About cardiac catheterizations:

What is a cardiac catheterization?
What is coronary angiography?
What is a left heart catheterization?
What are the risks of an angiography?
Is there an age limit for coronary angiograms?

The patient is prepared for the procedure with a medical history taking; physical examination; blood, EKG, and chest x-ray evaluations. They are asked to fast for approximately 12 hours prior to these procedures. Then, they are taken to a Cardiac Catheterization Laboratory. Under strict sterile precautions, a small catheter (a catheter is a preformed plastic tube of 2-3 mm in diameter) is inserted into the central aorta via the femoral or brachial artery. This entry of the catheter into the cardiovascular system is termed cardiac catheterization.

Under fluoroscopic control, this catheter is then advanced to the aortic root. The aortic root is the direct continuation of the left ventricle separated by the aortic valve. It is from the aortic root that the left and right coronary arteries take their origin. The two coronary arteries then divide into several branches, and eventually crowns the heart – hence the name “coronary arteries”. The left anterior descending artery, circumflex artery (both coming from the left main coronary artery) and the right coronary artery are the three major coronary arteries. From these three major conduit vessels and their branches, several small vessels perforate into the myocardium to perfuse every segment of the heart muscle.

Fig 9: Right coronary angiogram of a 48-year-old male with atypical complaints of chest pain. C – catheter. RCA – right coronary artery. Figure 9 is a normal right coronary angiogram. The right coronary artery supplies the atria, sinoatrial node, atrioventricular node, free wall of the right ventricle, the diaphragmatic portion of the left ventricle, and the lower intraventricular septum. Occlusion of the right coronary artery leads to a diaphragmatic myocardial infarction. Acute occlusion of the right coronary artery used to bear a mortality of at least 30% in the pre-thrombolytic and interventional era.

Fig 10: Left coronary angiography of a 90-year-old female showing diffuse coronary artery calcification without discrete stenosis. AO – aorta. CIR - circumflex artery. LAD – left anterior descending artery. LM – left main coronary artery. Figure 10 is a left coronary angiogram from a 90-year-old female. There was evidence of diffuse calcification on fluoroscopic examination. The angiogram did not show any evidence of discrete atherosclerosis. This is considered to be a “normal angiogram”, although there is a very high likelihood of having some diffuse generalized atherosclerosis if you further examine this vessel from within by an intravascular ultrasound.

From the aortic root the catheter is then directed to the ostia of the coronary arteries. Iodine-containing contrast material is then directly injected into the vessel. Whereas the contrast material is occupying the lumen of the coronary arteries, discrete atherosclerotic plaques sticking into the lumen of the coronary artery will be identified as a filling defect – a lesion. When the contrast is flowing through the arteries, angiogram pictures are recorded by using an x-ray machine in a film or digital video format. This step is called coronary angiography.

The left main coronary artery and its branches supply 70-80% of the left ventricle – the main pumping chamber of the human heart.

A total occlusion of the left main coronary artery is fatal with a massive myocardial infarction unless the distal branches get a copious supply of collateral filling from the right coronary artery.

Sudden occlusion of the proximal LAD can also be fatal. A critical blockage on the proximal LAD used to be called a “widow maker”. Now that we know CAD is an equal opportunity affliction, it must also be called a “widower maker” to be statistically and politically correct.

An occlusion of the circumflex can also be fatal. However, it is not just the amount of the myocardium in jeopardy that determines the mortality, but also the overall cardiac reserve ventricular function, vagal tone, and the propensity for ventricular fibrillation that finally determines the mortality of a given heart attack.

Cardiac catheterization is only a diagnostic procedure and not a treatment for coronary artery disease. The risk of mortality from this test is about 1 in 800 cases. Heart attack, stroke, aortic or coronary dissections, contrast reaction, and bleeding are the major complications.

There is no age limit for coronary angiograms in the United States. There are several countries in Europe and elsewhere where an upper age limit is set by health care rationing authorities usually the government. We know that all humans are not created equal when it comes to the aging of the protoplasm. The physiological age of the person, the strength of the indication, and the desire of the patient must be the major factors in the decision making process of performing an angiogram in an elderly person.