Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3597_Библиотеки_им_академика_М_И_Перельмана
.pdf
https://t.me/med1917
3 —
Coronary Angiography and Ventriculography 133
A B
C D
CORONARY IMAGING DEVICES IN THE CATHETER LAB
Angio IVUS NIRS OCTAngioscopy
Resolution (µm)
Probe size (µm)
Contact
Ionizing radiation
E
Figure 3-25
thrombus showing faint opacification around the thrombotic material after
the proximal segment. B, Image of femoral artery dissection with linear
lucency extending below the puncture site, down the common femoral artery
toward the bifurcation of the profunda and superficial ar tery. C, Cineangio graphic frame showing large ectatic and aneurysmal coronary ar teries. This
one involves both the circumflex (CF X) and left anterior descending (LAD)
coronary artery. D, Cineangiographic frame of patient who has fistula from
the proximal LAD moving upward over the anterior surface of the pulmonary
artery. This fistula may or may not be the cause of symptoms. E, Coronary
imaging devices used in the catheterization laborator y. IVUS, Intravascular
ultrasound; OCT, optical coherence tomography.
100 – 200
No Yes Yes Yes Yes
Other
Lumen
only
A, Angiographic frame of the right coronary artery (RCA) with
80 –
120
N/A N/A
=
Surface
only
10 – 15<200
1408001000700N/A
NoNoNoNoYes
Plaque
character
134 3 —
https://t.me/med1917
may not be associated with slow angiographic flow (Fig. 3-25, B).
bulbous segment of the vessel often with slow flow (Fig. 3-25, C). The
aneurysms may be diffuse or isolated and are usually associated with
atherosclerotic arterial disease.
circuit and other regions of the heart directly into the LV cavity or the
right-sided structures (Fig. 3-25, D).
Nonangiographic Lesion Assessment Tools (Fractional Flow
Reserve, Intr avascular Ultrasound, and Optical Coherence
Tomography) (See Chapter 10). Because the angiographic image
is a two-dimensional (2D) projection of a three-dimentional (3D)
structure, it does not accurately reflect the physiologic consequences
of a stenosis alone, especially for narrowings in the intermediate
ranges (40% to 80%). The use of nonangiographic lesion assessment
tools overcomes this limitation. There are three commonly used nonangiographic lesion assessment tools: a pressure sensor guidewire
measurement called fractional flow reserve (FFR) and two intravascular imaging methods, one using ultrasound and IVUS and the other
using laser light and OCT to create intraluminal images of the vascular
anatomy. FFR (distal/aortic pressure at hyperemia) is used to determine the functional significance of a coronary stenosis, that is, whether
the lesion is responsible for ischemia. IVUS and OCT provide visualization of intraluminal and transmural coronary anatomy. OCT has higher
resolution than IVUS and further improves visualization of various
plaque components and vessel structures. These adjunctive diagnostic
procedures, summarized in Figure 3-25, E, influence the decision for
coronary revascularization, guide the performance of PCIs, and optimize procedural outcomes.
Coronary Angiography and Ventriculography
A dissection is defined as a linear lucency in a vessel that may or
An aneurysm in a coronary artery typically is associated with a
A coronary artery fistula connects the artery to the pulmonar y
Classification of Angiographic Blood Flow
(TIMI Grades)
Angiographic blood flow has been qualitatively assessed by observing
the distal runoff and is classified into four grades (also known as TIMI
flow grades). The TIMI grade was developed from the Thrombolysis in
Myocardial Infarction Studies during the late 1980s.
The four grades of flow are described as follows:
•
TIMI 3: Flow rate equal to that in noninfarct arteries
• TIMI 2: Distal flow in the artery less than that in noninfarct arteries
• TIMI 1: Some contrast filling beyond the culprit lesion but no signifi-
cant antegrade flow
•
TIMI 0: No flow beyond the total occlusion
To quantitate TIMI flow rates, the number of angiographic frames
required for contrast media to traverse the coronary artery is reported
by Gibson M, et al. Calculated as the number of frames from the initial
appearance of the dye in the coronary artery to a distal predetermined
landmark. Gibson, et al has proposed a correction of this frame count
called the corrected TIMI frame count, which uses the distal targets in
the LAD artery as the distal bifurcation, the distal target in the CFX
artery as the distal bifurcation of the terminal segments at the longest
distance, and the RCA as the first branch of the posterolateral artery.
