CARDIAC CATHETERIZATION EQUIPMENT

Cardiac catheterization combines several techniques to assess haemodynamic function and cardiovascular structure. Cardiac catheterization is performed in almost all patients in whom heart surgery is contemplated. The procedure is performed in a specialized laboratory equipped with X-ray systems for visualizing heart structures and a battery of supplementary equipment for recording cardiac output, measuring respiratory and blood gases, blood oxygen saturation, and metabolic products. The injection of X-ray contrast medium into the ventricles or aorta allows assessment of ventricular or aortic function, and injection into the coronary arteries makes possible the assessment of coronary artery disease. A catheter may be passed from a peripheral vessel up into all four chambers of the heart to identify and recognize the characteristic pressure waveforms. By multichannel pressure recording the pressure gradients across all four valves can be measured.

Balloon-tipped flow-directed catheters may be used to make these recordings without the need for fluoroscopy and also the balloon may be passed into the pulmonary artery to record the wedge pressure when it becomes jammed in the pulmonary circulation. Blood samples may be drawn from within the various chambers and vessels and these may be used to determine blood gas partial pressure and metabolic products such as lactate, pyruvate, carbon dioxide, or the concentration of substances which have been injected such as radioactive materials or coloured dyes.

Cardiac output may be determined by the Fick method, dye dilution, thermal dilution or impedance cardiography.

Content and Design Copyright 2000 Dr. Malcolm C Brown.  See Title Page for more details