Coronary catheterization
| Coronary catheterization | |
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|---|---|
| Coronary catheterization:Left coronary artery injection |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Coronary Anatomy
Standard Angiographic Views
How to Assess Epicardial Coronary Blood Flow
How to Assess Myocardial Perfusion
- TIMI myocardial perfusion grade 0
- TIMI myocardial perfusion grade 1
- TIMI myocardial perfusion grade 2
- TIMI myocardial perfusion grade 3
How to Assess Thrombus or Clot
- Complications during and following cardiac catheterization
- Angiogram
- Suggested angiographic projections
- Congenital anomalies of the coronary circulation
- Anomalous origins of coronary arteries
- ST Elevation Myocardial Infarction Coronary Angiography
Coronary catheterization is an invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional (treatment) purposes. Coronary catheterization is one of the several cardiology diagnostic tests and procedures. Specifically, coronary catheterization is a visually interpreted test performed to recognize occlusion, stenosis, restenosis, thrombosis or aneurysmal enlargement the coronary artery lumens, heart chamber size, heart muscle contraction performance and some aspects of heart valve function. Important internal heart and lung blood pressures, not measurable from outside the body, can be accurately measured during the test. The relevant problems that the test deals with most commonly occur as a result of advanced atherosclerosis, atheroma activity within the wall of the coronary arteries. Less frequently, other issues, valvular, heart muscle or arrhythmia issues are the primary focus of the test.[1] [2] [3] [4]
Coronary artery luminal narrowing reduces the flow reserve for oxygenated blood to the heart, typically producing intermittent angina if very advanced; luminal occlusion usually produces a heart attack. However, it has been increasingly recognized, since the late 1980s, that coronary catheterization does not allow the recognition of the presence or absence of coronary atherosclerosis itself, only significant luminal changes which have occurred as a result of end stage complications of the atherosclerotic process. See IVUS and atheroma for a better understanding of this issue.
Essentials of Optimal Coronary Angiographic Projections
It is very important that the injection of contrast is delayed until fluoroscopy commences in order to identify calcification or staining of contrast. The acquisition should continue until the contrast has cleared from the arterial tree. Slightly longer acquisition times are needed for evaluation of TIMI Frame Count and TIMI Myocardial Perfusion Grade before and after treatment in percutaneous coronary interventions. Also, an important determinant of the length of injection is the need to visualise collaterals for occluded vessels.
Suggested Angiographic Projections
Congenital Anomalies of the Coronary Circulation
Therapeutic procedures
By changing the diagnostic catheter to a guiding catheter, physicians can also pass a variety of instruments through the catheter and into the artery to a lesion site. The most commonly used are 0.014 inch diameter guide wires and the balloon dilation catheters, see angioplasty.
By injecting radiocontrast agent through a tiny passage extending down the balloon catheter and into the balloon, the balloon is progressively expanded. The hydraulic pressures are chosen and applied by the physician, according to how the balloon within the stenosis responds. The radiocontrast filled balloon is watched under fluoroscopy (it typically assumes a "dog bone" shape imposed on the outside of the balloon by the stenosis as the balloon is expanded), as it opens. As much hydraulic brute force is applied as judged needed and visualized to be effective to make the stenosis of the artery lumen visibly enlarge.
Typical normal coronary artery pressures are in the <200 mmHg range (27 kPa). The hydraulic pressures applied within the balloon may extend to as high as 19000 mmHg (2,500 kPa). Prevention of over-enlargement is achieved by choosing balloons manufactured out of high tensile strength clear plastic membranes. The balloon is initially folded around the catheter, near the tip, to create a small cross-sectional profile to facilitate passage though luminal stenotic areas and designed to inflate to a specific pre-designed diameter. If over inflated, the balloon material simply tears and allows the inflating radiocontrast agent to simply escape into the blood.
Additionally, several other devices can be advanced into the artery via a guiding catheter. These include laser catheters, stent catheters, IVUS catheters, Doppler catheter, pressure or temperature measurement catheter and various clot and grinding or removal devices. Most of these devices have turned out to be niche devices, only useful in a small percentage of situations or for research.
Stents, which are specially manufactured expandable stainless steel mesh tubes, mounted on a balloon catheter, are the most commonly used device beyond the balloon catheter. When the stent/balloon device positioned within the stenosis, the balloon is inflated which, in turn, expands the stent and the artery. The balloon is removed and the stent remains in place, supporting the inner artery walls in the more open, dilated position. Current stents generally cost around $1,000 to 3,000 each U.S. 2004 dollars, the drug coated ones being the more expensive.
