Cardiac catheterisation laboratory – place where angiography and interventions are done
Cardiac catheterisation laboratory is the place where angiography (imaging of blood vessels and the heart) and interventions are done. It is akin to the theatre for surgical procedures and has to be maintained in a sterile (free of micro organisms causing infection). Cardiac catheterisation laboratory (cathlab) is a comprehensive setup used for diagnostic and therapeutic (treatment) cardiac catheterisation. Cardiac catheterisation is the process in which small tubes are introduced into various chambers of the heart under local anesthesia through branches of blood vessels reaching or arising from the heart. The most important equipment in that cathlab is the x-ray image intensifier system. The x-ray tube is a heavy duty one generating about 1000 mA of tube current and capable of continuous operation. In the fluroscopic mode, the current will be much smaller, in the order of a few millamperes, while in cine mode the currents are high, of the order of 600 – 800 mA. Operating voltage is in the range of 70 – 100 Kilo volts. Fluorscopic mode is to visualise the structures during a procedure while cine mode is used to make a permanent record of what is seen. Now a days most cathlab systems can also store fluroscopic images, given a provision for using lower X-ray exposures.
An invasive pressure monitor with facility for monitoring intracardiac pressures and ECG, pressure injector, intra aortic balloon pump (IABP – used for supporting cardiac function in critically ill patients when the contractile function of the heart is poor and the blood pressure dangerously low), cardiac monitor defibrillator (for monitoring cardiac electrical activity and giving electrical countershocks if a life threatening rhythm disorder is noted), infusion pumps, suction apparatus and other supporting equipment are part of the gadgets available in the cathlab. Since the X-ray unit is a source of ionizing radiation, protective hard ware like lead apron, lead glasses (goggles), thyroid shield to protect the thyroid gland in the neck and gonadal protection shields for the patient are needed. The room should have thick walls with adequate radiation protection. Wooden doors should be covered with lead shields and viewing windows should be of lead glass.