaporized by the laser.
Embolic Protection Devices (EPD)
These devices may become necessary during angioplasty and stenting procedures. While performing the balloon method, arteriosclerotic debris may dislodge posing a threat to smaller vessels clogging. The EPD is a filtering process to prevent distal embolization (distal refers to farther away or remote, and an embolus is a clot or plug).
Percutaneous Valve Repair or Replacement
An intricate interventional procedure used when one or more of a patient’s four heart valves is not functioning correctly. This method foregoes open-heart surgery that requires opening the chest cavity. One of the applications is mitral valve regurgitation, the condition when the valve between the left atrium (upper chamber) and the left ventricle (lower chamber) does not close properly. The cardiologist may recommend repair or, in severe cases, replacement of the valve. Robot-assisted heart surgery is an option for this minimally invasive procedure. The surgeon can use clips to repair mitral valves. One such product, the MitraClip manufactured by Abbott, is the world’s first transcatheter mitral valve repair therapy (TMVr). A team of specialists, including a cardiac surgeon and a cardiologist experienced in cardiac disease and valve repair, do the procedure.
The cardiologist may elect for one of these approaches:
- Transfemoral – Insertion of a catheter through the femoral (thigh) artery after making a small incision.
- Transapical – Insertion is made through an incision between the ribs to access the left ventricle, followed by a small puncture to the heart.
- Transaortic – This approach inserts the catheter through the top of the chest from an incision alongside the upper right breastbone.
All of these approaches require general anesthesia monitored by an anesthesiologist during the operation.
Final words about the Interventional Cardiologist
These specialists are foremost authorities on cardiovascular disease, diagnosis, and treatments. Some are members of the Society of Cardiovascular Angiography & Interventions (SCAI). Physicians applying for membership must submit a recommendation letter from a hospital administrator or complete the online Membership Attestation form. Candidates also need one full year of training in angiography and intervention. A Fellow of SCAI has higher standards; applicants need five years of practice in the specialty and a combined total of 2,000 diagnostic and intervention procedures.
The road to becoming a specialist is long. You start with a Bachelor’s degree loaded with biology and chemistry courses. In January of your junior year, you can take the Medical College Admission Test (MCAT), which tests your knowledge of science and principles of medicine. During the summer of your third year, you should begin working on the American Medical College Application Service (AMCAS) application. Upon acceptance to a medical school, you have three to four years at this stage. To specialize in cardiology, students require a three-year internal medicine residency. Following the residency, you will continue for another three years in a general cardiology fellowship where you learn various procedures, such as heart catheterization. Finally, you reach the specialty of interventional cardiology that lasts for one to two years.