Because the anterior descending artery is longer than the other
vessels, the normal TIMI frame count for the LAD artery is 36; for the
CFX artery, 21; and for the RCA, 22. The corrected TIMI frame count
divides the anterior descending count by 1.7 to equate the three
vessels. TIMI frame counts have been found to be of value in judging
clinical response after reperfusion therapy in the setting of acute
syndromes.
https://t.me/med1917
3 —
Coronary Angiography and Ventriculography 135
Coronary Angiography: Common
Problems and Solutions
Optimal angiographic data collection is a detailed series of sequential
steps designed to obtain the maximal amount of data with minimal
risk to the patient. This process begins with the nurse positioning the
patient on the table, followed by catheter placement and ascertainment of angiographic views, the display of the image for review, and
finally the recording and storing of the digital image for the archives.
The major causes of poor angiograms include factors specific to the
patient (size, hardware), angiographic technique, equipment-related
problems, and optical and digital imaging system issues (see Box 3-1).
Coronary Spasm
Spontaneous or catheter-induced coronary artery spasm may appear
as a fixed stenotic lesion. Catheter spasm has been observed in right
and left coronary arteries (including the LMCA) and must be considered and excluded (by the administration of intracoronary nitroglycerin) before the narrowing is considered to be an organic lesion.
Catheter-induced spasm may occur not only at the tip of the catheter
touching the artery but also more distally. Repositioning of the catheter and administration of nitroglycerin (100 to 200 µg through the
catheter) determines whether the presumed lesion is structural or
spastic. A change to a smaller-diameter (4 F or 5 F) catheter or catheters that do not seat deeply may also help.
Vessel Overlap
The purpose of coronary angiography is to adequately visualize each
segment of the coronary tree in at least two orthogonal imaging
planes. Given the individual variations of the coronary tree, multiple
angles are often required to reveal locations of lesions. Depending on
lesion location, steeper angles or even AP-cranial or -caudal views are
often helpful to minimize vessel overlap. For lesions whose significance remains uncertain, IVUS or physiologic measurements (FFR
and coronary flow reserve [CFR]) should be considered.
Inadequate Vessel Opacification
Poor contrast opacification of the vessel may lead to a false impression
of an angiographically significant lesion or lucency that could be
considered a clot. Inadequate mixing of contrast material and blood
(streaming) could be seen as a luminal irregularity. A satisfactory
bolus injection of contrast material must be delivered if adequate
opacification is to be achieved and the angiogram interpreted correctly. Contrast delivery can be enhanced by use of a larger catheter,
injection during Valsalva maneuver phase III, or use of a power injector. For patients who have elevated cardiac outputs (liver failure
patients) or who have large coronary arteries, use of a guiding catheter
that has a larger luminal diameter can be considered to preclude this
common problem.
Total Coronary Occlusion
Total occlusion of a vessel may be erroneously suspected if the catheter injection site is subselective or an anomalous origin or course of
a vessel is not recognized. A short LMCA may lead to selective opacification of only the LAD artery and a presumption of a CFX occlusion
or anomalous origin of the CFX. To address this, an aortic cusp “flush”
of contrast may reveal the second vessel. Subselective injections into
each vessel separately may be necessary if the LMCA is too short to
opacify both vessels simultaneously. This often can be done with different catheters: Longer catheters subselective for the CFX (JL5) and
shorter-tip catheters often engage the LAD (JL3 or JL3.5). Similarly,
136 3 —
https://t.me/med1917
Coronary Angiography and Ventriculography
subselective injection into a large RCA conus branch may not adequately visualize the main RCA. When target vessels are not well seen,
the operator should consider anomalous origins of the coronary artery
and review the aortogram and left ventriculogram (see section on
anomalous coronary arteries later in the chapter).
Dominance Determination
Determination of dominance identifies which vessel provides the PDA.
This is also important for avoiding erroneously labeling a CTO. Left
dominance is present in 7% of the population, and the PDA is best
visualized in the LAO-cranial injection during left coronary angiography, laying in the interventricular groove and feeding the inferior
septum. In these left-dominant individuals, the RCA is often small and
only supplies a few RV arteries marginally. These nondominant RCAs
are often small and may be prone to catheter-induced spasm. Eightyfive percent of patients are right dominant, that is, the PDA originates
from the distal RCA, whereas 7% of patients are codominant and the
inferior septum is supplied by parallel left and right PDAs.
