Basics of hemodynamic evaluation – 2

Basics of hemodynamic evaluation – 2 Click here to see Part 1 This is the article in the series on basics of hemodynamic evaluation. As mentioned earlier, pressure measurement in each chamber is an important aspect of hemodynamic evaluation. Two types of catheter based pressure measurements are possible. One is using a catheter tipped manometer, which is more ideal, but expensive. Second, more commonly used method is using fluid filled systems with an external transducer. While using fluid filled systems, care has to be taken to avoid air bubbles in the connecting tubings to avoid damping of pressure wave transmission. The external transducer is mounted at the mid thoracic level, midway between the anterior and posterior chest walls in the supine position. This is known as phlebostatic axis. This level is used to zero the transducer with the stop cock open to the atmosphere, prior to actual recording. It corresponds to the level of the right atrium typically at the tricuspid valve level. If the transducer position is below the phlebostatic axis, the pressure readings will be erroneously high and vice versa. Catheter whip artefact is an important problem, especially while measuring pulmonary artery pressure with fluid filled systems. Movement of the catheter during cardiac motion accelerates the fluid within the tubings and can get superimposed on the pressure tracing with a range up to 10 mm Hg. Though there are a, c and v waves for atrial pressure tracing, usually onl...
Source: Cardiophile MD - Category: Cardiology Authors: Tags: General Cardiology Source Type: blogs