Cardiac Interventional Procedures and Equipment
Catheters, wires, and access
Diagnostic coronary engagement typically uses Judkins Left (JL) and Judkins Right (JR) curves matched to aortic root size; the JL seats in the left main and the JR in the RCA. Amplatz curves help with upward or horizontal take-offs and anomalous origins. Radial access reduces access-site bleeding but increases radial spasm, a frequent question stem. Coronary guidewires are usually 0.014 inch; peripheral and drainage work often uses 0.035 inch. Sheath French size reflects outer diameter (1 Fr = 0.33 mm), so a 6 Fr sheath has a limited inner lumen that constrains device compatibility.
Procedures
Balloon angioplasty is sized roughly 1:1 to the reference vessel; stents are deployed at nominal pressure and post-dilated for apposition. Physiologic assessment: FFR of 0.80 or less is generally significant; iFR of 0.89 or less is significant. IVUS and OCT characterize plaque and stent expansion. Rotational or orbital atherectomy is used for calcified lesions; thrombectomy for heavy thrombus. Structural work includes TAVR, mitral balloon valvuloplasty, ASD/PFO closure, and pericardiocentesis.
Anticoagulation and support
ACT targets are commonly 250-300 s for PCI and higher with glycoprotein IIb/IIIa inhibitors. Mechanical support is chosen by physiology: IABP augments diastolic perfusion and reduces afterload; Impella provides continuous forward flow.
Traps
- Assuming a larger French catheter always means a larger usable lumen.
- Confusing FFR (physiologic) with angiographic stenosis severity.
- Ignoring balloon compliance and rated burst pressure when sizing.
Rule of thumb
A lesion that looks 60% but has FFR 0.75 is usually treated; one that looks 80% but has FFR 0.85 may be managed medically.