Types of Interventional Procedures
Cardiac catheterization, sometimes called cardiac cath, often is used to determine the severity and extent of cardiovascular problems. In this procedure, the cardiologist makes a small incision in the arm or groin and threads a catheter into a blood vessel. The catheter is then guided through the blood vessel to the heart.
Using cardiac catheterization, physicians can:
- analyze the location and size of plaque deposits,
- assess the strength of the heart muscle and valves,
- collect blood samples,
- take blood pressure readings, and
- inject dyes that are visible on x-rays into arteries to see how well blood is flowing.
Information from the cardiac cath can help determine if cardiac surgery or another interventional cardiology procedure, such as angioplasty, is necessary.
Angioplasty/Percutaneous Coronary Intervention
Coronary angioplasty, also called percutaneous coronary intervention (PCI), is used to open arteries that have been narrowed by atherosclerosis. In this procedure, a catheter is entered into a blood vessel through an incision (usually in the leg or wrist) and is threaded to the heart. This catheter has a collapsed balloon at its tip. When the balloon reaches the targeted area (e.g., blockage), it is inflated to push plaque to the artery walls and widen the artery to improve blood flow. In some cases, the balloon must be inflated and deflated more than one time during the procedure.
Approximately 70 percent of angioplasty procedures also involve stenting, which is the insertion of a small metal cylinder called a stent into a blood vessel. In this procedure, a collapsed stent is placed over the balloon at the tip of the catheter. When the balloon inflates, the stent pops open and reinforces the artery walls. The balloon and catheter are then withdrawn and the stent remains permanently. In a few weeks, tissue from the artery lining grows over the stent.
There are two types of stents. Bare-metal stents are plain, untreated metal cylinders. Drug-eluting stents (also called drug-coated stents) are coated with medication before they are placed in the artery. This medication helps prevent scarring and lowers the risk for restenosis (re-narrowing of the artery). Drug-eluting stents may present a higher risk for blood clot formation than bare-metal stents.
The word "embolic" comes from the word "embolus," which refers to an abnormal particle flowing with the blood. During interventional cardiology procedures, plaque fragments can become loose, travel through the bloodstream, and increase the risk for injury or stroke. Embolic protection devices, often called "filters," can be used to trap these particles.
Percutaneous Valve Repair
The human heart has four valves that control the way blood flows through heart chambers. Interventional cardiologists can use catheters to guide clips or other devices through the blood vessels to a damaged valve. These devices can then be used to repair the valve to allow blood to flow properly again.
Balloon valvuloplasty, also called balloon valvotomy, is used to repair narrow or constricted heart valves that do not open properly (e.g., aortic stenosis). In this procedure, a balloon at the tip of the catheter is inflated to stretch the valve open.
In this procedure, a rotary shaver (also called a "burr") is placed at the tip of a catheter, guided to the affected area, and used to remove plaque from the artery walls. In some cases, a laser catheter is used to vaporize the plaque.