Advances in catheter based physical treatments
Interventional procedures have been plagued by restenosis due to the formation of endothelial tissue overgrowth at the lesion site. Restenosis is the body's response to the injury of the vessel wall from angioplasty and to the stent as a foreign body. As assessed in clinical trials during the late 1980 and 1990s, using only balloon angioplasty (POBA, plain old balloon angioplasty), up to 50% of patients suffered significant restenosis but that percentage has dropped to the single to lower two digit range with the introduction of drug-eluting stents. Sirolimus and paclitaxel are the two drugs used in coatings which are currently FDA approved in the United States. As opposed to bare metal, drug eluting stents are covered with a medicine that is slowly dispersed with the goal of suppressing the restenosis reaction.
The key to the success of drug coating has been;
- choosing effective agents,
- developing ways of adequately binding the drugs to the stainless surface of the stent struts (the coating must stay bound despite marked handling and stent deformation stresses) and
- developing coating controlled release mechanisms that release the drug slowly over about 30 days.
Postmortem Angiogram of Coronary Arteries
-
Myocardial Infarction: Postmortem angiogram of coronary arteries -
Angiogram: X-ray, horizontal sections of ventricle showing penetrating artery distribution (a quite good example) -
Angiogram: X-ray, postmortem coronary arteries with multiple lesions -
Angiogram: X-ray postmortem normal coronaries -
Angiogram: Postmortem angiogram with apparent lesions in proximal right coronary artery -
Angiogram: X-ray, postmortem injection horizontal slice of left ventricle showing very well penetrating arteries -
Angiogram Saphenous Vein Bypass Graft: X-ray shows rather close-up large vein anastomosing to much smaller artery -
Angiogram Saphenous Vein Bypass Graft: X-ray postmortem injection showing vein anastomosis very well and the vasculature of the right and left ventricles -
Coronary artery: Atherosclerosis: X-ray postmortem extensive lesions in this x-ray of whole heart -
X-Ray Intramyocardial Arteries: X-ray three horizontal slices of ventricles showing quite well the penetrating arteries -
X-Ray Intramyocardial Arteries: X-ray three horizontal slices of ventricles showing quite well the penetrating arteries -
Coronary Artery Anomalous Origin; Left From Pulmonary Artery: Angiogram, postmortem, after switch of left coronary artery to aorta -
Coronary artery: Atherosclerosis: X-ray, postmortem, dissected arteries and extensive lesions -
Coronary artery: Atherosclerosis: X-ray, postmortem, close-up view of artery with extensive lesions (very good example) -
Coronary artery: Atherosclerosis: X-ray, postmortem, dissected artery, lesions in small branches
Related Chapters
- Interventional cardiology
- Cardiology
- TIMI flow grade 0
- TIMI flow grade 1
- TIMI flow grade 2
- TIMI flow grade 3
- TIMI frame count (TFC)
- TIMI myocardial perfusion grade 0
- TIMI myocardial perfusion grade 1
- TIMI myocardial perfusion grade 2
- TIMI myocardial perfusion grade 3
- Thrombus Grading
- Complications during and following cardiac catheterization
- Access site complications
- Angiogram
- Suggested angiographic projections
- Congenital anomalies of the coronary circulation
- Anomalous origins of coronary arteries
- ST Elevation Myocardial Infarction Coronary Angiography
References
- ↑ Connolly JE. The development of coronary artery surgery: personal recollections. Tex Heart Inst J 2002;29:10-4. PMID 11995842.
- ↑ Proudfit WL, Shirey EK, Sones FM Jr. Selective cine coronary arteriography. Correlation with clinical findings in 1,000 patients. Circulation 1966;33:901-10. PMID 5942973.
- ↑ Sones FM, Shirey EK. Cine coronary arteriography. Mod Concepts Cardiovasc Dis 1962;31:735-8. PMID 13915182.
- ↑ Smith SC Jr, Feldman TE, Hirshfeld JW Jr, Jacobs AK, Kern MJ, King SB 3rd, Morrison DA, O'neill WW, Schaff HV, Whitlow PL, Williams DO, Antman EM, Smith SC Jr, Adams CD, Anderson JL, Faxon DP, Fuster V, Halperin JL, Hiratzka LF, Hunt SA, Jacobs AK, Nishimura R, Ornato JP, Page RL, Riegel B; American College of Cardiology/American Heart Association Task Force on Practice Guidelines; ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention. ACC/AHA/SCAI 2005 Guideline Update for Percutaneous Coronary Intervention-Summary Article: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). J Am Coll Cardiol. 2006 Jan 3;47(1):216-35. PMID 16386696
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