CARDIAC CATHETERIZATION Flashcards
What constitutes cardiac catheterization?
Cardiac catheterization typically includes:
* Coronary angiogram
* Left heart catheterization
* Left ventricular (LV) angiogram
* Right heart catheterization
Coronary angiogram involves opacification of coronary arteries with iodinated contrast after selective cannulation.
What is a coronary angiogram?
Opacification of coronary arteries with iodinated contrast after selective cannulation using specialized end-hole catheters
Catheters are inserted via peripheral arterial access, usually femoral or radial.
What is the purpose of left heart catheterization?
To place a catheter within the LV to record LV systolic and end-diastolic pressures.
Why are most operators shying away from routinely performing LV angiogram?
To minimize contrast use and radiation exposure, especially when the same information can be obtained from an echocardiogram.
What are the indications for coronary angiogram?
Indications include:
* Candidates for coronary revascularization
* Unacceptable ischemic symptoms despite optimum medical therapy
* Suspected symptomatic CAD with indeterminate stress test results
* Unexplained left ventricular systolic dysfunction
* Stress testing suggesting multivessel disease.
What are the major complications of cardiac catheterization?
Major complications include:
* Death
* Periprocedure stroke
* Myocardial infarction
* Mechanical ventilation
* Major vascular complications
* Other risks include radiation exposure, contrast-induced nephropathy.
What percentage risk is there for any major complication during cardiac catheterization?
< 1%
What is the risk of procedural mortality during cardiac catheterization?
Approximately 1 in 1000.
Which patients should be premedicated to prevent allergic reactions to iodine-based contrast?
Patients with a history of true allergic reactions to iodine-based contrast.
What is the common premedication regimen for allergic patients?
50 mg prednisone orally at 13, 7, and 1 hour prior to the procedure, and 50 mg diphenhydramine an hour prior.
What are the major risk factors for contrast-induced nephropathy (CIN)?
Major risk factors include:
* Preexisting renal disease
* Diabetes.
What is the most important method to reduce the risk of contrast nephropathy?
Periprocedure hydration.
How are coronary angiographic projections named?
Named according to the position of the image intensifier and degree of angulation.
What does LAO stand for in angiographic projections?
Left anterior oblique.
What is considered a significant stenosis for the left main coronary artery (LMCA)?
≥ 50% diameter stenosis.
What is considered a significant stenosis for other coronary arteries?
≥ 70% diameter stenosis.
What does fractional flow reserve (FFR) measure?
The ratio of distal coronary pressure to proximal aortic pressure after maximal hyperemia.
What FFR value indicates a physiologically significant stenosis?
A ratio less than 0.75 to 0.80.
What is the significance of a coronary flow reserve decrease?
Begins to decrease when a coronary artery stenosis is 50% or more of the luminal diameter.
What is the role of quantitative coronary angiography (QCA)?
More objectively assesses lesion severity than ocular judgment.
What are the standard angiographic views to image the left coronary system?
Best visualized in AP projection with slight caudal angulation.
What is the initial imaging view for the right coronary artery (RCA)?
LAO 30-degree view.
What access is increasingly used over femoral access for cardiac catheterization?
Radial access.
What are the benefits of radial access for cardiac catheterization?
Lower incidence of vascular complications such as bleeding.
What does FFR stand for?
Fractional flow reserve
FFR is a measure used to assess the physiological significance of coronary artery stenosis.
What is the normal value range for FFR?
Close to 1
A ratio less than 0.75 to 0.80 indicates a physiologically significant stenosis.
What is considered a physiologically significant stenosis based on FFR values?
Less than 0.75 to 0.80
What is the relationship between the size of the myocardium supplied by a vessel and FFR significance?
The larger the myocardium, the more likely it will be found functionally significant by FFR.
What is the effect of an FFR-guided revascularization approach?
It significantly reduces overall costs, the number of stents placed, and the need for urgent revascularization.
What does iFR stand for?
Instantaneous wave-free ratio
iFR is a method to assess coronary artery lesions without the use of adenosine.
How does iFR differ from FFR?
iFR measures pressures during a specific diastolic interval, while FFR measures during maximal hyperemia induced by adenosine.
What is the cutoff ratio for significant stenosis in iFR?
Less than 0.90
What is the purpose of intravascular ultrasound (IVUS)?
To provide direct assessment of coronary arterial vasculature
IVUS utilizes a flexible catheter with a miniature ultrasound probe.
What can IVUS accurately assess regarding plaque morphology?
Plaque types ranging from fatty to fibrotic to calcific.
What is a key advantage of using IVUS in percutaneous coronary intervention?
It helps ensure optimal stent expansion and apposition, leading to decreased stent failure.
What imaging technique uses near-infrared light to assess arterial anatomy?
Optical coherence tomography (OCT)
OCT provides higher resolution images compared to IVUS.
What is a disadvantage of OCT compared to IVUS?
OCT requires the absence of blood in the visualized portion of the artery for image acquisition.
How is aortic regurgitation assessed during cardiac catheterization?
By performing an aortogram and noting the amount of contrast regurgitating into the left ventricle.
What is the grading scale used for regurgitation assessment?
1 to 4 system
1 indicates little if any regurgitation, while 4 indicates profound or severe regurgitation.
What are the three methods used to describe the aortic transvalvular gradient?
- Peak instantaneous gradient
- Peak-to-peak gradient
- Mean gradient
What are vascular closure devices (VCDs)?
Hemostatic devices that reduce the need for prolonged compression at the femoral access site.
What is intracardiac echo (ICE)?
Direct imaging of cardiac structures via transvenous insertion of a miniaturized echo probe.
What are some key tips for performing cardiac catheterization?
- Advance catheters only with a wire ahead
- Remove catheters with the wire ahead
- Do not advance equipment if resistance is felt
- Ensure catheters are suctioned and flushed before angiograms
- Visualize pressure tracings to check for dampening
What is the role of adenosine in FFR measurement?
To achieve maximal hyperemia in the coronary microcirculation.
What is a potential drawback of adenosine administration during FFR?
It can have side effects in certain patients and increases procedure duration.
