Download Do Angiographic Characteristics Explain Racial Differences In

Coronary Angiography
Mark East, MD, FACC
Consulting Associate of Medicine,
Duke University Medical Center
April 4,2009
Catheterization
Access
Common Femoral Arterial Access is the most common arterial access for
performing left heart catheterization.
The original catheterization procedure was performed via brachial access.
This site is still commonly used in patients with lower extremity peripheral
access issues. Arm access also facilitates internal mammary access,
especially in patients with tortuous innominant or subclavian arteries.
Radial artery access is also used commonly in some practice settings. Before
radial access is performed, competence of the radial artery arch should be
assessed with the Allen Test. Use of pulse oximetry can facilitate interpretation
of the test.
Anatomic landmarks are used to identify the correct site of arterial puncture.
For the femoral artery access, the femoral head provides the best visible
landmark.
Arterial puncture at this site remains below the inguinal ligamentIt is
recommended that this site should be observed under floroscopy
Catheters
•
•
Catheter selection for a routine left heart catheterization is generally straight forward.
Most often, Judkins catheter types are most routinely used. For engagement of the left
main coronary artery, A Judkins Left size 4 (JL4) catheter generally will generally
engaged the left coronary artery in most patients with relative ease. Increasing catheter
size (JL5) for tall patients or patients with dilated aorta or decreasing size (JL 3.5) in
small patients is sometimes required.
•
The right coronary artery is engaged in the LAO projection. Usually slow clockwise
rotation of the JR4 in the aortic root will engage the ostium of the RCA. Specialized
catheters are available to engage anomalous origins of coronary arteries and saphenous
and internal mammary artery bypass grafts.
•
Once the artery is engaged is is important to examine the pressure wave form. Normally,
the waveform should mimic aortic root pressure. Dampening or ventricularization of the
pressure waveform may indicate over engagement of the catheter or significant vessel
stenosis. Extreme care should be taken before instillation of contrast medium without
normal pressure waveforms.
•
• Figure 2. (B) With Judkins left
Basics of Coronary anatomy
•
•
•
•
The trileaflet aortic valve gives rise to 3 cusp or sinuses in the
aortic root. The left coronary and right coronary cusp give rise
to their respective coronary arteries while the noncoronary cusp
which arises from the posterior root usually does not give rise to
a coronary artery.
The major epicardial vessels supplying the myocardium are the
left main coronary artery that divides into the Left anterior
Descending artery and Left Circumflex Artery, and the Right
Coronary artery. These arteries lie on the epicardial surface and
supply smaller branch vessels that eventually give rise to the
microvascular network supplying the myocardium.
Coronary dominance is based on the vessel that gives rise to the
posterior descending artery (PDA) which travels in the posterior
interventricular groove and supplies the Atrio-ventricular node
(AV node). This vessel, which can be recognized by the
presence of septal perforating branches, arises from the RCA in
80% of the population and the LCx in 10% of the population.
Co-Dominance of the arterial circulation is found in 10% of the
population where the posterior interventricular artery is formed
by both the RCA and LCx.
The Left main coronary artery or Left Main Trunk (LMT)
originates from the left coronary cusp and bifurcates to give rise
to the Left anterior descending (LAD) and Left Circumflex
(LCx) coronary arteries. Occasionally, a third branch vessel, the
Ramus Intermedius (RI) arises from the LMT. The LMT varies
in length in many patients and in a small number of patients, the
two major branch vessels arise from separate origins.
•
•
The Left anterior descending coronary artery (LAD) provides
blood supply to the anterior wall of the left ventricle. As it
courses through the anterior intraventricular groove it provides
multiple septal branches to the interventricular septum and
diagonal branches to the anterior lateral wall. The LAD then
courses to the ventricular apex and in some patients wraps
around the apex to supply a small amount of the posterior apex.
The Left Circumflex coronary artery (LCx) courses around the
lateral or left atrio-ventricular groove and gives rise to multiple
marginal or lateral branches. The branches are termed obtuse
marginal (OM) or lateral branches depending on institutional
preference. OM branches are sequentially numbered (OM1,
OM2 etc…) while Lateral branches are termed based on the
segment of the lateral wall they supply (High Lateral, Lateral,
Posterior Lateral). As the LCx courses the AV groove it also
gives rise to several atrial branches, and occasionally the sinoatrial branch (40% of the population).
•
The Right Coronary artery (RCA) arises from the right coronary
cusp. This vessel follows the right AV groove and provides
branches to the right ventricle. The most proximal branches of
the RCA are the conus-branch which supplies the Right
ventricular outflow tract and a branch that supplies the sinoatrial (SA) node (60% of patients). The RCA then courses
through the interventricular and gives rise to marginal branches
and branches to the atrium. Manipulation of the coronary
arteries in 3-dimensions via spacial reconstructions of the
coronary arteries is helpful in interpreting coronary
angiographic images.
Standard Angiographic Views
• For the beginner angiographer the anatomic landmarks
formed by the spine, catheter and diaphragm provide
information to discern which tomographic view from
which the image is obtained. In the LAO view (figure 1)
the catheter and spine are seen on the right side of the
image, while in the RAO (figure 2) they are found on
the right.
RAO 20 Caud 20
PA 0 Caud 30
LAO 50 Caud 30
LAO 50 Cran 30
PA 0 Cran 40
Right Coronary Artery
Ventriculography:
• With the advancement of noninvasive imaging, less emphasis is placed
on the ventriculogram as part of a cardiac catheterization. However,
entry into the left ventricle with hemodynamic measurement and
visualization of the left ventricle using contrast ventriculography
remains an important aspect of a complete angiographic study.
• In patients presenting acutely with myocardial infarction, assessment
of myocardial and valvular function with ventriculography can provide
important information to the management of the patient. In obese
patients with difficult echocardiographic windows, ventriculography
may provide ventricular information not obtainable from the
echocardiogram.
Indications and Contraindications of
the LV Gram
• Indications:
• Contraindications:
•
•
Identification of Left Ventricular
Function including wall motion
abnormalities, ventricular size and
mass. Identification of mitral
regurgitation Identification of
ventricular septal defects
Decompensated heart Failure
Extreme elevation of LVEDP
Critical Aortic Stenosis Severe
HOCM Left Ventricular Thrombus
Contrast Allergy
Complications of the LV Gram
• Ventricular Arrythmias Embolization of air
or thrombus Contrast related complications
Decompensated heart failure Myocardial
staining
Optimal Ventriculography:
• Unfortunately, unless biplane angiography is available,
ventriculography only provides a 2-dimensional projection
of the ventricle and each image will not include all of the
left ventricular segments. The 2 standard views for
ventriculography are the RAO (30o) which demonstrates
the Anterior, Apical and Inferior ventricular walls. A LAO
60o LAO 20o Cranial view allows for better imaging of
the lateral and septal ventricular walls. The latter views are
particular useful in patients with lateral ischemia
(especially circumflex ischemia), suspected VSD and
mitral regurgitation.
RAO and LAO Ventriculography:
• RAO Ventricle
• LAO Ventricle
Left Ventriculogram
Systolic View
• RAO
Left Ventriculogram
Diastolic View
• RAO
• http://askdrwiki.com/mediawiki/index.php?t
itle=Coronary_Angiography