Special Clinical Situations and Problems
Left Main Coronary Artery Stenosis
A commonly encountered and potentially critical problem is coronary
angiography of patients who have LMCA stenosis (Fig. 3-26), which is
one of the few situations wherein the routine performance of angiography may be life threatening. An LM stenosis may occur at the ostium,
mid body, or distal bifurcation of LAD or CFX arteries, and the correct
diagnosis of lesion severity is critical for CABG and PCI decisions.
Figure 3-26 Cineangiographic frame showing distal left main (LM) coro-
nary stenosis at the trifurcation branch of the left anterior descending (LAD),
ramus intermedius, and circumflex (CF X) arteries. In critical LM stenoses,
only one to t wo views may be necessary. In this case, only one view was
obtained before recommending urgent coronar y ar tery bypass graft (CABG)
surger y.
https://t.me/med1917
3 —
Coronary Angiography and Ventriculography 137
LMCA stenosis is commonly associated with two clinical
presentations:
1. Patients who show evidence of significant low workload ischemia
or hypotension during exercise treadmill testing. Unstable angina
may be caused by LMCA stenosis in ~10% of patients.
2. Patients with atypical angina. The clinical history and resting or
stress electrocardiogram (ECG) may not be helpful, and often,
patients with resting or atypical chest pain syndromes do not have
previous exercise test data.
Technical notes for angiography of LMCA stenosis:
1. Either femoral or radial vascular access approach may be used
safely. Access should be based on the operator’s best working
method.
2. Recommended is coronary angiography before left ventriculography to obtain the most important information first, should a complication occur.
3. Careful slow advancement and seating of the left coronary catheter
prevents the femoral preshaped catheter from jumping into the
ostia. This maneuver is important for an ostial narrowing. Continuous observation of the arterial pressure for damping is important.
Most universal shaped radial catheters have end holes and may not
demonstrate damping.
4. For patients in which there is high suspicion of LMCA stenosis, the
catheter can be positioned beneath the ostia, and a “cusp” flush of
contrast material in the aortic sinus in an AP or shallow RAO projection may identify an ostial LM stenosis.
5. After catheter engagement, the operator should look for aortic pressure wave deformation (damping). If pressure damping occurs, a
limited contrast flush (1 to 2 mL) and rapid catheter withdrawal
(“hit and run”) during cineangiography should be performed to
obtain a first look (Fig. 3-27). Rarely, aortic pressure damping
occurs without LMCA narrowing because the coronary catheter is
seated deeply and subselectively into the LAD artery. Gradual withdrawal and repositioning of the catheter may eliminate pressure
damping. The absence of reflux of contrast media into the aortic
root on coronary injection is associated with an ostial LMCA stenosis. Some operators have advocated the use of a 6-inch collimated
initial view of the LM performed in shallow LAO to best visualize
the LM ostia for all coronary angiography.
6. Limit the number of coronary injections. Distal coronary artery
anatomy suitable for bypass grafting is assessed from the few views
(usually two or three) that are available. Additional injections
should be kept to a minimum. Two projections, an LAO with cranial
angulation and a steeper RAO with caudal angulation, are usually
sufficient. An LAO-caudal projection for an ostial narrowing is
ECG
200 mm Hg
Ao
0
Ventricularization “hit and run”
Figure 3-27 Damping of aortic (Ao) pressure in the left main coronary
artery (LMCA) with ventricularization in which immediate angiography was
performed with removal of the catheter in a “hit-and-run” maneuver, rapidly
restoring flow and perfusion after contrast media injection.
1 sec
138 3 —
https://t.me/med1917
sometimes better. Occasionally, one image may be sufficient. Frequent catheter engagement of the LMCA segment and contrast jet
stimulation of the lesion may precipitate coronary spasm or occlusion. In less critical LMCA stenosis with 40% to 60% narrowing, FFR
or IVUS may be critically important.
7. After the left coronary views are completed, right coronary angiography is performed. In symptomatic patients with RCA occlusion
and a critical LMCA stenosis, abdominal aortography and insertion
of an intraaortic counterpulsation balloon or percutaneous LV
support device, intensive-care-unit admission, and early CABG
surgery should be strongly considered.
