When is this exam indicated?
Cardiac catheterization serves to exploring the right or left side of the heart.
Left heart catheterization is the most commonly used to assess the anatomy of the coronary arteries and the evidence of coronary artery disease. It is also used to assess:
- Aortic blood pressure
- Systemic vascular resistance
- Aortic valve function
- Mitral valve function
- Left ventricular pressure and function.
In addition, this examination can enable the diagnosis of diseases such as amyloidosis, sarcoidosis, myocarditis, cardiotoxicity, storage diseases, and tumors. However, the clinical utility of the routine use of biopsy in cardiomyopathies remains controversial. Endomyocardial biopsy is a necessary method but of limited clinical utility. The individuals who undergo biopsy are those with unexplained myocardial dysfunction. The goal in these cases is exclusion of infiltrative or inflammatory disease.
Right heart catheterization is the most commonly used to assess:
- Right atrial pressure
- Right ventricular pressure
- Pulmonary artery pressure
- Pulmonary artery occlusion pressure
Pulmonary artery occlusion pressure approaches left atrial pressure and left ventricular telediastolic pressure. In acute cases, pulmonary artery occlusion pressure helps assess volaemia and, with simultaneous measurement of cardiac output, can help to guide the therapy.
Right heart catheterization is also useful in assessing cardiac filling pressure, pulmonary vascular resistances, tricuspid or pulmonary valve function, intracardiac shunts, and right ventricular pressure. Measurement of right ventricular pressure may be useful in diagnoses of cardiomyopathy, constrictive pericarditis, and cardiac tamponade when noninvasive investigations do not provide diagnostic conclusions, and it is an essential part of evaluation for cardiac transplantation or mechanical cardiac support (eg, use of a ventricular assist device).
How is it performed?
Left catheterization is performed by puncture of the femoral, subclavian, radial, or brachial artery, with passage of a catheter through the ostium of the coronary artery and/or through the aortic valve into the left ventricle. Catheterization of the left atrium and left ventricle is sometimes performed by transseptal puncture during right catheterization. By catheterization, cardiac biopsy, the collection of cardiac tissue samples from the left or right ventricle, is performed. Currently, cardiac biopsy allows therapeutic monitoring after cardiac transplantation; histological examination of the biopsy material allows early diagnosis of rejection and adjustment of immunosuppressive therapy.
Right catheterization is performed by puncture of the femoral, subclavian, internal jugular, or brachial veins. A catheter is pushed into the right atrium, then through the tricuspid, into the right ventricle, and through the pulmonary valve into the pulmonary artery.
Contraindications related to cardiac catheterization include:
- Acute renal impairment
- Chronic nephropathy
- Systemic infection
- Uncontrolled arrhythmia
- Uncontrolled hypertension
- Decompensated heart failure
- Allergies to radiopaque contrast agent by inadequately premedicated patients