The heart is a muscle that constantly beats to pump blood throughout the body. Coronary arteries are arteries that supply blood to the heart. Over time, due to various reasons, fatty deposits called plaque are deposited on the wall of the arteries in a process known as atherosclerosis. This process causes the arteries to narrow, thus reducing blood flow to the heart causing coronary artery disease (CAD). CAD may be responsible for symptoms like angina, which is chest discomfort or pain. A heart attack can occur if the circulation to the heart is cut off. Over time, CAD may lead to weakness of the heart muscle and other symptoms. CAD is the most common type of heart disease in the United States.
Cardiac catheterization also known as heart or coronary cath, is used to detect or confirm the presence of coronary artery disease, heart valve disease or disease of the aorta. In this procedure, a guide wire is inserted into the blood vessel via the groin area (femoral access) or the wrist area (radial access). A thin tube called catheter is then guided to the heart under x-ray to view the arteries, valves, muscles and aorta. Once the catheter is in place, one or more of the following can be performed: coronary angiography, angioplasty, stent placement, rotablation, LASER atherectomy. Depending on the procedure to be performed, the catheter will have an appropriate attachment.
Cardiac cath is also used to measure pressures in the four chambers of the heart, and evaluate pressures differences across heart valves. It is also used to estimate cardiac output, or the amount of blood pumped per minute by the heart, thus evaluating the functioning of the heart.
Angiography or angiogram is the x-ray imaging of blood vessels. Once the catheter is in place after cardiac catheterization, a contrast agent, or dye is injected into the blood vessels to make them visible by x-ray imaging within the study area. Angiography is used to detect narrowing, blockage or bulging of blood vessels.
Balloon angioplasty, also known as percutaneous transluminal coronary angioplasty (PTCA) is used to open coronary arteries, which may be narrowed by the presence of plaque. After cardiac cath, the balloon at the tip of the catheter is inflates at the narrowing. The plaque is pressed towards the walls of the artery, thus allowing blood to adequately flow.
Balloon angioplasty and stenting: The stent is a small, mesh-like tubing made of metal. It acts like a scaffold to support the arteries. The stent may be bare-metal or drug-eluting. Most of the time, angioplasty is followed by stenting.
Atherectomy is the grinding or cutting away of plaque for removal from the arteries. This procedure can be necessary as sometimes excessive narrowing can cause plaque to become heavily calcified, thus inflating the artery or advancing the stent is difficult. After cardiac catheterization, when the catheter reaches the narrowing, plaque can be removed by either cutting or the use of a rotating blade, like rotablation. Also, a laser beam can be utilized, which is known as laser atherectomy. The microscopic plaque then passes through the bloodstream and is excreted via the liver and spleen. Angioplasty and stent may be performed after atherectomy to improve the outcome.
Rotablation or rotational atherectomy is the insertion of a rotating burr through a catheter into the artery. A rotablator has a diamond burr tip, and is advanced to the beginning of the narrowing. The tip spins at a very high speed and grinds away the plaque.