Invasive Angiography.

20-12-2006Back to Article

Cardiac Catheterization and Coronary Angiogram

Cardiac catheterization is used to diagnose and plan the treatment for many heart diseases. Catheterizations are frequently performed to measure the pressure within the heart’s chambers, collect samples of heart muscle, measure blood oxygen levels and blood flow in the heart’s chambers, and evaluate heart muscle pumping ability. Cardiac catheterization or cardiac angiography is most commonly used to screen significant blocks in the vessels of the heart that may rupture to create a heart attack or are causing cardiac chest pain called angina.

This enables the cardiologist to access how well the heart is functioning. During cardiac catheterization, x-ray images, called angiograms, are usually recorded to examine the blood vessels supplying the heart muscle. This is necessary to determine the need for bypass surgery, angioplasty, or stent placement.

How is a Cardiac Catheterization Performed?
To perform a cardiac catheterization, a small needle puncture is made by the cardiologist at the catheterization site, usually at the groin or the wrist. The physician inserts a thin, hollow tube, the catheter, into a vein or artery. The catheter is carefully advanced through blood vessels using fluroscopy, real-time radiology, and into the heart chambers or coronary arteries. The catheter may be used to inject iodine-based dyes for angiography, producing immediate “live” x-ray images for the cardiologist to visualize, evaluate, and record heart problems. If need be, catheters can be used to, open narrowed arteries, with balloon angioplasty or stent placement or other corrective procedures to increase blood flow.

Indications for Cardiac Catheterization
Indications may include:

• Angina that is not easily controlled with medication, that disrupts daily routine, occurs at rest, or recurs after heart attack
• Heart failure with suspected coronary artery disease.
• Heart valve disease with symptoms (e.g., shortness of breath)
• Determine the state of the aorta and detect an aneurysm of this vessel.
• Markedly abnormal stress test results
• Recurring chest pain of unidentified cause

Complications and Risks

There are always risks with any medical procedure, and serious risks, such as stroke or heart attack, from this procedure are approximately 1 in 1000.

• Allergic reaction to iodine-based dye.
• Bleeding or bruising at catheter insertion site.
• Damage to veins or arteries, leading to bleeding around the heart or heart attack.
• Infection at insertion site.
• Temporary knot under the skin at insertion site.
• Kidney damage or kidney failure.
• Emergency heart surgery.
• Death.

Cardiac Catheterization Procedures
A wide variety of catheterization procedures are available in our cardiac catheterization laboratories. These are just some of the more advanced & commonly used cardiac catheterization services and procedures:

• Percutaneous Coronary– (balloon) Intervention (PCI):
• Athrectomy:
• Ventricular Angiogram (Ventriculogram):
• Coronary Flow Reserve (CFR) Measurements:
• Intravascular Ultrasound Imaging (IVUS):
• Pericardiocentesis:
• Heart Biopsy:

Percutaneous Coronary– (balloon) Intervention (PCI):
Once the catheter is in place, using a balloon attached to the tip, the cardiologist inflates the balloon compressing plaque and dilating the diameter of the blood vessel. The balloon is deflated and removed along with the catheter. Many times a coronary stent is placed in the blood vessel to prevent restenosis or blockage recurrence.

Athrectomy:
When the removal of plaque is necessary, the catheter is fitted with a special mini high-speed drill at the tip. The plaque or blockage can be shaved off and vacuumed out or vaporized. Athrectomy is performed in conjunction with PCI through one of the large groin vessels.

Ventricular Angiogram (Ventriculogram):
A catheter, for dye injection, is directed into the heart’s main pumping chamber, the left ventricle. The dye provides detailed images to access the pumping ability of the ventricule, and identify leaky valves, heart defects, or abnormal blood flow.

Ventricular Angiogram (Ventriculogram):
A catheter, for dye injection, is directed into the heart’s main pumping chamber, the left ventricle. The dye provides detailed images to access the pumping ability of the ventricule, and identify leaky valves, heart defects, or abnormal blood flow.

