Coronary angiography left coronary artery

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Coronary Angiography

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General Principles

Overview
Historical Perspective
Contraindications
Appropriate Use Criteria for Revascularization
Complications
Technique
Film Quality

Anatomy & Projection Angles

Normal Anatomy

Coronary arteries
Dominance
Right System
Left System
Left Main
Left Anterior Descending
Circumflex
Median Ramus

Anatomic Variants

Separate Ostia
Anomalous Origins
Case Example
Fistula

Projection Angles

Standard Views
Left Coronary Artery
Right Coronary Artery

Epicardial Flow & Myocardial Perfusion

Epicardial Flow

TIMI Frame Count
TIMI Flow Grade
TIMI Grade 0 Flow
TIMI Grade 1 Flow
TIMI Grade 2 Flow
TIMI Grade 3 Flow
TIMI Grade 4 Flow
Pulsatile Flow
Deceleration

Myocardial Perfusion

TIMI Myocardial Perfusion Grade
TMP Grade 0
TMP Grade 0.5
TMP Grade 1
TMP Grade 2
TMP Grade 3

Lesion Complexity

ACC/AHA Lesion-Specific Classification of the Primary Target Stenosis

Preprocedural Lesion Morphology

Eccentricity
Irregularity
Ulceration
Intimal Flap
Aneurysm
Sawtooth Pattern
Length
Ostial location
Angulation
Proximal tortuosity
Degenerated SVG
Calcification
Total occlusion
Coronary Artery Thrombus
TIMI Thrombus Grade
TIMI Thrombus Grade 0
TIMI Thrombus Grade 1
TIMI Thrombus Grade 2
TIMI Thrombus Grade 3
TIMI Thrombus Grade 4
TIMI Thrombus Grade 5
TIMI Thrombus Grade 6

Lesion Morphology

Quantitative Coronary Angiography
Definitions of Preprocedural Lesion Morphology
Irregular Lesion
Disease Extent
Arterial Foreshortening
Infarct Related Artery
Restenosis
Degenerated SVG
Collaterals
Aneurysm
Bifurcation
Trifurcation
Ulceration

Left ventriculography

Technique
Quantification of LV Function
Quantification of Mitral Regurgitation

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

The left main coronary artery gives rise to the left anterior descending (LAD) artery and the left circumflex coronary (LCx) artery. Complete visualization of these arteries and their branches requires care and rigor to ensure complete anatomical documentation. Often bifurcations and vessel foreshortening and overlap cause errors in stenosis estimation. There are no steadfast rules in which tomographic views are most useful. Generally, for circumflex and proximal epicardial visualization, the caudal views are most useful. For LAD and LAD/diagonal bifurcation visualization, the cranial views are most useful. Overall, if there is not a significant limitation on contrast utilization, standard 'around the world' angiography using a selection of the following angiographic views will document left coronary anatomy.

How to Engage the Left Coronary Artery

The left main coronary artery is typically cannulated in the 30° RAO position. Using the femoral arterial approach, a Judkins Left 4 (JL4) catheter is used to engage the left coronary artery. The JL catheter usually requires no manipulation other than a simple forward push by the operator. Variations in aortic root size may prevent selective engagement of the left main coronary artery and catheters of different sizes may be utilized accordingly. Variations in the location of ostium and orientation of left main stems may lead to difficult catheter engagement. For superiorly directed left main stems, a shorter Judkins catheter may be used, while inferiorly directed left main stems are engaged by a longer JL catheter or a left Amplatz catheter. If the ostium of the left main coronary artery has a posterior trajectory, a left Amplatz catheter may engage better.

Optimal Views of the Left Coronary Artery

An uniform sequence of four views is obtained to visualize the left coronary artery and its branches.

  1. RAO caudal view to visualize the left main, proximal LAD, and proximal LCx
  2. RAO cranial view to visualize the middle and distal LAD and diagonals
  3. LAO cranial view to visualize the middle and distal LAD in an orthogonal projection and the ostium of the left main
  4. LAO caudal view to visualize the left main and proximal LAD, ramus intermedius, and LCx

Right Anterior Oblique (RAO) Caudal

The RAO caudal view is considered as the best view for the initial injection of the left system. The left main coronary artery, the ostium and proximal segment of the left anterior descending artery, and the circumflex and obtuse marginal branches are optimally visualized. RAO caudal view is also the best overall view to assess the myocardial perfusion or blush of the left circumflex territory. However, this view obscures the origins of the diagonals and foreshortens the middle and distal segments of the left anterior descending artery. In this view, the system in question appears angiographically to the right of the spine. This is traditionally the first view that is obtained in case the patient becomes critically ill after the injection because the left main, the left anterior descending artery and the left circumflex artery are all well visualized.

LCA 30 RAO CAU .png
LCA 30 RAO CAU .gif

Diag= Diagonal artery; LAD= Left anterior descending artery; LCx= Left circumflex artery; LM= Left main artery; OM= Obtuse marginal artery.

Right Anterior Oblique (RAO) Cranial

The RAO cranial view clearly lays out the middle and distal segments of the left anterior descending artery as well as the origins of the diagonals. In general, the RAO cranial projection is not useful for visualizing the left circumflex artery except in cases of left dominant circulations in which case it may provide a view of the left posterior descending artery. The RAO cranial view is the best overall view to assess the myocardial perfusion grade or myocardial blush of the left anterior descending artery (LAD), as it minimizes intra- and inter-arterial overlap. In this view, the arterial system lies to the right of the spine. It is optimal to obtain the greatest cranial angulation possible to minimize the overalp of the circumflex artery. The magnitude of RAO angulation can be minimal (5° - 15°).

LCA 30 RAO CRA.png
LCA 30 RAO CRA.gif

Diag= Diagonal artery; LAD= Left anterior descending artery; LCx= Left circumflex artery; LM= Left main artery; OM= Obtuse marginal artery.

Left Anterior Oblique (LAO) Cranial

The LAO cranial view provides a clear view of the middle and distal segments of the left anterior descending artery and the origins of the diagonals. It also exposes the ostium of the left main coronary artery. However, the proximal segments of the left anterior descending artery is usually foreshortened thus requiring additional LAO angulation. In this view, the system in question appears angiographically to lie to the left of the spine with a slight anterior angulation.

LCA 30 LAO CRA.png
LCA 30 LAO CRA.gif

Diag= Diagonal artery; LAD= Left anterior descending artery; LCx= Left circumflex artery; LM= Left main artery; OM= Obtuse marginal artery.

Left Anterior Oblique (LAO) Caudal

The LAO caudal view is also referred to as the 'spider view' and offers visualization of the left main coronary artery and the proximal segments of the left anterior descending artery, the ramus intermedius, and the left circumflex artery. In this view, the system in question appears angiographically to lie to the left of the spine with a slight inferior angulation.

LCA 30 LAO CAU.png
LCA 30 LAO CAU.gif

Diag= Diagonal artery; LAD= Left anterior descending artery; LCx= Left circumflex artery; LM= Left main artery; OM= Obtuse marginal artery.


References



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