Coronary anatomy: Difference between revisions

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For collateral connections, it is necessary to make longer angiographic projections. In a RCA obstruction, intercoronary collaterals can form between the septal branches of the LAD and the RDP through the interventricular septum. Collaterals connecting distal portions of two arteries are frequently observed, p.e. connections between the distal RCx and RCA in the interventricular groove and between diagonal branches of the LAD. A collateral between the conus branch of the RCA to the proximal LAD is called a ring of Vieussens. Atrial branches from the RCA or the Kugel’s artery (mostly an small artery arising from proximal RCA anastomosing with branches of sinus node artery) can form connections between the proximal and distal RCA.
For collateral connections, it is necessary to make longer angiographic projections. In a RCA obstruction, intercoronary collaterals can form between the septal branches of the LAD and the RDP through the interventricular septum. Collaterals connecting distal portions of two arteries are frequently observed, p.e. connections between the distal RCx and RCA in the interventricular groove and between diagonal branches of the LAD. A collateral between the conus branch of the RCA to the proximal LAD is called a ring of Vieussens. Atrial branches from the RCA or the Kugel’s artery (mostly an small artery arising from proximal RCA anastomosing with branches of sinus node artery) can form connections between the proximal and distal RCA.


=Time-out procedure=


In surgery, the use of a pre-operative checklist has improved the outcome. Implementation of a 19-item surgical safety checklist improved team communication and reduced rates of death and complications in patients undergoing noncardiac surgery<cite>Haynes</cite>. Implementation of a comprehensive preoperative checklist targeting the entire surgical pathway (including items such as medication, marking of operative side and the use of postoperatieve instructions) was associated with a reduction in surgical complications and mortality in hospitals with a high standard of care<cite>deVries</cite>.
Although the goal of most procedures in interventional cardiology is to access the heart and its associated vasculature (making wrong site procedures less of a concern), a preprocedure checklist is also recommended in the catheterization laboratory<cite>Naidu</cite>. Information obtained preprocedural should include procedural indication, patients history, informed consent, a review of medication (in particular antiplatelet therapies and metformin) and a risk of bleeding assessment. Renal function should be less than 90 days old. If the patient is using VKA an INR is obtained < 24 preprocedural.  Images of prior catheterizations are obtained and procedural reports of any coronary or peripheral bypass surgery reviewed. The history should be reviewed for previous heparin-induced thrombocytopenia (HIT). Allergies should be checked, especially contrast allergies or allergies to medication used periprocedural (p.e. heparin). Each laboratory has a protocol for preventing contrast allergic reaction (using p.e. Prednison and an antihistaminic).
Before procedure a time-out procedure is performed by all team members before vascular access is obtained. Patient identification should be checked and confirmed and agreement on the right procedure obtained. Figure 1 shows a sample of a time-out checklist.
Figure 1
<br/>
Sample ‘‘Time Out’’ Preprocedure Checklist
The physician taking ultimate responsibility for the procedure should lead the Time Out and ensure each of the following items is announced:
#Patient’s name and medical record number
#Procedure to be performed (e.g., left heart catheterization, coronary angiography, right heart catheterization)
#Route to be used (e.g., right femoral artery)
#Confirm that the equipment needed is available or alternatives are available including intended stent type for PCI or cath-possible patients
#Patient’s allergies and premedication if appropriate (e.g., heparin-induced thrombocytopenia, contrast allergy)
#Special laboratory or medical conditions (e.g., elevated INR, chronic kidney disease)
=Left ventriculography=
Left ventriculography provides information about global and segmental left ventricular function and mitral regurgitation, and some other abnormalities (ventricular septal defect, hypertrophic cardiomyopathy, left ventricular thrombi)<cite>Baim</cite>.
''Technique''
<br/>
The large amount of contrast that is needed in short time, is delivered by a pigtail catheter with multiple side holes. The RAO 30° projection is used without magnification. The catheter is placed on the aortic valve with a guidewire, retracted a few centimeters in the catheters. After pushing the pigtail on the valve until bending, it is retracted slowly while being rotated clockwise, untill passing into the left ventricle (figure 1<cite>Hartcatheterisatie</cite>). The optimal catheter position is midcavitary. About 35 ml of contrast is delivered at 10ml/second at a PSI of maximal 1000 at RAO 30° and LAO 60°. Left ventriculography can be performed with normal quiet breathing (in LAO, the diaphragm can be obstructive during expiration).
''Interpretation''
<br/>
The left ventriculogram is analysed qualitatively on a sinus beat following a previous sinus beat since ectopic of postectopic beats give a false impression of ventricular function. Overall ventricular function is described. In RAO view, the anterolateral, apical, inferior and posterobasal segment can be seen, in LAO view the posterolateral, lateral and septal segments (figure 1). The degree of mitral regurgitation can be estimated.
''Complications''
<br/>
It is normal for the patient to experience a hot feeling due to powerful vasodilatation of the contrast. Ventricular extrasystoles occur frequently but also ventricular tachycardia or ventricular fibrillation can occur. The pigtail can be placed under chordae (catheter close to inferior wall). If it is placed under the papillary muscles with a side hole firmly against the endocardium, deposition of contrast material within the endocardium and myocardium can occur, leading rarely to myocardial perforation. A possible complication that can lead to death is the injection of air (air embolism). If the catheter is placed in the left ventricular outflow tract, a left anterior fascicular block can occur, leading to complete heart block in pre-existing right bundle branch block and left posterior fascicular block.
Figure 1
[[File:TimeOut_figure1.png]]
Figure 2
Figure 3


= References =
= References =
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#Jukema4 Jukema JW, Vliegen HW, Bruschke AVG. Coronary angiography: principles, technique and interpretation. 1e druk, Leiden, the Netherlands, 2009. Chapter 3: 23-34.
#Jukema4 Jukema JW, Vliegen HW, Bruschke AVG. Coronary angiography: principles, technique and interpretation. 1e druk, Leiden, the Netherlands, 2009. Chapter 3: 23-34.
#Jukema5 Jukema JW, Vliegen HW, Bruschke AVG. Coronary angiography: principles, technique and interpretation. 1e druk, Leiden, the Netherlands, 2009. Chapter 4: 35-40.
#Jukema5 Jukema JW, Vliegen HW, Bruschke AVG. Coronary angiography: principles, technique and interpretation. 1e druk, Leiden, the Netherlands, 2009. Chapter 4: 35-40.
#Haynes pmid=19144931
#deVries pmid=21067384
#Naidu pmid=22434598
#Baim Baim DS. Grossman’s cardiac catheterization, angiography, and intervention. 7th edition 2006. Lipincott Williams & Wilkins, Philadelphia PA USA. Chapter 12: 222-233.
#Hartcatheterisatie https://www.mst.nl/opleidingcardiologie/modules/hartcatheterisatie/
</biblio>
</biblio>

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