Cardiac catheterization and coronary angiography
are most commonly performed to diagnose and
examine the severity of coronary artery disease.
They are the gold standard for diagnosing coronary artery disease.
Coronary artery disease is caused
by narrowing or blockage of the coronary arteries
due to the formation of atherosclerotic plaques
in the walls of these arteries,
thus restricting blood flow to cardiac muscle.
Coronary artery disease is the main cause for angina,
myocardial infarction (or heart attack), and heart failure.
Coronary artery disease must be
present in varying degrees in all three of the clinical diagnoses
of acute coronary syndrome (ACS).
Patients present in one of three ways:
unstable angina, myocardial infarction
without ST segment elevation (NSTEMI),
and myocardial infarction with ST segment elevation (STEMI).
In patients with congestive heart failure and left ventricular dysfunction,
cardiologists use cardiac catheterization
to obtain critical information on the condition of the heart,
and therefore, decide on appropriate therapeutic interventions.
In congestive heart failure,
the heart fails to pump blood adequately
to maintain blood circulation in the body.
This results in congestion of blood,
and therefore, edema in tissues of the body,
such as, in the lungs, liver, feet, and ankles.
Liver congestion is a large part of
congestive heart failure as well.
Left ventricular dysfunction
refers to a condition where there is decreased movement of the left ventricle,
resulting in dilation of the ventricle and weakening of the cardiac muscle.
Left ventricular dysfunction may progress into congestive heart failure.
Cardiac catheterization can help cardiologists
evaluate the underlying cause of symptoms
associated with left ventricular dysfunction and congestive heart failure,
measure the extent of dysfunction in the left ventricle,
measure the pressures inside the right side of the heart
to evaluate fluid status,
and measure cardiac output.
Cardiac catheterization is also indicated for patients with myocardial infarction.
Myocardial infarction refers to damage and death
to an area of the myocardium,
usually caused by coronary artery disease.
Cardiac catheterization
allows cardiologists to assess the extent of damage
caused to the heart muscle,
and to decide on a therapeutic approach
for the underlying cause of the infarction.
Cardiac catheterization may be also used
to evaluate patients with cardiomyopathies.
Cardiomyopathies refer to a group of diseases,
with or without a known cause,
that primarily affect cardiac muscle function.
In patients with valvular heart disease,
cardiologists use cardiac catheterization
to assess the functioning of cardiac valves.
Cardiac catheterization allows the identification of structural anomalies
in the valves,
and the evaluation of hemodynamic consequences of these anomalies,
such as blood flow and oxygen levels in different parts of the heart.
This helps cardiologists evaluate the risk
and benefits of a surgical approach to treatment.
In some cases, cardiac catheterization can also be used
to measure hemodynamic values
that may be needed prior to surgery in congenital heart disease,
a condition caused by heart defect at birth.
Cardiac catheterization is also indicated
when percutaneous interventional approach
(insertion of wires and catheters through the skin to treat cardiovascular problems)
is selected to correct defects in congenital heart disease.