Cath Lab Basics and Coronary Anatomy
Understand the coronary tree and what happens in the cath lab — enough to follow up, spot complications, and escalate.
Learning Objectives
- 1.Describe the major coronary arteries and dominance.
- 2.Understand what diagnostic catheterization involves.
- 3.Recognize post-cath complications and when to escalate.
Overview
You won’t do the cath, but you’ll consent-adjacent conversations, follow these patients, and catch complications. Knowing the coronary map and the lab workflow makes you useful and safe.
Coronary anatomy
- •Left main (LM) → branches into the LAD and the left circumflex (LCx).
- •LAD supplies the anterior wall and septum (diagonal branches).
- •LCx supplies the lateral wall (obtuse marginal branches).
- •Right coronary artery (RCA) supplies the inferior wall and, in most people, the AV node.
- •Dominance = which artery gives the posterior descending artery (right-dominant in ~85%).
What the cath does
- •Diagnostic coronary angiography defines the coronary anatomy and stenoses.
- •Access via the radial (preferred) or femoral artery.
- •Can proceed to PCI in the same setting if indicated (see PCI Concepts).
Post-cath complications to recognize
- •Access site: bleeding, hematoma, pseudoaneurysm; retroperitoneal bleed (femoral) — back/flank pain, hypotension.
- •Limb ischemia distal to the access site.
- •Contrast-associated kidney injury; contrast/allergic reactions.
- •Recurrent chest pain (possible acute closure/stent thrombosis if stented).
Escalate
Active access bleeding, an expanding mass, a cold/painful limb, hypotension (consider retroperitoneal bleed), or recurrent chest pain are emergencies — escalate immediately.
Scope
This is conceptual understanding for follow-up, complication recognition, and escalation. APPs do not perform these procedures, program devices beyond recognition/triage, or read raw images — those are the proceduralist’s/imager’s role.
Common beginner mistakes
- •Missing a retroperitoneal bleed (hypotension + back/flank pain after femoral access).
- •Dismissing recurrent post-PCI chest pain.
- •Not checking renal function/hydration around contrast.
Nurse / MA workflow connection
- •Nurses run post-cath access checks and calls; you interpret concerns and escalate complications.
Mini cases
A few hours after femoral cath, the patient becomes hypotensive with new back/flank pain and a falling hematocrit.
Concern?
Show answer
Retroperitoneal hemorrhage — a femoral-access emergency. Escalate emergently for resuscitation and imaging; don’t attribute hypotension to "just being tired."
You’re told a lesion is in the "LAD."
Which wall is at risk?
Show answer
The LAD supplies the anterior wall and septum, so anterior/septal territory is at risk — useful context for EKG correlation and follow-up.