Let Diagnostics Be Your Guide: Nine Tips For Successful Coronary Angiographic Assessment
“Dreams are extremely important. You can’t do it unless you imagine it.” — George Lucas
As I was interviewing for interventional fellowship, program directors all stressed the concept that mastering my performance of diagnostic angiography would lead to an overall optimal intervention strategy. The same theme sounded throughout several conferences designed for trainees that I have attended, where I heard numerous speakers highlight the noticeable differences between angiography when performed by a nonproceduralist versus an interventionalist. In planning my interventions now, I’ve taken many ideas from these experts and now have an arsenal of advice that I draw on for continued success.
1. Consider patient size when selecting a diagnostic catheter
Your catheter should be engaged in a coaxial fashion with the coronary ostium and should “seat” well, allowing contrast injections to fill the artery lumen. For the left coronary and dilated aortic root, a JL 5 might be appropriate, whereas a JL 3.5 might seat better in short aortic root. Some noninterventionalists use 4-Fr and 5-Fr catheters, as images obtained with a 4 Fr seem to be of equal quality as those attained with a 6 Fr when automated contrast injection is available. But keep in mind: manifold contrast injections can reduce image quality.Smaller catheters can provide good angiographic images in lean patients, but 6-Fr catheters are preferable in those who are overweight.
2. Thoughtfully approach tortuosity
If you decide to practice a pure radialist strategy, you may encounter patients with tortuous aortas that make it difficult to torque the catheter. In some instances, to maintain the 0.035-inch J guidewire into the catheter, aim to position the catheter close to the ostium. In other instances, EBU 3.0 guides with the 0.035-inch J wire might be needed to “amplatz” the catheter around the left ostium. Another alternative is the use of a 0.014-inch wire, which will also help in cases of coronary ostium anomalies.
3. Do not hesitate to use guide catheters
Guide catheters have larger inner diameters and can opacify the vessel well. This is often beneficial when treating hemodialysis patients with arteriovenous fistulas. An under-filled artery may not demonstrate the real severity of stenosis.
4. Use nitroglycerine liberally
Utilizing intracoronary vasodilators to evaluate catheter-induced vasospasm and pseudostenosis or to properly assess the size of the vessels can enable you to better understand the extension of the diseased vessel. In case of tortuous arteries, ensure more angiographic views exposing all segments of the vessel and side branches in at least two orthogonal views.
5. Adjust your view prior to the cine acquisition
A contrast puff can assist in changing your traditional cranial/caudal angulation. In overweight patients, views like the spider view will be grainy and not clear enough due to body habitus. The use of lateral views is sometimes necessary to expose ostial disease.
6. Avoid panning of the table during cine run
Doing so can reduce the motion artifact during imaging. This also important in chronic total occlusions to study the collateral flow.
7. Slow the heart rate
In cases with supraventricular tachycardia or rapid A-fib, reducing the heart rate can better show the degree of stenosis and TIMI flow.
8. Use filters and shutters to minimize lung density interference
Also, do not allow EKG electrodes or wires to appear in the images, as these can obscure segments of the coronary vessels.
9. Adapt your eyesight vision to low fluoroscopy settings
In the current era of long complex interventions, adhering to radiation safety recommendations by using low fluoroscopy settings and obtaining cine images at 7.5 frames/second will decrease your radiation exposure.