Coronary Flow Reserve (CFR) Measurements: Cardiac catheters equipped with sensor-tipped guide wires measure coronary flow reserve assessing the functional severity of coronary artery stenosis and microvascular disease. CFR measurements provide objective data that complement angiography for clinical decision-making.

Intravascular Ultrasound Imaging (IVUS): A miniature ultrasound transducer, mounted on the tip of the cardiac catheter produces IVUS images. Guided by X-ray, the transducer is inserted into a coronary artery producing real-time high-resolution images of the vascular lumen (internal cavity of the veins and arteries), and the arterial wall (vessel and related structures). IVUS allows physicians to closely inspect a suspicious coronary segment analyzing artery walls and plaque prior to PTCA as the ultrasound catheter moves through the vessel.

Pericardiocentesis: The heart muscle is surrounded by a protective fluid-filled membrane, cushioning and lubricating the heart, called the pericardium. Due to a variety or reasons, from myocardial infarction and congestive heart failure to infection or trauma, the pericardial fluids build up and compress the heart constricting pumping action. In the cardiac catheterization lab the excess fluid is removed to reduce heart muscle constriction and evaluate the cause of fluid buildup. A needle is inserted through the skin and guided into the pericardial sac to aspirate fluid.

Heart-Biopsy: Small samples of heart muscle tissue are removed using cardiac catheterization. Tissue samples are sent to the lab to view heart cells under a microscope, helping physicians determine diagnosis of heart infection, virus, or heart failure of unknown origin. In the cardiac catheterization lab physicians insert the catheter into either the jugular or the femoral vein and then thread it into the heart.

Angioplasty and Stenting
Atherosclerotic plaque can buildup inside arteries and block the normal flow of blood, limiting the amount of blood that reaches body tissues. Angioplasty is a method or procedure by which a significantly obstructed plaque (70% and above) is removed using a balloon, or other methods in specific patients who do not fit into a cardiac bypass category.

• Why are angioplasties required?
As people age, the normal flow of blood through the arteries can be affected by the buildup of plaque inside the arteries. Over time, plaque continues to grow on arterial walls as cholesterol circulates in the blood; as the plaques enlarge, the arteries become narrow and stiffened. This process is called atherosclerosis, commonly known as hardening of the arteries, because the plaque buildup thickens the walls of the arteries and narrows the space through which the blood flows. When this happens, it reduces the circulation of blood through the area of the body that gets its blood from the artery.
• How are angioplasties done?

Angioplasty is a procedure done during an angiography in which a cardiologist or physician inflates a small balloon inside a blood vessel to eliminate or reduce areas of narrowing. The goal of angioplasty is the restoration of adequate blood flow (revascularization) through the affected part of the body. This is accomplished by enlarging the blood vessel from within and improving blood flow.

• What are Stents?
Stents are slender metal-mesh tubes placed inside a blood vessel to act as scaffolding that helps keep blood vessels wide open.
• How is a Stent being placed?
Stenting is a procedure in which a physician inserts a tiny, slender, expandable metal-mesh tube (stent) that fits inside an artery once the artery has been widened by angioplasty. The goal of stenting is to prevent the artery from collapsing or being closed by plaque again
• What to expect during an angiography ?

During the angiography, the patient's skin is cleaned and any hair around the insertion point of the catheter (wrist or thigh) is shaved. The insertion point is numbed or made painless with a local anesthetic, and a physician makes a tiny deep incision (deep cut on the skin) to access the artery below. Through the incision, a guidewire is inserted into the artery. A short hollow tube (catheter sheath) is then guided over the wire, and then a hollow guide catheter is inserted through the sheath.

Using fluoroscopy (a type of x ray that projects images onto a monitor), the physician guides the catheter or guidewire through the arterial system to the site where angioplasty is needed. Balloon catheters may then be inserted and withdrawn through the guide catheter or over the guidewire during the procedure. The physician uses a catheter that carries a balloon on its tip, choosing a balloon that, when inflated, will be just barely larger than the normal inside diameter of the blocked artery and long enough to cover any plaque deposits. The balloon catheter is passed through to the point of blockage in the artery and partially inflated. The balloon is then fully inflated and may be deflated and re-inflated until the blockage is flattened and the artery has been adequately opened.