A diagnostic procedure is performed in the cath lab to determine the extent of disease present in the vascular system. Left heart catheterization (arterial) is performed to determine blockages in the coronary vascular system. Right heart catheterization (venous) is performed to determine how well the heart valves are functioning and how effective the heart is pumping blood to the lungs.

During left heart catheterization a sheath (small flexible catheter) is inserted into the femoral or brachial artery. A heart catheter is then advanced through the sheath to the aortic arch and engaged in the ostium of the coronary artery to be visualized. There are two main coronary artery systems; the right and the left. Once the catheter is engaged, contrast (iodine based dye) is injected into the artery and visualized under fluoroscopy to detect blockages. During the left heart catheterization additional contrast may be injected to visualize the left ventricle, carotid, renal, and peripheral arteries. Pressure readings are taken at various sites to determine stenosis (narrowing of an artery) and valve function.

During right heart catheterization a sheath is inserted into the femoral or brachial vein. A catheter (usually a swan ganz catheter) is then advanced to the pulmonary artery via the right atrium and ventricle. Pressure readings and blood oxygen saturations are obtained from the different chambers to determine abnormalities. If significant abnormalities are noted a cardiac output study may be performed.

A right heart biopsy is performed either from the internal jugular or femoral vein. A sheath is first introduced in the vein and a swan ganz catheter is advanced to measure right heart pressures prior to obtaining biopsy specimens. After pressure readings are obtained a bioptome (tissue biting forceps) is advanced to the right ventricle and multiple specimens are obtained and sent to the pathology laboratory. During the procedure absolute care is taken not puncture the wall of the ventricle.

Electrophysiology Study (EPS) is the study or detailed analysis of normal and abnormal electrical conduction systems of the heart. The EP study enables the physician to assess the function of the SA node, AV node, and the His-Purkinje system. It can also help to evaluate the electrophysiologic properties such as automaticity, conduction velocity and refractoriness of the cardiac tissue. Conduction intervals are measured within the heart by means of intra-cardiac electrode catheters. From these measurements the doctor is able to identify problem areas of conduction.

In a controlled clinical environment this test permits the electrophysiologist to study cardiac abnormalities and locate the cardiac activation and arrhythmia mechanism that are responsible for these abnormalities. The electrophysiology procedure is an invasive examination, similar to a heart catheterization that is performed by introducing electrode catheters into the right side of the heart via the femoral vein, brachial vein, or jugular vein. The catheters are positioned in the heart and then used to measure and record the activating sequence of the cardiac circuit.

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Cardiac Catheterization