A left heart catheterization (LHC) is a common, minimally invasive medical procedure used to diagnose and sometimes treat various heart conditions. It involves inserting a thin, flexible tube, called a catheter, into an artery and guiding it up to the left side of the heart. Performed by a cardiologist in a specialized cardiac catheterization lab, the procedure offers physicians a direct look inside the heart’s chambers and arteries.
Why This Procedure Is Performed
The primary function of a left heart catheterization is to gather precise, real-time diagnostic information about the heart’s function and blood vessels. A frequent goal is the performance of a coronary angiogram, which involves injecting a contrast dye to visualize the coronary arteries under X-ray guidance. This imaging identifies the location and severity of any blockages or narrowings within the arteries, diagnosing coronary artery disease.
The procedure is also performed to measure pressures within the left side of the heart, specifically the left ventricle and left atrium. This provides data about the efficiency of the heart’s pumping action and can help diagnose heart failure. An LHC also allows for a detailed evaluation of heart valve function, particularly the aortic and mitral valves, by assessing blood flow patterns and pressure gradients. Physicians may also use the LHC to assess the function of the left ventricle through a test called a ventriculography.
How the Catheterization Is Executed
The procedure typically begins with the patient lying on a specialized table in the catheterization lab, where a mild sedative is often administered to promote relaxation. The interventional cardiologist selects an access site, usually an artery in the groin (femoral) or the wrist (radial), with the radial approach often preferred due to a lower risk of bleeding. The chosen area is then cleaned and numbed with a local anesthetic.
Once the area is numb, a small puncture is made to insert a short, hollow plastic tube called an introducer sheath into the artery. The catheter is then threaded through this sheath and carefully guided through the arterial network toward the heart. The entire process is monitored using a specialized X-ray technique called fluoroscopy. As the catheter reaches the heart, a contrast dye is injected, which makes the coronary arteries and heart chambers visible on the screen.
The dye injection allows the cardiologist to capture a series of rapid X-ray images, creating a detailed map of the coronary circulation to identify any plaques or obstructions. The catheter is then advanced across the aortic valve and into the left ventricle to measure pressures and potentially perform a ventriculogram. After all necessary diagnostic images and measurements are collected, the catheter and introducer sheath are removed from the artery.
Patient Preparation and Immediate Recovery
Preparation for a left heart catheterization involves several steps to ensure patient safety and clear results. Patients are instructed to fast for six to eight hours before the procedure, which helps prevent complications related to sedation. Specific instructions are also given regarding routine medications, especially blood thinners, which may need to be temporarily stopped or adjusted.
Prior to the procedure, blood tests are performed to check kidney function, as the contrast dye is cleared from the body by the kidneys. Following the procedure, the immediate recovery phase focuses on stopping the bleeding (hemostasis) at the arterial access site. This is accomplished either by applying manual pressure or by using a specialized closure device that seals the puncture.
The patient is required to remain in a recovery area for several hours. The duration of bed rest depends on the access site; for example, a femoral artery approach often requires lying flat for a few hours. Nurses closely monitor the puncture site for any signs of bleeding or swelling, and check the patient’s heart rate and blood pressure. Patients are encouraged to drink extra fluids to help flush the contrast dye from their system.
Recognizing and Managing Risks
While left heart catheterization is a routine procedure, it does carry a small spectrum of potential risks. The most common issues are minor and localized, including bruising, mild pain, or a small lump (hematoma) at the puncture site. These minor complications are usually managed with simple care and resolve within a few days or weeks.
More serious complications are infrequent, with the combined risk of a major event like a heart attack, stroke, or death being less than 1 in 1,000 diagnostic procedures. Other rare possibilities include significant bleeding at the access site, an allergic reaction to the contrast dye, or damage to the blood vessel. Patients should contact their doctor immediately if they experience uncontrolled bleeding, fever, new chest pain, or shortness of breath after returning home.