CADIOLOGISTS IN VIDHYARANYAPURA
Coronary angiography (cardiac catheterisation)
This procedure enables the cardiologist to visualise the coronary arteries It is the
standard against which other less-invasive investigations are assessed. Selective catheterisation
of the right and left coronary ostia is performed. Contrast is then injected into the vessels and
digital tape or disc storage of the images obtained. In most hospitals the patient is admitted on
the morning of the test and allowed to go home that afternoon.
The procedure is most often performed through the femoral artery (Judkins technique)
This artery can be punctured through the skin under local anaesthetic. A fine softtipped
guide wire is then advanced into the artery and the needle withdrawn (Seldinger method).
A short guiding sheath can then be placed over the wire and long cardiac catheters advanced
through this sheath along a long guide wire into the femoral artery and up via the aorta to the
aortic arch. The catheter and wire are advanced under X-ray control. Usually one catheter with
a curved tip (pig-tail catheter; is advanced across the aortic valve into the left ventricle
where left ventricular pressures are measured via a pressure transducer connected to the other
end of the catheter.
Measurement of the left ventricular end-diastolic pressure gives an indication of left ventricular
function. Raised end-diastolic pressure (over 15 mmHg) suggests left ventricular dysfunction
The catheter is then connected to a pressure injector. This enables injection of a large
volume of contrast over a few seconds; for example, 35 mL at 15 mL/second. X-ray recording
during injection produces a left ventriculogram . Here left ventricular
contraction can be assessed and the ejection fraction (percentage of end-diastolic volume
ejected with each systole) estimated. The normal is 60% or more. The figure obtained by this
method tends to be higher than that produced by the nuclear imaging method—gated blood
The guide wire is reintroduced and the catheter withdrawn to be replaced by one shaped to
fit into the right or left coronary orifice. Hand injections of 5–10 mL of contrast are then made.
Modern equipment enables numerous views of the coronaries to be obtained in both right and
4• THE PATIENT WITH CHEST PAIN 129
left oblique and caudal and cranial angulated views. The left system (left main, left anterior
descending and circumflex arteries) is more complicated than the right, and more views are
It is also possible to catheterise the heart by direct puncture of the radial artery at the wrist,
using a long sheath and a technique similar to the Judkins. Problems may be encountered advancing
the catheters around the shoulder or if spasm of the radial or brachial artery occurs.