Cardiac Catheterization I: Pre-Procedure Overview

Cardiac catheterization is an invasive diagnostic technique that identifies and evaluates structural and functional diseases of the heart and major blood vessels. It diagnoses conditions such as congenital heart disease, coronary artery disease, valvular heart disease, and coronary spasms. The procedure also assesses ventricular function and measures intracardiac pressures and oxygen levels directly, helping guide treatment decisions including revascularization procedures.

Fluoroscopy guides catheters through major blood vessels into the heart's right and left chambers. Radiopaque catheters are inserted through a major vein, such as the femoral vein, and a major artery, such as the radial artery. Using contrast media and fluoroscopy enables visualization of the coronary arteries, delineation of heart chambers, and assessment of wall motion throughout the procedure.

Patients undergo blood tests to assess metabolic and renal function, including serum electrolytes and creatinine levels. Baseline coagulation studies such as prothrombin time and international normalized ratio guide anticoagulation dosage during the procedure. A complete blood count including hematocrit levels is also necessary to establish baseline values and monitor for blood loss post-procedure.

Before cardiac catheterization, healthcare providers check for previous reactions to contrast agents to prevent allergic complications. Patients at risk for contrast-induced nephropathy, a typically reversible acute kidney injury, include those with chronic kidney disease, nephrotoxic medication use, dehydration, heart failure, and hypotension. Identifying these risk factors allows for appropriate preventive measures and patient monitoring.

Right heart catheterization typically precedes left heart catheterization during the procedure. Right heart catheterization alone may suffice for specific procedures like myocardial biopsies or pulmonary artery pressure evaluations. Left heart catheterization requires a contrast agent to visualize coronary artery patency and evaluate left ventricular function, making it essential for comprehensive cardiac assessment.

Continuous monitoring for dyspnea, chest pain, blood pressure changes, and ECG alterations is critical during the procedure, as these may indicate myocardial ischemia, hemodynamic instability, or arrhythmias. Patients receive one or more IV catheters to administer fluids and medications like sedatives and heparin. Resuscitation equipment must be easily accessible and ready for advanced cardiac life support.

Post-procedure, patients require bed rest for 2 to 6 hours before ambulating. The length of bed rest depends on factors including catheter size, insertion site (femoral or radial artery), anticoagulation status, age, and bleeding disorders. Individual patient factors determine the specific duration needed to minimize complications such as hematoma formation or bleeding at the puncture site.