Invasive Cardiac Procedures and Equipment
This domain covers the tools and steps of diagnostic and interventional catheterization. Know catheter types (pigtail, Judkins, Amplatz, multipurpose), guidewire characteristics (hydrophilic vs. support), sheath sizing, and the sequence of a diagnostic study: access, engagement, pressure measurement, angiography, and hemostasis. Understand contrast properties, injection rate and volume, and the trade-off between opacification and contrast load. Interventional concepts include balloon angioplasty, stent deployment and post-dilation, fractional flow reserve, intravascular imaging, and the basics of structural procedures such as TAVR and ASD closure.
Expect questions on equipment selection for a given anatomy, radiation dose reduction (collimation, lower frame rates, pulsed fluoroscopy), and recognizing complications like dissection, perforation, no-reflow, and air embolism. Traps include choosing an oversized sheath, confusing FFR with a purely anatomic measure, and forgetting that stent sizing follows the reference vessel diameter with appropriate post-dilation for expansion.
Rule of thumb: FFR ≤ 0.80 indicates a hemodynamically significant lesion. Worked example: a 70% angiographic stenosis with FFR 0.75 is functionally significant and warrants revascularization, whereas the same lesion with FFR 0.88 is deferred - the pressure wire, not the visual estimate, drives the decision. Match the tool to the task and always weigh benefit against contrast and radiation burden.