Interpretation Of Tracings

Categories: Uncategorized
Sources: Disturbances Of The Heart

The interpretation of the arterial tracing shows that the nearly

vertical tip-stroke is due to the sudden rise of blood pressure

caused by the contraction of the ventricles. The long and irregular

down-stroke means a gradual fall of the blood pressure. The first

upward rise in this gradual decline is due to the secondary

contraction and expansion of the artery; in other words, a tidal

wave. The second upward rise in the decline is called the recoil, or

the dicrotic wave, and is due to the sudden closure of the aortic

valves and the recoil of the blood wave. The interpretation of the

jugular tracing, or phlebogram as the vein tracing may be termed,

shows the apex of the rise to be due to the contraction of the

auricle. The short downward curve from the apex means relaxation of

the auricle. The second lesser rise, called the carotid wave, is

believed to be due to the impact of the sudden expansion of the

carotid artery. The drop of the wave tracing after this cartoid rise

is due to the auricular diastole. The immediate following second

rise not so high as that of the auricular contraction is known as

the ventricular wave, and corresponds to the dicrotic wave in the

radial. The next lesser decline shows ventricular diastole, or the

heart rest. A tracing of the jugular vein shows the activity of the

right side of the heart. The tracing of the carotid and radial shows

the activity of the left side of the heart. After normal tracings

have been carefully taken and studied by the clinician or a

laboratory assistant, abnormalities in these readings are readily

shown graphically. Especially characteristic are tracings of

auricular fibrillation and those of heart block.