LMCA stenosis:
1. Prevention of hypotension is paramount. If we assume an LMCA
stenosis pressure gradient of 40 mm Hg, aortic diastolic blood pressure of 80 mm Hg, and LV end-diastolic pressure of 10 mm Hg, the
coronary perfusion pressure can be approximated to be 80 − (40 +
10) =
the perfusion pressure can decrease to 10 mm Hg, exacerbating
myocardial ischemia and hypotension, leading to a downward
spiral of LV dysfunction and death.
2. Treat the hypotension of vasovagal reactions immediately. Vagal
reactions can occur during painful sheath removal. Consider a
vascular closure device (VCD) or the radial approach.
3. Administer adequate volumes of intravenous (IV) fluids (at least
1000 mL of normal saline in 4 hours) and monitor the patient’s
blood pressure and urine output.
4. Any signs of ischemia in the postcatheterization period require
immediate evaluation and urgent revascularization. LV support
with an IABP, TandemHeart, or Impella pump should be strongly
considered.
5. Change the patient’s admission status and monitor patient in an
intensive care unit.
6. Consult the cardiothoracic surgeon to determine the best timing
for CABG surger y. If a problem should develop, immediate communication between the cardiologist and surgeon makes a crucial
difference in timing for urgent intervention.
7. Under urgent conditions or complicating comorbidities that preclude urgent surgery, LM stenting may be lifesaving.
Coronary Angiography and Ventriculography
Important points for postcatheterization care of the patient with
30 mm Hg. If diastolic blood pressure decreases to 60 mm Hg,
Angiography of Common
Coronary Anomalies
Coronary artery anomalies should be considered when on a routine
angiography there appears to be a missing coronary artery or a large
area of myocardium that is not perfused by visible vasculature. It is an
error to assume that a vessel is occluded when it has not been visualized because of an anomalous origin. Because the natural history of
a patient with an anomalous origin of a coronary artery may depend
on the initial course of the anomalous vessel, it is the angiographer’s
responsibility to define accurately the origin and course of the vessel.
Historically, the simple “dot and eye” method for determining the
proximal course of an anomalous artery was performed using RAO
ventriculography and/or aortography. During the injection, the location of the dot and eye in relation (anterior or posterior) to the aorta
aids in determination of the vessel course. Placement of right-sided
catheters or injection of contrast material into the PA is unnecessary
and often misleading. Among all coronary anomalies, the highest
https://t.me/med1917
potential for adverse sequelae is with an anomalous vessel that runs
an interarterial course. These malignant variants can manifest in
young individuals as sudden cardiac death, angina, syncope, angina,
myocardial infarction, acute pulmonary edema, dyspnea, and palpitations. The mechanism causing myocardial ischemia appears to be the
slit-like opening in the aortic wall that narrows further during activity
with dynamic compression of the obliquely arising LMCA ostium as it
courses between the aortic root and the root of the pulmonary trunk.
The performance of CTA or magnetic resonance imaging/angiography
(MRI/A) studies should be considered when angiography is unclear
in confirming the diagnosis of specific anomalies of the coronary
vasculature.
3 —
Coronary Angiography and Ventriculography 139
Absent Left Main Trunk (Separate Ostia of
Left Anterior Descending and LCX)
Likely the most common coronary anomaly (incidence ~0.47%), separate ostia of the two major branches of the LCA is often referred to as
a “double barrel” LM. Subselective cannulation of only one branch
may mistakenly lead one to believe there to be an occlusion of the
other. If the LAD is subselectively cannulated, the catheter should be
pulled back into the aorta and clockwise torque administered to gain
access into the CFX. If this is unsuccessful, one may opt for a longer
catheter such as a JL5. The converse is true for subselective cannulation of the left CFX: A smaller catheter (JL3.5) can be used to engage
the LAD.
Anomalous Origin of the Circumflex
Coronary Artery
The next most common coronary anomaly (0.45%) is the origin of the
left CFX from the right coronary cusp or from the RCA ostia. This
feature is often suggested during left coronar y angiography when the
operator sees a long LMCA segment (Fig. 3-28) with a presumed small
or trivial CFX branch (sometimes thought to be occluded). When this
occurs, a visual reflex should suggest the following mantra to the
operator: “Gee, that LM seems very long… I wonder if there is an
anomalous CFX?” When the CFX coronary artery arises from the right
coronary cusp or the proximal RCA, it invariably follows a retroaortic
course and passes posteriorly around the aortic root to its normal
position. During RAO ventriculography, aortography, or coronary angiography, the CFX artery is seen “on end,” appearing as a radiopaque
dot posterior to the aorta. The missing CFX coronary artery is often
found arising from the right coronar y cusp or the proximal RCA and
invariably follows a posterior path, moving behind and around the
aortic root ultimately supplying the lateral wall of the LV. The retroaortic course can be easily seen in the RAO projection as the CFX moves
leftward and behind the aorta (Fig. 3-29).
