Cardiac Catheterization

The cardiac catheterization is a method of relatively old hemodynamic exploration. It consists in introducing a probe into the various cardiac cavities to measure pressures and the rate of oxygen saturation of blood.

History

This method dates of more than one century and was introduced by Chauveau. It obtains the first recordings of pressure of the cardiac cavities by introducing a Cathéter by the jugular Veine into the heart of a horse.

In 1929, Werner Forssman practices on itself the first human cardiac catheterization.

During the Second world war, Andre Cournand and his collaborators develop the techniques of the left and right cardiac catheterization.

Indications of hemodynamic exploration

This exploration has several goals:

to confirm a cardiac disease suspected by other examinations;
to quantify the importance of the disease in question and its repercussion on the cardiac function;
to seek a cause with a Symptom (breathlessness, signs of Cardiac failure;
to make an assessment before a cardiac Surgery.

The technique of the cardiac catheterization can be used in various circumstances:

in the valvular cardiopathies acquired, congenital, or ischemic;
among patients presenting a sign of arterial Hypertension pulmonary or Cardiac failure;

Techniques of the cardiac catheterization

It is a question of introducing a probe (in general opaque with x-rays) into the right cavities or left of the heart. One uses it for:

to measure the intravascular and intracardiac pressures;
to take samples of blood;
to inject various indicators to measure the cardiac Flow, to detect and quantify an intracardiac shunt;
to inject products of contrast for the morphological and kinetic study of the cavities and the vessels.

Catheterization of the right cavities

This technique requires the use of a désilet and a probe (technique of Seldinger). Before any handling, the vein either is stripped or punctured by transcutanée way.

The exploration of these cavities is carried out under Local anesthesia and surgical asepsis. The catheter is introduced into a surface vein (cephalic vein on the level of the fold of the elbow) or into a deep vein (femoral vein).

Puncture of the vein by a needle;
Introduction of the metaliic guide into the needle into the light of the vein;
Introduction of the unit puncher-sheath (désilet) on the guide;
Shrinking of the puncher: there thus remains only the sheath in the vein.
successive Introduction of probes different according to the type from the examination.

The probes are radiopaque and their introduction is controlled under radioscopy x-rays per amplifier of brightness.

Catheterization of the left cavities

Always under local anesthesia and asepsis surgical, the same technique, known as “of Seldinger” is employed. The femoral Artère (or the Artery humérale or the radial artery) is punctured by making sure that there exists jet of a red and pulsatile blood. The metal guide is placed in the light of the artery and the probe is pushed until in the left ventricle.

It is noted that the left auricle does not make it possible to be reached by this way, his opening being practically parallel to that of the aorta. In this case, one uses the way transeptale : the probe provided at its end with a needle, is introduced by the common femoral vein, passes in the right auricle, then in the left auricle through the septum (wall separating the two auricles).

Measure pressures intravascular and intracardiac

The measurement of the pressure is done using a Manomètre. In the case of a cardiac catheterization, there exist two types of pressure gauges.

the apparatus located outside the organization: the electric system which is associated for him receives the pressure transmitted via the liquid column included in the catheter. It is the most frequent case.
the micromanometer: it is placed at the end of the probe and is thus introduced directly into circulation.

Diagnoses after the cardiac catheterization

Detection of the presence of an obstacle by the description of a gradient of pressure on both sides of the cardiac valves.
Detection of the intracardiac shunts by the presence of anomalies of the way of the catheter or by the increase in the oxygen rate in the cavities.

Coronarography

See article Coronarographie.

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