For all artery pathways that travel behind the aorta, the RAO
projection during left ventriculography, aortography, or coronary angiography will visualize the artery on end and appear as a radiopaque
“dot” posterior to the aorta. The anomalous CFX from the RCA is a
benign variant of no clinical significance unless a significant stenosis
is also present.
This variant is benign.
Anomalous Origin of the Left Main Coronary
Artery from the Right Sinus of Valsalva
This very rare anomaly (0.02%) can be malignant depending on its
course. Although most variants are benign, it is imperative to exclude
140 3 —
https://t.me/med1917
Coronary Angiography and Ventriculography
A
B
Figure 3 -28
left anterior descending (L AD) with 70% stenosis. The circumflex (CFX) is
not visible. B, Long LM artery segment with stenosis. Note that the CFX is
not evident. (Reprinted with permission from the Cath Lab Digest, copyright
HMP Communications.)
A, Left anterior oblique (LAO) projection of left main (LM) and
the interatrial course of this anomaly. When the LMCA arises from the
right sinus of Valsalva or the proximal RCA, it may follow one of four
pathways (Table 3-2):
1. Septal course (benign): The LMCA runs an intramuscular course
through the septum along the floor of the RV outflow tract (RVOT)
https://t.me/med1917
3 —
Coronary Angiography and Ventriculography 141
A
B
Figure 3 -29
artery can be seen originating in the proximal ostial part of the right coronary
artery (RCA) in the left anterior oblique (L AO) projection. B, Right anterior
oblique (RAO) projection of RCA with anomalous CF X traveling behind the
aorta, looping around to the lateral aspect of the heart. (Reprinted with
permission from the Cath Lab Digest, copyright HMP Communications.)
(Fig. 3-30). It then surfaces in the mid septum, at which point it
branches into the LAD artery and left CFX artery. Because the
artery divides in the mid septum, the initial portion of the CFX
artery courses toward the aorta (the normal position of the proximal LAD), and the LAD artery is relatively short (i.e., only the mid
A, In the same patient as in Figure 3 -28, the circumflex (CF X)
142 3 —
“Eye”
https://t.me/med1917
Table 3 -2
Coronary Angiography and Ventriculography
Radiographic Appearance of Anomalous Origin of the Left
Main Coronary Artery from the Right Sinus of Valsalva
Right Anterior Oblique Aortography or Ventriculography
Course of
LMCA Dot Eye
Septal
Anterior
Retroaortic
Interarterial
+, Present; −, absent. Posterior and anterior are in reference to t he aorta root. CFX ,
Circumflex coronar y ar tery; LAD, lef t anterior descending coronary arter y; LMCA, left
main coronar y arter y.
− + (Upper CF X)
(lower LMCA)
− + (Upper LMCA)
(lower CFX)
+ (Posterior) −
+ (Anterior) −
LAD
Length
Short Yes
Short No
Normal No
Normal No
M
Septal Branches
Arising from
LMCA
C
S
L
Figure 3-30 Diagram of septal course of anomalous left coronary artery
(LCA). C, Circumflex; L, left anterior descending artery; M, left main; S,
septals.
M
Figure 3 -31 Diagram of anterior course of anomalous left coronary artery
(LCA). C, Circumflex; L, left anterior descending artery; M, left main.
and distal LAD are present). During RAO ventriculography, aortog-
“Eye”
C
L
raphy, or coronary angiography, the LMCA and the CFX coronary
artery form an ellipse (similar to the shape of an eye) to the left of
the aorta. The LMCA forms the inferior portion and the CFX artery
forms the superior portion. Septal perforating arteries are evident
branching from the LMCA.
2. Anterior free wall course (benign): The LMCA crosses the anterior
free wall of the right ventricle and then divides at the mid septum
into the LAD and CFX arteries (Fig. 3-31). Because the artery divides
Соседние файлы в папке Библиотека им академика М.И. Перельмана